植物纤维素原料的生物转化与利用

采用生物技术对植物纤维原料进行转化利用,是一项具有重要意义的研究工作。本文简要介绍了纤维素酶的生产、利用纤维素原料生产酒精、乳酸、2,3-丁二醇及木糖醇等方面的研究进展。     

1-氯甲酰基-2-咪唑烷酮的合成

以2-咪唑烷酮及三光气为原料,合成了阿洛西林钠的关键中间体1-氯甲酰基-2-咪唑烷酮。研究了反应溶剂、滴加时间、原料配比、母液利用对反应收率的影响,在最佳工艺条件下收率能达到90%以上。     

2,2-二氟乙胺的合成

以2,2-二氟乙醇、液氨为原料,在催化剂作用下,利用固定床反应器采用连续法操作合成2,2-二氟乙胺。研究了原料配比、反应温度及二氟乙醇的流速对产物收率的影响,得出了合成2,2-二氟乙胺的最佳工艺条件。     

挤压造粒生产有机无机复混肥的工艺技术

介绍利用广西本地泥炭土、花生麸、糖厂滤泥、鸡粪等有机原料,采用轮碾动辊式挤压造粒机生产8-3-4-20(有机质)、10-5-5-20(有机质)等有机无机复混肥的生产技术,讨论了原料预处理、各种有机原料的选择配比、物料水分含量对产品质量的影响;轮碾动辊式挤压造粒机的结构、材料及主要故障及其处理措施。产品的农田试验获得较好效果。     

γ-硝基庚二酸二甲酯的合成研究

以硝基甲烷和丙烯酸甲酯为原料,通过迈克尔加成反应得到目标产物γ-硝基庚二酸二甲酯,详细研究了催化剂、原料物质的量比对反应的影响,并利用1HNMR和IR对产物进行表征。     

α-蒎烯化学性质的应用

介绍了以α-蒎烯为原料 ,利用其不同的化学性质 ,可合成一系列重要香料原料和其它产品 ,并对其合成路线进行了简单的概括。     

羟基丙酮的合成研究

以乙醛和甲醛(以多聚甲醛形式存在)为原料,利用极性转换的原理,合成制备了羟基丙酮。考察了原料配比、催化剂品种及用量、溶剂种类、反应时间等因素对反应的影响。结果表明:在原料摩尔比n(乙醛):n(甲醛)=1:1.2,3-乙基-4-甲基-5-羟乙基噻唑盐为催化剂,n(催化剂):n(乙醛)=1:10,二恶烷为催化剂,碱为1,8-二氮杂环[5,4,0]十一碳-7-烯,pH8-9,反应温度60℃,反应时间5h反应条件下,原料乙醛转化率达90.5%,产品选择性达87.6%,合成收率为76.6%。     

煤制油费托α-烯烃增值利用及发展展望

煤制油费托α-烯烃增值利用对实现煤炭清洁利用与延长煤制油产业链具有重要意义。该文介绍了费托α-烯烃在精细化工产业发展的应用及市场情况。综述了以费托油为原料进行α-烯烃分离、聚α-烯烃、高碳醇、AOS生产的生产工艺比对,并对煤化工与精细化工产业结合进行了展望。     

四丁基溴化铵催化氧化β-甲基萘的研究

利用溴酸钾在冰醋酸溶剂下氧化β-甲基萘制备β-甲基萘醌。考察了催化剂种类、反应温度、反应时间、氧化剂与原料的摩尔比等因素对目标产物收率的影响,从而获得了较优的反应条件:相转移催化剂为四丁基溴化铵,反应温度80℃,反应时间5h,氧化剂与原料的摩尔比2.5∶1。在以上较优条件下,β-甲基萘转化率为81.46%,β-甲基萘醌的选择率59.07%。     

胆甾烷-3-醇及胆甾烷-3-酮的合成研究进展

甾族化合物在生物、医药等诸多方面具有很重要的利用价值.本文在大量文献的基础上对以胆固醇为原料,经还原反应制备胆甾烷-3-醇和以胆甾烷-3-醇为原料经氧化反应制备胆甾烷-3-酮的合成工艺进行了综述,重点对上述合成工艺的催化剂及催化方法进行了阐述,并分析了不同催化剂的优缺点,对今后的研究方向进行了归纳.     

Iodine-initiated,solid-state copolymerization of tetraoxane with 1,3-dioxolane in the presence of methylal. VII. Treatment of copolymer after polymerization

The various procedures for removing the residual reactants and impurities from the polymer particle obtained by the solid-state copolymerization of tetraoxane with 1,3-dioxolane have been examined. The removal of the residual reactants by washing with solvents, such as acetone or water, were very difficult, because the residual reactants are mainly located in the central part of the polymerized particle. By evacuation of the polymeric system just after polymerization, however, the residual reactants were found to be easily eliminated from the polymer particle. It was also found that the polymer degradation caused by the acid impurities formed during polymerization can be prevented satisfactorily by neutralization using gaseous ammonia. On the basis of these findings, the simple process for polyoxymethylene production has been achieved; i.e., it was found that the polymer particle including the residual reactants and impurities can be directly pelletized using a vent-type extruder, immediately after the copolymerization procedure and the ammonia gas treatment, to obtain the polyoxymethylene pellet with an excellent thermal stability and a well controlled molecular weight.     

