Pub Date : 2025-09-01Epub Date: 2024-09-11DOI: 10.1016/j.crcon.2024.100283
Yaling Mu , Zitong Zhuang , Kun Jiang , Yimeng Wei , Anjun Meng , Hui Jin
The dye and textile industry commonly employs activated carbon adsorption technology due to its cost-effectiveness and high efficiency. However, disposing of waste-activated carbon has a significant environmental and human health impact, and it’s a huge economic waste. This study investigates the kinetic and isothermal adsorption characteristics of Acid Red G dye adsorption by Powdered Activated Carbon derived from coconut shells. To effectively reuse activated carbon and maximise resource conservation, regeneration experiments were carried out using Supercritical Water at 24 MPa and 400 ℃ for 30 min. The experimental results demonstrated that, in comparison with thermal regeneration, supercritical water possesses the benefits of environmental protection, economic efficiency and extensive applicability. This is of considerable importance to the field of research concerning the regeneration of activated carbon.
{"title":"Study on supercritical water regeneration of bio-based activated carbon saturated with acid red G","authors":"Yaling Mu , Zitong Zhuang , Kun Jiang , Yimeng Wei , Anjun Meng , Hui Jin","doi":"10.1016/j.crcon.2024.100283","DOIUrl":"10.1016/j.crcon.2024.100283","url":null,"abstract":"<div><div>The dye and textile industry commonly employs activated carbon adsorption technology due to its cost-effectiveness and high efficiency. However, disposing of waste-activated carbon has a significant environmental and human health impact, and it’s a huge economic waste. This study investigates the kinetic and isothermal adsorption characteristics of Acid Red G dye adsorption by Powdered Activated Carbon derived from coconut shells. To effectively reuse activated carbon and maximise resource conservation, regeneration experiments were carried out using Supercritical Water at 24 MPa and 400 ℃ for 30 min. The experimental results demonstrated that, in comparison with thermal regeneration, supercritical water possesses the benefits of environmental protection, economic efficiency and extensive applicability. This is of considerable importance to the field of research concerning the regeneration of activated carbon.</div></div>","PeriodicalId":52958,"journal":{"name":"Carbon Resources Conversion","volume":"8 3","pages":"Article 100283"},"PeriodicalIF":6.4,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144606037","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-09-01Epub Date: 2024-08-28DOI: 10.1016/j.crcon.2024.100272
Diana D. Alcalá-Galiano-Morell , Luis B. Ramos-Sánchez , Patrick Fickers , Evelyn Romero-Borbón , Néstor D. Ortega-de la Rosa , Jesús Córdova
The advancement of more precise tools for sustainable process design in enzymatic biodiesel synthesis from renewable sources is crucial. Kinetics of solvent-free transesterification reactions were conducted across a temperature spectrum from 30 °C to 60 °C, utilizing Jatropha curcas oil (TG) and ethanol as substrates, alongside a fermented solid by Rhizopus homothallicus as the biocatalyst. The dynamics of chemical species concentrations were monitored through High-performance Thin-Layer Chromatography. Maximum productivities were achieved at 35 °C and 60 °C for biodiesel (293.24 and 299.02 g kg biocat−1 h−1, respectively), at 40 °C for diglycerides (1018.36 g kg biocat−1 h−1), and at 35 °C for monoglycerides (560.75 g kg biocat−1 h−1). Maximum yields were determined at 30 °C for fatty acid ethyl esters (0.56 g gTG−1), and at 40 °C for diglycerides (0.53 g gTG−1) and monoglycerides (0.30 g gTG−1). Based on the experimental findings, a kinetic model was formulated encompassing three reversible transesterification reactions. Individual reactions were structured following classical biochemical kinetics, inclusive of ethanol inhibition. Model fitting was executed through non-linear multivariable regression techniques, with the minimum of the average coefficient of variation of the residuals (ACVR) serving as the objective function. The resulting fit of the kinetic model to the experimental data proved satisfactory, with an ACVR of less than 5 % across all instances. Notably, the maximum biodiesel productivity, obtained in this work, represented the highest value, compared to other related studies, using a fermented solid as a biocatalyst.
