Methane Pub Date : 2023-05-04 DOI: 10.3390/methane2020015

G. Krishnamoorthy

{"title":"Particle Size Distribution and Its Impacts on Ash Deposition and Radiative Transfer during Oxy-Combustion of Rice Husk–Natural Gas","authors":"G. Krishnamoorthy","doi":"10.3390/methane2020015","DOIUrl":"https://doi.org/10.3390/methane2020015","url":null,"abstract":"Rice husk (RH) co-combustion with natural gas in highly oxygen-enriched concentrations presents a net carbon-negative energy production opportunity while minimizing flue gas recycling. However, recent experiments have shown enhanced ash deposition rates in oxygen-enriched conditions, with deposition/shedding also being dependent on the particle size distribution (PSD) of the parent RH fuel. To uncover the causative mechanisms behind these observations, add-on models for ash deposition/shedding and radiative properties were employed in computational fluid dynamics simulations. The combustion scenarios investigated encompassed two types of RH (US RH, Chinese RH) with widely varying ash contents (by % mass) and inlet fuel PSD with air and O2/CO2 (70/30 vol %, OXY70) as oxidizers. Utilizing the measured fly-ash PSDs near the deposit surface and modeling the particle viscosity accurately, particle kinetic-energy (PKE)-based capture and shedding criteria were identified as the keys to accurate deposition/shedding rate predictions. The OXY70 scenarios showed higher ash-capturing propensities due to their lower PKE. Conversely, higher erosion rates were predicted in the AIR firing scenarios. In addition, the radiative characteristics across all the scenarios were dominated by the gases and were not sensitive to the fly-ash PSD. Therefore, the higher particle concentrations in the OXY70 conditions did not negatively impact the heat extraction.","PeriodicalId":74177,"journal":{"name":"Methane","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47584827","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Biogas and Syngas Production from Sewage Sludge: A Sustainable Source of Energy Generation 利用污泥生产沼气和合成气：可持续能源

Methane Pub Date : 2023-04-29 DOI: 10.3390/methane2020014

Nwabunwanne Lilian Enebe, C. Chigor, Kechrist Obileke, M. Lawal, M. Enebe

{"title":"Biogas and Syngas Production from Sewage Sludge: A Sustainable Source of Energy Generation","authors":"Nwabunwanne Lilian Enebe, C. Chigor, Kechrist Obileke, M. Lawal, M. Enebe","doi":"10.3390/methane2020014","DOIUrl":"https://doi.org/10.3390/methane2020014","url":null,"abstract":"Sewage sludge to energy conversion is a sustainable waste management technique and a means of militating against the environmental concerns associated with its disposal. Amongst the various conversion technologies, anaerobic digestion and gasification have been identified as the two most promising. Therefore, this study is focused on a detailed evaluation of the anaerobic digestion and gasification of sewage sludge for energy production. Moreover, the key challenges hindering both technologies are discussed, as well as the practical measures for addressing them. The applicable pretreatment measures for efficient transformation into valuable energy vectors were further evaluated. Specifically, the study evaluated various properties of sewage sludge in relation to gasification and anaerobic digestion. The findings showed that a high ash content in sewage sludge results in sintering and agglomeration, while a high moisture content promotes tar formation, which has been identified as one of the key limitations of sewage sludge gasification. More importantly, the application of pretreatment has been shown to have some beneficial features in promoting organic matter decomposition/degradation, thereby enhancing biogas as well as syngas production. However, this has additional energy requirements and operational costs, particularly for thermal and mechanical methods.","PeriodicalId":74177,"journal":{"name":"Methane","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47373687","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Growth Media Efficacy in Biochemical Methane Potential Assays. 生长培养基在生化甲烷势测定中的功效。

Methane Pub Date : 2023-04-18 DOI: 10.3390/methane2020013

Giles Chickering, Thabet Tolaymat

引用次数: 0

Heterogeneous Electrocatalysis of Carbon Dioxide to Methane 二氧化碳制甲烷的多相电催化

Methane Pub Date : 2023-04-17 DOI: 10.3390/methane2020012

Yugang Wu, Huitong Du, Peiwen Li, Xiangyang Zhang, Yanbo Yin, Wenlei Zhu

引用次数: 2

PdxNiy/TiO2 Electrocatalysts for Converting Methane to Methanol in An Electrolytic Polymeric Reactor—Fuel Cell Type (PER-FC) PdxNiy/TiO2电催化剂在电解聚合反应器-燃料电池型(PER-FC)中转化甲烷为甲醇

