共查询到20条相似文献,搜索用时 46 毫秒
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利用特殊培养基从光照充裕、有机质含量高的猪场粪便排放处的污泥中富集培养光合细菌混合产氢菌群,对该混合菌群的产氢培养基进行优化,并研究混合菌群的产氢特性。实验结果表明,此菌群的最佳产氢培养基配方为:氯化铵0.4g/L,氯化镁0.2g/L,酵母膏0.1g/L,磷酸氢二钾0.5g/L,氯化钠2.0g/L,谷氨酸钠3.5g/L。此菌群以1%的葡萄糖为基质时,产氢时间长达204h,最大产氢量为3.41L/L,最大产氢速率为44.17mL/(L.h),最高氢气含量为46.73%,具有工业化应用价值。 相似文献
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光合细菌产氢系统累积热量对酶活性的影响 总被引:1,自引:0,他引:1
研究了外界因素引起累积热量的不同对光合细菌酶活性的影响,结果表明温度为27℃有热量累积的系统固氮酶和放氢酶活性的表达最为显著;光照强度在500~3000lx范围内,有热量累积的系统,固氮酶活性和放氢酶活性都高于无热量累积的系统;10%接种有热量累积的系统固氮酶活性最大为554mmlC2H4/mL菌液/h,放氢酶活性也最大为860nmolH2/mL菌液/h;除葡萄糖浓度为0.5%的放氢酶活性不表达,其它有热量累积的系统固氮酶和放氢酶活性都高于无热量累积的系统,葡萄糖浓度为3.0%有热量累积的系统固氮酶和放氢酶活性最高;不同NW4+浓度,累积热量都有利于固氮酶和放氢酶活性的表达,NH4+浓度为0.4g/L有热量累积的系统酶活性表达最为显著. 相似文献
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针对不同浓度的Fe2+、Co2'和Ni2+对混合菌种的光合产氢与生长的影响进行实验研究.结果表明适当浓度的二价铁系离子对产氢及生长具有一定促进作用.Fe2+、Co2+和Ni2+最佳产氢浓度分别为9.00、0.45和0.10wnol/L,而对产氢的影响作用大小顺序为:Fe2+>Ni2+>Co2+.二价铁系离子在适当浓度范围内可提高生长速率,其中Co2+对生长的促进作用最大.由于pH值影响二价铁系离子对产氢酶活性的作用,针对Fe2+浓度在不同初始pH值时对混合菌种光合产氢的影响进行实验研究.结果表明当pH=7.0时,Fe2+ 浓度的变化对产氢的影响最显著.而在本试验范围内,随着pH值偏离7.0,Fe2+浓度的变化对产氢的影响逐渐减小. 相似文献
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应用固定化细胞技术,研究红假单胞菌菌株D(Rhodopseudomonas sp.D)利用有机物光产氢的过程特性,发现以琼脂包埋的固定化细胞,在以苹果酸作为基质的条件下,光照培养120h,总产氢量达到119.5ml,产氢速率为19.92ml(1·h)~(-1)。与悬浮细胞相比,产氢能力提高90%,而且光产氢持续时时延长。菌体菌龄、颗粒内生物量、光照强度、光照/黑暗时间、基质初始pH以及基质浓度均影响产氢过程。试验还证实除苹果酸外,废水中常见污染物如葡萄糖、乳酸、丙酸也是良好的产氢基质。本实验结果表明用光合细菌处理有机废水同时回收氢能的可能性。 相似文献
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Bita Baghchehsaraee George NakhlaDimitre Karamanev Argyrios Margaritis 《International Journal of Hydrogen Energy》2009
In this paper we report the effect of extrinsic lactic acid on hydrogen production from a starch-containing medium by a mixed culture. Study of the effect of addition of four metabolites, namely ethanol, lactic acid, butyric acid and acetic acid illustrated that lactic acid had a positive effect on both the maximum hydrogen production and hydrogen production rate. The addition of 10 mM lactic acid to a batch containing starch increased the hydrogen production rate and hydrogen production yield from 4.31 to 8.23 mL/h and 5.70 to 9.08 mmol H2/g starch, respectively. This enhancement in hydrogen production rate and yield was associated with a shift from acetic acid and ethanol formation to formation of butyric acid as the predominant metabolite. The increase in hydrogen production yield was attributed to the increase in the available residual NADH for hydrogen production. When lactic acid was used as the sole carbon source, no significant hydrogen production was observed. 相似文献
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Sathyanarayanan Sevilimedu Veeravalli Subba Rao Chaganti Jerald A. Lalman Daniel D. Heath 《International Journal of Hydrogen Energy》2013
The effects of furans (furfural and 5-hydroxymethylfurfural (HMF)) on hydrogen (H2) production using mixed anaerobic cultures were evaluated by conducting batch experiments. Two mixed anaerobic cultures (culture A and B) fed furans plus glucose and treated with and without linoleic acid (LA) at pH 5.5 were maintained at 37 °C. In the LA inhibited cultures A and B fed 0.75 g L−1 furfural and 0.25 g L−1 HMF, the maximum H2 yields observed were 1.89 ± 0.27 mol mol−1 glucose and 1.75 ± 0.22 mol mol−1 glucose, respectively. In cultures with maximum H2 yields, Clostridium sp. and Flavobacterium sp. were dominant. Acetate, butyrate and ethanol were the major soluble metabolites detected in cultures A and B whereas propionate was also dominant in culture B. A canonical correspondence analysis based on the byproducts and the relative abundance of the terminal-restriction fragments revealed less variation between cultures treated with LA and low correlation value between the factors and the species composition. 相似文献
