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  • 1.
    Abas, Naeem
    et al.
    University of Gujrat, Hafiz Hayat Campus, Pakistan.
    Kalair, Ali Raza
    COMSATS University Islamabad, Pakistan.
    Seyedmahmoudian, Mehdi
    Swinburne University, Australia.
    Naqvi, Muhammad
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för ingenjörs- och kemivetenskaper (from 2013).
    Campana, Pietro Elia
    Mälardalen University, Sweden.
    Khan, Nasrullah
    COMSATS University Islamabad, Pakistan.
    Dynamic simulation of solar water heating system using supercritical CO2 as mediating fluid under sub-zero temperature conditions2019Ingår i: Applied Thermal Engineering, ISSN 1359-4311, E-ISSN 1873-5606, Vol. 161, artikel-id 114152Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    CO2 is becoming increasingly important as a mediating fluid, and simulation studies are indispensable for corresponding developments. In this study, a simulation-based performance investigation of a solar water heating system using CO2 as a mediating fluid under sub-zero temperature condition is performed using the TRNSYS (R) software. The maximum performance is achieved at a solar savings fraction of 0.83 during July. The as lowest solar savingss fraction of 0.41 is obtained during December. The annual heat production of the proposed system under Fargo climate is estimated to be about 2545 kWh. An evacuated glass tube solar collector is designed, fabricated and tested for various climate conditions. Moreover, a detailed comparison of the system's performance at sub/supercritical and supercritical pressures shows that the annual heat transfer efficiency of the modeled system is 10% higher at supercritical pressure than at sub/supercritical pressures. This result can be attributd to the strong convection flow of CO2 caused by density inhomogeneities, especially in the near critical region. This condition resuls in high heat transfer rates.

  • 2.
    Anukam, Anthony
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för ingenjörs- och kemivetenskaper (from 2013). Karlstad Univ, Dept Engn & Chem Sci, Environm & Energy Syst, SE-65188 Karlstad, Sweden..
    Mohammadi, Ali
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för ingenjörs- och kemivetenskaper (from 2013). Karlstad Univ, Dept Engn & Chem Sci, Environm & Energy Syst, SE-65188 Karlstad, Sweden..
    Naqvi, Muhammad
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för ingenjörs- och kemivetenskaper (from 2013). Karlstad Univ, Dept Engn & Chem Sci, Environm & Energy Syst, SE-65188 Karlstad, Sweden..
    Granström, Karin
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för ingenjörs- och kemivetenskaper (from 2013). Karlstad Univ, Dept Engn & Chem Sci, Environm & Energy Syst, SE-65188 Karlstad, Sweden..
    A Review of the Chemistry of Anaerobic Digestion: Methods of Accelerating and Optimizing Process Efficiency2019Ingår i: Processes, Vol. 7, nr 8, s. 1-19, artikel-id 504Artikel, forskningsöversikt (Refereegranskat)
    Abstract [en]

    The anaerobic digestion technology has been in existence for centuries and its underlying theory established for decades. It is considered a useful technology for the generation of renewable energy, and provides means to alleviate problems associated with low access to energy. However, a great deal of current research is targeted towards the optimization of this technology under diverse digestion process conditions. This review presents an in-depth analysis of the chemistry of anaerobic digestion and discusses how process chemistry can be used to optimize system performance through identification of methods that can accelerate syntrophic interactions of different microorganisms for improved methanogenic reactions. Recent advances in addition to old research are discussed in order to offer a general but comprehensive synopsis of accumulated knowledge in the theory of anaerobic digestion, as well as an overview of previous research and future directions and opportunities of the AD technology. Achieving a sustainable energy system requires comprehensive reforms in not just economic, social and policy aspects, but also in all technical aspects, which represents one of the most crucial future investments for anaerobic digestion systems.

  • 3.
    Dahlquist, Erik
    et al.
    Mälardalen University (MDH), Sweden.
    Naqvi, Muhammad
    Mälardalen University (MDH), Sweden.
    Thorin, Eva
    Mälardalen University (MDH), Sweden.
    Kyprianidis, Jinyue Yan: Konstantinos
    Mälardalen University (MDH), Sweden.
    Hartwell, Philip
    BioRegional MiniMills (UK) Ltd.
    Modeling of Black Liquor Gasification2016Ingår i: Proceedings of 2016 9th EUROSIM Congress on Modelling and Simulation / [ed] Esko Juuso, Erik Dahlquist, Kauko Leiviskä, 2016Konferensbidrag (Refereegranskat)
    Abstract [en]

    The energy situation in both process industries andpower plants is changing. It is becoming interesting toperform system analysis on how to integrate gasificationinto chemical recovery systems in the pulp & paperindustry and into the CHP systems in power plantapplications to complement with production ofchemicals aside of heat and power. The potentialchemicals are methane, hydrogen, and methanol. It isalso interesting to estimate the potential to introducecombined cycles with gas turbines and steam turbinesusing both black liquors and other type of biomass likepellets, wood chips etc. To perform such type ofanalysis, it is vital to have relevant input data on whatgas composition we can expect from running differenttypes of feedstock. In this paper, we focus on blackliquors as feedstock for integrated gasification systems.The experimental results are correlated into partial leastsquares models to predict major composition of thesynthesis gas produced under different conditions.These quality prediction models are then combined withphysical models using Modelica for the investigation ofdynamic energy and material balances for completeplants. The data can also be used as input to analysisusing e.g. ASPEN plus and similar system analysistools

  • 4.
    Dahlquist, Erik
    et al.
    Malardalen Univ MDH, Sweden..
    Naqvi, Muhammad
    Malardalen Univ MDH, Sweden..
    Thorin, Eva
    Malardalen Univ MDH, Sweden..
    Yan, Jinyue
    Malardalen Univ MDH, Sweden.;Royal Inst Technol KTH, Sweden..
    Kyprianidis, Konstantinos
    Malardalen Univ MDH, Sweden..
    Comparison of gas quality from black liquor and wood pellet gasification using Modelica simulation and pilot plant results2017Ingår i: 8TH INTERNATIONAL CONFERENCE ON APPLIED ENERGY (ICAE2016) / [ed] Yan, J Sun, F Chou, SK Desideri, U Li, H Campana, P Xiong, R, Amsterdam: Elsevier, 2017, s. 992-998Konferensbidrag (Refereegranskat)
    Abstract [en]

    There is a potential to integrate biomass gasification with pulp & paper and CHP plants in order to complement the existing systems with production of chemicals, such as methane, hydrogen, and methanol etc. To perform system analysis of such integration, it is important to gain knowledge of relevant input data on expected synthesis gas composition by gasifying different types of feed stock. In this paper, the synthesis gas quality from wood pellets gasification (WPG) has been compared with black liquor gasification (BLG) through modeling and experimental results at pilot scale. In addition, the study develops regression models like Partial Least Squares (PLS) made from the experimental data. The regression models are then combined with dynamic models developed in Modelica for the investigation of dynamic energy and material balances for integrated plants. The data presented in this study could be used as input to relevant analysis using e.g. ASPEN plus and similar system analysis tools.

  • 5.
    Dahlquist, Erik
    et al.
    Mälardalens högskola.
    Naqvi, Muhammad
    Mälardalens högskola.
    Thorin, Eva
    Mälardalens högskola.
    Yan, Jinyue
    Mälardalens högskola; KTH.
    Kyprianidis, Konstantinos
    Mälardalens högskola.
    Hartwell, Philip
    BioReg MiniMills Ltd, England.
    Experimental and numerical investigation of pellet and black liquor gasification for polygeneration plant2017Ingår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 204, s. 1055-1064Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    It is vital to perform system analysis on integrated biomass gasification in chemical recovery systems in pulp and paper and heat and power plants for polygeneration applications. The proposed integration complements existing pulp and paper and heat and power production systems with production of chemicals such as methane and hydrogen. The potential to introduce gasification-based combined cycles comprising gas turbines and steam turbines to utilize black liquors and wood pellets also merits investigation. To perform such analysis, it is important to first build knowledge on expected synthesis gas composition by gasifying at smaller scale different types of feed stock. In the present paper, the synthesis gas quality from wood pellets gasification has been compared with black liquor gasification by means of numerical simulation as well as through pilot-scale experimental investigations. The experimental results have been correlated into partial least squares models to predict the composition of the synthesis gas produced under different operating conditions. The gas quality prediction models are combined with physical models using a generic open-source modelling language for investigating the dynamic performance of large-scale integrated polygeneration plants. The analysis is further complemented by considering potential gas separation using modern membrane technology for upgrading the synthesis gas with respect to hydrogen content. The experimental data and statistical models presented in this study form an important literature source for future use by the gasification and polygeneration research community on further integrated system analysis. (C) 2017 Elsevier Ltd. All rights reserved.

  • 6.
    Dahlquist, Erik
    et al.
    Mälardalen University, .
    Naqvi, Muhammad
    Mälardalen University, KTH.
    Thorin, Eva
    Mälardalen University, .
    Yan, Jinyue
    Mälardalen University, KTH.
    Kyprianidis, Konstantinos
    Mälardalen University, .
    Hartwell, Philip
    BioRegional MiniMills Ltd., United Kingdom..
    Modeling of Wood Gasification in an Atmospheric CFB Plant2016Ingår i: Proceedings of 2016 9th EUROSIM Congress on Modelling and Simulation / [ed] Esko Juuso, Erik Dahlquist, Kauko Leiviskä, Linköping University Electronic Press , 2016, s. 872-877Konferensbidrag (Refereegranskat)
    Abstract [en]

    The energy situation in both process industries andpower plants is changing and it is of interest toinvestigate new polygeneration solutions combiningproduction of chemicals with the production of powerand heat. Examples of such chemicals are methane,hydrogen, and methanol etc. Integration of gasificationinto chemical recovery systems in the pulp and paperproduction systems and into the combined heat andpower (CHP) systems in power plant applications areamong the possible polygeneration systems. It is alsointeresting to look at the potential to introduce combinedcycles with gas turbines and steam turbines as acomplement. To perform such analysis, it is importantto have relevant input data on what gas composition wecan expect from running different type of feed stock. Inthis paper, we focus on the wood pellets. Experimentalresults are correlated into partial least squares models topredict major composition of the synthesis gas producedunder different operating conditions. The qualityprediction models then are combined with physicalmodels using Modelica for investigation of dynamicenergy and material balances for large plants. The datacan also be used as input to analysis using e.g. ASPENplus and similar system analysis tools.

