This paper analyzes the mitigation of enteric methane (CH4) emissions from ruminants with the use of feed additives inhibiting rumen methanogenesis to limit the global temperature increase to 1.5 °C. A mathematical simulation conducted herein predicted that pronounced inhibition of rumen methanogenesis with pure chemicals or bromoform-containing algae with an efficacy higher than that obtained in most studies can be important to limiting global temperature increase by 2050 to 1.5 °C but will likely need to be accompanied by improved production efficiency and other mitigation measures. Currently, the most important limitations to the adoption of antimethanogenic feed additives are increased feeding cost without a consistent return in production efficiency and achieving sustained delivery of inhibitors to grazing animals, especially in extensive systems. Economic incentives could be applied in some countries to favor adoption of inhibitors. Changes in rumen microbial and whole animal metabolism caused by inhibiting methanogenesis could potentially be used to make the methanogenesis inhibition intervention cost-effective, although research in this direction is unlikely to yield results in the short term. Future research directions to maximize the adoption and efficacy of inhibitors of methanogenesis are examined.
{"title":"Opportunities and Hurdles to the Adoption and Enhanced Efficacy of Feed Additives towards Pronounced Mitigation of Enteric Methane Emissions from Ruminant Livestock","authors":"E. Ungerfeld","doi":"10.3390/methane1040021","DOIUrl":"https://doi.org/10.3390/methane1040021","url":null,"abstract":"This paper analyzes the mitigation of enteric methane (CH4) emissions from ruminants with the use of feed additives inhibiting rumen methanogenesis to limit the global temperature increase to 1.5 °C. A mathematical simulation conducted herein predicted that pronounced inhibition of rumen methanogenesis with pure chemicals or bromoform-containing algae with an efficacy higher than that obtained in most studies can be important to limiting global temperature increase by 2050 to 1.5 °C but will likely need to be accompanied by improved production efficiency and other mitigation measures. Currently, the most important limitations to the adoption of antimethanogenic feed additives are increased feeding cost without a consistent return in production efficiency and achieving sustained delivery of inhibitors to grazing animals, especially in extensive systems. Economic incentives could be applied in some countries to favor adoption of inhibitors. Changes in rumen microbial and whole animal metabolism caused by inhibiting methanogenesis could potentially be used to make the methanogenesis inhibition intervention cost-effective, although research in this direction is unlikely to yield results in the short term. Future research directions to maximize the adoption and efficacy of inhibitors of methanogenesis are examined.","PeriodicalId":74177,"journal":{"name":"Methane","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47595796","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}
Julles Mitoura dos Santos Junior, J. Gomes, Antônio Carlos Daltro de Freitas, R. Guirardello
The thermal cracking process of methane does not present the emissions of polluting gases, forming only hydrogen with a high degree of purity and solid carbon that can be commercialized for other industrial purposes globally. Thermodynamic methodologies based on Gibbs energy minimization and entropy maximization are used in the present study to simulate operating conditions of isothermal and adiabatic reactors, respectively. The chemical equilibrium and combined phases problem were written in a non-linear programming form and optimized with the GAMS software using the CONOPT 3 solver. The results obtained by the methodology described in this study present a good agreement with the data reported in the literature, with mean relative deviations lower than 1.08%. High temperatures and low pressures favor the decomposition of methane and the formation of products. When conditioned in an isothermal reactor, total methane conversions are obtained at temperatures above 1200 K at 1 bar. When conditioned to an adiabatic reactor, due to the lack of energy support provided by the isothermal reactor and taking into account that it is an endothermic process, high methane-conversion rates are obtained for temperatures above 1600 K at 1 bar. As an alternative, the combined effects of the addition of hydrogen to the feed combined with a system of extreme pressure variation indicate a possibility of conducting the thermal cracking process of methane in adiabatic systems. Setting the CH4/H2 ratio in the system feed at 1:10 at 1600 K and 50 bar, following severe depressurization through an isentropic valve, varying the pressure from 50 to 1 bar, the methane conversion varies from 0 to 94.712%, thus indicating a possible operational conformation for the process so that the amount of carbon generated is not so harmful to the process, taking into account that the formation of the same occurs only after the reaction and heating processes. Under the same operating conditions, it is possible to use about 40.57% of the generated hydrogen to provide energy for the process to occur.