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《International Journal of Hydrogen Energy》2023,48(22):8093-8100
Numerous catalysts have been widely investigated for accelerating hydrogen production from NaBH4 hydrolysis. However, these catalysts are usually complicated in structures, costly in fabrication, and hazardous for environment. In this work, cheap and environment-friendly acetic acid, CH3COOH, is employed to promote NaBH4 hydrolysis to produce hydrogen in a considerable rate. The experimental results demonstrate that the addition of suitable amount of CH3COOH into NaBH4 solutions stabilized with NaOH could dramatically accelerate the hydrolysis reaction. Additionally, the start/stop of NaBH4 hydrolysis could be controlled by adding acid or base into the solution to realize “go-as-you-please” on-site hydrogen production. 相似文献
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In this paper, a new photochemical cell is developed and analyzed for copper disproportionation within the Cu–Cl water splitting cycle. In the disproportionation step, cuprous chloride reacts with hydrochloric acid to generate cupric chloride and hydrogen gas. In past literature, it has been demonstrated that this reaction can be conducted electrochemically at 24 bars and 100 °C. This reaction is attractive because it generates compressed hydrogen. Consequently, the work required to compress hydrogen from standard pressure – to 350 bars for example – reduces approximately by 95%. To conduct this reaction electrochemically, the process requires electricity input. Rather than using an external supply, the method proposed in this paper drives the reaction 2CuCl(aq) + 2HCl(aq) → 2CuCl2(aq) + H2(g) with photonic energy derived from solar radiation. The photochemical cell comprises one photochemical and one electrochemical reactor separated by a proton conducting membrane. The electrochemical reactor is a half electrolysis cell where CuCl liquid is disproportionated with hydrochloric acid by releasing protons, according to 2CuCl(aq) + 2HCl(g) → 2CuCl2(aq) + 2H+ + 2e−. The electrons are transferred to the second reactor by an electron-conducting media, consisting of electrodes and an external circuit. In the photochemical reactor, there are supramolecular complexes dissolved in dimethylformamide that generate multi-electrons at active sites under the influence of solar radiation and catalyze water reduction according to 2H2O + 2e− → H2(g) + 2OH−. Gaseous hydrogen is collected from above the second reactor, while hydroxyl ions combine with the protons that cross the PEM to supply water according to 2OH− + 2H+ → 2H2O. The overall process is assisted electrically by a dye sensitized solar cell. An optical system including solar concentration, spectral splitting and an optical fibre is developed for enhanced solar energy absorption to supply thermally and electrically the Cu–Cl cycle with energy input. This paper examines the feasibility and expected efficiency of the photochemical disproportionation cell and describes the potential benefits of the thermo-photochemical water splitting process, in contrast to conventional thermochemical water splitting. 相似文献