  • 7.
    Danish, Muhammad
    et al.
    East China Univ Sci & Technol, Peoples R China..
    Gu, Xiaogang
    East China Univ Sci & Technol, Peoples R China..
    Lu, Shuguang
    East China Univ Sci & Technol, Peoples R China..
    Ahmad, Ayyaz
    Muhammad Nawaz Sharif Univ Engn & Technol, Pakistan..
    Naqvi, Muhammad
    Malardalen Univ, Sweden..
    Farooq, Usman
    East China Univ Sci & Technol, Peoples R China..
    Zhang, Xiang
    East China Univ Sci & Technol, Peoples R China..
    Fu, Xiaori
    East China Univ Sci & Technol, Peoples R China..
    Miao, Zhouwei
    East China Univ Sci & Technol, Peoples R China..
    Xue, Yunfei
    East China Univ Sci & Technol,Peoples R China..
    Efficient transformation of trichloroethylene activated through sodium percarbonate using heterogeneous zeolite supported nano zero valent iron-copper bimetallic composite2017Ingår i: Chemical Engineering Journal, ISSN 1385-8947, E-ISSN 1873-3212, Vol. 308, s. 396-407Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Zeolite supported nano zero valent iron copper bimetallic composite (Z-nZVFe-Cu) was synthesized using an ion exchange method. The morphology and physico-chemical properties of the Z-nZVFe-Cu composite were determined using transmission electron microscopy (TEM), scanning electron microscopy (SEM), Brunauer Emmett Teller (BET), energy dispersive X-ray spectra (EDS), Fourier transform infrared spectroscopy (FTIR) and X-ray diffractometer (XRD). The results showed that iron and copper nano particles were well dispersed on the zeolite sheet. The degradation efficiency of trichloroethylene (TCE) achieved was more than 95% using Z-nZVFe-Cu as a heterogeneous Fenton like catalyst. An efficient removal of total organic carbon (TOC) was promoted as compared to zeolite supported iron nano composite (Z-nZVFe) and unsupported nano iron (nZVFe). Electron spin resonance (ESR) detection confirmed the intensity of hydroxyl radicals (OH.) in the system. While benzoic acid (BA), a probe indicator for the quantification of OH., demonstrated the higher intensity of hydroxyl radicals in Z-nZVFe-Cu as compared to Z-nZVFe and nZVFe. The less iron and copper leaching of from Z-nZVFe-Cu presented its higher stability and better catalytic activity, displaying its potential long term applications for TCE degradation in groundwater. (C) 2016 Elsevier B.V. All rights reserved.

  • 8.
    Danish, Muhammad
    et al.
    East China Univ Sci & Technol, Peoples R China..
    Gu, Xiaogang
    East China Univ Sci & Technol, Peoples R China..
    Lu, Shuguang
    East China Univ Sci & Technol, Peoples R China..
    Brusseau, Mark L.
    Univ Arizona, USA.
    Ahmad, Ayyaz
    Muhammad Nawaz Sharif Univ Engn & Technol, Pakistan..
    Naqvi, Muhammad
    Malardalen Univ, Sweden..
    Farooq, Usman
    East China Univ Sci & Technol, State Environm Protect Key Lab Environm Risk Asse, Shanghai 200237, Peoples R China..
    Zaman, Waqas Qamar
    East China Univ Sci & Technol, Peoples R China..
    Fu, Xiaori
    East China Univ Sci & Technol, Peoples R China..
    Miao, Zhouwei
    East China Univ Sci & Technol, Peoples R China..
    An efficient catalytic degradation of trichloroethene in a percarbonate system catalyzed by ultra-fine heterogeneous zeolite supported zero valent iron-nickel bimetallic composite2017Ingår i: Applied Catalysis A: General, ISSN 0926-860X, E-ISSN 1873-3875, Vol. 531, s. 177-186Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Zeolite supported nano iron-nickel bimetallic composite (Z-nZVI-Ni) was prepared using a liquid-phase reduction process. The corresponding surface morphologies and physico-chemical properties of the Z-nZVI-Ni composite were determined using scanning electron microscopy (SEM), transmission electron microscopy (TEM), Energy dispersive X-ray spectra (EDS), Brunauer Emmett Teller (BET) adsorption, wide angle X-ray diffractometry (WA-XRD), and Fourier transform infrared spectroscopy (FTIR). The results indicated high dispersion of iron and nickel nano particles on the zeolite sheet with an enhanced surface area. Complete destruction of trichloroethene (TCE) and efficient removal of total organic carbon (TOC) were observed by using Z-nZVI-Ni as a heterogeneous catalyst for a Fenton-like oxidation process employing sodium percarbonate (SPC) as an oxidant. The electron spin resonance (ESR) of Z-nZVI-Ni verified the generation and intensity of hydroxyl radicals (OH center dot). The quantification of OH center dot elucidated by using p-chlorobenzoic acid, a probe indicator, confirmed the higher intensity of OH center dot. The transformation products were identified using GC-MS. The slow iron and nickel leaching offered higher stability and better catalytic activity of Z-nZVI-Ni, demonstrating its prospective long term applications in groundwater for TCE degradation. (C) 2016 Elsevier B.V. All rights reserved.

  • 9.
    Danish, Muhammad
    et al.
    East China Univ Sci & Technol, Peoples R China..
    Gu, Xiaogang
    East China Univ Sci & Technol, Peoples R China..
    Lu, Shuguang
    East China Univ Sci & Technol, Peoples R China..
    Farooq, Usman
    East China Univ Sci & Technol, Peoples R China..
    Ahmad, Ayyaz
    Univ Engn & Technol, Pakistan..
    Naqvi, Muhammad
    Malardalen Univ, Sweden..
    Zhang, Xiang
    East China Univ Sci & Technol, Peoples R China..
    Fu, Xiaori
    East China Univ Sci & Technol, Peoples R China..
    Xue, Yunfei
    East China Univ Sci & Technol, Peoples R China..
    Effect of solution matrix and pH in Z-nZVI-catalyzed percarbonate system on the generation of reactive oxygen species and degradation of 1,1,1-trichloroethane2017Ingår i: Water Science and Technology: Water Supply, ISSN 1606-9749, E-ISSN 1607-0798, Vol. 17, nr 6, s. 1568-1578Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This study primarily focuses on evaluating the effects of solution matrix and pH for the generation of reactive oxygen species (ROSs) in a Z-nZVI-catalyzed sodium percarbonate (SPC) system to degrade 1,1,1-trichloroethane (1,1,1-TCA) in the absence and presence of a reducing agent (RA), i.e. hydroxylamine. Degradation of 1,1,1-TCA was 49.5% and 95% in the absence and presence of RA. Probe tests confirmed the generation of major hydroxyl radicals (OH center dot) and minor superoxide species (O-2(-center dot)), and scavenger tests verified the key role of OH center dot and less of O-2(-center dot) radicals. Degradation of 1,1,1-TCA decreased significantly in the presence of Cl- and HCO3-, while NO3- and SO42- had negligible effects in the absence of RA. Addition of RA significantly enhanced 1,1,1-TCA degradation by generating more OH center dot and O-2(-center dot) radicals in the presence of anions. Degradation of 1,1,1-TCA increased in the acidic range (1-5), while an inhibitive trend from neutral to basic (7-9) was observed. In contrast, a significant increase in 1,1,1-TCA degradation was observed with the addition of RA at all pH values (1-9). In conclusion, the anions and pH significantly influenced the generation and intensity of ROSs and 1,1,1-TCA was effectively degraded in the Z-nZVI-catalyzed SPC system in the presence of RA.

  • 10.
    Danish, Muhammad
    et al.
    E China Univ Sci & Technol, State Environm Protect Key Lab Environm Risk Asse, Shanghai 200237, Peoples R China..
    Gu, Xiaogang
    E China Univ Sci & Technol, State Environm Protect Key Lab Environm Risk Asse, Shanghai 200237, Peoples R China..
    Lu, Shuguang
    E China Univ Sci & Technol, State Environm Protect Key Lab Environm Risk Asse, Shanghai 200237, Peoples R China..
    Naqvi, Muhammad
    Mälardalens högskola.
    Degradation of chlorinated organic solvents in aqueous percarbonate system using zeolite supported nano zero valent iron (Z-nZVI) composite2016Ingår i: Environmental science and pollution research international, ISSN 0944-1344, E-ISSN 1614-7499, Vol. 23, nr 13, s. 13298-13307Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Chlorinated organic solvents (COSs) are extensively detected in contaminated soil and groundwater that pose long-term threats to human life and environment. In order to degrade COSs effectively, a novel catalytic composite of natural zeolite-supported nano zero valent iron (Z-nZVI) was synthesized in this study. The performance of Z-nZVI-catalyzed sodium percarbonate (SPC) in a heterogeneous Fenton-like system was investigated for the degradation of COSs such as 1,1,1-trichloroethane (1,1,1-TCA) and trichloroethylene (TCE). The surface characteristics and morphology of the Z-nZVI composite were tested using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Total pore volume, specific surface area, and pore size of the natural zeolite and the Z-nZVI composite were measured using Brunauer-Emmett-Teller (BET) method. SEM and TEM analysis showed significant elimination of aggregation and well dispersion of iron nano particles on the framework of natural zeolite. The BET N-2 measurement analysis indicated that the surface area of the Z-nZVI composite was 72.3 m(2)/g, much larger than that of the natural zeolite (0.61 m(2)/g). For the contaminant analysis, the samples were extracted with n-hexane and analyzed through gas chromatograph. The degradation of 1,1,1-TCA and TCE in the Z-nZVI-catalyzed percarbonate system were 48 and 39 % respectively, while strong augmentation was observed up to 83 and 99 %, respectively, by adding the reducing agent (RA), hydroxyl amine (NH2OH center dot HCl). Probe tests validated the presence of OH center dot and O-2(center dot-) which were responsible for 1,1,1-TCA and TCE degradation, whereas both free radicals were strengthened with the addition of RA. In conclusion, the Z-nZVI/SPC oxidation with reducing agent shows potential technique for degradation of groundwater contaminated by 1,1,1-TCA and TCE.

  • 11.
    Danish, Muhammad
    et al.
    East China Univ Sci & Technol, State Environm Protect Key Lab Environm Risk Asse, Shanghai 200237, Peoples R China..
    Gu, Xiaogang
    East China Univ Sci & Technol, State Environm Protect Key Lab Environm Risk Asse, Shanghai 200237, Peoples R China..
    Lu, Shuguang
    East China Univ Sci & Technol, State Environm Protect Key Lab Environm Risk Asse, Shanghai 200237, Peoples R China..
    Xu, Minhui
    East China Univ Sci & Technol, State Environm Protect Key Lab Environm Risk Asse, Shanghai 200237, Peoples R China..
    Zhang, Xiang
    East China Univ Sci & Technol, State Environm Protect Key Lab Environm Risk Asse, Shanghai 200237, Peoples R China..
    Fu, Xiaori
    East China Univ Sci & Technol, State Environm Protect Key Lab Environm Risk Asse, Shanghai 200237, Peoples R China..
    Xue, Yunfei
    East China Univ Sci & Technol, State Environm Protect Key Lab Environm Risk Asse, Shanghai 200237, Peoples R China..
    Miao, Zhouwei
    East China Univ Sci & Technol, State Environm Protect Key Lab Environm Risk Asse, Shanghai 200237, Peoples R China..
    Naqvi, Muhammad
    Mälardalens högskola.
    Nasir, Muhammad
    COMSATS Inst Informat Technol, IRCBM, Lahore, Pakistan..
    Role of reactive oxygen species and effect of solution matrix in trichloroethylene degradation from aqueous solution by zeolite-supported nano iron as percarbonate activator2016Ingår i: Research on chemical intermediates (Print), ISSN 0922-6168, E-ISSN 1568-5675, Vol. 42, nr 9, s. 6959-6973Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The role of reactive oxygen species (ROSs) and effect of solution matrix have been investigated for the degradation of trichloroethylene (TCE). Zeolite-supported nano iron (Z-nZVI) was synthesized as an activator to catalyze sodium percarbonate (SPC) with or without hydroxylamine, i.e. as reducing agent (RA). The probe tests confirmed the generation of OH center dot and O-2(-center dot) in the Z-nZVI activated SPC system in absence of the RA, while the presence of RA significantly increased the generation of OH center dot and O-2(-center dot) radicals. Scavenger tests demonstrated that OH center dot was the main ROS responsible for TCE degradation, whereas O-2(-center dot) also participated in TCE degradation. From the solution matrix perspective, the experimental results confirmed significant scavenging effects of Cl- (1.0, 10.0, and 100 mmol L-1) and HCO3- (1.0 and 10.0 mmol L-1), whereas the scavenging effects were fairly impeded at 100 mmol L-1 concentration of HCO3-. On the other hand, a considerable decline in scavenging effect was observed in the presence of RA in tested Cl and HCO3- concentration ranges. In addition, negligible scavenging effects of NO3- and SO42- anions were found in all tested concentrations. The effect of initial solution pH on catalytic activity indicated a significant increase in the TCE degradation in the presence of RA even at higher pH value of 9. The results indicated that the Z-nZVI activated SPC system in presence of RA can effectively degrade chlorinated organic solvents, but it is important to consider the intensive existence of anions in groundwater.