Methane Pub Date : 2023-04-13 DOI: 10.3390/methane2020011

Jéssica F. Coelho, Isabely M. Gutierrez, Nivaldo G. P. Filho, Priscilla J. Zambiazi, A. O. Neto, R. D. de Souza

引用次数: 0

Effect of Pressure on Hydrogen Isotope Fractionation in Methane during Methane Hydrate Formation at Temperatures Below the Freezing Point of Water 在低于水冰点的温度下甲烷水合物形成过程中压力对甲烷中氢同位素分馏的影响

Methane Pub Date : 2023-04-12 DOI: 10.3390/methane2020010

A. Hachikubo, Taichi Nezu, Kaede Takizawa, S. Takeya

{"title":"Effect of Pressure on Hydrogen Isotope Fractionation in Methane during Methane Hydrate Formation at Temperatures Below the Freezing Point of Water","authors":"A. Hachikubo, Taichi Nezu, Kaede Takizawa, S. Takeya","doi":"10.3390/methane2020010","DOIUrl":"https://doi.org/10.3390/methane2020010","url":null,"abstract":"Isotopic fractionation of methane between gas and solid hydrate phases provides data regarding hydrate-forming environments, but the effect of pressure on isotopic fractionation is not well understood. In this study, methane hydrates were synthesized in a pressure cell, and the hydrogen isotope compositions of the residual and hydrate-bound gases were determined. The δ2H of hydrate-bound methane formed below the freezing point of water was 5.7–10.3‰ lower than that of residual methane, indicating that methane hydrate generally encapsulates lighter molecules (CH4) instead of CH32H. The fractionation factors αH-V of the gas and hydrate phases were in the range 0.9881–0.9932 at a temperature and pressure of 223.3–268.2 K and 1.7–19.5 MPa, respectively. Furthermore, αH-V increased with increasing formation pressure, suggesting that the difference in the hydrogen isotopes of the hydrate-bound methane and surrounding methane yields data regarding the formation pressure. Although the differences in the hydrogen isotopes observed in this study are insignificant, precise analyses of the isotopes of natural hydrates in the same area enable the determination of the pressure during hydrate formation.","PeriodicalId":74177,"journal":{"name":"Methane","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45825214","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Techno-Economic Assessment of On-Site Production of Biomethane, Bioenergy, and Fertilizer from Small-Scale Anaerobic Digestion of Jabuticaba By-Product Jabuticaba副产品小型厌氧消化现场生产生物甲烷、生物能源和肥料的技术经济评价

Methane Pub Date : 2023-03-28 DOI: 10.3390/methane2020009

W. Sganzerla, Rafael Gabriel da Rosa, Tiago Barroso, L. Castro, T. Forster‐Carneiro

{"title":"Techno-Economic Assessment of On-Site Production of Biomethane, Bioenergy, and Fertilizer from Small-Scale Anaerobic Digestion of Jabuticaba By-Product","authors":"W. Sganzerla, Rafael Gabriel da Rosa, Tiago Barroso, L. Castro, T. Forster‐Carneiro","doi":"10.3390/methane2020009","DOIUrl":"https://doi.org/10.3390/methane2020009","url":null,"abstract":"Bioenergy recovery from biomass by-products is a promising approach for the circular bioeconomy transition. However, the management of agri-food by-products in stand-alone treatment facilities is a challenge for the low-capacity food processing industry. In this study, the techno-economic assessment of a small-scale anaerobic digestion process was evaluated for the management of jabuticaba by-product and the production of biomethane, electricity, heat, and fertilizer. The process was simulated for a treatment capacity of 782.2 m3 y−1 jabuticaba peel, considering the experimental methane production of 42.31 L CH4 kg−1 TVS. The results of the scaled-up simulated process demonstrated the production of biomethane (13,960.17 m3 y−1), electricity (61.76 MWh y−1), heat (197.62 GJ y−1), and fertilizer (211.47 t y−1). Economic analysis revealed that the process for biomethane recovery from biogas is not profitable, with a net margin of −19.58% and an internal rate of return of −1.77%. However, biogas application in a heat and power unit can improve project feasibility, with a net margin of 33.03%, an internal rate of return of 13.14%, and a payback of 5.03 years. In conclusion, the application of small-scale anaerobic digestion can prevent the wrongful open-air disposal of jabuticaba by-products, with the generation of renewable energy and biofertilizer supporting the green economy toward the transition to a circular economy.","PeriodicalId":74177,"journal":{"name":"Methane","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44388328","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Morphology-Controlled WO3 for the Photocatalytic Oxidation of Methane to Methanol in Mild Conditions 温和条件下甲烷光催化氧化制甲醇的形态控制WO3