更精确的工具的进步，可持续的过程设计酶合成生物柴油从可再生资源是至关重要的。在30 ~ 60℃的温度范围内，以麻疯树油（TG）和乙醇为底物，以同质根霉（Rhizopus homthallicus）发酵固体为生物催化剂，进行了无溶剂酯交换反应动力学研究。通过高效薄层色谱法监测化学物质浓度的动态变化。生物柴油在35°C和60°C的条件下（分别为293.24和299.02 g kg biocat - 1 h - 1），双甘油酯在40°C的条件下（1018.36 g kg biocat - 1 h - 1），单甘油酯在35°C的条件下（560.75 g kg biocat - 1 h - 1）达到最大生产率。在30°C时测定脂肪酸乙酯（0.56 g gTG−1）的最大产率，在40°C时测定二甘油酯（0.53 g gTG−1）和单甘油酯（0.30 g gTG−1）的最大产率。根据实验结果，建立了包含三个可逆酯交换反应的动力学模型。个体反应遵循经典生化动力学，包括乙醇抑制。采用非线性多变量回归技术进行模型拟合，以残差平均变异系数（ACVR）的最小值作为目标函数。动力学模型与实验数据的拟合结果令人满意，所有实例的ACVR均小于5%。值得注意的是，与使用发酵固体作为生物催化剂的其他相关研究相比，本研究中获得的最大生物柴油产量代表了最高的价值。
{"title":"A multi reaction kinetic model to describe the enzymatic transesterification reaction of jatropha oil using a fermented solid containing lipases","authors":"Diana D. Alcalá-Galiano-Morell , Luis B. Ramos-Sánchez , Patrick Fickers , Evelyn Romero-Borbón , Néstor D. Ortega-de la Rosa , Jesús Córdova","doi":"10.1016/j.crcon.2024.100272","DOIUrl":"10.1016/j.crcon.2024.100272","url":null,"abstract":"<div><div>The advancement of more precise tools for sustainable process design in enzymatic biodiesel synthesis from renewable sources is crucial. Kinetics of solvent-free transesterification reactions were conducted across a temperature spectrum from 30 °C to 60 °C, utilizing <em>Jatropha curcas</em> oil (T<sub>G</sub>) and ethanol as substrates, alongside a fermented solid by <em>Rhizopus homothallicus</em> as the biocatalyst. The dynamics of chemical species concentrations were monitored through High-performance Thin-Layer Chromatography. Maximum productivities were achieved at 35 °C and 60 °C for biodiesel (293.24 and 299.02 g kg biocat<sup>−1</sup> h<sup>−1</sup>, respectively), at 40 °C for diglycerides (1018.36 g kg biocat<sup>−1</sup> h<sup>−1</sup>), and at 35 °C for monoglycerides (560.75 g kg biocat<sup>−1</sup> h<sup>−1</sup>). Maximum yields were determined at 30 °C for fatty acid ethyl esters (0.56 g gT<sub>G</sub><sup>−1</sup>), and at 40 °C for diglycerides (0.53 g gT<sub>G</sub><sup>−1</sup>) and monoglycerides (0.30 g gT<sub>G</sub><sup>−1</sup>). Based on the experimental findings, a kinetic model was formulated encompassing three reversible transesterification reactions. Individual reactions were structured following classical biochemical kinetics, inclusive of ethanol inhibition. Model fitting was executed through non-linear multivariable regression techniques, with the minimum of the average coefficient of variation of the residuals (ACV<sub>R</sub>) serving as the objective function. The resulting fit of the kinetic model to the experimental data proved satisfactory, with an ACV<sub>R</sub> of less than 5 % across all instances. Notably, the maximum biodiesel productivity, obtained in this work, represented the highest value, compared to other related studies, using a fermented solid as a biocatalyst.</div></div>","PeriodicalId":52958,"journal":{"name":"Carbon Resources Conversion","volume":"8 3","pages":"Article 100272"},"PeriodicalIF":6.4,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144606038","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The two-stage anaerobic digestion of palm oil mill effluent (POME) was optimized through trace metal supplementation (Mo2+, Ni2+, Co2+, and Fe2+). Optimal concentrations were determined as 10 mg·L−1 Mo2+, 6 mg·L−1 Ni2+, 6 mg·L−1 Co2+, and 10 mg·L−1 Fe2+, resulting in significant biogas yield improvements on hydrogen yield increased by 86.4 % (29.5 ± 0.9 to 55.0 ± 2.1 mL-H2·g−1-VS) and methane yield by 84 % (from 173.8 ± 7.8 to 320.0 ± 8.4 mL-CH4·g−1-VS). Gas composition improved, with H2 content increasing from 18.5 % to 32.0 % and CH4 content from 58.2 % to 72.5 %. Maximum process efficiency was achieved at 4-day HRT for hydrogen production and 20-day HRT for methanogenesis with metal removal 0f 93.5–94.8 %. Statistical analysis revealed strong correlations between metal concentrations and enzyme activities (R2 = 0.94, p < 0.001) and enzyme activities with biogas yields (R2 = 0.92, p < 0.001). Metabolite profiles showed an 81 % increase in acetic acid (3,800 ± 120 mg·L−1) and a 93 % increase in butyric acid (2,900 ± 95 mg·L−1), while propionic acid decreased by 57 % in H2 stage. Thermoanaerobacterium thermosaccharolyticum was dominant in the H2 stage, while Methanobacter sp. and Methanosarcina sp. dominated in the CH4 stage, with their abundance influenced by specific trace metal supplementation. Process stability was maintained through precise control systems (temperature stability index of 0.95 ± 0.05 and pH stability index of 0.92 ± 0.05) with rapid response times (<5 min). COD removal efficiency increased from 65.3 % to 85.2 %, while metal removal efficiencies exceeded 90 % for all supplemented metals. These findings demonstrate significant enhancement in biogas production through optimized trace metal supplementation and precise process control strategies.