  • 12.
    Danish, Muhammad
    et al.
    East China Univ Sci & Technol, State Environm Protect Key Lab Environm Risk Asse, Shanghai 200237, Peoples R China..
    Gu, Xiaogang
    East China Univ Sci & Technol, State Environm Protect Key Lab Environm Risk Asse, Shanghai 200237, Peoples R China..
    Lu, Shuguang
    East China Univ Sci & Technol, State Environm Protect Key Lab Environm Risk Asse, Shanghai 200237, Peoples R China..
    Zhang, Xiang
    East China Univ Sci & Technol, State Environm Protect Key Lab Environm Risk Asse, Shanghai 200237, Peoples R China..
    Fu, Xiaori
    East China Univ Sci & Technol, State Environm Protect Key Lab Environm Risk Asse, Shanghai 200237, Peoples R China..
    Xue, Yunfei
    East China Univ Sci & Technol, State Environm Protect Key Lab Environm Risk Asse, Shanghai 200237, Peoples R China..
    Miao, Zhouwei
    East China Univ Sci & Technol, State Environm Protect Key Lab Environm Risk Asse, Shanghai 200237, Peoples R China..
    Ahmad, Ayyaz
    Muhammad Nawaz Sharif Univ Engn & Technol, Dept Chem Engn, Multan, Pakistan..
    Naqvi, Muhammad
    Mälardalens högskola.
    Qureshi, Abdul Sattar
    Univ Sindh, Inst Biotechnol & Genet Engn, Jamshoro 76080, Pakistan..
    The Effect of Chelating Agents on Enhancement of 1,1,1-Trichloroethane and Trichloroethylene Degradation by Z-nZVI-Catalyzed Percarbonate ProcessL2016Ingår i: Water, Air and Soil Pollution, ISSN 0049-6979, E-ISSN 1573-2932, Vol. 227, nr 9, s. 1-14, artikel-id 301Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This study primarily focused on the performance of 1,1,1-trichloroethane (1,1,1-TCA) and trichloroethylene (TCE) degradation involving redox reactions in zeolite-supported nanozerovalent iron composite (Z-nZVI)-catalyzed sodium percarbonate (SPC) system in aqueous solution with five different chelating agents (CAs) including oxalic acid (OA), citric acid monohydrate (CAM), glutamic acid (GA), ethylenediaminetetraacetic acid (EDTA), and L-ascorbic acid (ASC). The experimental results showed that the addition of OA achieved almost 100 % degradation of 1,1,1-TCA and TCE. The addition of CAM and GA also significantly increased the contaminant degradation, while excessive addition of them inhibited the degradation. In contrast, EDTA and ASC showed negative impacts on 1,1,1-TCA and TCE degradation, which might be due to the strong reactivity with iron and OH center dot scavenging characteristics. The efficiency with CA addition on 1,1,1-TCA and TCE degradation decreased in the order of OA > CAM > GA > no CAs > EDTA> ASC. The extensive investigations using probe compound tests and scavenger tests revealed that both contaminants degraded primarily by OH center dot and O-2(-center dot) in chelated Z-nZVI-catalyzed SPC system. The significant improvement in 1,1,1-TCA and TCE degradation efficiency was accredited due to the (i) increase in concentration of Fe2+ and (ii) continuous generation of OH center dot radicals and maintenance of its quantity, ensuring more stability in the aqueous solution. Finally, the complete mineralization of 1,1,1-TCA and TCE in the OA-chelated, Z-nZVI-catalyzed SPC system was confirmed without any chlorinated intermediate by-products detected, demonstrating a great potential of this technique in the application of groundwater remediation.

  • 13.
    Danish, Muhammad
    et al.
    E China Univ Sci & Technol, Peoples R China; Gujarat Univ, Pakistan.
    Naqvi, Muhammad
    Malardalen Univ.
    Farooq, Usman
    Gujarat Univ, Pakistan.
    Naqvi, Salman
    Univ Teknol PETRONAS, Malaysia..
    Characterization of South Asian agricultural residues for potential utilization in future 'energy mix'2015Ingår i: Energy Procedia / [ed] J. Yan, T. Shamim, H Li SK Chou, Elsevier, 2015, Vol. 75, s. 2974-2980Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper characterizes various locally available agricultural residues in South Asian region to evaluate their potential as feedstock for renewable energy production and contributing toward solving energy crisis and environmental issues. The thermo-chemical characterization has been performed in order to determine if the residues have potential to be used in biomass conversion technologies producing combined heat and power. The characterization methods for comparing different agricultural residues include proximate and ultimate analysis, heating value, ash content, thermo gravimetric analysis (TGA) and structural composition analysis (SCA). Widely available agricultural wastes in South Asian region were selected for the characterization i.e. bagasse, almond shell, corn cob, cotton stalks, wheat straw, sawdust, corn leaf, rice husk, rice straw, and corn straw. The analysis showed that the corn cob had the highest moisture content that will result in low energy efficiency of the thermal conversion technology due to energy requirement for drying. Whereas almond shell had the lowest moisture content. Ash and volatile contents were found to be highest in rice straw and almond shell respectively. The thermo gravimetric analysis showed that most of the agricultural residues can be easily decomposed and represent potential feedstock for biomass flexible combined heat and power systems through pyrolysis or gasification.

  • 14.
    Inayat, Abrar
    et al.
    University of Sharjah, United Arab Emirates.
    Ghenai, Chaouki
    University of Sharjah, United Arab Emirates.
    Naqvi, Muhammad
    Mälardalens University.
    Ammar, Muhammad
    Universiti Teknologi Petronas, Malaysia.
    Ayoub, Muhammad
    Universiti Teknologi Petronas, Malaysia.
    Hussin, M. N. B.
    Universiti Teknologi Petronas, Malaysia.
    Parametric Study for Production of Dimethyl Ether (DME) As a Fuel from Palm Wastes2017Ingår i: / [ed] Jinyue Yan, Fengchun Sun, SK Chou, Umberto Desideri, Hailong Li, Pietro Campana, Rui Xiong, Amsterdam, Netherlands: Elsevier, 2017, Vol. 105, s. 1242-1249Konferensbidrag (Refereegranskat)
    Abstract [en]

    Dimethyl Ether (DME) has been getting numerous attention as it's potential as the second generation bio-fuel. Traditionally DME is produced from the petroleum based stock which involves two steps of synthesis (methanol synthesis from the syngas and DME synthesis from methanol). DME synthesis via single step is one of the promising methods that has been developed. In Malaysia, due to the abundance of oil palm waste, it is a good candidate to be used as a feedstock for DME production. In this paper, single step process of DME synthesis was simulated and investigated using the Aspen HYSYS. Empty Fruit Bunch (EFB) from palm wastes has been taken as the main feed stock for DME synthesis. Four parameters (temperature, pressure, steam/biomass ratio and oxygen/biomass ratio) have been studied on the H-2/CO ratio and DME yield. The results showed that optimum H-2/CO ratio of 1.0 has been obtained when having an oxygen to biomass ratio (O/B) of 0.37 and steam to biomass ratio (S/B) of 0.23. The increment in the steam to biomass ratio increased the production of DME while the increment in oxygen to biomass ratio will cause reduction in DME production. (C) 2017 The Authors. Published by Elsevier Ltd.

  • 15. Khan, Z.
    et al.
    Yusup, S.
    Kamble, P.
    Naqvi, Muhammad
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för ingenjörs- och kemivetenskaper (from 2013).
    Watson, I.
    Assessment of energy flows and energy efficiencies in integrated catalytic adsorption steam gasification for hydrogen production2018Ingår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 225, s. 346-355Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This study addresses the energy flows and energy efficiency of integrated catalytic adsorption biomass steam gasification for hydrogen production in a pilot scale bubbling fluidized bed system utilizing palm kernel shell as feedstock. The integrated catalytic adsorption utilizes catalyst and CO2 adsorbent together in the single fluidized bed gasifier. Various variables such as effect of temperature (600–750 °C), steam to biomass ratio (1.5–2.5 w/w), adsorbent to biomass ratio (0.5–1.5 w/w), fluidization velocity (0.15–0.26 m/s) and biomass particle size (0.355–0.500 to 1.0–2.0 mm) are investigated. The results imply that the overall requirement of gasification energy increases with increasing gasification temperature, steam to biomass ratio, fluidization velocity, and decreases with adsorbent to biomass ratio whilst no significant increase is observed by varying the biomass particle size. However, a slight reduction in required energy is observed from 600 °C to 675 °C which might be due to strong CO2 adsorption, an exothermic reaction, and contributes to the energy requirements of the process. Besides, hydrogen-based energy efficiencies increase with increasing temperature while first increases to a medium value of steam to biomass ratio (2.0), adsorbent to biomass ratio (1.0) and fluidization velocity (0.21 m/s) followed by a slight decrease (or remains unchanged). The integrated catalytic adsorption steam gasification is found to be a high energy consuming process and thus, waste heat integration needs to be implemented for feasible hydrogen production

  • 16.
    Khan, Zakir
    et al.
    Department of Chemical Engineering, COMSATS University, Pakistan.
    Yusup, Suzana
    Chemical Engineering Department, Biomass Cluster Centre of Biofuel and Biochemical Research, Institute of Sustainable Living, Universiti Teknologi PETRONAS, Malaysia.
    Ahmad, Murni M.
    Chemical Engineering Department, Biomass Cluster Centre of Biofuel and Biochemical Research, Institute of Sustainable Living, Universiti Teknologi PETRONAS, Malaysia.
    Inayat, Abrar
    Department of Sustainable and Renewable Energy Engineering, University of Sharjah, United Arab Emirates.
    Naqvi, Muhammad
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för ingenjörs- och kemivetenskaper (from 2013).
    Sheikh, Rizwan
    Department of Chemical Engineering, NFC Institute of Engineering and Technology, Pakistan.
    Watson, Ian
    Systems Power and Energy, School of Engineering, University of Glasgow.
    Integrated catalytic adsorption steam gasification in a bubbling fluidized bed for enhanced H2 production: Perspective of design and pilot plant experiences2018Ingår i: Biofuels, Bioproducts and Biorefining, ISSN 1932-104X, E-ISSN 1932-1031, Vol. 12, nr 5, s. 735-748Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    It is important to build knowledge about the design of an integrated catalytic adsorption (ICA) steam gasification process in a bubbling fluidized bed, which can reduce CO2 content with enhanced hydrogen production. The value of this study is its presentation of detailed design considerations for the performance evaluation of an ICA system using palm oil waste as feedstock. The main advantage of using ICA gasification systems is the CO2 adsorption through a carbonation reaction (using CaO), which helps the water gas shift reaction to move forward. The activity of a catalyst improves steam methane reforming in parallel, which not only produces additional hydrogen but also releases CO to enhance the activity of the water gas shift reaction. The performance of the developed system has shown <1% of temperature variation inside the reactor, which suggested a positive role for exothermic reactions between reactive bed material (CaO) and CO2 in the product gas. The low pressure drop in the gasifier (100-130mbar) further strengthens the design strategy for the ICA gasification system for hydrogen production. Challenges encountered during the pilot plant operations, and their potential solutions, are discussed to optimize the operation, especially for downstream equipment and auxiliaries.