{"title":"An Analysis of the Methane Cracking Process for CO2-Free Hydrogen Production Using Thermodynamic Methodologies","authors":"Julles Mitoura dos Santos Junior, J. Gomes, Antônio Carlos Daltro de Freitas, R. Guirardello","doi":"10.3390/methane1040020","DOIUrl":"https://doi.org/10.3390/methane1040020","url":null,"abstract":"The thermal cracking process of methane does not present the emissions of polluting gases, forming only hydrogen with a high degree of purity and solid carbon that can be commercialized for other industrial purposes globally. Thermodynamic methodologies based on Gibbs energy minimization and entropy maximization are used in the present study to simulate operating conditions of isothermal and adiabatic reactors, respectively. The chemical equilibrium and combined phases problem were written in a non-linear programming form and optimized with the GAMS software using the CONOPT 3 solver. The results obtained by the methodology described in this study present a good agreement with the data reported in the literature, with mean relative deviations lower than 1.08%. High temperatures and low pressures favor the decomposition of methane and the formation of products. When conditioned in an isothermal reactor, total methane conversions are obtained at temperatures above 1200 K at 1 bar. When conditioned to an adiabatic reactor, due to the lack of energy support provided by the isothermal reactor and taking into account that it is an endothermic process, high methane-conversion rates are obtained for temperatures above 1600 K at 1 bar. As an alternative, the combined effects of the addition of hydrogen to the feed combined with a system of extreme pressure variation indicate a possibility of conducting the thermal cracking process of methane in adiabatic systems. Setting the CH4/H2 ratio in the system feed at 1:10 at 1600 K and 50 bar, following severe depressurization through an isentropic valve, varying the pressure from 50 to 1 bar, the methane conversion varies from 0 to 94.712%, thus indicating a possible operational conformation for the process so that the amount of carbon generated is not so harmful to the process, taking into account that the formation of the same occurs only after the reaction and heating processes. Under the same operating conditions, it is possible to use about 40.57% of the generated hydrogen to provide energy for the process to occur.","PeriodicalId":74177,"journal":{"name":"Methane","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44336181","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}
D. Panwar, R. Chaurasia, V. K. Saxena, Ashutosh Kumar Singh
Demand for a cleaner source of energy is increasing in India. In the search for alternate energy sources, coal bed methane gas receives considerable attention for its potential as a good energy source. During the coalification process, methane gas is captured in the coal seams and later released during coal mining operations. Coal bed methane separation is crucial for both economic benefit and methane emission reduction. The methane production from seams is an efficient way to reduce greenhouse emissions and provide a safe mining operation environment. In India, the production of coal bed methane on a commercial scale has been recently observed. In the present paper, an attempt is made to understand and establish a 3-D excavation of coal bed methane from reservoir simulation (COMET3) for Gondwana coal seams in the Sitarampur block of the Raniganj coalfield in India. The simulation study was carried out for a period of 25 years for the recovery of methane from the reservoir. It is observed from the simulation study that 372 million cubic meters CO2 equivalent greenhouse gas emissions can be prevented by the extraction of methane with space and time. The fracture gas concentration increases with time, and it is observed that fractures are fully saturated with gas in 3000 days.