{"title":"Synergistic effects of trace metals on hydrogen and methane production from palm oil mill effluent using two-stage anaerobic digestion","authors":"Wisarut Tukanghan , Jiravut Seengenyoung , Supattra In-chan , Chonticha Mamimin , Sukonlarat Chanthong , Sompong O-Thong","doi":"10.1016/j.crcon.2025.100309","DOIUrl":"10.1016/j.crcon.2025.100309","url":null,"abstract":"<div><div>The two-stage anaerobic digestion of palm oil mill effluent (POME) was optimized through trace metal supplementation (Mo<sup>2+</sup>, Ni<sup>2+</sup>, Co<sup>2+</sup>, and Fe<sup>2+</sup>). Optimal concentrations were determined as 10 mg·L<sup>−1</sup> Mo<sup>2+</sup>, 6 mg·L<sup>−1</sup> Ni<sup>2+</sup>, 6 mg·L<sup>−1</sup> Co<sup>2+</sup>, and 10 mg·L<sup>−1</sup> Fe<sup>2+</sup>, resulting in significant biogas yield improvements on hydrogen yield increased by 86.4 % (29.5 ± 0.9 to 55.0 ± 2.1 mL-H<sub>2</sub>·g<sup>−1</sup>-VS) and methane yield by 84 % (from 173.8 ± 7.8 to 320.0 ± 8.4 mL-CH<sub>4</sub>·g<sup>−1</sup>-VS). Gas composition improved, with H<sub>2</sub> content increasing from 18.5 % to 32.0 % and CH<sub>4</sub> content from 58.2 % to 72.5 %. Maximum process efficiency was achieved at 4-day HRT for hydrogen production and 20-day HRT for methanogenesis with metal removal 0f 93.5–94.8 %. Statistical analysis revealed strong correlations between metal concentrations and enzyme activities (R<sup>2</sup> = 0.94, p < 0.001) and enzyme activities with biogas yields (R<sup>2</sup> = 0.92, p < 0.001). Metabolite profiles showed an 81 % increase in acetic acid (3,800 ± 120 mg·L<sup>−1</sup>) and a 93 % increase in butyric acid (2,900 ± 95 mg·L<sup>−1</sup>), while propionic acid decreased by 57 % in H<sub>2</sub> stage. <em>Thermoanaerobacterium thermosaccharolyticum</em> was dominant in the H<sub>2</sub> stage, while <em>Methanobacter</em> sp. and <em>Methanosarcina</em> sp. dominated in the CH<sub>4</sub> stage, with their abundance influenced by specific trace metal supplementation. Process stability was maintained through precise control systems (temperature stability index of 0.95 ± 0.05 and pH stability index of 0.92 ± 0.05) with rapid response times (<5 min). COD removal efficiency increased from 65.3 % to 85.2 %, while metal removal efficiencies exceeded 90 % for all supplemented metals. These findings demonstrate significant enhancement in biogas production through optimized trace metal supplementation and precise process control strategies.</div></div>","PeriodicalId":52958,"journal":{"name":"Carbon Resources Conversion","volume":"8 3","pages":"Article 100309"},"PeriodicalIF":6.4,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144606006","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-09-01Epub Date: 2025-02-11DOI: 10.1016/j.crcon.2025.100306
Xuejing Liu , Jiaqi Xie , Xiyan Li , Shuai Xu , Hong Zhang , Xin Jia , Guangwen Xu
This study utilizes a combination of micro fluidized bed analysis technology and isotope-tagging methodology to investigate the decomposition of carbonate ores in CO2 atmospheres. Utilizing the decomposition of magnesite in an atmosphere containing 13CO2 as a case study, the reaction behavior and kinetics were investigated using a micro fluidized bed reaction analyzer (MFBRA). The results reveal that 13CO2 in the atmosphere hinders the decomposition process, thereby increasing the time required for complete decomposition. The activation energy was observed to increase with the concentration of 13CO2 in the reaction atmosphere. Compared to the results obtained from thermogravimetric analysis (TG), the activation energy and pre-exponential factor values determined by the MFBRA are lower. Due to the excessive suppression caused by the accumulation of product gas within the sample crucible, the apparent activation energy calculated based on TG data was overestimated, particularly in atmospheres containing the product gas CO2. The MFBRA, operating in an environment characterized by essentially eliminated external gas diffusion, extensive gas–solid mixing, and high rates of mass and heat transfer, has proven to be highly capable of accurately determining the kinetics of carbonate ore decomposition in CO2-rich atmospheres. This study provides a straightforward and reliable method for elucidating the reaction characteristics and kinetics of carbonate ore decomposition in atmosphere of CO2.
