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Sustainable Production of Biomethanol and Its Environmental Impacts
(2025-01-01)
Detchusananard, Thanaphorn
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Im-Orb, Karittha
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Wiranarongkorn, Kunlanan
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Chen, Yong Song
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Arpornwichanop, Amornchai
Utilizing biomass and biogas sourced from various organic waste materials as renewable feedstocks for biomethanol production offers a sustainable alternative to fossil fuels such as coal, petroleum oil, and natural gas. This chapter provides an exploration of several technologies employed in biomethanol production, including biomass gasification, biomass pyrolysis, and biogas upgrading. Syngas production and conditioning, methanol synthesis and separation, and integrating systems with other renewable energy sources are found to be crucial stages towards achieving sustainable production. The chapter comprehensively evaluates the technical, economic, and environmental aspects of each biomethanol production process. Furthermore, it delves into ongoing efforts to improve and develop biomethanol-production processes to achieve the carbon neutrality goals. The chapter also outlines emerging trends and future research directions in the field of biomethanol production.
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Performance Analysis of Biomass Gasification with Biogas Co-Feeding for Hydrogen Production
(2025-01-01)
Saebea, Dang
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Patcharavorachot, Yaneeporn
To improve the hydrogen yield in biomass gasification, the addition of biogas for co-feeding with biomass in gasification was proposed in this work. The gasification model developed in Aspen Plus software was validated with experimental data. The performance of biomass gasification with biogas co-feeding using steam as a gasifying agent was investigated. The effect of the steam-to-fuel ratio on the gasification of mixed biomass and biogas was studied. The results show that the simulation results of biomass gasification were consistent with experimental data. Biomass gasification with biogas co-feeding can raise the amount of hydrogen and carbon monoxide in gas products by 22.12% and 18.44%, respectively. Moreover, the increase in the steam-to-fuel ratio enhances hydrogen in syngas. However, the system efficiency decreases with increasing steam-to-fuel ratio.
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Effect of CoMo metal loading on H2 and CNTs production from biogas by integrative process
(2022-12-19)
Aieamsam-Aung, Pichawee
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Nantapong, Paveenuch
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Rattanaamonkulchai, Raminda
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Kludpantanapan, Thunyathon
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Srifa, Atthapon
Effect of CoMo metal loading to MgO (1, 5, 30 and 50 wt%) on conversion of biogas by an integrative process was investigated at 900 °C under atmospheric pressure. The integrative process combines the direct methanation of CO<inf>2</inf> in biogas and the CH<inf>4</inf> decomposition to upgrade biogas to CH<inf>4</inf> and decompose to hydrogen and carbon nanotubes. Methane dissociative reaction is governed by the concentration of active metals on the catalyst surface, while DRM reaction is suppressed. The 30 wt%CoMo catalyst shows the optimal loading for production of high-purity H<inf>2</inf> (>90v/v%) and high yield of MWCNTs (2.33 gCNT/gCat-h) with 100%CO<inf>2</inf> conversion and 95%CH<inf>4</inf> conversion. Meanwhile, 1 wt%CoMo catalyst provided the single-walled CNTs with diameter of 2.5 nm, high surface area of 165 m2/g and high graphitization of I<inf>G</inf>/I<inf>D</inf> = 6.14.