{"title":"Modeling and Forecasting of Coal Bed Methane Reservoir from Raniganj Coalfield, India","authors":"D. Panwar, R. Chaurasia, V. K. Saxena, Ashutosh Kumar Singh","doi":"10.3390/methane1040019","DOIUrl":"https://doi.org/10.3390/methane1040019","url":null,"abstract":"Demand for a cleaner source of energy is increasing in India. In the search for alternate energy sources, coal bed methane gas receives considerable attention for its potential as a good energy source. During the coalification process, methane gas is captured in the coal seams and later released during coal mining operations. Coal bed methane separation is crucial for both economic benefit and methane emission reduction. The methane production from seams is an efficient way to reduce greenhouse emissions and provide a safe mining operation environment. In India, the production of coal bed methane on a commercial scale has been recently observed. In the present paper, an attempt is made to understand and establish a 3-D excavation of coal bed methane from reservoir simulation (COMET3) for Gondwana coal seams in the Sitarampur block of the Raniganj coalfield in India. The simulation study was carried out for a period of 25 years for the recovery of methane from the reservoir. It is observed from the simulation study that 372 million cubic meters CO2 equivalent greenhouse gas emissions can be prevented by the extraction of methane with space and time. The fracture gas concentration increases with time, and it is observed that fractures are fully saturated with gas in 3000 days.","PeriodicalId":74177,"journal":{"name":"Methane","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45603990","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}
C. Godoi, Isabely M. Gutierrez, Paulo V. R. Gomes, Jéssica F. Coelho, Priscilla J. Zambiazi, L. Otubo, A. O. Neto, R. D. de Souza
The search for alternatives for converting methane into value-added products has been of great interest to scientific, technological, and industrial society. An alternative to this could be the use of copper-doped palladium catalysts with different proportions supported on metal oxides, such as Sb2O5.SnO2 (ATO) catalysts. These combinations were employed to convert the methane-to-methanol in mild condition using a fuel cell polymer electrolyte reactor. The catalysts prepared presents Pd, CuO, and Sb2O5.SnO2 phases with a mean particle size of about 9 nm. In activity experiments, the Pd80Cu20/ATO indicated maximum power density and maximum rate reaction for methanol production when compared to other PdCu/ATO materials. The use of ATO as a support favored the production of methanol from methane, while PdCu with high copper content demonstrated the production of more oxidized compounds, such as carbonate and formate.
{"title":"Production of Methanol on PdCu/ATO in a Polymeric Electrolyte Reactor of the Fuel Cell Type from Methane","authors":"C. Godoi, Isabely M. Gutierrez, Paulo V. R. Gomes, Jéssica F. Coelho, Priscilla J. Zambiazi, L. Otubo, A. O. Neto, R. D. de Souza","doi":"10.3390/methane1030018","DOIUrl":"https://doi.org/10.3390/methane1030018","url":null,"abstract":"The search for alternatives for converting methane into value-added products has been of great interest to scientific, technological, and industrial society. An alternative to this could be the use of copper-doped palladium catalysts with different proportions supported on metal oxides, such as Sb2O5.SnO2 (ATO) catalysts. These combinations were employed to convert the methane-to-methanol in mild condition using a fuel cell polymer electrolyte reactor. The catalysts prepared presents Pd, CuO, and Sb2O5.SnO2 phases with a mean particle size of about 9 nm. In activity experiments, the Pd80Cu20/ATO indicated maximum power density and maximum rate reaction for methanol production when compared to other PdCu/ATO materials. The use of ATO as a support favored the production of methanol from methane, while PdCu with high copper content demonstrated the production of more oxidized compounds, such as carbonate and formate.","PeriodicalId":74177,"journal":{"name":"Methane","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46726872","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}
J. Gere, Mônica Feksa Frasson, Marisa Wawrzkiewicz, M. G. Fernández Pepi, M. L. Ramos, Ricardo A. Bualó, M. E. Cerón-Cucchi, G. Jaurena
Livestock systems based on subtropical and tropical pastures are characterized by the low productivity of livestock due to the poor nutritional value of the forage (low nitrogen concentration and digestibility, and high fiber and lignin concentrations). These conditions lead to low productivity and, consequently, high absolute emissions of methane (CH4) per unit of product. Dry distilled grains with solubles (DDGS) are the main by-product resulting from ethanol production, and they are characterized by their high-energy fibrous and protein content, thus becoming an option for the supplementation of low-quality forage. This research investigated the effects of dietary DDGS inclusion on dry matter digestibility (DMD) and enteric CH4 emission. Eight adult sheep of 64 ± 8 kg live weight were used. The duration of the study was 54 days, divided into two periods (changeover design), which comprised a 17-day pre-experimental period and 10 days for experimental data collection. Animals were allocated to one of two treatments used: hay (H) as a control treatment, where animals were fed with Rhodes grass hay alone; and H + DDGS, where animals were fed with H supplemented with DDGS. CH4 emissions were estimated using the sulfur hexafluoride (SF6) tracer technique. Diets containing DDGS increased DMI by 22% (p < 0.05) and reduced daily CH4 emissions by 24% (g/d), the CH4 yield by 35% (g/kg DMI), and the average value of CH4 energy per gross energy intake (Ym) by 44%, compared to the control treatment (p < 0.05). The experiment demonstrated that supplementation with DDGS in low-quality roughage reduced daily CH4 emissions, yields, and Ym.