{"title":"Isotope-tagging atmosphere to characterize carbonate ore decomposition reaction in carbon dioxide","authors":"Xuejing Liu , Jiaqi Xie , Xiyan Li , Shuai Xu , Hong Zhang , Xin Jia , Guangwen Xu","doi":"10.1016/j.crcon.2025.100306","DOIUrl":"10.1016/j.crcon.2025.100306","url":null,"abstract":"<div><div>This study utilizes a combination of micro fluidized bed analysis technology and isotope-tagging methodology to investigate the decomposition of carbonate ores in CO<sub>2</sub> atmospheres. Utilizing the decomposition of magnesite in an atmosphere containing <sup>13</sup>CO<sub>2</sub> as a case study, the reaction behavior and kinetics were investigated using a micro fluidized bed reaction analyzer (MFBRA). The results reveal that <sup>13</sup>CO<sub>2</sub> in the atmosphere hinders the decomposition process, thereby increasing the time required for complete decomposition. The activation energy was observed to increase with the concentration of <sup>13</sup>CO<sub>2</sub> in the reaction atmosphere. Compared to the results obtained from thermogravimetric analysis (TG), the activation energy and pre-exponential factor values determined by the MFBRA are lower. Due to the excessive suppression caused by the accumulation of product gas within the sample crucible, the apparent activation energy calculated based on TG data was overestimated, particularly in atmospheres containing the product gas CO<sub>2</sub>. The MFBRA, operating in an environment characterized by essentially eliminated external gas diffusion, extensive gas–solid mixing, and high rates of mass and heat transfer, has proven to be highly capable of accurately determining the kinetics of carbonate ore decomposition in CO<sub>2</sub>-rich atmospheres. This study provides a straightforward and reliable method for elucidating the reaction characteristics and kinetics of carbonate ore decomposition in atmosphere of CO<sub>2</sub>.</div></div>","PeriodicalId":52958,"journal":{"name":"Carbon Resources Conversion","volume":"8 3","pages":"Article 100306"},"PeriodicalIF":6.4,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144606004","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-06-01Epub Date: 2024-06-15DOI: 10.1016/j.crcon.2024.100265
Mengjuan Zhang , Cong Zhang , Binwenbo Zhu , Chao Wang , Xin Jia , Guoqing Guan , Xi Zeng , Erfeng Hu , Zhennan Han , Guangwen Xu
This study investigated how biomass pyrolysis varies with the different fractions of magnesite mixing into biomass. The pyrolysis occurred with simultaneous decomposition of magnesite without use of any gasification reagent, and was analyzed in terms of producer gas yield and quality. As magnesite fraction increased from 0 to 30 %, the yield of producer gas and its calorific value increased from 48.6 % to 66.3 % and 8.29 to 8.93 MJ/Nm3, respectively. The carbon and hydrogen conversion increased from 44.1 % to 60.7 % and 43.1 % to 66.2 %, respectively. The characterization results revealed that magnesite particles facilitated the conversion of fixed carbon and the thermal/catalytic cracking of tar to produce H-rich gas. The in-situ generated CO2 from magnesite decomposition could be reduced to CO/CH4 in the reductive atmosphere of the pyrolysis products. This study proposes the concept of converting low-energy–density biomass into gas without oxygen and provides a novel approach for producing H-rich gas from biomass.
