利用氯乙酸尾气中氯化氢制备盐酸乙脒

氯乙酸尾气中富含氯化氢气体，以往都吸收成盐酸，利用值得小；而盐酸乙脒的生产又因为原料氯化氢的限制得不发展。针对此种情况，详细介绍了以氯乙酸尾气中的氯化氢为原料，制备盐酸乙脒的新方法。     

利用氯化苄尾气生产盐酸乙脒

利用氯化苄尾气生产盐酸乙脒盐酸乙脒是维生素Ｂ１的重要中间体。近年来维生素Ｂ１在化妆品、养殖行业得到广泛应用，供应十分紧俏。目前国内盐酸乙脒生产厂家较少，主要分布在天津、上海等地。因此，上马盐酸乙脒产品具有较广阔的前景。但其原料氯化氢气体不便贮存和运输...     

副产氯化氢综合利用技术进展

介绍了副产氯化氢用于生产氯气、氯乙酸、盐酸乙脒、环氧氯丙烷、氯磺酸等产品的关键技术,对副产氯化氢的综合利用前景进行了探讨。     

盐酸乙脒生产新工艺研究

介绍了以乙腈，甲醇，液氮，和氯化氢为原料，生产医药维生素Ｂ１中间体盐酸乙脒的生产新工艺。新工艺优化了传统工艺指标，改变了过程的操作方法，使产品收率提高１０％以上，产品质量好，年产３００吨盐酸乙脒生产新工艺已通过省级鉴定。     

利用化工副产物制备盐酸乙脒

开展了以化工副产品氯化氢、乙腈为原料合成盐酸乙脒的生产工艺研究。对影响反应的主要因素进行了考察，选择出最佳的工艺条件为乙腈：甲醇：氯化氢（摩尔比）为1：1.06:1.02，在6－10℃下保温2－3天。在此工艺条件下，制得了合格的盐酸乙脒产量产品，其收率达到96％，产品纯度为95.0%。     

氯乙酸副产尾废氯化氢制高纯盐酸工艺改造及运行总结

介绍了氯乙酸副产尾气氯化氢制高纯盐酸的工艺改进、盐酸中游离氯的去除方法和氯化氢中尾氯的分离输送。     

氯乙酸工艺尾气制高纯盐酸的研究

在乙酸催化氯化法制取氯乙酸工艺中,会产生主要成分为氯化氢的尾气。研究了采用氯化氢尾气制备高纯盐酸的工艺,找到了降低和脱除醋酸、游离氯等杂质的方法和工业化应用方案,提高了副产盐酸的品质,降低了生产消耗。     

利用付产鹽酸生产氨三乙酸

我厂在合成氯油、敌百虫、氯乙酸的过程中,产生大量氯化氢气体。如全部回收,每年可得3000吨31％盐酸。氯化氢气体具有强烈的腐蚀性,用水冲入下水道,腐蚀下水系统,影响农田灌溉。为了化害为利,变废为宝,必须回收付产盐酸,但因数量大,销售困难,还必须为所回收的盐酸广寻出路。去年,我们用回收盐酸土法上马,试生产无氰电镀原料氨三乙酸。     

国内外简讯

副产盐酸提纯精制技术及设备由江苏省南通市三圣换热设备制造厂开发的尾气副产盐酸提纯精制技术及设备日前在江苏中丹集团泰辉化工有限公司氯乙酸工艺中投产获得成功。由于以氯化氢为主的化工生产尾气中含有大量的有机、无机杂质，综合利用受到限制，既造成资源浪费，又使...     