{"title":"Enteric Methane Emission from Sheep Fed with Rhodes Grass Hay (Chloris gayana) Alone or Supplemented with Dried Distillers’ Grains with Solubles","authors":"J. Gere, Mônica Feksa Frasson, Marisa Wawrzkiewicz, M. G. Fernández Pepi, M. L. Ramos, Ricardo A. Bualó, M. E. Cerón-Cucchi, G. Jaurena","doi":"10.3390/methane1030017","DOIUrl":"https://doi.org/10.3390/methane1030017","url":null,"abstract":"Livestock systems based on subtropical and tropical pastures are characterized by the low productivity of livestock due to the poor nutritional value of the forage (low nitrogen concentration and digestibility, and high fiber and lignin concentrations). These conditions lead to low productivity and, consequently, high absolute emissions of methane (CH4) per unit of product. Dry distilled grains with solubles (DDGS) are the main by-product resulting from ethanol production, and they are characterized by their high-energy fibrous and protein content, thus becoming an option for the supplementation of low-quality forage. This research investigated the effects of dietary DDGS inclusion on dry matter digestibility (DMD) and enteric CH4 emission. Eight adult sheep of 64 ± 8 kg live weight were used. The duration of the study was 54 days, divided into two periods (changeover design), which comprised a 17-day pre-experimental period and 10 days for experimental data collection. Animals were allocated to one of two treatments used: hay (H) as a control treatment, where animals were fed with Rhodes grass hay alone; and H + DDGS, where animals were fed with H supplemented with DDGS. CH4 emissions were estimated using the sulfur hexafluoride (SF6) tracer technique. Diets containing DDGS increased DMI by 22% (p < 0.05) and reduced daily CH4 emissions by 24% (g/d), the CH4 yield by 35% (g/kg DMI), and the average value of CH4 energy per gross energy intake (Ym) by 44%, compared to the control treatment (p < 0.05). The experiment demonstrated that supplementation with DDGS in low-quality roughage reduced daily CH4 emissions, yields, and Ym.","PeriodicalId":74177,"journal":{"name":"Methane","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46441302","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}
Rama Rao Ganteda, Sai Kiran Burla, Jagan Mohan Reddy Boggu, P. Prasad
Natural gas is a promising future source for the increasing energy demand. It is partially clean energy with fewer environmental impacts, and it is necessary to develop technologies to cater to the supply chain. Due to their inherent structural properties, gas hydrates or clathrate hydrates are promising materials for capturing and storing methane gas. In the present study, the experimental investigations were performed to assess the utilization of soybean powder (SBP) as a promoting additive compared to sodium dodecyl sulfate (SDS) for methane hydrate formation. The methane hydrate formation temperature and pressure with SBP are 277.8 ± 3.2 K, 7050.9 ± 76.2 kPa, similar to SDS 277.2 ± 0.3 K, 7446.3 ± 5.7 kPa in the non-stirred system. The gas uptake capacity is about 94.2 ± 4.5 v/v and 92.4 ± 4.6 v/v with SBP and SDS, which is ~60% of the practical, achievable limit. The time for the 90% of hydrate conversion is ~4.6 times higher for SBP than SDS. The more prolonged kinetics is ascribed to the complex constituents in the SBP. In contrast to the SDS solution, no foam was produced in the sample of the SBP solution. The current studies demonstrate that SBP can be utilized to develop cleaner and more effective promoters for methane hydrate formation without foam creation.