{"title":"Pyrolysis of biomass to produce H-rich gas facilitated by simultaneously occurring magnesite decomposition","authors":"Mengjuan Zhang , Cong Zhang , Binwenbo Zhu , Chao Wang , Xin Jia , Guoqing Guan , Xi Zeng , Erfeng Hu , Zhennan Han , Guangwen Xu","doi":"10.1016/j.crcon.2024.100265","DOIUrl":"10.1016/j.crcon.2024.100265","url":null,"abstract":"<div><div>This study investigated how biomass pyrolysis varies with the different fractions of magnesite mixing into biomass. The pyrolysis occurred with simultaneous decomposition of magnesite without use of any gasification reagent, and was analyzed in terms of producer gas yield and quality. As magnesite fraction increased from 0 to 30 %, the yield of producer gas and its calorific value increased from 48.6 % to 66.3 % and 8.29 to 8.93 MJ/Nm<sup>3</sup>, respectively. The carbon and hydrogen conversion increased from 44.1 % to 60.7 % and 43.1 % to 66.2 %, respectively. The characterization results revealed that magnesite particles facilitated the conversion of fixed carbon and the thermal/catalytic cracking of tar to produce H-rich gas. The <em>in-situ</em> generated CO<sub>2</sub> from magnesite decomposition could be reduced to CO/CH<sub>4</sub> in the reductive atmosphere of the pyrolysis products. This study proposes the concept of converting low-energy–density biomass into gas without oxygen and provides a novel approach for producing H-rich gas from biomass.</div></div>","PeriodicalId":52958,"journal":{"name":"Carbon Resources Conversion","volume":"8 2","pages":"Article 100265"},"PeriodicalIF":6.4,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141395988","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study assesses a two-stage anaerobic digestion process designed to efficiently recover energy through hydrogen and methane production by co-digesting filter cake (FC), biogas effluent (BE), and anaerobic sludge (AS) from the sugar and ethanol industry. The optimal proportions of FC, BE, and AS were determined in batch fermentation experiments using Design Expert software, which identified a suitable ratio of 31.05:28.95:0.00 (g VS/L), respectively. The results indicated that hydrogen production in the first stage could occur solely through the hydrogenic bacteria present in the BE and FC mixture, without the need for AS as an inoculum. This optimized FC:BE ratio was then applied in a semi-continuous fermentation system, achieving a hydrogen production rate of 193.6 mL H2/L.d and a hydrogen yield of 9.8 mL H2/g VS at an optimal hydraulic retention time (HRT) of 3 d. In the subsequent second stage, the effluent from the hydrogen reactor was used for methane production. This stage achieved a methane production rate of 422.0 mL CH4/L·d and a methane yield of 140.2 mL CH4/g VS, with an HRT of 20 d. Overall, the two-stage process exhibited an impressive energy output, peaking at 5.17 kJ/g VS. This suggests the potential for an annual electricity generation of 194,655 MWh and an estimated reduction of 85,668 tCO2eq/year in greenhouse gas emissions. This study highlights the efficiency of the two-stage anaerobic digestion process for harnessing energy through the co-digestion of FC and BE, without the need for additional AS inoculum. The findings demonstrate the potential for sustainable energy recovery from industrial waste streams while mitigating environmental impacts.
本研究评估了一种两阶段厌氧消化工艺，该工艺旨在通过共消化来自糖和乙醇工业的滤饼（FC）、沼气排出物（BE）和厌氧污泥（AS），有效地通过产生氢气和甲烷来回收能量。采用Design Expert软件进行分批发酵实验，确定了FC、BE和AS的最佳配比，确定的最佳配比分别为31.05:28.95:0.00 （g VS/L）。结果表明，第一阶段的产氢可以完全通过BE和FC混合物中存在的产氢细菌进行，而不需要AS作为接种物。然后将优化后的FC:BE比例应用于半连续发酵系统，产氢率为193.6 mL H2/L。d，在最佳水力停留时间（HRT）为3 d的情况下，产氢量为9.8 mL H2/g VS。在随后的第二阶段，氢气反应器的出水用于甲烷生产。这一阶段的甲烷产率为422.0 mL CH4/L·d，甲烷产率为140.2 mL CH4/g VS， HRT为20 d。总的来说，这两阶段的过程表现出了令人印象深刻的能量输出，峰值为5.17 kJ/g VS.这表明年发电量可能达到194,655兆瓦时，温室气体排放量估计减少85,668吨二氧化碳当量/年。这项研究强调了两阶段厌氧消化过程的效率，通过FC和BE的共同消化来利用能量，而不需要额外的AS接种。研究结果表明，在减轻环境影响的同时，从工业废物流中可持续回收能源的潜力。