  • 17.
    Naqvi, Muhammad
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för ingenjörs- och kemivetenskaper (from 2013). Department of Energy, Building, and Environment, Mälardalen University, Sweden.
    Dahlquist, E.
    Department of Energy, Building, and Environment, Mälardalen University, Sweden.
    Yan, J.
    Department of Energy, Building, and Environment, Mälardalen University, Sweden & Department of Chemical Engineering, Royal Institute of Technology (KTH), Sweden.
    Naqvi, S. R.
    School of Chemical & Materials Engineering, NUST, Pakistan.
    Nizami, A. S.
    Center of Excellence in Environmental Studies, King Abdulaziz University, Saudi Arabia.
    Salman, C. A.
    Department of Energy, Building, and Environment, Mälardalen University, Sweden.
    Danish, M.
    State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, ECUST, China.
    Farooq, U.
    State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, ECUST, China.
    Rehan, M.
    Center of Excellence in Environmental Studies, King Abdulaziz University, Saudi Arabia.
    Khan, Z.
    Systems Power and Energy, School of Engineering, University of Glasgow, UK.
    Qureshi, A. S.
    Institute of Biotechnology and Genetic Engineering, University of Sindh, Pakistan.
    Polygeneration system integrated with small non-wood pulp mills for substitute natural gas production2018Ingår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 224, s. 636-646Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This study aims to examine the potential substitute natural gas (SNG) production by integrating black liquor gasification (BLG) island with a small wheat straw-based non-wood pulp mills (NPM), which do not employ the black liquor recovery cycle. For such integration, it is important to first build knowledge on expected improvements in an overall integrated non-wood pulp mill energy system using the key performance indicators. O2-blown circulating fluidized bed (CFB) gasification with direct causticization is integrated with a reference small NPM to evaluate the overall performance. A detailed economic analysis is performed together with a sensitivity analysis based on variations in the rate of return due to varying biomass price, total capital investment, and natural gas prices. The quantitive results showed considerable SNG production but significantly reduced electricity production. There is a substantial CO2 abatement potential combining CO2 capture and CO2 mitigation from SNG use replacing compressed natural gas (CNG) or gasoline. The economic performance through sensitivity analysis reflects significant dependency on both substitute natural gas production and natural gas market price. Furthermore, the solutions to address the challenges and barriers for the successful commercial implementation of BLG based polygeneration system at small NPMs are discussed. The system performance and discussion on the real application of integrated system presented in this article form a vital literature source for future use by large number of small non-wood pulp industries.

  • 18.
    Naqvi, Muhammad
    et al.
    Mälardalen University, Sweden.
    Dahlquist, Erik
    Mälardalen University, Sweden.
    Nizami, Abdul-Sattar
    King Abdulaziz University, Saudi Arabia.
    Danish, Muhammad
    ECUST, China.
    Naqvi, Salman
    School of Chemical & Materials Engineering, Pakistan..
    Farooq, Usman
    ECUST, China.
    Qureshi, Abdul Sattar
    University of Sindh, Pakistan.
    Rehan, Mohammad
    King Abdulaziz University, Saudi Arabia.
    Gasification integrated with small chemical pulp mills for fuel and energy production2017Ingår i: PROCEEDINGS OF THE 9TH INTERNATIONAL CONFERENCE ON APPLIED ENERGY / [ed] Yan, J Wu, J Li, H, Elsevier, 2017, s. 977-983Konferensbidrag (Refereegranskat)
    Abstract [en]

    Pulp mills without black liquor recovery cycle could play a major role in employing black liquor gasification (BLG) to produce transport fuels. In conventional chemical pulp mills, black liquor is burnt in recovery boilers to generate steam and electricity to meet energy demands. The inorganic chemicals are reused for the digestion process. However, the energy content and inorganic chemicals are not recovered in small scale pulp mills especially in the developing countries which do not employ recovery cycle. This study investigates the potential of synthetic natural gas (SNG) production by integrating BLG island with a reference pulp mill without chemical recovery cycle. The improvements in overall energy efficiency are evaluated using performance indicators such as biofuel production potential, integrated system's efficiency, and energy ratios. The oxygen-blown circulating fluidized bed (CFB) gasification with direct causticization is integrated with reference pulp mill. The results showed considerable SNG production without external biomass import. However to compensate total electricity deficit, the electricity will be imported from the grid. There is a substantial CO2 abatement potential of combining CO2 capture using seloxol absorption, and CO2 mitigation from SNG by replacing gasoline. (C) 2017 The Authors. Published by Elsevier Ltd.

  • 19.
    Naqvi, Muhammad
    et al.
    Malardalen Univ, Dept Energy Bldg & Environm, S-72123 Vasteras, Sweden..
    Dahlquist, Erik
    Malardalen Univ, Dept Energy Bldg & Environm, S-72123 Vasteras, Sweden..
    Yan, Jinyue
    Malardalen Univ, Dept Energy Bldg & Environm, S-72123 Vasteras, Sweden.;Royal Inst Technol KTH, Dept Chem Engn, Stockholm, Sweden..
    Complementing existing CHP plants using biomass for production of hydrogen and burning the residual gas in a CHP boiler2017Ingår i: Biofuels, ISSN 1759-7269, E-ISSN 1759-7277, Vol. 8, nr 6, s. 675-683Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Biorefinery systems at combined heat and power (CHP) plants represent numerous technical, economic and environmental benefits by utilizing the existing biomass handling infrastructure and producing biofuels together with heat and power. This study evaluates the economic feasibility of integrating biomass gasification to an existing CHP plant. Integration includes biomass gasification with downstream processing of the synthesis gas to remove particles and tars, condense out water, remove CO2 and use membrane filtration (polyamide membrane) to extract hydrogen. The separated residual gas components are utilized as extra fuel to the boiler in the CHP plant. Approximately 58.5 MWth of synthesis gas can be produced from a 90 MWth plant that represents 16.4 MWth of hydrogen. The rest of the heating value of produced synthesis gas (in the form of methane and carbon monoxide) is utilized for heat and power production. From an economic perspective, the production cost of hydrogen is estimated to be 0.125 - 0.75 (sic)/kg. This can be compared to the US governments goal that H-2 produced by wind power plus electrolyzers should have a maximum cost of 2.8 - 3.4 (sic)/kg. The lower cost is for a unit operating at 3 bar and assuming that the costs are split between H-2 and the syngas residue that is combusted, while the higher prices assume an atmospheric gasifier and all costs are put on the H-2 produced.

  • 20. Naqvi, Muhammad
    et al.
    Farooq, Usman
    East China University of Science and Technology, China.
    Danish, Muhammad
    East China University of Science and Technology, China.
    Qureshi, Abdul Sattar
    University of Sindh, Pakistan.
    Prediction of oil extraction and yield from pyrolysis of rice bran using Response Surface Methodology (RSM)2016Ingår i: ECO-BIO 2016, 6-9 March Rotterdam, Netherlands, 2016Konferensbidrag (Refereegranskat)
  • 21. Naqvi, Muhammad
    et al.
    Yan, Jinyue
    Dahlquist, Erik
    Bio-refinery system in a pulp mill for methanol production with comparison of pressurized black liquor gasification and dry gasification using direct causticization2012Ingår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 90, nr 1, s. 24-31Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Black liquor gasification (BLG) for bio-fuel or electricity production at the modern pulp mills is a field in continuous evolution and the efforts are considerably driven by the climate change, fuel security, and renewable energy. This paper evaluates and compares two BLG systems for methanol production: (i) oxygen blown pressurized thermal BLG; and (ii) dry BLG with direct causticization, which have been regarded as the most potential technology candidates for the future deployment. A key objective is to assess integration possibilities of BLG technologies with the reference Kraft pulp mill producing 1000 air dried tonnes (ADt) pulp/day replacing conventional recovery cycle. The study was performed to compare the systems’ performance in terms of potential methanol production, energy efficiency, and potential CO2 reductions. The results indicate larger potential of black liquor conversion to methanol from the pressurized BLG system (about 77 million tonnes/year of methanol) than the dry BLG system (about 30 million tonnes/year of methanol) utilizing identical amount of black liquor available worldwide (220 million tDS/year). The potential CO2 emissions reduction from the transport sector is substantially higher in pressurized BLG system (117 million tonnes/year CO2 reductions) as compared to dry BLG system (45 million tonnes/year CO2 reductions). However, the dry BLG system with direct causticization shows better results when considering consequences of additional biomass import. In addition, comparison of methanol production via BLG with other bio-refinery products, e.g. hydrogen, dimethyl ether (DME) and bio-methane, has also been discussed

  • 22.
    Naqvi, Muhammad
    et al.
    Royal Institute of Technology, Stockholm.
    Yan, Jinyue
    Royal Institute of Technology, Stockholm; Mälardalen University, Västerås.
    Dahlquist, Erik
    Mälardalen University, Västerås.
    Black liquor gasification integrated in pulp and paper mills: A critical review2010Ingår i: Bioresource Technology, ISSN 0960-8524, E-ISSN 1873-2976, Vol. 101, nr 21, s. 8001-8015Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Black liquor gasification (BLG) has potential to replace a Tomlinson recovery boiler as an alternative technology to increase safety, flexibility and energy efficiency of pulp and paper mills. This paper presents an extensive literature review of the research and development of various BLG technologies over recent years based on low and high temperature gasification that include SCA-Billerud process, Manufacturing and Technology Conversion International (MTCI) process, direct alkali regeneration system (DARS), BLG with direct causticization, Chemrec BLG system, and catalytic hydrothermal BLG. A few technologies were tested on pilot scale but most of them were abandoned due to technical inferiority and very fewer are now at commercial stage. The drivers for the commercialization of BLG enabling bio-refinery operations at modern pulp mills, co-producing pulp and value added energy products, are discussed. In addition, the potential areas of research and development in BLG required to solve the critical issues and to fill research knowledge gaps are addressed and highlighted.

  • 23. Naqvi, Muhammad
    et al.
    Yan, Jinyue
    Dahlquist, Erik
    Energy conversion performance of black liquor gasification to hydrogen production using direct causticization with CO2 capture2012Ingår i: Bioresource Technology, ISSN 0960-8524, E-ISSN 1873-2976, Vol. 110, s. 637-644Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This paper estimates potential hydrogen production via dry black liquor gasification system with direct causticization integrated with a reference pulp mill. The advantage of using direct causticization is elimination of energy intensive lime kiln. Pressure swing adsorption is integrated in the carbon capture process for hydrogen upgrading. The energy conversion performance of the integrated system is compared with other bio-fuel alternatives and evaluated based on system performance indicators. The results indicated a significant hydrogen production potential (about 141 MW) with an energy ratio of about 0.74 from the reference black liquor capacity (about 243.5 MW) and extra biomass import (about 50 MW) to compensate total energy deficit. About 867,000 tonnes of CO2 abatement per year is estimated i.e. combining CO2 capture and CO2 offset from hydrogen replacing motor gasoline. The hydrogen production offers a substantial motor fuel replacement especially in regions with large pulp and paper industry e.g. about 63% of domestic gasoline replacement in Sweden.