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Simultaneous production of hydrogen and carbon nanotubes from biogas: On the design of combined process
(2022-04-15)
Rattanaamonkulchai, Raminda
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Kludpantanapan, Thunyathon
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Nantapong, Paveenuch
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Srifa, Atthapon
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Koo-Amornpattana, Wanida
We introduced a novel combined process of CO<inf>2</inf> methanation (METH) and catalytic decomposition of methane (CDM) for simultaneous production of hydrogen (H<inf>2</inf>) and carbon nanotubes (CNTs) from biogas. In this process, biogas is catalytically upgraded into CH<inf>4</inf>-rich gas in METH reactor using Ni/CeO<inf>2</inf> catalyst, and the obtained CH<inf>4</inf>-rich gas is subsequently decomposed into H<inf>2</inf> and CNTs in CDM reactor over CoMo/MgO catalyst. Among the three different process scenarios proposed, the combined process with a steam condenser equipped between METH and CDM reactors could greatly improve a CNTs productivity. The CNTs production yield increased by more than 2.5-fold, maximizing at 9.08 gCNTs/gCat with a CNTs purity of 90%. The deposited carbon product was characterized as multi-walled carbon nanotubes (MWCNTs) with a surface area of 136.0 m2/g, comparable with commercial CNTs of 199.8 m2/g. The remarkable I<inf>G</inf>/I<inf>D</inf> ratio of 2.18 confirms a superior portion of graphitic carbon in the synthesized CNTs upon the commercial CNTs with I<inf>G</inf>/I<inf>D</inf> = 0.74. Notably, the CH<inf>4</inf> conversion reached 94.5%, while the CO<inf>2</inf> conversion achieved 100%, resulting in the H<inf>2</inf> yield and H<inf>2</inf> purity higher than 90%. This combined process demonstrates a promising route for production of high quality CNTs and high purity H<inf>2</inf> with complete CO<inf>2</inf> conversion using biogas as abundant renewable energy resources. In addition, the test of raw biogas showed no deactivation of catalyst, justifying the implementation of the developed process for real biogas without purification.
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Performance Evaluation of Solid Oxide Fuel Cell Coupling to Biogas Tri-reforming with Installation of Hydrogen-Selective Membrane Separator
(2020-01-01)
Saebea, D.
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Soisuwan, S.
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Patcharavorachot, Y.
Due to high CO<inf>2</inf> composition in biogas, hydrogen concentration produced from the biogas reforming process is low, which has negative effect on the SOFC efficiency. Therefore, aims of this study are to improve and analyze the performance of solid oxide fuel cell (SOFC) integrated with hydrogen production from tri-reforming process of biogas coupling to hydrogen-selective membrane separator. The simulation results show that the increase of pressure increases the hydrogen separation in Pd/Ag membrane separator. The Pd/Ag membrane separator can separate hydrogen of 47.5 %, at 8 bar. When comparing the integrated system of SOFC and biogas tri-reforming without/with installing hydrogen-selective membrane separator, the efficiency of system with coupling to hydrogen-selective membrane separator is higher than that without coupling to hydrogen-selective membrane separator about 13-14.7 %.
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Performance and environmental study of a biogas-fuelled solid oxide fuel cell with different reforming approaches
(2018-03-01)
Chatrattanawet, Narissara
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Saebea, Dang
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Authayanun, Suthida
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Arpornwichanop, Amornchai
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Patcharavorachot, Yaneeporn
In this work, solid oxide fuel cells (SOFCs) using biogas as the fuel with two different reforming approaches, i.e., external and internal reforming, were studied to determine the optimal operation conditions for each approach. Thermodynamic analysis was performed using a flowsheet simulator. The equilibrium gas composition was calculated by minimizing the Gibbs free energy. An electrochemical model that includes three voltage losses (i.e., activation, ohmic, and concentration losses) was used to predict the performance of the SOFCs. The simulation results showed that the reformer in the external reforming SOFC should be operated at a temperature of 973 K, a pressure of 1 atm, and a steam-to-carbon molar ratio of 0.5. In performance analysis, the simulation results indicated that both approaches have the same optimal operating conditions, i.e. a temperature of 1173 K, a pressure of 3 atm, and a current density of 5000 A/m2. Under the same operating conditions, the internal reforming SOFC exhibited better electrical efficiency than that of the external reforming SOFC. Considering the CO<inf>2</inf> and CO emissions, the exhaust gas obtained from the anode side of the internal reforming SOFC contained 7.4% CO<inf>2</inf> and 37.9% CO, which are higher values than those for the external reforming SOFC (1.9% CO<inf>2</inf> and 32.5% CO).