{"title":"Co-digestion of filter cake, biogas effluent, and anaerobic sludge for hydrogen and methane production: Optimizing energy recovery through two-stage anaerobic digestion","authors":"Worapong Wongarmat , Sureewan Sittijunda , Tsuyoshi Imai , Alissara Reungsang","doi":"10.1016/j.crcon.2024.100248","DOIUrl":"10.1016/j.crcon.2024.100248","url":null,"abstract":"<div><div>This study assesses a two-stage anaerobic digestion process designed to efficiently recover energy through hydrogen and methane production by co-digesting filter cake (FC), biogas effluent (BE), and anaerobic sludge (AS) from the sugar and ethanol industry. The optimal proportions of FC, BE, and AS were determined in batch fermentation experiments using Design Expert software, which identified a suitable ratio of 31.05:28.95:0.00 (g VS/L), respectively. The results indicated that hydrogen production in the first stage could occur solely through the hydrogenic bacteria present in the BE and FC mixture, without the need for AS as an inoculum. This optimized FC:BE ratio was then applied in a semi-continuous fermentation system, achieving a hydrogen production rate of 193.6 mL H<sub>2</sub>/L.d and a hydrogen yield of 9.8 mL H<sub>2</sub>/g VS at an optimal hydraulic retention time (HRT) of 3 d. In the subsequent second stage, the effluent from the hydrogen reactor was used for methane production. This stage achieved a methane production rate of 422.0 mL CH<sub>4</sub>/L·d and a methane yield of 140.2 mL CH<sub>4</sub>/g VS, with an HRT of 20 d. Overall, the two-stage process exhibited an impressive energy output, peaking at 5.17 kJ/g VS. This suggests the potential for an annual electricity generation of 194,655 MWh and an estimated reduction of 85,668 tCO<sub>2</sub>eq/year in greenhouse gas emissions. This study highlights the efficiency of the two-stage anaerobic digestion process for harnessing energy through the co-digestion of FC and BE, without the need for additional AS inoculum. The findings demonstrate the potential for sustainable energy recovery from industrial waste streams while mitigating environmental impacts.</div></div>","PeriodicalId":52958,"journal":{"name":"Carbon Resources Conversion","volume":"8 2","pages":"Article 100248"},"PeriodicalIF":6.4,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140756574","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-06-01Epub Date: 2024-04-27DOI: 10.1016/j.crcon.2024.100249
Emad Al-Shafei , Mohammed Albahar , Reem Albashrayi , Mohammad F. Aljishi , Wala Algozeeb , Ahmed Alasseel , Gazali Tanimu , Abdullah Aitani
Ethane, one of the key components of shale gas, is a valuable feedstock for the production of syngas (CO + H2) via the CC bond cleavage during dry reforming of ethane (DRE) reaction. Selective catalysts are needed to direct this reaction pathway against the competing CH bond cleavage for ethylene formation. In this study, Fe, V and Rh oxides supported on TiO2 catalysts were prepared by impregnation method. The catalysts were tested for DRE with the main target of enhancing selectivity to syngas (CO and H2) and reducing byproducts (methane and ethylene) formation. The catalysts were characterized using X-ray diffraction, scanning electron microscopy, NH3/CO2 temperature programmed desorption and H2-temperature programmed reduction. Temperature programmed oxidation was utilized to characterize the coke contents of the spent catalysts. The catalysts were evaluated for DRE reaction in a fixed-bed reactor at the temperature range from 500 °C to 650 °C and CO2/ethane ratio from 2:1 to 10:1 (mol/mol). It was found that ethane conversion over the three catalysts increased in the order Rh/TiO2 > Fe/TiO2 > V/TiO2. Rh/TiO2 catalyst exhibited > 99 % ethane conversion, 36 % and 61 % yields of H2 and CO, respectively, at 650 °C and CO2/ethane ratio of 5.0. The high conversion of ethane was mainly attributed to the enhanced dispersion of Rh oxides on the TiO2 support coupled with the balanced surface acidic and basic sites. The Rh catalyst facilitated CC bond dissociation of ethane thereby forming methyl intermediates which then reacted with adsorbed CO2, thereby enhancing higher syngas production during DRE reaction.