  • 24.
    Naqvi, Muhammad
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för ingenjörs- och kemivetenskaper (from 2013).
    Yan, Jinyue
    Dahlquist, Erik
    Synthetic gas production from dry black liquor gasification process using direct causticization with CO2 capture2012Ingår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 97, s. 49-55Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Synthetic natural gas (SNG) production from dry black liquor gasification (DBLG) system is an attractive option to reduce CO2 emissions replacing natural gas. This article evaluates the energy conversion performance of SNG production from oxygen blown circulating fluidized bed (CFB) black liquor gasification process with direct causticization by investigating system integration with a reference pulp mill producing 1000 air dried tonnes (ADt) of pulp per day. The direct causticization process eliminates use of energy intensive lime kiln that is a main component required in the conventional black liquor recovery cycle with the recovery boiler. The paper has estimated SNG production potential, the process energy ratio of black liquor (BL) conversion to SNG, and quantified the potential CO2 abatement. Based on reference pulp mill capacity, the results indicate a large potential of SNG production (about 162 MW) from black liquor but at a cost of additional biomass import (36.7 MW) to compensate the total energy deficit. The process shows cold gas energy efficiency of about 58% considering black liquor and biomass import as major energy inputs. About 700 ktonnes per year of CO2 abatement i.e. both possible CO2 capture and CO2 offset from bio-fuel use replacing natural gas, is estimated. Moreover, the SNG production offers a significant fuel replacement in transport sector especially in countries with large pulp and paper industry e.g. in Sweden, about 72% of motor gasoline and 40% of total motor fuel could be replaced.

  • 25. Naqvi, Muhammad
    et al.
    Yan, Jinyue
    Dahlquist, Erik
    System analysis of dry black liquor gasification based synthetic gas production comparing oxygen and air blown gasification systems2013Ingår i: Applied energy, Vol. 112, s. 1275-1282Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The black liquor gasification based bio-fuel production at chemical pulp mill is an attractive option to replace conventional recovery boilers increasing system energy efficiency. The present paper studies circulating fluidized bed system with direct causticization using TiO2 for the gasification of the black liquor to the synthesis gas. The advantage of using direct causticization is the elimination of energy-intensive lime kiln which is an integral part of the conventional black liquor recovery system. The study evaluates the effects of gasifying medium i.e. oxygen or air, on the fluidized bed gasification system, the synthesis gas composition, and the downstream processes for the synthesis gas conversion to the synthetic natural gas (SNG). The results showed higher synthetic natural gas production potential with about 10% higher energy efficiency using oxygen blown gasification system than the air blown system. From the pulp mill integration perspective, the material and energy balance results in better integration of air blown system than the oxygen blown system, e.g. less steam required to be generated in the power boiler, less electricity import, and less additional biomass requirement. However, the air blown system still requires a significant amount of energy in terms of the synthesis gas handling and gas upgrading using the nitrogen rejection system.

  • 26.
    Naqvi, Muhammad
    et al.
    Mälardalens högskola.
    Yan, Jinyue
    Mälardalens högskola; KTH.
    Dahlquist, Erik
    Mälardalens högskola.
    Naqvi, Salman Raza
    National University of Sciences & Technology (NUST), Pakistan.
    Off-grid electricity generation using mixed biomass compost: A scenario-based study with sensitivity analysis2017Ingår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 201, s. 363-370Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The aim of the study is to investigate the viability of waste gasification based off-grid electricity generation utilizing mixed biomass composts (mixture of rice hulls with cow/poultry manure compost). The economic viability is studied on the different scenarios with considerations of (1) levels of electricity demand and utilization, (2) costs of variable biomass mix, (3) combined domestic and cottage industry business model, and (4) influence of governmental investments. The levelized cost of electricity (LCOE) is used as an indicator to measure the competitiveness of gasification based off-grid electricity generation. The plant loading and the capacity factor have been used to assess the impacts of different scenarios. A sensitivity analysis of key parameters based on variations in annual operational hours, plant efficiency, plant cost and biomass supply cost is conducted. Based on levels of electricity demand and utilization, the LCOE ranged between 40 US cents/kW h and 29 US cents/kW h based on the plant loading and the capacity factor. The business revenue would not change considerably despite better plant utilization and reduced levelized cost of electricity if all the consumers, both basic or medium, are charged with the flat tariff. The part load operation will be costly despite considerably low capital investment per kW in comparison with PV or solar based plants. There is a large potential of off-grid electricity generation but the estimated off-grid electricity price is found to be higher in all scenarios than average grid-based electricity tariff. Moreover, the challenges for the implementation of the real off-grid electricity generation plant are discussed. (C) 2017 Elsevier Ltd. All rights reserved.

  • 27.
    Naqvi, Muhammad
    et al.
    Mälardalen University, Västerås.
    Yan, Jinyue
    Mälardalen University, Västerås; Royal Institute of Technology, Stockholm.
    Dahlquist, Erik
    Royal Institute of Technology, Stockholm.
    Naqvi, Salman Raza
    National University of Sciences & Technology, Islamabad.
    Waste biomass gasification based off-grid electricity generation: A case study in Pakistan2016Ingår i: PROCEEDINGS OF RENEWABLE ENERGY INTEGRATION WITH MINI/MICROGRID (REM2016) / [ed] Yan, J Zhai, Y Wijayatunga, P Mohamed, AM Campana, PE, Elsevier, 2016, Vol. 103, s. 406-412Konferensbidrag (Refereegranskat)
    Abstract [en]

    The objective is to investigate the waste gasification based off-grid electricity generation in developing countries like Pakistan utilizing mixed biomass composts (mixture of agricultural wastes including rice hulls and wheat straw with cow/poultry manure compost). Different scenarios are compared; ( 1) levels of electricity demand and utilization, ( 2) costs for variable biomass mix, ( 3) combined domestic and cottage industry business model. The levelized cost of electricity (LCOE) is used as an indicator to measure the competitiveness of off-grid electricity generation. There is a large potential of off-grid electricity generation. However, the estimated off-grid electricity price is found to be higher in all scenarios than average governmental electricity tariff. (C) 2016 The Authors. Published by Elsevier Ltd.

  • 28.
    Naqvi, Muhammad
    et al.
    Malardalen Univ MDH, Sch Sustainable Dev Soc & Technol, Vasteras, Sweden..
    Yan, Jinyue
    Malardalen Univ MDH, Sch Sustainable Dev Soc & Technol, Vasteras, Sweden.;Royal Inst Technol KTH, Dept Chem Engn, Stockholm, Sweden..
    Danish, Muhammad
    E China Univ Sci & Technol, State Environm Protect Key Lab Environm Risk Asse, Shanghai, Peoples R China..
    Farooq, Usman
    E China Univ Sci & Technol, State Environm Protect Key Lab Environm Risk Asse, Shanghai, Peoples R China..
    Lu, Shuguang
    E China Univ Sci & Technol, State Environm Protect Key Lab Environm Risk Asse, Shanghai, Peoples R China..
    An experimental study on hydrogen enriched gas with reduced tar formation using pre-treated olivine in dual bed steam gasification of mixed biomass compost2016Ingår i: International journal of hydrogen energy, ISSN 0360-3199, E-ISSN 1879-3487, Vol. 41, nr 25, s. 10608-10618Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The study investigated the effects of pre-treated olivine in dual bed steam gasification (DBSG) of biomass compost in order to produce H-2 enriched synthesis gas with significantly reduced tar formation. The DBSG employed circulating fluidized bed (CFB) of silica sand as first stage and fixed catalytic bed of pre-treated olivine as second stage. The mixed biomass compost contained 15-20 wt. % of agri-residues (mainly wheat straw) and 80-85 wt. % of cow manure. The study compared the synthesis gas distribution and tar reductions using pre-treated olivine in the DBSG scheme with Ni-Al based DBSG scheme. The effects of operating condition on the synthesis gas distribution and tar formation are studied such as: (i) effect of steam to biomass ratio, (ii) effects of relative oxidation (relox), (iii) operating temperature of the reactor, (iv) performance and comparison of employed catalysts, and (v) yield of synthesis gas together with carbon conversion efficiency. Experimental analysis showed that H-2 concentration obtained from pre-treated olivine based DBSG is considerably higher than H-2 produced from compared gasification schemes. The H-2 production is favoured at higher temperatures and higher SBR under the influence of pre-treated olivine catalyst. However, the conditions are less advantageous for the production of CO and CH4. Among all experiments, the synthesis gas composition obtained at SBR = 1.40 and at 800 degrees C consisted of highest H-2 concentration (35 vol.% d.n.f) in the pre-treated olivine DBSG. Higher steam to biomass ratio (SBR) resulted in lower cold gas energy efficiency and lower heating value of the synthesis gas mainly due to large steam content in the gas. The tar removal efficiency of 98% is achieved with the pre-treated olivine DBSG system. The total tar content is significantly reduced (approximate to 40%) in the DBSG with pre-treated olivine. Higher relative oxidation resulted in increased concentration of CO2 in the synthesis gas due to increased partial oxidation of organic matter in the gasifier. The pre-treated olivine catalyst in the DBSG consistently promoted the process of steam reforming and tar cracking and thus improved the quality of the syngas by limiting the tar contents. (C) 2016 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

  • 29.
    Naqvi, Salman Raza
    et al.
    National University of Sciences and Technology, Islamabad, Pakistan.
    Bibi, Ayesha
    National University of Sciences and Technology, Islamabad,Pakistan.
    Naqvi, Muhammad
    Mälardalen University, Västerås, Sweden.
    Noor, Tayyaba
    National University of Sciences and Technology, Islamabad, Pakistan.
    Nizami, Abdul-Sattar
    King Abdulaziz University, Jidda, Saudi Arabia.
    Rehan, Mohammad
    King Abdulaziz University, Jidda, Saudi Arabia.
    Ayoub, Muhammad
    Universiti Teknologi PETRONAS, Bandar Seri Iskandar, Malaysia.
    New trends in improving gasoline quality and octane through naphtha isomerization: a short review2018Ingår i: APPLIED PETROCHEMICAL RESEARCH, ISSN 2190-5533, Vol. 8, nr 3, s. 131-139Artikel, forskningsöversikt (Refereegranskat)
    Abstract [en]

    The octane enhancement of light straight run naphtha is one of the significant solid acid catalyzed processes in the modern oil refineries due to limitations of benzene, aromatics, and olefin content in gasoline. This paper aims to examine the role of various catalysts that are being utilized for the isomerization of light naphtha with an ambition to give an insight into the reaction mechanism at the active catalyst sites, and the effect of various contaminants on catalyst activity. In addition, different technologies used for isomerization process are evaluated and compared by different process parameters.