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The methanol and water solvents were used for the production of hydrogen from potassium borohydride. In addition, phosphoric acid was selected as the green catalyst so that this semi-methanolysis reaction would be more effective for the first time. The semi-methanolysis of potassium borohydride is investigated depend on potassium borohydride, phosphoric acid concentrations and temperatures. The maximum normalized hydrogen production rate obtained from this semi-methanolysis reaction with 1 M phosphoric acid as a catalyst was 5779 ml min ?1 g?1. In addition, this semi-methanolysis reaction was completed in 5 s. Kinetic studies have been carried out with the power law kinetic model. The activation energy obtained for this semi-methanolysis reaction is 1.45 kJ mol?1. 相似文献
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A microwave-assisted acid pretreatment (MAP) strategy has been developed to enhance hydrogen production via thermophilic fermentation of corn stover. Pretreatment of corn stover by combining microwave irradiation and acidification resulted in the increased release of soluble substances and made the corn stover more accessible to microorganisms when compared to thermal acid pretreatment (TAP). MAP showed obvious advantages in short duration and high efficiency of lignocellulosic hydrolysis. Analysis of the particle size and specific surface area of corn stover as well as observation of its cellular microstructure were used to elucidate the enhancement mechanism of the hydrolysis process by microwave assistance. The cumulative hydrogen volume reached 182.2 ml when corn stover was pretreated by MAP with 0.3 N H2SO4 for 45 min, and the corresponding hydrogen yield reached 1.53 mol H2/mol-glucose equivalents converted to organic end products. The present work demonstrates that MAP has potential to enhance the bioconversion efficiency of lignocellulosic waste to renewable biofuel. 相似文献
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A variety of supported metal catalysts were tested under conditions of steam reforming of acetic acid (HAc), which was selected as a model compound for pyrolysis oil. The influence of several parameters on catalytic activity and selectivity were examined, including catalyst composition, i.e. nature of the metal and the carrier, reaction temperature and time on stream. The metallic phase of such catalysts was comprised of various metals, such as Pt, Pd, Rh, Ru and Ni, which were supported on metal oxides carriers, such as Al2O3, La2O3/Al2O3, MgO/Al2O3 and CeO2/Al2O3. It was found that Ni-based and Ru-based catalysts present high activity and selectivity toward hydrogen production. Ru catalysts supported on La2O3/Al2O3 and MgO/Al2O3 carriers, showed good long-term stability as a function of time on stream. However, Ni catalysts were not as stable as Ru catalysts. The amount of carbon deposited on each catalyst was estimated, and it was found that it depends strongly on the nature of the catalyst. 相似文献
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Xian Wang Qinglei Meng Liqin Gao Zhao Jin Junjie Ge Changpeng Liu Wei Xing 《International Journal of Hydrogen Energy》2018,43(14):7055-7071
Formic acid, as the simplest carboxylic acid which can be obtained as an industrial by-product, is colorless, low toxicity, and easy to transport and storage at room temperature. Recently, Formic acid has aroused wide-spread interest as a promising material for hydrogen storage. Compared to other organic small molecules, the temperature for formic acid decomposition to produce hydrogen is lower, resulting in less CO toxicant species. Lots of catalysts on both homogeneous catalysts and heterogeneous were reported for the decomposition of formic acid to yield hydrogen and carbon dioxide at mild condition. In this paper, the recent development of mechanism and the material study for both homogeneous catalysts and heterogeneous catalysts are reviewed in detail. 相似文献