盐酸乙脒生产过程中氯化氢气体水分含量测定

用五氧化二磷吸收,直接称重水分,用氢氧化钠溶液吸收氯化氢气体,硝酸银标准溶液滴定氯离子,建立了氯化氢气体中水分测定的分析方法,从而为盐酸乙脒的生产解决了氯化氢气体中水分的测定问题     

Model of Cellular Instability of Flames of Ternary Mixtures

A simple phenomenological diffusive-thermal model of cellular instability of premixed flames of ternary mixtures is developed and presented. The model shows that preferential diffusion can alter stoichiometry of the mixture, i.e., the ratio of the fuel and oxidizer concentrations, and also its effective dilution by an inert. Key parameters of the model are estimated using numerical modeling of burning velocities. Laminar burning velocities are calculated for hydrogen-oxygen-nitrogen, methane-oxygen-nitrogen, and propane-oxygen-nitrogen mixtures. Conditions for the appearance of cellular instability in ternary mixtures are determined and compared with experiments. In good agreement with experimental observations, the diffusive-thermal instability is predicted in hydrogen flames with equivalence ratios φ ≲ 1.45, in lean methane flames with φ ≲ 1.02, and in rich propane flames with φ ≳ 1.03. The magnitude of the change in the local flame velocity due to preferential diffusion is evaluated. It is demonstrated that nitrogen diffuses faster than oxygen in hydrogen-air and methane-air flames, while oxygen diffuses faster than nitrogen in flames of propane and other heavier hydrocarbons. In mixtures of air with propane or heavier hydrocarbons, the transition between stable and unstable regimes is predicted in mixtures that are leaner than the mixture corresponding to the peak of the burning velocity curve, in agreement with experimental observations. __________ Translated from Fizika Goreniya i Vzryva, Vol. 41, No. 5, pp. 14–22, September–October, 2005.     

阿司匹林系列综合性实验的教学改革

将以往实验教学中分散的、孤立的关于阿司匹林方面的实验加以总结和进一步延伸,使其系列实验内容涉及知识面较广、较深,涵盖的基本技能操作较全面,使之达到培养学生的综合能力、创新能力及提高综合素质的一项综合性实验。     

3种肠杆菌科细菌的耐药性变迁

目的研究大肠埃希菌、肺炎克雷伯菌、阴沟肠杆菌的耐药性变迁。方法对2007～2009年临床分离的大肠埃希菌(645株)、肺炎克雷伯菌(260株)和阴沟肠杆菌(150株),采用纸片扩散法进行体外药敏测定,并依据美国临床实验室标准化协会(Clinical and Laboratory Standards Institute,CLSI)规定的标准,分析3种肠杆菌科细菌的耐药性变迁。结果大肠埃希菌、肺炎克雷伯菌、阴沟肠杆菌对氨苄西林的耐药率均较高;对头孢他啶的耐药率低于头孢噻肟;与2007年比较,2008年和2009年对头孢吡肟的耐药率明显增长;未发现对亚胺培南耐药菌株的产生。结论细菌耐药性不断增强已成为临床治疗面临的重要难题,应从耐药监测、医院感染控制、合理使用抗生素等多方面努力,减少细菌耐药性的产生。     

降冰片二烯光敏异构反应动力学

以降冰片二烯为原料,四乙基米氏酮为光敏剂,在无溶剂条件下,采用循环式反应器研究了降冰片二烯光敏异构反应动力学。结果表明,反应前期降冰片二烯的浓度下降较快,反应后期降冰片二烯的浓度下降变缓。反应速率可用一级反应动力学方程表达,反应活化能为29 173 J/mol,指前因子为1026 min-1。     

水泥水化热测定方法综述

水泥水化热是中、低热水泥和核电工程用水泥的一项关键的技术指标。全球范围内测定水泥水化热的方法有溶解法、直接法/半绝热法、等温传导量热法三种。本文总结了中、美、欧相关方法标准,对其测试原理、仪器设备、试验过程等方面进行了比对,并对其在领域的应用做了简单的概括。     

谈化学教学过程中哲学观点的应用

高职阶段学生的辩证逻辑思维开始占优势，在化学教学过程中贯彻应用哲学观点既有利于学生辩证逻辑思维的开发，又能更好地掌握化学学科的思想精髓。     

Synthesis of fine powders of KTP-group compounds of stoichiometric composition

Precipitation of crystalline monophase nanopowders (50-100 nm in diameter) of stoichiometric binary orthophosphates of titanyl and alkaline metal in aqueous solutions has been studied. It has been shown that, in the formation of those powders, titanyl hydrophosphate can be used as a precursor. Rising temperature and alkaline ion concentration in the solution decrease the size of the powder grains, while elongating the exposure of the synthesized solid phase in the suspension increases grain sizes. An effective technique to synthesize fine-dispersed powders of monophase stoichiometric binary orthophosphates of titanyl and alkaline metal has been developed.     