  • 30.
    Naqvi, Salman Raza
    et al.
    Natl Univ Sci & Technol, Sch Chem & Mat Engn, H-12, Islamabad 54000, Pakistan..
    Jamshaid, Sana
    Yeungnam Univ, Sch Chem Engn, Gyongsan 38541, South Korea..
    Naqvi, Muhammad
    Malardalen Univ MDH, Sch Sustainable Dev Soc & Technol, Vasteras, Sweden..
    Farooq, Wasif
    Natl Univ Sci & Technol, Sch Chem & Mat Engn, H-12, Islamabad 54000, Pakistan.;King Fahd Univ Petr & Minerals, Dept Chem Engn, Dhahran 31261, Saudi Arabia..
    Niazi, Muhammad Bilal Khan
    Natl Univ Sci & Technol, Sch Chem & Mat Engn, H-12, Islamabad 54000, Pakistan..
    Aman, Zaeem
    Natl Univ Sci & Technol, Sch Chem & Mat Engn, H-12, Islamabad 54000, Pakistan..
    Zubair, Muhammad
    Natl Univ Sci & Technol, US Pakistan Ctr Adv Studies Energy, H-12, Islamabad 54000, Pakistan..
    Ali, Majid
    Natl Univ Sci & Technol, US Pakistan Ctr Adv Studies Energy, H-12, Islamabad 54000, Pakistan..
    Shahbaz, Muhammad
    Univ Teknol PETRONAS, Dept Chem Engn, Biomass Proc Lab, Ctr Bio Fuel & Biochem Res CBBR, Bandar Seri Iskandar 32610, Perak, Malaysia..
    Inayat, Abrar
    Univ Sharjah, Dept Sustainable & Renewable Energy Engn, Sharjah, U Arab Emirates..
    Afzal, Waheed
    Univ Aberdeen, Sch Engn, Aberdeen AB24 3UF, Scotland..
    Potential of biomass for bioenergy in Pakistan based on present case and future perspectives2018Ingår i: Renewable & sustainable energy reviews, ISSN 1364-0321, E-ISSN 1879-0690, Vol. 81, nr 1, s. 1247-1258Artikel, forskningsöversikt (Refereegranskat)
    Abstract [en]

    Future energy security and environmental issues are major driving forces for increased biomass utilization globally and especially in developing countries like Pakistan. For efficient utilization of indigenous biomass resources in the future energy mix, it is important to gain knowledge of current energy system in various sectors. Some of the technologies and initiatives are under development to achieve transition from non-renewable resources to renewable resources, and reducing fossil fuel dependency and greenhouse gas emissions. Recently, number of proposals has been presented for the development of sustainable biofuels production methods for promise for accelerating a shift away from an unsustainable approach to possible sustainable production practices or a sustainable social, economic and environment. This article presents an extensive literature review of the biomass-based renewable energy potential in Pakistan based on current energy scenario and future perspectives. It also highlights the availability of the indigenous and local biomass resources and potential biomass conversion technologies to convert such resources to bioenergy. The drivers for utilization of indigenous biomass resources in future energy mix and challenges regarding awareness among stakeholders and R & D to fill knowledge gaps are economically restraints. The article concludes with suggestions on future directions and policies for effective implementation of biomass based renewable energy production.

  • 31.
    Naqvi, Salman Raza
    et al.
    Natl Univ Sci & Technol NUST, Sch Chem & Mat Engn, Islamabad, Pakistan..
    Naqvi, Muhammad
    Malardalen Univ, Sch Business Soc & Engn, Vasteras, Sweden..
    Catalytic fast pyrolysis of rice husk: Influence of commercial and synthesized microporous zeolites on deoxygenation of biomass pyrolysis vapors2018Ingår i: International journal of energy research (Print), ISSN 0363-907X, E-ISSN 1099-114X, Vol. 42, nr 3, s. 1352-1362Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Research on utilization of abundant rice residue for valuable bioenergy products is still not explored completely. A simple, robust, cheap, and one-step fast pyrolysis reactor is still a key demand for production of bioenergy products, ie, high quality bio-oil and biochar. Bio-oil extracted from fast pyrolysis does not have adequate quality (eg, acidic and highly oxygenated). Catalytic fast pyrolysis using zeolites in the fast pyrolysis process effectively reduces the oxygen content (no H-2 required). In this paper, the zeolites with different pore sizes and shapes (small pore, SAPO-34 (0.56) and ferrierite (30); medium pore, ZSM-5 (30), MCM-22 (30), and ITQ-2 (30); and large pore zeolite, mordenite (30)) were tested in a drop-type fixed-bed pyrolyzer. Catalytic deoxygenation is conducted at 450 degrees C at the catalyst/biomass ratio of 0.1. Zeolite catalysts, its pore size and shape, could influence largely on deoxygenation. It was found that the small pore zeolites did not produce aromatics as compared to higher amount of aromatics formed in case of medium pore zeolites. ZSM-5 and ITQ-2 zeolites were especially efficient for the higher deoxygenation of biomass pyrolysis vapors due to better pore dimension and higher acidity.

  • 32.
    Naqvi, Salman Raza
    et al.
    Univ Twente, Fac Engn Technol, Enschede, Netherlands; Natl Univ Sci & Technol, Islamabad, Pakistan.
    Tariq, R.
    Natl Univ Sci & Technol, Islamabad, Pakistan.
    Hameed, Z.
    Natl Univ Sci & Technol, Islamabad, Pakistan.
    Ali, I.
    King Abdulaziz Univ, Dept Chem, Rabigh, Saudi Arabia; King Abdulaziz Univ, Dept Mat Engn, Rabigh, Saudi Arabia.
    Taqvi, S. A.
    Univ Teknol PETRONAS, Dept Chem Engn, Seri Iskandar, Malaysia; NED Univ Engn & Technol, Chem Engn Dept, Karachi 75270, Pakistan.
    Naqvi, Muhammad
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för ingenjörs- och kemivetenskaper (from 2013).
    Niazi, M. B. K.
    Natl Univ Sci & Technol, Sch Chem & Mat Engn, Islamabad, Pakistan.
    Noor, T.
    Natl Univ Sci & Technol, Sch Chem & Mat Engn, Islamabad, Pakistan.
    Farooq, W.
    KFUPM, Dept Chem Engn, Dhahran, Saudi Arabia.
    Pyrolysis of high-ash sewage sludge: Thermo-kinetic study using TGA and artificial neural networks2018Ingår i: Fuel, ISSN 0016-2361, E-ISSN 1873-7153, Vol. 233, s. 529-538Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Pyrolysis of high-ash sewage sludge (HASS) is a considered as an effective method and a promising way for energy production from solid waste of wastewater treatment facilities. The main purpose of this work is to build knowledge on pyrolysis mechanisms, kinetics, thermos-gravimetric analysis of high-ash (44.6%) sewage sludge using model-free methods & results validation with artificial neural network (ANN). TG-DTG curves at 5,10 and 20 °C/min showed the pyrolysis zone was divided into three zone. In kinetics, E values of models ranges are; Friedman (10.6–306.2 kJ/mol), FWO (45.6–231.7 kJ/mol), KAS (41.4–232.1 kJ/mol) and Popescu (44.1–241.1 kJ/mol) respectively. ΔH and ΔG values predicted by OFW, KAS and Popescu method are in good agreement and ranged from (41–236 kJ/mol) and 53–304 kJ/mol, respectively. Negative value of ΔS showed the non-spontaneity of the process. An artificial neural network (ANN) model of 2 * 5 * 1 architecture was employed to predict the thermal decomposition of high-ash sewage sludge, showed a good agreement between the experimental values and predicted values (R2 ⩾ 0.999) are much closer to 1. Overall, the study reflected the significance of ANN model that could be used as an effective fit model to the thermogravimetric experimental data. © 2018 Elsevier Ltd

  • 33.
    Naqvi, Salman Raza
    et al.
    University of Twente, The Netherlands; National University of Sciences & Technology, Pakistan..
    Tariq, Rumaisa
    National University of Sciences & Technology, Pakistan.
    Hameed, Zeeshan
    National University of Sciences & Technology, Pakistan.
    Ali, Imtiaz
    King Abdulaziz University, Saudi Arabia.
    Naqvi, Muhammad
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för ingenjörs- och kemivetenskaper (from 2013).
    Chen, Wei-Hsin
    National Cheng Kung University, Taiwan.
    Ceylan, Selim
    Ondokuz Mayıs University, Turkey.
    Rashid, Harith
    Eindhoven University of Technology, The Netherlands.
    Ahmad, Junaid
    Free University of Bolzano, Italy.
    Taqvi, Syed A
    NED University of Engineering and Technology, Pakistan; Universiti Teknologi PETRONAS, Malaysia.
    Shahbaz, Muhammad
    University of Gujrat, Pakistan.
    Pyrolysis of high ash sewage sludge: Kinetics and thermodynamic analysis using Coats-Redfern method2019Ingår i: Renewable energy, ISSN 0960-1481, E-ISSN 1879-0682, Vol. 131, s. 854-860Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This study aims to investigate the thermo-kinetics of high-ash sewage sludge using thermogravimetric analysis. Sewage sludge was dried, pulverized and heated non-isothermally from 25 to 800 °C at different heating rates (5, 10 and 20 °C/min) in N2 atmosphere. TG and DTG results indicate that the sewage sludge pyrolysis may be divided into three stages. Coats-Redfern integral method was applied in the 2nd and 3rd stage to estimate the activation energy and pre-exponential factor from mass loss data using five major reaction mechanisms. The low-temperature stable components (LTSC) of the sewage sludge degraded in the temperature regime of 250–450 °C while high-temperature stable components (HTSC) decomposed in the temperature range of 450–700 °C. According to the results, first-order reaction model (F1) showed higher Ea with better R2 for all heating rates. D3, N1, and S1 produced higher Ea at higher heating rates for LTSC pyrolysis and lower Ea with the increase of heating rates for HTSC pyrolysis. All models showed positive ΔH except F1.5. Among all models, Diffusion (D1, D2, D3) and phase interfacial models (S1, S2) showed higher ΔG as compared to reaction, nucleation, and power-law models in section I and section II.

  • 34.
    Naqvi, Salman Raza
    et al.
    National University of Sciences & Technology, Islamabad.
    Uemura, Yoshimitsu
    Universiti Teknologi PETRONAS, Tronoh.
    Yusup, Suzana
    Universiti Teknologi PETRONAS, Tronoh.
    Nishiyama, Naoki
    Osaka University, Toyonaka.
    Naqvi, Muhammad
    Malardalens University, Vasteras.
    Catalytic consequences of micropore topology on biomass pyrolysis vapors over shape selective zeolites2017Ingår i: 8TH INTERNATIONAL CONFERENCE ON APPLIED ENERGY (ICAE2016) / [ed] Yan, J; Sun, F; Chou, SK; Desideri, U; Li, H; Campana, P; Xiong, R, Elsevier, 2017, Vol. 105, s. 557-561Konferensbidrag (Refereegranskat)
    Abstract [en]

    Research on utilization of abundant rice residue for valuable bioenergy products is still not explored completely. A simple, robust, cheap and one step fast pyrolysis reactor is still a key demand for production of bioenergy products, i.e. high quality bio-oil and bio char. Bio-oil produced from fast pyrolysis has poor quality (e.g. acidic and highly oxygenated). Catalytic fast pyrolysis using zeolites in the fast pyrolysis process effectively reduce the oxygen content (no H-2 required). In this paper, zeolites having a variety of pore size and shape (small pore: SAPO-34 (0.56), Ferriertite (20), medium pore: ZSM-5 (23), MCM-22 (20), ITQ-2 (20) and large pore zeolite Mordenite (20) were tested in a drop type fixed-bed pyrolyzer. The catalytic deoxygenation is conducted at 450 degrees C at the catalyst/biomass ratio of 0.1. Zeolite catalysts, its pore size and shape could influence largely on deoxygenation. Small pore zeolites did not produce aromatics while medium pore zeolites formed higher amount of aromatics. ZSM-5 and ITQ-2 zeolites were especially efficient for the higher deoxygenation of biomass pyrolysis vapors due to better pore dimension and higher acidity. (C) 2017 The Authors. Published by Elsevier Ltd.