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A Multi-Objective Optimization Model for Solid Waste Disposal Under Uncertainty: A Case Study of Bangkok, Thailand
(2017-03-01)
Laokhongthavorn, Laemthong
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U-tapao, Chalida
This paper has applied operation research to solid waste disposal by which two objective functions are optimized to minimize the expected operational costs (maximize revenues) and the expected net carbon dioxide equivalent (CDE) emissions. Types and uncertain amounts of solid wastes as well as costs of electricity were factored into the selection decision of solid waste disposal, i.e., landfill, incineration, composting and recycling. An optimization model was applied to the solid waste disposal of Bangkok, Thailand. In addition, a multi-objective optimization technique was proposed for a trade-off decision-making between minimum operational costs and CDE emissions. Composting and landfill are effective alternatives for Bangkok’s solid waste disposal system. The operational costs and net CDE emissions are highly correlated with the quantity of solid waste. Policy makers and plant operators could adopt the proposed optimization model under uncertainty in the selection of an optimal solid waste disposal.
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Biogas production from bakery wastewater in two-stage anaerobic digestion system
(2017-01-01)
Singharat, Kanchai
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Sangkarak, Sirirat
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Pongsuk, Onuma
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Junyapoon, Suwannee
Biogas production from bakery wastewater was studied using a semi-continuous, two-stage anaerobic digestion system, consisting of 2 l-first-stage digester and 5 l-second-stage digester under temperature of 35°C. Substrate feed rates were examined in a batch experiment by varying in the range of 50 to 200 ml/l/d. Characteristics of substrate and effluent of the digester (i.e. pH, SS, TS, VS, VFAs, COD, sCOD, TN, TP, TSO 2- <inf>4</inf> ), biogas yields and compositions were investigated. The experimental results showed that substrate feed rate of 100 ml/l/d produced maximum yield of biogas. The biogas yield was directly proportional to concentration of VFAs in the second-stage digester. The approximate pH values in the first stage and the second stage digesters were 6.13 and 7.25, respectively. The average biogas yield of 0.481 l/ g VS removed and 0.609 l/ g sCOD removed was observed at a hydraulic retention time (HRT) of 10 days. Biogas contained 46.4%-60.8% methane. Removal efficiencies of SS, VS, COD and sCOD in this system were 85.58%, 93.35%, 87.91% and 75%, respectively. The amounts of total nitrogen and total phosphorus after digestion increased whereas that of sulfate decreased.
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Theoretical analysis of a biogas-fed PEMFC system with different hydrogen purifications: Conventional and membrane-based water gas shift processes
(2014-01-01)
Authayanun, Suthida
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Aunsup, Pounyaporn
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Patcharavorachot, Yaneeporn
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Arpornwichanop, Amornchai
This study presents a thermodynamic analysis of biogas reforming and proton electrolyte membrane fuel cell (PEMFC) integrated process with different hydrogen purifications: conventional and membrane-based water gas shift processes. The aim is to determine the optimal reforming process for hydrogen production from biogas in the PEMFC system. The formation of carbon is concerned in the hydrogen production. The simulation results show that increases in the steam-to-methane ratio and reformer temperature can improve the hydrogen yield and reduce the carbon formation. From the performance analysis, it is found that when the PEMFC is operated at high temperature and fuel utilization, the overall system efficiency enhances. The performance of the PEMFC system with the installation of a water gas shift membrane unit in the hydrogen purification step is slightly increased, compared with a conventional process. © 2014 Elsevier Ltd. All rights reserved.
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Thermodynamic analysis of hydrogen production from the adsorption-enhanced steam reforming of biogas
(2014-01-01)
Saebea, Dang
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Authayanun, Suthida
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Patcharavorachot, Yaneeporn
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Arpornwichanop, Amornchai
Biogas is considered a potential, renewable fuel to be used as a hydrogen source. At present, a steam reforming is widely used process in hydrogen production, but it needs to be operated at high temperature to achieve high hydrogen yield. Because biogas consists of mostly CO<inf>2</inf>, the hydrogen purification of a reformate gas obtained is another important issue, especially for fuel cell applications. In this study, an enhanced-adsorption steam reforming process in which steam reforming reaction and CO<inf>2</inf> adsorption are occurred in a single unit is investigated. A thermodynamic analysis is performed to study effects of important operating parameters on hydrogen yield and product distribution. It is found that a biogas processor should be operated at high temperatures and inlet steam-T o-methane ratio. The content of CO in the reformate gas increases with increased operating temperature. The steam reforming of biogas coupled with a CO<inf>2</inf> adsorption gives a higher hydrogen product with considerable low CO content, compared to the conventional steam reforming of biogas.

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