Effects of pH and ferrous iron on the coproduction of butanol and hydrogen by Clostridium beijerinckii IB4

Butanol and hydrogen gas are main products in butanol production by solventogenic Clostridia. Effects of pH and ferrous iron on hydrogen and butanol production by Clostridium beijerinckii IB4 were investigated in this work. With the increasing of the pH value, the hydrogen yields increased during acidogenic phase and decreased during solventogenic phase. Compared with the process without pH control, butanol and hydrogen increased by 15.43% and 11.77%, respectively, when pH was controlled at 5.2. Under the control of pH at 5.2 and supplementation of 250 mg/L of FeSO₄·7H₂O, the maximum hydrogen quantity of 8.24 L/L was obtained, and hydrogen productivity achieved 187 mL/L/h with yield of 145 mL/g glucose, which increased by 65%, 46% and 37%, respectively. However, butanol yield was reduced slightly by 4.8%. The reducing power was enhanced in solventogenic phase with supplementation of 250 mg/L FeSO₄·7H₂O, and the energy content of fuel produced in this process also remained stable. These results indicated that hydrogen production was enhanced by pH control and ferrous iron regulation, and butanol production performance was also maintained, which was favorable for coproduction of butanol and hydrogen in ABE fermentation.     

Separation of butanol from acetone-butanol-ethanol fermentation by a hybrid extraction-distillation process

The alternative fuel butanol can be produced via acetone-butanol-ethanol (ABE) fermentation from biomass. The high costs for the separation of ABE from the dilute fermentation broth have so far prohibited the industrial-scale production of bio-butanol. In order to facilitate an effective and energy-efficient product removal, we suggest a hybrid extraction-distillation downstream process with ABE extraction in an external column. By means of computer-aided molecular design (CAMD), mesitylene is identified as novel solvent with excellent properties for ABE extraction from the fermentation broth. An optimal flowsheet is developed by systematic process synthesis which combines shortcut and rigorous models with rigorous numerical optimization. Optimization of the flowsheet structure and the operating point, consideration of heat integration, and the evaluation of the minimum energy demands are covered. It is shown that the total annualized costs of the novel process are considerably lower compared to the costs of alternative hybrid or pure distillation processes.     

Concomitant hydrogen and butanol production via co-digestion of organic wastewater and nitrogenous residues

Hydrogen is recognized as zero-carbon fuel having the highest calorific value per unit mass as compared to other fuels. Butanol is also a promising biofuel having better fuel characteristics as compared to bioethanol. Thus, aim of the present study was concomitant hydrogen and n-butanol production via codigestion of organic wastewater such as cane molasses (CM), distillery effluent (DE) and starchy wastewater (SWW) and nitrogenous residues. The addition of co-substrate to organic wastewater has resulted in 12.2, 1.1 and 6.6 folds increase in hydrogen production in comparison to CM, DE and SWW, respectively as the sole substrate. Maximum energy conversion efficiency and positive net energy gain of 50.16% and 7.29 KJ gCOD⁻¹, respectively were achieved using SWW supplemented with water hyacinth (WH). Acid pretreatment of WH leads to higher hydrogen and butanol production of 3160 mL L⁻¹ and 4.5 g L⁻¹, respectively with 89% energy conversion efficiency. This study shows the suitability of SWW with acid treated WH as feedstock for sustainable and efficient bioenergy generation with an additional advantage of waste management.     

硫代氨基甲酸酯中间体的合成

氨基甲酸酯系农药已成为农药行业第二大类农药系列,硫代氨基甲酸酯是其中一类重要的杀虫剂,而正丁基硫醇是硫代氨基甲酸酯的一种重要的中间,并且它在其他农药,赋臭剂以及有机合成方面都有很重要的作用,它的工业合成现在国内还是个空白,所以是一个很值得研究的课题。     