{"title":"Dry reforming of ethane over titania-based catalysts for higher selectivity and conversion to syngas","authors":"Emad Al-Shafei , Mohammed Albahar , Reem Albashrayi , Mohammad F. Aljishi , Wala Algozeeb , Ahmed Alasseel , Gazali Tanimu , Abdullah Aitani","doi":"10.1016/j.crcon.2024.100249","DOIUrl":"10.1016/j.crcon.2024.100249","url":null,"abstract":"<div><div>Ethane, one of the key components of shale gas, is a valuable feedstock for the production of syngas (CO + H<sub>2</sub>) via the C<img>C bond cleavage during dry reforming of ethane (DRE) reaction. Selective catalysts are needed to direct this reaction pathway against the competing C<img>H bond cleavage for ethylene formation. In this study, Fe, V and Rh oxides supported on TiO<sub>2</sub> catalysts were prepared by impregnation method. The catalysts were tested for DRE with the main target of enhancing selectivity to syngas (CO and H<sub>2</sub>) and reducing byproducts (methane and ethylene) formation. The catalysts were characterized using X-ray diffraction, scanning electron microscopy, NH<sub>3</sub>/CO<sub>2</sub> temperature programmed desorption and H<sub>2</sub>-temperature programmed reduction. Temperature programmed oxidation was utilized to characterize the coke contents of the spent catalysts. The catalysts were evaluated for DRE reaction in a fixed-bed reactor at the temperature range from 500 °C to 650 °C and CO<sub>2</sub>/ethane ratio from 2:1 to 10:1 (mol/mol). It was found that ethane conversion over the three catalysts increased in the order Rh/TiO<sub>2</sub> > Fe/TiO<sub>2</sub> > V/TiO<sub>2</sub>. Rh/TiO<sub>2</sub> catalyst exhibited > 99 % ethane conversion, 36 % and 61 % yields of H<sub>2</sub> and CO, respectively, at 650 °C and CO<sub>2</sub>/ethane ratio of 5.0. The high conversion of ethane was mainly attributed to the enhanced dispersion of Rh oxides on the TiO<sub>2</sub> support coupled with the balanced surface acidic and basic sites. The Rh catalyst facilitated C<img>C bond dissociation of ethane thereby forming methyl intermediates which then reacted with adsorbed CO<sub>2</sub>, thereby enhancing higher syngas production during DRE reaction.</div></div>","PeriodicalId":52958,"journal":{"name":"Carbon Resources Conversion","volume":"8 2","pages":"Article 100249"},"PeriodicalIF":6.4,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144068081","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Kefiran is an exopolysaccharide derived from kefir grains that has antioxidant and antimicrobial properties. The high production cost of kefiran is primarily attributed to the expensive fermentation media. Therefore, the use of byproducts from agro-industries could present an economically favorable alternative. In this study, locally available mature coconut water (MCW) and whey lactose (WL) were used as cost-effective nutrient sources for kefiran production by Lactobacillus kefiranofaciens JCM 6985. MCW gave a higher yield of kefiran and acid than WL and was comparable to the commercial medium. The optimal sugar concentration for kefiran and acid production from MCW was 30 g/L, and the pH control during cultivation could alleviate the inhibitory effect of acidic pH and enhance kefiran and acid production. When the MCW was added with yeast extract at 3 g-nitrogen/L, the kefiran and acid production increased up to 3.26 ± 0.03 g/L and 15.5 ± 0.7 g/L, respectively. Moreover, the kefiran and acid production was scaled up in the bioreactor and enhanced by the repeated-batch cultivation for six cycles. The structure analysis indicated that kefiran produced by L. kefiranofaciens when using MCW had a similar structure to that extracted from kefir grains. The findings demonstrate promising methods for cost-effective production of kefiran and lactic acid using inexpensive nutrient sources such as MCW.