Analysis of products of high-temperature pyrolysis of various hydrocarbons

Ethane, ethylene, acetylene, propane and neopentane have been pyrolyzed at 1173 K, and methane at 1372 K in a flow system, and the volatile pyrolysis products analyzed. Eleven aromatic hydrocarbons, containing 14 or fewer carbon atoms, accounted for 98 + % of the liquid products recovered in each case. Benzene was the main product, followed by naphthalene. No compounds with branched chains or multiple substituents were present, and compounds containing even numbers of carbons comprised 93–99% of each mixture. Acetylene was a major component of the gaseous effluent from each of the initial hydrocarbons. The effect of temperature on the composition of the gaseous effluent during pyrolysis of methane, ethane and ethylene was determined. Carbon film deposition from methane commenced at about 1273 K; from ethane at 1015 K and from ethylene at 1100 K, in each instance coinciding with the appearance of acetylene in the effluent. As the temperature was raised, at first the increase in the rate of carbon deposition closely followed the increase in the concentration of acetylene in the effluent. It is proposed that acetylene may be a common factor in the pyrolysis of aliphatic hydrocarbons, perhaps acting as the precursor of both surface carbon and aromatic hydrocarbons by a process of head-to-tail linkage of two-carbon units at active surface sites to form chains that then undergo dehydrogenation to carbon or cyclization and desorption as aromatic species.     

Kinetics of Dehydration of Green Alfalfa

Artificial drying is an important step in processing of green crops in order to preserve their freshness and nutrients for longer time at relatively lower costs. Forage crops, tea and tobacco are the major green crops where the commercial drying is a major operation in their processing. Fresh green alfalfa at about 75 to 80% moisture is subjected to drying in different types of dryers.ln the case of alfalfa, the raw material consists of leaves, stems, chops and fine stems, each varying distinctly in their physical and structural characteristics. The moisture content is reduced from initial level to about 10%. The drying air temperatures range from 40 b 800°C; the lower temperatures are used inconveyor dryers whereas high temperatures are used in rotary drum drycn.The results on drying behavior, and changes in physico-chemical propedes during drying for components of green alfalfa over the temperature range of 40 m 800°C are presented in this paper. The optimum temperature for drying from the stand point of color and protein solubility was found to be 175°C.     

Effect of shear rate on the rate of polymerization of styrene

Application of shear was found to have considerable effect on the radical polymerization of styrene initiated by benzoyl peroxide. The initial rate of polymerization decreases by as much as 30% for low shear rates (γ), but on further increasing γ it increases slightly, levelling ultimately at the 10% reduction level. The effect of solvent was shown to have negligible effect, in direct contrast to that observed by Kumar et al.^1–3 for methyl methacrylate and acrylonitrile. Experiments confirm that the reduction in the rate of initial polymerization can be attributed largely to the change in initiator efficiency on the application of shear rate. As a further test, the decomposition rate of benzoyl peroxide in nitrobenzene at 80°C was measured and was found to increase significantly on application of shear. This confirms the importance of mass transfer resistance in removal of CO₂. The reduction in the rate of polymerization of styrene can now be explained as follows. In the reaction mass, there are benzoyloxy as well as phenyl radicals and styrene molecules have been shown by Bevington⁴ to react preferentially with the former. The fall in the rate of polymerization of styrene occurs because, on the application of shear, decomposition of benzoyloxy radicals is favoured in the forward direction and its concentration in the reaction mass falls. As a result the initiation of polymer radicals reduces, which in turn gives a lower rate of polymerization.