In order to enhance the biogas production and provide nitrogen sources for the growth of microorganisms,experiments on urea ammonia pretreatment of corn stovers were implemented at(35±1)°C to investigate the...In order to enhance the biogas production and provide nitrogen sources for the growth of microorganisms,experiments on urea ammonia pretreatment of corn stovers were implemented at(35±1)°C to investigate the effects of urea ammonia pretreatment on the batch anaerobic fermentation efficiency of corn stovers.This study assessed the effects of urea ammonia contents(2%,4%,and 6%)and moisture contents(30%,50%,70%and 90%)on the physical structures of lignocelluloses and the efficiency of biogas production from anaerobic fermentation of corn stovers.The results indicated that the methane production reached 230.31 mL/g VS(volatile solids)at pretreatment with 4%urea ammonia and 70%moisture contents for the batch anaerobic fermentation,which was 26.6%higher than that of the untreated group.The degradation rates of cellulose and hemicellulose were 66.34%and 75.47%after the anaerobic fermentation,respectively,which were about 22.6%and 20.9%higher than that of the untreated group,respectively.Thus,it was concluded that urea ammonia pretreatment can improve the efficiency of biogas production from anaerobic fermentation of corn stovers.展开更多
In this study,experiments were designed to reveal in-depth information of the effect of pH and hydraulic retention time（HRT）on biohydrogen fermentation from liquid swine manure supplemented with glucose using an Ana...In this study,experiments were designed to reveal in-depth information of the effect of pH and hydraulic retention time（HRT）on biohydrogen fermentation from liquid swine manure supplemented with glucose using an Anaerobic Sequencing Batch Reactor（ASBR）System.Five values of HRT（8,12,16,20,and 24 h）were first tested and the best HRT determined was further studied at five p H levels（4.4,4.7,5.0,5.3,and 5.6）.The results showed that for HRT 24 h,there was a dividing H2 content（around 37%）related to the total biogas production rate for the ASBR System running at p H 5.0.When the H2 content went beyond 37%,an appreciable decline in biogas production rate was observed,implying that there might exist an H2 content limit in the biogas.For other HRTs（8 through 20 h）,an average H2 content of 42%could be achieved.In the second experiment（HRT 12 h）,the highest H2 content（35%）in the biogas was found to be associated with p H 5.0.The upswing of p H from 5.0 to 5.6 had a significantly more impact on biogas H2 content than the downswing of p H from5.0 to 4.3.The results also indicated good linear relationships of biogas and H2 production rates with HRT（r=0.9971 and0.9967,respectively）.Since the optimal ASBR operating conditions were different for the biogas/H2 production rates and the H2 yield,a compromised combination of the running parameters was determined to be HRT 12 h and pH 5.0 in order to achieve good biogas/H2 productions.展开更多
A new cleaner production process for cassava ethanol has been developed, in which the thin stillage by-product was treated initially by anaerobic digestion, and the digestate further processed by hydrogen-form cation ...A new cleaner production process for cassava ethanol has been developed, in which the thin stillage by-product was treated initially by anaerobic digestion, and the digestate further processed by hydrogen-form cation exchange resin before being recycled as process water to make mash for the next ethanol fermentation batch.Thus wastewater was eliminated and freshwater and energy consumption was significantly reduced. To evaluate the new process, ten consecutive batches of ethanol fermentation and anaerobic digestion at lab scale were carried out. Average ethanol production in the recycling batches was 11.43%(v/v) which was similar to the first batch, where deionized(DI) water was used as process water. The chemical oxygen demand(COD) removal rate reached 98% and the methane yield was 322 ml per gram of COD removed, suggesting an efficient and stable operation of the anaerobic digestion. In conclusion, the application of the new process can contribute to sustainable development of the cassava ethanol industry.展开更多
基金This study was supported by a grant from the Southwest University Talent Introduction Project(SWU118104).
文摘In order to enhance the biogas production and provide nitrogen sources for the growth of microorganisms,experiments on urea ammonia pretreatment of corn stovers were implemented at(35±1)°C to investigate the effects of urea ammonia pretreatment on the batch anaerobic fermentation efficiency of corn stovers.This study assessed the effects of urea ammonia contents(2%,4%,and 6%)and moisture contents(30%,50%,70%and 90%)on the physical structures of lignocelluloses and the efficiency of biogas production from anaerobic fermentation of corn stovers.The results indicated that the methane production reached 230.31 mL/g VS(volatile solids)at pretreatment with 4%urea ammonia and 70%moisture contents for the batch anaerobic fermentation,which was 26.6%higher than that of the untreated group.The degradation rates of cellulose and hemicellulose were 66.34%and 75.47%after the anaerobic fermentation,respectively,which were about 22.6%and 20.9%higher than that of the untreated group,respectively.Thus,it was concluded that urea ammonia pretreatment can improve the efficiency of biogas production from anaerobic fermentation of corn stovers.
基金the funding for this project was provided by the Minnesota Environment and Natural Resources Trust Fund as recommended by the Legislative-Citizen Commission on Minnesota Resources (LCCMR),USA
文摘In this study,experiments were designed to reveal in-depth information of the effect of pH and hydraulic retention time（HRT）on biohydrogen fermentation from liquid swine manure supplemented with glucose using an Anaerobic Sequencing Batch Reactor（ASBR）System.Five values of HRT（8,12,16,20,and 24 h）were first tested and the best HRT determined was further studied at five p H levels（4.4,4.7,5.0,5.3,and 5.6）.The results showed that for HRT 24 h,there was a dividing H2 content（around 37%）related to the total biogas production rate for the ASBR System running at p H 5.0.When the H2 content went beyond 37%,an appreciable decline in biogas production rate was observed,implying that there might exist an H2 content limit in the biogas.For other HRTs（8 through 20 h）,an average H2 content of 42%could be achieved.In the second experiment（HRT 12 h）,the highest H2 content（35%）in the biogas was found to be associated with p H 5.0.The upswing of p H from 5.0 to 5.6 had a significantly more impact on biogas H2 content than the downswing of p H from5.0 to 4.3.The results also indicated good linear relationships of biogas and H2 production rates with HRT（r=0.9971 and0.9967,respectively）.Since the optimal ASBR operating conditions were different for the biogas/H2 production rates and the H2 yield,a compromised combination of the running parameters was determined to be HRT 12 h and pH 5.0 in order to achieve good biogas/H2 productions.
基金Supported by the National Natural Science Foundation of China(21506075)the Natural Science Foundation of Jiangsu Province(BK20150131)the Fundamental Research Funds for the Central Universities(JUSRP51504)
文摘A new cleaner production process for cassava ethanol has been developed, in which the thin stillage by-product was treated initially by anaerobic digestion, and the digestate further processed by hydrogen-form cation exchange resin before being recycled as process water to make mash for the next ethanol fermentation batch.Thus wastewater was eliminated and freshwater and energy consumption was significantly reduced. To evaluate the new process, ten consecutive batches of ethanol fermentation and anaerobic digestion at lab scale were carried out. Average ethanol production in the recycling batches was 11.43%(v/v) which was similar to the first batch, where deionized(DI) water was used as process water. The chemical oxygen demand(COD) removal rate reached 98% and the methane yield was 322 ml per gram of COD removed, suggesting an efficient and stable operation of the anaerobic digestion. In conclusion, the application of the new process can contribute to sustainable development of the cassava ethanol industry.