{"title":"Utilization of agro-industrial byproducts as low-cost nutrient sources for production of kefiran and lactic acid by Lactobacillus kefiranofaciens","authors":"Apisara Iadcharoen , Benjamas Cheirsilp , Jariya Ruangwicha , Sirasit Srinuanpan , Sompong O-Thong","doi":"10.1016/j.crcon.2024.100268","DOIUrl":"10.1016/j.crcon.2024.100268","url":null,"abstract":"<div><div>Kefiran is an exopolysaccharide derived from kefir grains that has antioxidant and antimicrobial properties. The high production cost of kefiran is primarily attributed to the expensive fermentation media. Therefore, the use of byproducts from agro-industries could present an economically favorable alternative. In this study, locally available mature coconut water (MCW) and whey lactose (WL) were used as cost-effective nutrient sources for kefiran production by <em>Lactobacillus kefiranofaciens</em> JCM 6985. MCW gave a higher yield of kefiran and acid than WL and was comparable to the commercial medium. The optimal sugar concentration for kefiran and acid production from MCW was 30 g/L, and the pH control during cultivation could alleviate the inhibitory effect of acidic pH and enhance kefiran and acid production. When the MCW was added with yeast extract at 3 g-nitrogen/L, the kefiran and acid production increased up to 3.26 ± 0.03 g/L and 15.5 ± 0.7 g/L, respectively. Moreover, the kefiran and acid production was scaled up in the bioreactor and enhanced by the repeated-batch cultivation for six cycles. The structure analysis indicated that kefiran produced by <em>L. kefiranofaciens</em> when using MCW had a similar structure to that extracted from kefir grains. The findings demonstrate promising methods for cost-effective production of kefiran and lactic acid using inexpensive nutrient sources such as MCW.</div></div>","PeriodicalId":52958,"journal":{"name":"Carbon Resources Conversion","volume":"8 2","pages":"Article 100268"},"PeriodicalIF":6.4,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141839613","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-06-01Epub Date: 2024-08-13DOI: 10.1016/j.crcon.2024.100270
Maria Mavrommati , Christina N. Economou , Stamatina Kallithraka , Seraphim Papanikolaou , George Aggelis
Saccharomyces cerevisiae is the main yeast used in the winemaking industry. Its innate glucophilicity provokes a discrepancy in glucose and fructose consumption during alcoholic fermentation of grape must, which, combined with the inhibitory effect of ethanol accumulated in the fermentation broth, might lead to stuck or sluggish fermentations. In the present study, we realized an Adaptive Laboratory Evolution strategy, where an alcoholic fermentation of a 20 g/L fructose broth was followed by cell selection in a high ethanol concentration environment, employed in two different S. cerevisiae strains, named CFB and BLR. The evolved populations originated from each strain after 100 generations of evolution exhibited diverse fermentative abilities. One evolved population, originated from CFB strain, fermented a synthetic broth of 100 g/L glucose and 100 g/L fructose to dryness in 170 h, whereas the parental strain did not complete the fermentation even after 1000 h of incubation. The parameters of growth of the parental and evolved populations of the present study, as well as of the ethanol tolerant populations acquired in a previous study, when grown in a synthetic broth of 100 g/L glucose and 100 g/L fructose, were calculated through a kinetic model, and were compared to each other in order to identify the effect of evolution on the biochemical behavior of the strains. Finally, in a 200 g/L fructose synthetic broth fermentation, only the evolved population derived from CFB strain showed improved fermentative behavior than its parental strain.
{"title":"Simultaneous improvement of fructophilicity and ethanol tolerance of Saccharomyces cerevisiae strains through a single Adaptive Laboratory Evolution Strategy","authors":"Maria Mavrommati , Christina N. Economou , Stamatina Kallithraka , Seraphim Papanikolaou , George Aggelis","doi":"10.1016/j.crcon.2024.100270","DOIUrl":"10.1016/j.crcon.2024.100270","url":null,"abstract":"<div><div><em>Saccharomyces cerevisiae</em> is the main yeast used in the winemaking industry. Its innate glucophilicity provokes a discrepancy in glucose and fructose consumption during alcoholic fermentation of grape must, which, combined with the inhibitory effect of ethanol accumulated in the fermentation broth, might lead to stuck or sluggish fermentations. In the present study, we realized an Adaptive Laboratory Evolution strategy, where an alcoholic fermentation of a 20 g/L fructose broth was followed by cell selection in a high ethanol concentration environment, employed in two different <em>S. cerevisiae</em> strains, named CFB and BLR. The evolved populations originated from each strain after 100 generations of evolution exhibited diverse fermentative abilities. One evolved population, originated from CFB strain, fermented a synthetic broth of 100 g/L glucose and 100 g/L fructose to dryness in 170 h, whereas the parental strain did not complete the fermentation even after 1000 h of incubation. The parameters of growth of the parental and evolved populations of the present study, as well as of the ethanol tolerant populations acquired in a previous study, when grown in a synthetic broth of 100 g/L glucose and 100 g/L fructose, were calculated through a kinetic model, and were compared to each other in order to identify the effect of evolution on the biochemical behavior of the strains. Finally, in a 200 g/L fructose synthetic broth fermentation, only the evolved population derived from CFB strain showed improved fermentative behavior than its parental strain.</div></div>","PeriodicalId":52958,"journal":{"name":"Carbon Resources Conversion","volume":"8 2","pages":"Article 100270"},"PeriodicalIF":6.4,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144070458","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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