{"title":"Efficient Storage of Methane in Hydrate Form Using Soybean Powder","authors":"Rama Rao Ganteda, Sai Kiran Burla, Jagan Mohan Reddy Boggu, P. Prasad","doi":"10.3390/methane1030016","DOIUrl":"https://doi.org/10.3390/methane1030016","url":null,"abstract":"Natural gas is a promising future source for the increasing energy demand. It is partially clean energy with fewer environmental impacts, and it is necessary to develop technologies to cater to the supply chain. Due to their inherent structural properties, gas hydrates or clathrate hydrates are promising materials for capturing and storing methane gas. In the present study, the experimental investigations were performed to assess the utilization of soybean powder (SBP) as a promoting additive compared to sodium dodecyl sulfate (SDS) for methane hydrate formation. The methane hydrate formation temperature and pressure with SBP are 277.8 ± 3.2 K, 7050.9 ± 76.2 kPa, similar to SDS 277.2 ± 0.3 K, 7446.3 ± 5.7 kPa in the non-stirred system. The gas uptake capacity is about 94.2 ± 4.5 v/v and 92.4 ± 4.6 v/v with SBP and SDS, which is ~60% of the practical, achievable limit. The time for the 90% of hydrate conversion is ~4.6 times higher for SBP than SDS. The more prolonged kinetics is ascribed to the complex constituents in the SBP. In contrast to the SDS solution, no foam was produced in the sample of the SBP solution. The current studies demonstrate that SBP can be utilized to develop cleaner and more effective promoters for methane hydrate formation without foam creation.","PeriodicalId":74177,"journal":{"name":"Methane","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45079357","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}
J. Alino, J. Bastos, P. Remor, L. Frare, F. Orssatto, F. M. Damaceno, T. Edwiges
Sugarcane bagasse (SCB) is the main residue obtained from sugarcane processing, and it has been widely investigated as a strategic renewable energy source. The typical recalcitrant characteristic of SCB requires the use of pretreatments (e.g., chemicals) to increase methane production through anaerobic digestion, which is normally reported to generate toxic effluents and increase operational costs. Based on this, the present study evaluated the efficiency of an inexpensive, alternative, and more sustainable method to improve the biodegradability of SCB and increase methane production by pre-storing it with acidic organic biowastes, such as cheese whey (CW) and fruit and vegetable waste (FVW). Different fresh weight-based proportions of FVW (5:95, 10:90, and 15:85) and CW (10:90, 20:80, and 25:75) were soaked with SBC for 7 days at 25 °C. These treatments were compared with traditional alkaline pretreatment using NaOH at concentrations of 1%, 5%, and 10% (w/v). The best result was obtained with SCB + FVW (5:95), being 520 ± 7 NL CH4 kg VS−1 (27.6% higher than the control) with degradation time (T90) reduced from 13 to 7 days. Pretreatment with SBC + CW resulted in antagonistic effects due to process inhibition, while alkaline pretreatment with NaOH at concentrations of 5% and 10% similarly increased methane yield by 21.2% and 34.1%, respectively. Therefore, pre-storage of SBC with FVW proved to be the best strategy to increase methane production from SCB, while simultaneously avoiding the use of chemical reagents that result in toxic effluents.