  • 35.
    Naqvi, Salman Raza
    et al.
    Universiti Teknologi PETRONAS, Tronoh.
    Uemura, Yoshimitu
    Universiti Teknologi PETRONAS, Tronoh.
    Yusup, Suzana
    Universiti Teknologi PETRONAS, Tronoh.
    Sugiur, Y
    Osaka University, Toyonaka.
    Nishiyama, Naoki
    Osaka University, Toyonaka.
    Naqvi, Muhammad
    The role of zeolite structure and acidity in catalytic deoxygenation of biomass pyrolysis vapors2015Ingår i: CLEAN, EFFICIENT AND AFFORDABLE ENERGY FOR A SUSTAINABLE FUTURE / [ed] Yan, J; Shamim, T; Chou, SK; Li, H, Elsevier, 2015, Vol. 75, s. 793-800Konferensbidrag (Refereegranskat)
    Abstract [en]

    Catalytic upgrading of paddy husk was performed over 10-MR zeolites (MCM-22, ITQ-2 and ZSM-5) in a drop type fixed-bed reactor. This work investigated the role of structure and acidity of zeolites on pyrolysis-oil yield and degree of deoxygenation. Catalytic pyrolysis experiments were carried out at the catalyst/biomass ratio (0.05 -0.5) at temperature of 450 degrees C. The oil yield decreased by using catalyst and this decrease oil yield is attributed to catalytic cracking of bio-oil vapor on the catalyst. The route for deoxygenation of pyrolysis vapors was identified to be dehydration, decarboxylation and decarboxylation. ITQ-2 showed high degree of deoxygenation as compare to MCM-22 which is due to more accessible external active sites of ITQ-2. The organics yield in pyrolysis oil was highest with ZSM-5 in comparison with other zeolites. (C) 2015 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license

  • 36.
    Nizami, Abdul-Sattar
    et al.
    King Abdulaziz University, Jeddah.
    Rehan, Mohammad
    King Abdulaziz University, Jeddah.
    Naqvi, Muhammad
    Mälardalen University.
    Ouda, Omar
    Prince Mohamed Bin Fahd University, Al Khobar.
    Shahzad, Khurram
    King Abdulaziz University, Jeddah.
    Syamsiro, Mohammad
    Janabadra University, Yogyakarta.
    Waqas, Muhammad
    King Abdulaziz University, Jeddah.
    Miandad, Rashid
    King Abdulaziz University, Jeddah.
    Asam, Zaki-ul-Zaman
    University of Gujrat, Gujrat.
    Ismail, Iqbal Mohammad
    King Abdulaziz University, Jeddah.
    Energy, economic and environmental savings by waste recycling: A case study of Madinah City2017Ingår i: PROCEEDINGS OF THE 9TH INTERNATIONAL CONFERENCE ON APPLIED ENERGY / [ed] Yan, J Wu, J Li, H, Elsevier, 2017, Vol. 142, s. 910-915Konferensbidrag (Refereegranskat)
    Abstract [en]

    In the Kingdom of Saudi Arabia (KSA), millions of worshippers come from across the globe to perform religious rituals of Pilgrimage (Hajj) and Umrah. Madinah-tul-Munawara is one of the holiest city, where pilgrims come after performing rituals in Makkah. In this city, most of the collected municipal solid waste (MSW) is disposed of in the landfills after a partial recycling of paper, cardboard, and metals (similar to 10-20% of total MSW). The Saudi's government has recently launched a new policy of Vision 2030, which outlined the safeguard of local environment through increased efficiency of waste recycling and management, pollution prevention strategies and generating renewable energy from indigenous sources, including the waste. Currently, the recycling practices in KSA are mainly regulated by an informal sector through waste pickers or waste scavengers. This has led to the need of recycling schemes, especially in the holiest cities of Makkah and Madinah through a public-private partnership (PPP). Huge amounts of energy can be conserved, that would otherwise be spent on raw material extraction, transportation, and manufacturing of materials, through recycling into the same materials. Around 10,009 TJ of energy can be saved through recycling of 24.21% of MSW in Madinah city, including glass, metals, aluminum, cardboard, and paper. It is estimated that around 10,200 tons of methane (CH4) emissions and 254,600 Mt center dot CO2 eq. of global warming potential (GWP) can also be saved. In addition, carbon credit revenue of US $5.92 million, and landfill diversion worth of US $32.78 million can be achieved with a net revenue of US $49.01 million every year only by recycling 24.21% of MSW in Madinah city. The waste recycling doesn't require high technical skills and labor, and complicated technologies for large-scale implementation, and therefore, can be implemented easily in the holiest cities of Makkah and Madinah to achieve multiple economic and environmental benefits. (C) 2017 The Authors. Published by Elsevier Ltd.

  • 37.
    Nizami, Abdul-Sattar
    et al.
    King Abdulaziz University, Jeddah.
    Rehan, Mohammad
    King Abdulaziz University, Jeddah.
    Waqas, Muhammad
    King Abdulaziz University, Jeddah.
    Naqvi, Muhammad
    Mälardalen University, Sweden.
    Ouda, Omar K. M.
    Prince Mohamed Bin Fahd University, Al Khobar.
    Shahzad, Khurram
    King Abdulaziz University, Jeddah.
    Miandad, R
    King Abdulaziz University, Jeddah.
    Khan, Mohammad Zain
    Aligarh Muslim University, Aligarh.
    Syamsiro, Mochamad
    Janabadra University, Yogyakarta.
    Ismail, Iqbal M. I.
    King Abdulaziz University, Jeddah.
    Waste biorefineries: enabling circular economies in developing countries2017Ingår i: Bioresource Technology, ISSN 0960-8524, E-ISSN 1873-2976, Vol. 241, s. 1101-1117Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This paper aims to examine the potential of waste biorefineries in developing countries as a solution to current waste disposal problems and as facilities to produce fuels, power, heat, and value-added products. The waste in developing countries represents a significant source of biomass, recycled materials, chemicals, energy, and revenue if wisely managed and used as a potential feedstock in various biorefinery technologies such as fermentation, anaerobic digestion (AD), pyrolysis, incineration, and gasification. However, the selection or integration of biorefinery technologies in any developing country should be based on its waste characterization. Waste biorefineries if developed in developing countries could provide energy generation, land savings, new businesses and consequent job creation, savings of landfills costs, GHG emissions reduction, and savings of natural resources of land, soil, and groundwater. The challenges in route to successful implementation of biorefinery concept in the developing countries are also presented using life cycle assessment (LCA) studies. (C) 2017 Elsevier Ltd. All rights reserved.

  • 38.
    Qureshi, Abdul Sattar
    et al.
    University of Sindh, Jamshoro.
    Khushk, Imrana
    University of Sindh, Jamshoro.
    Naqvi, Salman Raza
    National University of Sciences & Technology, Islamabad.
    Simiar, Altaf Ahmed
    Donghua University, Shanghai.
    Ali, Chaudhry Haider
    University of Engineering & Technology, Lahore.
    Naqvi, Muhammad
    Mälardalen University, Västerås.
    Danish, Muhammad
    State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, ECUST, Shanghai.
    Ahmed, Ayyaz
    Muhammad Nawaz Sharif University of Engineering and Technology, Multan.
    Majeed, Hamid
    Jiangnan University, Wuxi.
    Jatt, Abdul Nabi Mir
    University of Sindh, Jamshoro.
    Rehan, Mohammad
    King Abdulaziz University, Jeddah.
    Nizami, Abdul-Sattar
    King Abdulaziz Univ, Jeddah.
    Fruit waste to energy through open fermentation2017Ingår i: PROCEEDINGS OF THE 9TH INTERNATIONAL CONFERENCE ON APPLIED ENERGY / [ed] Yan, J Wu, J Li, H, Amsterdam: Elsevier, 2017, Vol. 142, s. 904-909Konferensbidrag (Refereegranskat)
    Abstract [en]

    This study aims to examine the nonsterilized fermentation conditions for coproduction of pectinases and lipase enzymes using several fruit wastes as an energy source. Thermophilic fungal strain, Penicillium expansum CM,1 39671 was used as a fermenting strain. The effect of process conditions including; nitrogen sources, pH, temperature, time and moisture contents, on the production of both enzymes were studied. The highest activities of pectinase and lipase (2817, 1870 U/g dry substrate) enzymes were found with orange peel feedstock, whereas the lowest activities of 1662 U/g and 1266 U/g were found with banana peel and papaya peel feedstocks respectively. Overall, pectinase showed higher enzymatic activities than lipase enzymes, both having similar increasing and decreasing trends, at all studied conditions. The optimum process conditions of peptone as a nitrogen source, pH 7, 40 degrees C, 5 days and 70% moisture contents, were found to show highest enzymatic activities for both enzymes. The orange peel feedstock showed no significant difference in both enzymes' activities at sterilized and nonnotarized process conditions. Pectinase and lipase enzymes showed (13791 U/g) and (8114 U/g) for sterilized and (14091 U/g) and (8324 U/g) for nonnotarized process conditions respectively. In addition, the fungal strains also produce bacteriocin-like compounds that could inhibit microbial growth. These findings will help to design and develop robust, cost-effective and less energy intensive enzyme production processes and consequently an efficient fruit waste to energy system through open fermentation. (C) 2017 The Authors. Published by Elsevier Ltd.

  • 39.
    Rehan, Mohammad
    et al.
    King Abdulaziz Univ, CEES, Jeddah, Saudi Arabia..
    Nizami, Abdul-Sattar
    King Abdulaziz Univ, CEES, Jeddah, Saudi Arabia..
    Asam, Zaki-ul-Zaman
    Univ Gujrat, Gujrat, Pakistan..
    Ouda, Omar K. M.
    Prince Mohamed Bin Fand Univ, Al Khobar, Saudi Arabia..
    Gardy, Jabbar
    Univ Leeds, W Yorkshire, England..
    Raza, Ghulam
    Univ Leeds, W Yorkshire, England..
    Naqvi, Muhammad
    Malardalen Univ, Vasteras, Sweden..
    Ismail, Iqbal Mohammad
    King Abdulaziz Univ, CEES, Jeddah, Saudi Arabia..
    Waste to Energy: A Case Study of Madinah City2017Ingår i: PROCEEDINGS OF THE 9TH INTERNATIONAL CONFERENCE ON APPLIED ENERGY / [ed] Yan, J Wu, J Li, H, Amsterdam: Elsevier, 2017, s. 688-693Konferensbidrag (Refereegranskat)
    Abstract [en]

    The concept of energy from waste is getting popular nowadays across the globe, as being capable of producing multi fuels and value-added products from different fractions of municipal solid waste (MSW). The energy recovery technologies under this concept are anaerobic digestion (AD), pyrolysis, transesterification, refuse derived fuel (RDF) and incineration. This concept is very relevant to implementation in countries like Saudi Arabia, who wants to cut their dependence on oil. Moreover, the waste to energy becomes the imperative need of the time because of new governmental policy 'Vision 2030' that firmly said to produce renewable energy from indigenous sources of waste, wind and solar and due to given situations of Hajj and Umrah with massive amounts of waste generation in a short period. This study focused on two waste to energy technologies, AD and pyrolysis for food (40% of MSW) and plastic (20% of MSW) waste streams respectively. The energy potential of 1409.63 and 5619.80 TJ can be produced if all of the food and plastic waste of the Madinah city are processed through AD and pyrolysis respectively. This is equivalent to 15.64 and 58.81 MW from biogas and pyrolytic oil respectively or total 74.45 MW of continuous electricity supply in Madinah city throughout the whole year. It has been estimated that the development of AD and pyrolysis technologies will also benefit the economy with net savings of around US $63.51 and US $53.45 million respectively, totaling to an annual benefit of US $116.96 million Therefore, in Saudi Arabia and particularly in Holiest cities of Makkah and Madinah the benefits of waste to energy are several, including the development of renewable-energy, solving MSW problems, new businesses, and job creation and improving environmental and public health. (C) 2017 The Authors. Published by Elsevier Ltd.