Methane Pub Date : 2023-02-17 DOI: 10.3390/methane2010008

Dumindu Premachandra, M. Heagy

{"title":"Morphology-Controlled WO3 for the Photocatalytic Oxidation of Methane to Methanol in Mild Conditions","authors":"Dumindu Premachandra, M. Heagy","doi":"10.3390/methane2010008","DOIUrl":"https://doi.org/10.3390/methane2010008","url":null,"abstract":"Since WO3 is a relatively abundant metal oxide and features the ability to absorb in the visible spectrum, this non-toxic semiconductor is a promising photocatalyst among sustainable materials. These properties have delivered intriguing catalytic results in the conversion of methane to methanol; however, initial investigations indicate low photocatalytic efficiency resulting from fast recombination of photogenerated charges. To explore this aspect of inefficiency, five different morphologies of WO3 consisting of micron, nanopowder, rods, wires, and flowers were obtained and characterized. In addition, several electron capture agents/oxidizers were investigated as a means of improving the separation of photogenerated charges. The photocatalytic activity of different morphologies was assessed via CH3OH formation rates. Based on our results, WO3 flowers produced the highest methanol productivity (38.17 ± 3.24 µmol/g-h) when 2 mM H2O2 was present, which is approximately four times higher in the absence of H2O2. This higher methanol production has been attributed to the unique structure-related properties of the flower-like structure. Photoluminescence emission spectra and diffuse reflectance data reveal that flower structures are highly catalytic due to their reduced electron/hole recombination and multiple light reflections via petal-like hollow chambers.","PeriodicalId":74177,"journal":{"name":"Methane","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45177674","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Investigating the Effect of Ni Loading on the Performance of Yttria-Stabilised Zirconia Supported Ni Catalyst during CO2 Methanation Ni负载量对钇稳定氧化锆负载Ni催化剂CO2甲烷化性能影响的研究

Methane Pub Date : 2023-02-08 DOI: 10.3390/methane2010007

Osaze Omoregbe, A. Majewski, R. Steinberger‐Wilckens, A. El-kharouf

{"title":"Investigating the Effect of Ni Loading on the Performance of Yttria-Stabilised Zirconia Supported Ni Catalyst during CO2 Methanation","authors":"Osaze Omoregbe, A. Majewski, R. Steinberger‐Wilckens, A. El-kharouf","doi":"10.3390/methane2010007","DOIUrl":"https://doi.org/10.3390/methane2010007","url":null,"abstract":"CO2 methanation was studied on Ni-based yttria-stabilised zirconia (Ni/YSZ) catalysts. The catalysts were prepared by the wet impregnation method, where the amount of Ni content was varied from 5% to 75%. Thereafter, the prepared catalysts were analysed by BET, XRD, SEM and H2-TPR. BET results showed an initial increase in the surface area with an increase in Ni loading, then a decrease after 30% Ni loading. The XRD results revealed that the Ni crystallite size increased as the Ni loading increased, while the H2-TPR showed a shift in reduction peak temperature to a higher temperature, indicating that the reducibility of the catalysts decreased as the Ni loading increased. The activity of the synthesised catalysts for CO2 methanation was studied by passing a mixture of H2, CO2 and N2 with a total flow of 135 mL min−1 and GHSV of 40,500 mL h−1 g−1 through a continuous flow quartz tube fixed-bed reactor (I.D. = 5.5 mm, wall thickness = 2 mm) containing 200 mg of the catalyst at a temperature range of 473 to 703 K under atmospheric pressure and a H2:CO2 ratio of 4. The tested Ni/YSZ catalysts showed an improvement in activity as the reaction temperature increased from 473 K to around 613 to 653 K, depending on the Ni loading. Beyond the optimum temperature, the catalyst’s activity started to decline, irrespective of the Ni loading. In particular, the 40% Ni/YSZ catalyst displayed the best performance, followed by the 30% Ni/YSZ catalyst. The improved activity at high Ni loading (40% Ni) was attributed to the increase in hydrogen coverage and improved site for both H2 and CO2 adsorption and activation.","PeriodicalId":74177,"journal":{"name":"Methane","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44694773","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Acknowledgment to the Reviewers of Methane in 2022 向2022年甲烷评审员致谢

Methane Pub Date : 2023-01-17 DOI: 10.3390/methane2010005

引用次数: 0

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