Papers by Keyword: Biohydrogen Production

Abstract: For the properties of activated sludge studies, three kinds of activated sludge were obtained from continuous hydrogen production reactor. Activated sludge was got under organic loading rate (OLR) of 3, 7 and 25 kgCOD/m³·d condition, respectively. Sedimentation performance and activities of sludge were investigated. When OLR was 3 kgCOD/m³·d, activated sludge showed good sedimentation performance. After 30 minutes sedimentation, the volume of activated sludge in total mixture volume was about 39%. When OLR was 7 and 25kgCOD/m³·d, after 30 minutes sedimentation, the volume of activated sludge in total mixture volume was 80% and 83%, respectively. The increase of biomass is the main reason for increase of sedimentation performance. MLVSS/MLSS of activated sludge was 37.7% and 79.6% under OLR of 3 and 25kgCOD/m³·d condition, therefore, activities of activated sludge was high under high OLR condition. Since sedimentation performance of sludge is high under high OLR condition, hydraulic retention time should controlled carefully in engineering operation.

Abstract: A continuous stirred-tank reactor (CSTR) was used to produce biohydrogen gas from organic wastewater. The hydrogen producing reactor was operated under high organic loading rate of 21 kgCOD/m³·d, and molasses wastewater was used as substrate. Hydrogen production rate, pH value, sugar utilizing rate and fermentative products in effluent were investigated in continuous fermentation. When Organic Loading Rate was controlled at 21 kgCOD/m³·d, the average concentrations of acetic acid, ethanol, propionic acid, butyric acid and valeric acid in liquid fermentative products were 833, 748, 482, 484 and 256mg/L respectively. There is not any fermentation product playing dominant role absolutely in hydrogen production fermentation. The pH value in effluent was about 4.7~4.9, the average utilizing rate of sugar reached 92.1%, most of the sugar in molasses wastewater was utilized. The biogas production rate in hydrogen producing fermentation was from 21.2 to 27.1L/d, and the average biogas production rate was about 25.1L/d. The hydrogen content was about 37%.

Abstract: A high efficiency simultaneous cellulose degradation and hydrogen production strain X9 was obtained from the screening of the 125 strains of fermentative hydrogen production bacteria which were isolated from a continuous stirred-tank hydrogen production bioreactor (CSTR) with LM-1 and microcrystalline cellulose (MCC) medium and improved Hungered technique in this study. X9 was confirmed a new category by analyzing the results of biochemical and physiological test, shape character, 16S rDNA sequencing and phylogenetic, and then analysis characteristics of growth, culture parameters, the effects of components of medium on growth and ability of hydrogen production, the optimum technological parameters have been determined from orthogonal experiment and single factor test. Finally, X9 achieved maximum specific hydrogen yield of 4.9mmol/g with MCC under the optimal conditions.

Abstract: Hydrogen-producing zymogenous bacteria YUAN-3 (Ethanoligenens harbinense) is used as the study object, on which the intermittent hydrogen production test is applied to examine the influence of Na-ion concentration on the growth and gas generation of YUAN-3. Research results show that when Na ion concentration is 1.5g/L, cell concentration reaches the maximum level 0.892g/L; when Na-ion concentration is maintained at 2.0~3.0g/L, culture medium is applicable for hydrogen generation of YUAN-3.

Abstract: Hydrogen production from molasses wastewater was investigated in continuously-stirred tank reactor (CSTR). The CSTR was operated at an hydraulic retention time (HRT) of 6 hours and the temperature at 35°C. The highest gas production of 25.39 L/d using mixed culture fermentation, corresponding to a peak hydrogen production volume of 11.39 L/d were achieved in the CSTR reactor. While the variation of chemical oxygen demand (COD) ranged from 5500 to 8000 mg/L, the soluble end product system underwent a transition of fermentation type and the reactor gave fluctuating and increasing of ORP. These experimental results demonstrate that the shock-loading and micro-anaerobic circumstance are important factors for enhancing and stabilizing H₂ production.

Abstract: This study has investigated the effects of K₂HPO₄ to the cell growth and hydrogen production ration to Biohydrogenbacterium R3 sp.nov.. The results found that: K₂HPO₄ can promote the cell growth and hydrogen production effectively and it can maintain the pH value stably in culture. The biogas yield, hydrogen production yield and specific hydrogen production ration(SHPR) had the maximum of 4960 ml/L, 2107.5 ml/L and 1.93 mol H₂/mol glucose respectively when the concentration of K₂HPO₄ was 1.5g/L. The final pH in the culture was always kept at 3.0~5.0.

Abstract: Continuous dark fermentative hydrogen production technology is suitable for commercial application. This review summarized several main basic factors influencing the operation of the reactor, followed by some suggestions and outlooks. The factors included temperature, pH, HRT and COD were briefly introduced and discussed. This review demonstrated that the optimal value of a given factor under different conditions was great different. This indicates that reactor operation is affected by many factors and sensitive to environmental change. To make the technology more feasible into practice, deeply understanding about the characteristics and rules of the operation is necessary. Thus more researches in this respect are recommended.

Abstract: As a very important material, the use of hydrogen is increasingrapidly. Because the main advantage of hydrogen is that it is a clean and renewable energy source/carrier with high specific heat of combustion and no contribution to the Greenhouse effect, and can be used in many industrial applications. Many countries are developing to reduce operational cost of bio-producing hydrogen technology. So the key to realize industrialization is to improve biohydrogen-producing capacity and reduce the cost. This article discusses fermentative hydrogen production from various points of view. First, the theoretical principles of the biological processes taking place in hydrogen production, and the organisms responsible for this process are described at the same time. Second, Laboratory Experiments of fermentative hydrogen production are introduced. Types of fermentative and applicable reactor designs are discussed. Finally, the challenges faced by fermentative hydrogen production are discussed.

Abstract: Isolation and culture of hydrogen-producing and fermentative bacteria is an important foundation on biohydrogen production process. There are complicated operation and composition in present anaerobic techniques and culture media. Hungate technique was improved and plate of culture bottle was established by comparing anaerobic methods and bacterium growth. Isolation and enrichment culture media were confirmed by the test of different composition and the species and amount of hydrogen-producing and fermentative bacterium. 550 bacterium strains were isolated by the anaerobic operation.

Abstract: Improving bio-hydrogen-producing capacity is the key to realize industrialization for the H2-producing technology. One of the most effective approaches is to investigate the factors that affect the H2-producing capacity. Different glucose concentrations and pH were designed in anaerobic Clostridium R33 sp.nov. cultures. The hydrogen production varies according to glucose concentration and pH, respectively. It is founded the optimal glucose concentration is 12.5 g/L and the optimal pH is about 4.0.