甘蔗渣（SCB）是甘蔗加工过程中的主要残留物，作为一种战略性可再生能源已被广泛研究。SCB的典型顽固不化特性要求使用预处理（如化学品）通过厌氧消化增加甲烷产量，据报道，厌氧消化通常会产生有毒废水并增加运营成本。基于此，本研究评估了一种廉价、替代和更可持续的方法的效率，该方法通过将SCB与酸性有机生物废物（如奶酪乳清（CW）和水果蔬菜废物（FVW））预储存来提高SCB的生物降解性并增加甲烷产量。将不同鲜重比例的FVW（5:95、10:90和15:85）和CW（10:90、20:80和25:75）在25°C下用SBC浸泡7天。将这些处理与使用浓度为1%、5%和10%（w/v）的NaOH的传统碱性预处理进行比较。SCB+FVW（5:95）的降解效果最好，为520±7NL CH4 kg VS−1（比对照高27.6%），降解时间（T90）从13天减少到7天。SBC+CW预处理由于过程抑制而产生拮抗作用，而浓度为5%和10%的NaOH碱预处理同样使甲烷产率分别提高21.2%和34.1%。因此，用FVW预储存SBC被证明是增加SCB甲烷产量的最佳策略，同时避免使用导致有毒废水的化学试剂。
{"title":"Alkaline Pretreatment and Pre-Hydrolysis Using Acidic Biowastes to Increase Methane Production from Sugarcane Bagasse","authors":"J. Alino, J. Bastos, P. Remor, L. Frare, F. Orssatto, F. M. Damaceno, T. Edwiges","doi":"10.3390/methane1030015","DOIUrl":"https://doi.org/10.3390/methane1030015","url":null,"abstract":"Sugarcane bagasse (SCB) is the main residue obtained from sugarcane processing, and it has been widely investigated as a strategic renewable energy source. The typical recalcitrant characteristic of SCB requires the use of pretreatments (e.g., chemicals) to increase methane production through anaerobic digestion, which is normally reported to generate toxic effluents and increase operational costs. Based on this, the present study evaluated the efficiency of an inexpensive, alternative, and more sustainable method to improve the biodegradability of SCB and increase methane production by pre-storing it with acidic organic biowastes, such as cheese whey (CW) and fruit and vegetable waste (FVW). Different fresh weight-based proportions of FVW (5:95, 10:90, and 15:85) and CW (10:90, 20:80, and 25:75) were soaked with SBC for 7 days at 25 °C. These treatments were compared with traditional alkaline pretreatment using NaOH at concentrations of 1%, 5%, and 10% (w/v). The best result was obtained with SCB + FVW (5:95), being 520 ± 7 NL CH4 kg VS−1 (27.6% higher than the control) with degradation time (T90) reduced from 13 to 7 days. Pretreatment with SBC + CW resulted in antagonistic effects due to process inhibition, while alkaline pretreatment with NaOH at concentrations of 5% and 10% similarly increased methane yield by 21.2% and 34.1%, respectively. Therefore, pre-storage of SBC with FVW proved to be the best strategy to increase methane production from SCB, while simultaneously avoiding the use of chemical reagents that result in toxic effluents.","PeriodicalId":74177,"journal":{"name":"Methane","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48428225","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}
This study presents a new method to remove lignin from wheat straw (lignocellulosic) using the ozonation technique. Lignocellulosic material is a complex biopolymer composed of cellulose, hemicellulose and lignin. Apart from lignin, which acts as a chemical resistant, lignocellulosic is the main resource of cellulose and hemicellulose sugars. The ozonation reaction takes place in a two-phase solid–gas fluidization stainless steel reactor. The focus of this paper is to investigate the kinetics that govern lignin removal from lignocellulosic material after ozonation treatment. The kinetics of lignin removal did not agree with the experimental data until the suggested model is modified to a pseudo-second-order. The results showed that at a higher ozone supply of 150 mg min−1, the surface reaction and intra-particular diffusion were the most significant factors to remove the lignin. Moreover, at a lower ozone supply of 30 mg min−1, the intra-particular diffusion was the only contributor towards lignin removal.