双氧水催化氧化乳酸合成丙酮酸

本文研究了以乳酸为原料，用双氧水催化氧化合成丙酮酸，并探讨了催化剂，温度，原料配比，反应时间等因素对合成反应的影响，确定了最佳合成条件。     

水合氯化铁合成氯乙烷的研究

报导了以水合氯化铁和酒精为原料合成氯乙烷的工艺及产品指标。对反应机理,副反应、三废处理等问题进行了讨论。     

新型织物卫生整理剂磷酸酯叔胺盐的合成

研究了合成磷酸酯叔胺盐原料配比、反应温度、反应时间等条件对产物收率的影响，找到了一条比较理想的工艺路线。     

Organic reactions in emulsions—Preparation of glycerol and polyglycerol esters of fatty acids by transesterification reaction

Monoglycerol and polyglycerol esters of fatty acids have been prepared in an emulsion medium of polyglycerol in esters of fatty acids. Transesterification between glycerol or polyglycerols and methyl esters of fatty acids is made at relatively low temperatures (95–150 C) in the presence of alkaline catalyst and anionic or nonionic emulsifiers. The reaction system consists of two immiscible phases transformed into a “milky” (macro) or transparent (micro) emulsion throughout the heating process. The product obtained using this technology is not a highly substituted ester since the transesterification reaction is selective. The type and the amount of emulsifier have to be carefully selected. Unsuitable emulsifiers which will not stabilize the emulsion are ineffective in enlarging the contact between the reactants; therefore, the conversion of the reactants is very poor. With suitable emulsifiers, the conversions and the yields improved due to a better contact between reactants.     

1-丁基-3-甲基咪唑六氟磷酸盐离子液体合成

按照两步法合成了离子液体1-丁基-3-甲基咪唑六氟磷酸盐([Bmim]PF6),探讨了时间、温度、溶剂、反应物配比等对中间体1-丁基-3-甲基咪唑溴盐([Bmim]Br)以及离子液体[Bmim]PF6产率的影响。结果表明,反应物配比为(1∶1.1)~(1∶2),温度70℃,反应30 h,中间体产率为95.91%;中间体中加入等摩尔KPF6,25℃下反应10 h后,离子液体产率为97.26%。     

KF/Al_2O_3催化下亚胡椒基丙醛的合成

KF Al2O3作催化剂,催化洋茉莉醛和丙醛进行Claisen-Schmidt缩合反应合成了亚胡椒基丙醛。通过正交实验确定了适宜的工艺条件,洋茉莉醛∶丙醛为0 3∶0 42(摩尔比),14g催化剂,丙醛滴加时间2h,反应温度60℃～70℃,反应时间2h。平均摩尔收率80 2%。     

Reaction path of ethanol and acetic acid steam reforming over Ni–Zn–Al catalysts. Flow reactor studies

Ethanol steam reforming (ESR) experiments have been performed in dilute conditions over a NiZnAl catalyst. Experiments have been performed by varying catalyst surface area, reactants flow rate, contact time, reactants feed composition and temperature. Acetic acid steam reforming experiments have also been performed. The data suggest that adsorbed acetaldehyde and acetic acid play an important role as intermediates of ESR, while also acetone may have a role in the ESR reaction. The key step for high hydrogen yield during ESR is represented by the evolution of acetate species, either towards decomposition giving rise to methane + CO_x, or to steam reforming to CO₂ and H₂. At high temperature hydrogen production depends on approaching methane steam reforming and reverse water gas shift equilibria. Ethylene end dimethylether are parallel products found at low conversion. With excess water acetaldehyde is not found among the products, and hydrogen yields as high as 95% have been obtained at 853 K.     

马铃薯淀粉渣的羧甲基化研究

研究了马铃薯淀粉渣与氯乙酸进行羧甲基化反应的一般规律，考察了反应温度、反应时间、原料配比等因素对产物取代度的影响，通过正交试验，找到了最佳反应条件，并对产物性能进行了测试。     

Three-dimensional CFD modelling of PEM fuel cells: An investigation into the effects of water flooding

In this work, a three-dimensional PEM fuel cell model has been developed and is used to investigate the effects of water flooding on cell performance parameters. The presence of liquid water in the cathode gas diffusion layer (GDL) limits the flow of reactants to the cathode catalyst layer, thereby reducing the overall reaction rate and curtailing the maximum power that can be derived from the cell. To characterize the effects of water flooding on gas diffusion, effective diffusivity models that account for the tortuosity and relative water saturation of the porous fuel cell electrodes have been derived from percolation theory and coupled with the CFD model within a single phase flow skeleton. The governing equations of the overall three-dimensional PEM fuel cell model, which are a representative of the coupled CFD and percolation theory based effective diffusivity models, are then solved using the finite volume method. Parametric studies have been conducted to characterize the effects of GDL permeability, inlet humidity and diffusivity of the reactants on the various cell performance parameters such as concentration of reactants/products and cell current densities. It is determined that the GDL permeability has little or no effect on the current densities due to the diffusion dominated nature of the gas flow. However, through the incorporation of percolation theory based effective diffusivity model; a marked reduction in the cell performance is observed which closely resembles published experimental observations. This is a reasonable approximation for effects of water flooding which has been inherently used for further parametric studies.