Study on the Synthesis of n‐Butyl Acetate by Catalytic Rectification

With Hβ zeolite as the catalyst and θ rings as the fillings, the technological process of synthesizing n‐butyl acetate with acetic acid and n‐butanol in a Φ 30 mm and 2 m tall catalytic rectifying column was studied. The influence of factors such as catalyst loading height, material feed site, reflux ratio and feed rate on the esterification reaction and the rectification effect was investigated. The study results suggested that the appropriate conditions of n‐butyl acetate synthesis by catalytic rectification include: The height ratio of the rectifying section, the reaction section and the stripping section is 1:1:1; acetic acid and n‐butanol are fed in upside and downside of the reaction section, respectively; the reflux ratio is 2.5; the liquid hourly space velocity of n‐butanol is 0.64 h^–1. Under these conditions, the mass fraction of n‐butyl acetate in the column bottom is 98.64 %, and the total yield of n‐butyl acetate is 91.5 %.     

Study of the Involvement of Phosphatidic Acid Formation in the Expression of Wound‐Responsive Genes in Cotton

Plants use phospholipase D (PLD, EC 3.1.4.4)/phosphatidic acid (PtdOH) for the transduction of environmental signals including those coming from wounding. Based on our previous findings suggesting that wound‐induced PLDα‐derived PtdOH can act as a local signaling molecule in cotton (Gossypium hirsutum), we show that wounding immediately increases local NADPH oxidase (NADPHox) and cellulose synthase A (CeSA) gene expression. After developing a novel fluorimetric assay for the investigation of n‐butanol inhibitory effect on PLD activity, we show that only NADPHox gene upregulation is reduced when n‐butanol is applied prior to wounding. This suggests that NADPHox is a possible downstream target of PLD function, while a different CeSA‐involving response system may exist in cotton. Overall, this study provides new knowledge on signal‐transduction mechanisms following wounding of cotton leaves.     

Combustion of non-halogenated volatile organic compounds over group VIII metal catalysts

Catalytic combustion of volatile organic compounds (VOCs), present in low concentrations (10–1000 ppm) in industrial effluent streams, is a promising air abatement technology. The oxidation of benzene, butanol and ethyl acetate over group VII metal catalysts supported on alumina carriers has been investigated. Pt, Pd and Co were found to be the most active among group VIII metals, while ethyl acetate was found to be the most-difficult-to-oxidize compound. Benzene and ethyl acetate oxidations over Pt/Al₂O₃ were found to be structure sensitive reactions with the turnover frequency (TOF) increasing with increasing mean metal particle size. The presence of chloride on the catalyst surface, originating from chloride-containing metal precursor compounds was found to exert an inhibiting effect on the activity of Pt. Apparent activation energies of the reactions over Pt and Pd catalysts were found to be in the 70–120 kJ/mol range while the reaction order with respect to the VOC was positive in all cases. During oxidation of benzene-butanol mixtures, benzene oxidation was completely suppressed as long as butanol was present in the reaction mixture.     

A porous ruthenium silica catalyst modified with amino benzoic acid for the oxidation of butanol with molecular oxygen

Silica was extracted from rice husk (RH) and modified with ruthenium and amino benzoic acid. The catalysts RH–Ru and RH–Ru–A (incorporated with 5% of 4-(methylamino)benzoic acid) were synthesized from rice husk via solvent extraction and sol–gel technique. XRD diffractogram showed both catalysts were amorphous. BET results showed that the surface area of RH–Ru–A (73.9 m² g⁻¹) was smaller compared with RH–Ru (138 m² g⁻¹). After calcinations at 700 °C, RH–Ru-700 and RH–Ru–A-700 showed a lower specific surface area, i.e. 21.8 and 19.0 m² g⁻¹, respectively. The SEM micrograph of RH–Ru-700 showed the presence of elongated nano fibers, while RH–Ru–A-700 showed the presence of large regular pore structures. RH–Ru and RH–Ru–A were used as catalyst for the oxidation of 1-butanol with molecular oxygen as the oxidant. The oxidation yielded only one product, i.e. 1-butanal. Although the yield of 1-butanal was less than 10% both catalyst showed great potential for the oxidation of primary alcohols into aldehydes at moderate reaction conditions. A plausible mechanism was suggested for the catalyzed oxidation.     

正丁醇生产新工艺

采用氟化钾对正丁醇传统生产方法进行改进，节能计算表明，新方法比传统方法节能２０％。