  • 40.
    Rehan, Mohammad
    et al.
    King Abdulaziz University, Saudi Arabia.
    Nizami, Abdul-Sattar
    King Abdulaziz University, Saudi Arabia.
    Rashid, Umer
    Universiti Putra Malaysia, Malaysia.
    Naqvi, Muhammad Raza
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för ingenjörs- och kemivetenskaper (from 2013).
    Editorial: Waste Biorefineries: Future Energy, Green Products and Waste Treatment2019Ingår i: Frontiers in Energy Research, E-ISSN 2296-598X, Vol. 7, s. 1-3, artikel-id 55Artikel i tidskrift (Övrigt vetenskapligt)
  • 41. Salman, Chaudhary Awais
    et al.
    Naqvi, Muhammad
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för ingenjörs- och kemivetenskaper (from 2013).
    Thorin, Eva
    Yan, Jinyue
    A MULTI-CRITERIA DECISION ANALYSIS TO ASSESS DIFFERENT BIOFUELS PRODUCTION IN CHP-GASIFICATION BASED POLYGENERATION SYSTEMS2019Konferensbidrag (Refereegranskat)
  • 42.
    Salman, Chaudhary Awais
    et al.
    Mälardalen University, Västerås.
    Naqvi, Muhammad
    Mälardalen University, Västerås.
    Thorin, Eva
    Mälardalen University, Västerås.
    Yan, Jinyue
    Mälardalen University, Västerås; Royal Institute of Technology, Stockholm.
    A polygeneration process for heat, power and DME production by integrating gasification with CHP plant: Modelling and simulation study2017Ingår i: PROCEEDINGS OF THE 9TH INTERNATIONAL CONFERENCE ON APPLIED ENERGY / [ed] Yan, J Wu, J Li, H, Amsterdam: Elsevier, 2017, Vol. 142, s. 1749-1758Konferensbidrag (Refereegranskat)
    Abstract [en]

    Biofuels are a good substitute for the transport sector petroleum fuels to minimize carbon footprint and greenhouse gases emissions. Di-Methyl Ether (DME) is one such alternative with properties similar to liquefied petroleum gas but with lower SOx, NOx, and particulate emissions. In this work, a polygeneration process, integrating an existing combined heat and power (CHP) plant with biomass gasification to synthesize DME, is proposed and modelled. Process integration is based on a hypothesis that the CHP plant provides the necessary heat to run the co-located gasification plant for DME synthesis and the waste heat from the gasification process is recovered and transferred to the CHP plant. The feed for gasification is taken as refuse derived fuel (RDF) instead of conventional wood derived biomass. The process integration leads to higher overall combined efficiency (up to 71%) which is greater than standalone efficiencies (up to 63%) but lower than stand-alone CHP plant efficiency (73.2%). The further technical evaluation shows that the efficiency of the polygeneration process is depends heavily on the gasifier capacity integrated with the existing CHP plant and also on the conversion route selected for DME synthesis i.e. recycling of unconverted syngas to the DME reactor or transferring it to the boiler of the CHP plant. The simulation results also indicate that once-through conversion yields less DME than recycling, but at the same time, once-through conversion affects the district heat and electric power production of the CHP plant lesser than by using the recycling route. (C) 2017 The Authors. Published by Elsevier Ltd.

  • 43.
    Salman, Chaudhary Awais
    et al.
    Mälardalen University.
    Naqvi, Muhammad
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för ingenjörs- och kemivetenskaper (from 2013). Mälardalen University.
    Thorin, Eva
    Mälardalen University.
    Yan, Jinyue
    Mälardalen University; KTH.
    Gasification process integration with existing combined heat and power plants for polygeneration of dimethyl ether or methanol: A detailed profitability analysis2018Ingår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 226, s. 116-128Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Combustion of waste for cogeneration of heat and power is the most convenient and practical choice to carry out through combined heat and power (CHP) plants. But, seasonal variation in heat demand throughout the year affects the operation of CHP plants. This fluctuation in the CHP operation cause less annual operating hours for the plant equipment and is also not profitable for stakeholders. This study aims to assess the technical potential of integrated gasification process with existing CHP plants for either dimethyl ether (DME) or methanol production through refuse-derived fuel (RDF). Process integration considers that the CHP plant provides the necessary heat for biofuel synthesis during off-peak hours. Mass and heat integration methods are used to develop and simulate the polygeneration processes for heat, power, and biofuel production. Both technical and economic indicators are reported and compared to assess the potential for both biofuels through process integration. Annual operation data of a real CHP plant has been extracted to evaluate the integrated processes. A flexible gasification configuration is selected for the integrated approach i.e. CHP runs at full load to provide the heat demand and only the excess heat of CHP plant is utilized for biofuel production. The energetic efficiencies of the polygeneration systems are compared with the standalone systems. Technical analysis of process integration shows the enhancement of the operational capacity of CHP during off-peak hours and it can produce biofuels without compromising the annual heat demand. Production of methanol through process integration shows ∼67% energetic efficiency while methanol production gives ∼65%. The efficiencies are higher than standalone DME and methanol processes (51% and 53%, respectively) but lower than standalone CHP plant i.e. 81%, however the process integration increases the operating time of the CHP plant with more economic benefits. Economic analysis coupled with uncertainty analysis through Monte Carlo simulations shows that by integrating CHP with gasifier to produce biofuels is significantly profitable as compared with only heat and electricity production. But, DME as a potential product shows more economic benefits than methanol. The uncertainty analysis through Monte Carlo simulations shows that the profitable probability of DME as a product in future is also greater than methanol due to higher DME selling price. The uncertainty analysis further shows that prices of DME and methanol with waste biomass prices in future will have a greater impact on the economic performance of the proposed polygeneration process.

  • 44.
    Salman, Chaudhary Awais
    et al.
    Malardalen Univ, Sch Business Soc & Engn, POB 883, SE-72123 Vasteras, Sweden..
    Naqvi, Muhammad
    Mälardalens högskola.
    Thorin, Eva
    Mälardalens högskola.
    Yan, Jinyue
    Mälardalens högskola; KTH.
    Impact of retrofitting existing combined heat and power plant with polygeneration of biomethane: A comparative techno-economic analysis of integrating different gasifiers2017Ingår i: Energy Conversion and Management, ISSN 0196-8904, E-ISSN 1879-2227, Vol. 152, s. 250-265Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    It is vital to identify and evaluate the optimal gasifier configuration that could be integrated with existing or new combined heat and power (CHP) plants to maximize the utilization of boiler operating capacity during off-peak hours with minimal effect on the boiler performance. This study aims to identify technically and economically most suitable gasification configuration and the reasonable operational limits of a CHP plant when integrated with different types of gasifiers. The selected gasifiers for the study are, (i) indirectly heated dual fluidized bed gasifier (DFBG), (ii) directly heated circulating fluidized bed gasifier (CFBG), and (iii) entrained flow gasifier (EFG). The gasifiers are selected on their ability to produce high-quality syngas from waste refused derived fuel (RDF). The syngas from the gasifiers is utilized to produce biomethane, whereas the heat and power from the CHP plant are consumed to run the gasification process. A detailed techno-economic analysis is performed using both flexible capacity and fixed capacity gasifiers and integrated with the CHP plant at full load. The results reveal that the integration leads to increase in operating time of the boiler for all gasifier configurations. The indirectly heated DFBG shows the largest biomethane production with less impact on the district heat and power production. Extra heat is available for biomethane production when the district heat and biomethane are prioritized, and the electric power is considered as a secondary product. Furthermore, the economic indicators reflect considerable dependency of integrated gasification performance on variable prices of waste biomass and biomethane.

  • 45.
    Salman, Chaudhary Awais
    et al.
    Mälardalen University.
    Schwede, Sebastian
    Mälardalen University.
    Naqvi, Muhammad
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för ingenjörs- och kemivetenskaper (from 2013).
    Thorin, Eva
    Mälardalen University.
    Yan, Jinyue
    Mälardalen University; KTH.
    Synergistic combination of pyrolysis, anaerobic digestion, and CHP plants2019Ingår i: Energy Procedia, Elsevier, 2019, s. 1323-1329Konferensbidrag (Refereegranskat)
    Abstract [en]

    The anaerobic digestion of biodegradable fraction of municipal solid waste (MSW) is a widely used process for biogas production. However, the biodegradable fraction of MSW also contains lignocellulosic waste which hinders the biogas production if added to the digester in higher quantity. So it needs to be separated from biodegradable waste and sent for alternate treatment, e.g., incineration, landfilling or compositing. Pyrolysis of lignocellulosic waste to produce biochar, syngas, and bio oil is an alternate treatment to consider. Furthermore, there is a reported correlation between the addition of biochar in the digester and higher biogas production. Previously, we coupled the pyrolysis of lignocellulosic waste with anaerobic digestion plant. Pyrolysis produces the biochar and vapors. Biochar was added in the digester to enhance the biomethane production. The vapors produced in the pyrolysis process were converted to biomethane through the catalytic methanation process. The combination gives the overall efficiency of 67%. In this work, we modified the process concept to increase the integration level of these processes. The main issue with the pyrolysis process is its heat required to operate, while some of its downstream processes also generate excess heat. In this study, the pyrolysis of lignocellulosic waste is integrated with an operating combined heat and power (CHP) plant, by using its existing infrastructure for heat transport among different pyrolysis operations. The combustor of the CHP plant provides the heat for drying and pyrolysis while the excess heat is transferred back to the combustor. The biochar produced from pyrolysis is transported back to the digester as an adsorbent. The process simulation results show that the combined efficiency of pyrolysis with CHP plant reached 80%. If the biochar is sent back to the anaerobic digester, the synergetic efficiency of all three processes, i.e., pyrolysis-CHP and anaerobic digestion was obtained at 79.7% as compared with the 67% efficiency when the pyrolysis was only integrated with the anaerobic digestion process.

  • 46.
    Tahir, M. H.
    et al.
    University of Science and Technology of China.
    Zhao, Z.
    Shenzhen Graduate School, Shenzhen.
    Ren, J.
    Chongqing Technology and Business University, Chongqing, China.
    Naqvi, Muhammad
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för ingenjörs- och kemivetenskaper (from 2013).
    Ahmed, M. S.
    Hebei University of Technology, Tianjin, China.
    Shah, T. -U.-H.
    University of Science and Technology of China,.
    Shen, B.
    Hebei University of Technology, Tianjin, China.
    Elkamel, A.
    University of Waterloo, Waterloo, Ontario, Canada.
    Irfan, R. M.
    University of Sargodha, Sargodha, Pakistan.
    Rahman, A. U.
    University of Peshawar, Peshawar, Pakistan.
    Fundamental investigation of the effect of functional groups on the variations of higher heating value2019Ingår i: Fuel, ISSN 0016-2361, E-ISSN 1873-7153, Vol. 253, s. 881-886Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The aims of this study is to investigate the effects of functional groups like [sbnd]C[dbnd]C[sbnd]and C[sbnd]OH on variation of higher heating values (HHV)of organic compounds. HHV of fuel hydrocarbons, gaseous and liquids including single bonded and multiple bonded carbons and green tea polyphenols (GTP)were determined by using Bomb Calorimeter. It was observed that, multiple bonded carbon and oxygen bonded carbon i.e. [sbnd]C[dbnd]C[sbnd]and [sbnd]C[sbnd]O[sbnd]result in less carbon reduced state while, also increase endothermicity of reactants by changing hybridization state with more s-character and hence, contribute to lower level of HHV. Besides, hydrogen bonding was also considered as the major cause of the difference in HHV of fuel hydrocarbons having the same molecular formula but different oxygen-bearing functional groups due to structure stabilization. These statements were further supported by the combination of Fourier transform infra-red spectra (FTIR)and HHV calculation of raw GTP (set as a representative of biomass)and its solid products obtained at 250 °C and 350 °C by thermal treatment done by using high temperature tube furnace.

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