{"title":"Kinetics of Lignin Removal from the Lignocellulosic Matrix after Ozone Transportation","authors":"K. S. Baig","doi":"10.3390/methane1030014","DOIUrl":"https://doi.org/10.3390/methane1030014","url":null,"abstract":"This study presents a new method to remove lignin from wheat straw (lignocellulosic) using the ozonation technique. Lignocellulosic material is a complex biopolymer composed of cellulose, hemicellulose and lignin. Apart from lignin, which acts as a chemical resistant, lignocellulosic is the main resource of cellulose and hemicellulose sugars. The ozonation reaction takes place in a two-phase solid–gas fluidization stainless steel reactor. The focus of this paper is to investigate the kinetics that govern lignin removal from lignocellulosic material after ozonation treatment. The kinetics of lignin removal did not agree with the experimental data until the suggested model is modified to a pseudo-second-order. The results showed that at a higher ozone supply of 150 mg min−1, the surface reaction and intra-particular diffusion were the most significant factors to remove the lignin. Moreover, at a lower ozone supply of 30 mg min−1, the intra-particular diffusion was the only contributor towards lignin removal.","PeriodicalId":74177,"journal":{"name":"Methane","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42383356","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}
In this paper, a predictive combustion model is developed and implemented in GT-Power. The model consists of a detailed physically/chemically based ignition delay model, including a 1D spray model. The spray model results at the start of combustion are used to initialize the combustion model. The spray zone and the homogenous natural gas/air mixture are burned with different combustion models, to account for the effect of the inhomogeneous fuel distribution. NOx-emissions are modelled using a standard Extended Zeldovich Mechanism, and for the HC-emissions, two flame quenching models are included and extended with an empirical correlation. The models are calibrated with measurement data from a single cylinder engine, except for the ignition delay model which needs no calibration. The start of combustion and the combustion parameters are predicted well for a wide range of injection timings and operation conditions. Furthermore, considering unburned fuel, the engine operation parameters BSFC and IMEP are also predicted satisfactory. Due to the detailed description of the different combustion phases, the influence of the injection timing on the NOx-emission is captured satisfactorily, with the standard NOx-model. Finally, the knock limited MFB50 is also predicted within an acceptable range.
{"title":"A New Combustion Model for Medium Speed Dual-Fuel Engines in the Course of 0D/1D Simulation","authors":"J. Frerichs, P. Eilts","doi":"10.3390/methane1030013","DOIUrl":"https://doi.org/10.3390/methane1030013","url":null,"abstract":"In this paper, a predictive combustion model is developed and implemented in GT-Power. The model consists of a detailed physically/chemically based ignition delay model, including a 1D spray model. The spray model results at the start of combustion are used to initialize the combustion model. The spray zone and the homogenous natural gas/air mixture are burned with different combustion models, to account for the effect of the inhomogeneous fuel distribution. NOx-emissions are modelled using a standard Extended Zeldovich Mechanism, and for the HC-emissions, two flame quenching models are included and extended with an empirical correlation. The models are calibrated with measurement data from a single cylinder engine, except for the ignition delay model which needs no calibration. The start of combustion and the combustion parameters are predicted well for a wide range of injection timings and operation conditions. Furthermore, considering unburned fuel, the engine operation parameters BSFC and IMEP are also predicted satisfactory. Due to the detailed description of the different combustion phases, the influence of the injection timing on the NOx-emission is captured satisfactorily, with the standard NOx-model. Finally, the knock limited MFB50 is also predicted within an acceptable range.","PeriodicalId":74177,"journal":{"name":"Methane","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48177752","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}
Xingyuan Gao, Weihao Lin, Z. Ge, Hongming Ge, S. Kawi
Syngas generated from the catalytic dry reforming of methane (DRM) enables the downstream production of H2 fuel and value-added chemicals. Ni-based catalysts with metal oxides, as both supports and promoters, are widely applied in the DRM reaction. In this review, four types of metal oxides with support confinement effect, metal-support interaction, oxygen defects, and surface acidity/basicity are introduced based on their impacts on the activity, selectivity, and stability of the Ni-based catalyst. Moreover, the structure–performance relationships are discussed in-depth. Finally, conclusive remarks and prospects are proposed.
{"title":"Modification Strategies of Ni-Based Catalysts with Metal Oxides for Dry Reforming of Methane","authors":"Xingyuan Gao, Weihao Lin, Z. Ge, Hongming Ge, S. Kawi","doi":"10.3390/methane1030012","DOIUrl":"https://doi.org/10.3390/methane1030012","url":null,"abstract":"Syngas generated from the catalytic dry reforming of methane (DRM) enables the downstream production of H2 fuel and value-added chemicals. Ni-based catalysts with metal oxides, as both supports and promoters, are widely applied in the DRM reaction. In this review, four types of metal oxides with support confinement effect, metal-support interaction, oxygen defects, and surface acidity/basicity are introduced based on their impacts on the activity, selectivity, and stability of the Ni-based catalyst. Moreover, the structure–performance relationships are discussed in-depth. Finally, conclusive remarks and prospects are proposed.","PeriodicalId":74177,"journal":{"name":"Methane","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47661144","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：