氯乙酸副产盐酸除硫酸根方法探讨

氯乙酸作为重要的化工原料，广泛应用于农药、医药、有机合成中，目前国内生产氯乙酸多采用冰醋酸加热通氯气制得。在氯化过程中，采用不同的催化剂硫磺或醋酐，其产生的尾气氯化氢被吸收为副产工业盐酸进行销售。我公司采用硫磺作催化剂，发现副产酸中有硫磺析出，并且含有硫酸根，经分析化验含量为1．2％-1．5％。硫酸根含量高造成净水剂行业用酸大户无法很好应用。为了降低硫酸根含量提高其品质以扩大产品销路，我们查阅了大量相关资料，制定合理的实验方案，并做实验如下：     

氯乙酸副产盐酸除硫酸根方法探讨

探讨了去除氯乙酸副产盐酸中的硫酸根的方法，确认了用氯化钙法去除硫酸根是有效的，并将其应用到工业生产中。     

氯化石蜡副产盐酸精制的研究

针对氯化石蜡副产盐酸的特点,采用不同过滤介质进行精制试验,并在此基础上对 该工艺进行了经济技术评价。     

氯乙酸副产盐酸中二氧化硫的脱除方法研究

氯乙酸企业生产过程中副产大量盐酸,由于含硫杂质质量分数较高,所以应用范围很窄,成为企业面临的一大难题。笔者采用氯气氧化的方法将二氧化硫氧化为硫酸,然后用碳酸钡沉淀除去硫酸。着重探讨了氯气通入速率、氯气氧化时间、碳酸钡加入量及反应时间对盐酸中硫质量分数的影响。实验结果表明:最佳反应条件为氯气空速为1.8~2.4 h-1,反应时间为100~120 min,加入碳酸钡的量为n(BaCO3)∶n(SO2)=1.1~1.2,反应时间为60~80 min,脱硫率最高达95.8%。     

氯乙酸副产盐酸的处理和利用

介绍了利用氯气氧化氯乙酸副产盐酸中的亚硫酸等还原性物质,处理后的盐酸可以满足草甘膦的生产.     

氯乙酸生产副产盐酸中SO2的消除

介绍了采用氧化法解决氯乙酸生产中盐酸吸收管道的堵塞问题的技术改进措施。     

氯乙酸副产气中总硫含量间接分光光度法测定

研究了铬酸钡分光光度法应用于氯乙酸副产混合气中总硫含量测定的实例。探讨了气体采集、样品溶液处理和铬酸钡悬浮液配制等关键问题。硫元素经碱液吸收和双氧水氧化完全转化为硫酸根,硫酸根再与铬酸钡悬浊液反应,定量置换出铬酸根,溶液的吸光度即与硫酸根的浓度成正比。该方法的测定波长为372 nm,硫酸根质量浓度在0～10 mg/L线性关系好。该方法操作简单,精密度和准确度均符合测定要求,适用于工厂气体的实时监测。     

实验室精制高透光率石油醚

在实验室中使用浓硫酸和高锰酸钾除去石油醚中含有的少量不饱和烃,通过重蒸馏获得高透光率纯无水石油醚。     

利用氯乙酸尾气生产盐酸乙脒

1 前言盐酸乙脒是制造维生素B_1的重要中间体。国内盐酸乙脒的生产厂家较少,主要分布在天津、上海、山东和南通等地。近年来维生素B_1在养殖行业得到了应用,产量呈上升趋势,     

氯化苄副产盐酸的精制

氯化苄是一种重要的医药、化工中间体,随着其产量的提升,尾气吸收产生的副产物盐酸也大量增加。该盐酸中含有的部分甲苯会影响盐酸品质。介绍了氯化苄尾气生产盐酸的现状,着重探究了在工业上,采用大孔径树脂吸处理副产盐酸中甲苯的技术,这样即能得到合格的盐酸又能回收部分甲苯,进而降低生产成本。     

氯乙酸生产中副产盐酸能否作为盐水中和用酸的论证

对氯乙酸生产中副产盐酸能否作为盐水中和用酸的问题进行了探讨,通过理论论证得出,为了电解槽及膜的安全,该副产酸不能作为盐水中和用酸.     

工艺气体分析仪在氯乙酸生产中的应用

简介了工艺气体分析仪在氯乙酸生产中的应用。     

Production of FAME from acid oil,a by-product of vegetable oil refining

Simple alkyl FA esters have numerous uses, including serving as biodiesel, a fuel for compression ignition (diesel) engines. The use of acid-catalyzed esterification for the synthesis of FAME from acid oil, a by-product of edible vegetable oil refining that is produced from soapstock, was investigated. Soybean acid oil contained 59.3 wt% FFA, 28.0 wt% TAG, 4.4 wt% DAG, and less than 1% MAG. Maximum esterification occurred at 65°C and 26 h reaction at a molar ratio of total FA/methanol/sulfuric acid of 1∶15∶1.5. Residual unreacted species under these conditions, as a fraction of their content in unesterified acid oil, were FFA, 6.6%; TAG, 5.8%; and DAG, 2.6%. This corresponds to estimated concentrations of FFA, 3.2%; TAG, 1.3%; and DAG, 0.2%, on a mass basis, in the ester product. In an alternative approach, the acylglycerol species in soapstock were saponified prior to acidulation. High-acid (HA) acid oil made from this saponified soapstock had an FFA content of 96.2 wt% and no detectable TAG, DAG, or MAG. Optimal esterification conditions for HA acid oil at 65°C were a mole ratio of FFA/methanol/acid of 1∶1.8∶0.17, and 14 h incubation. FAME recovery under these conditions was 89% of theoretical, and the residual unesterified FFA content was approximately 20 mg/g. This was reduced to 3.5 mg/g, below the maximum FFA level allowed for biodiesel, by washing with NaCl, NaHCO₃, and Ca(OH)₂ solutions. Alternatively, by subjecting the unwashed ester layer to a second esterification, the FFA level was reduced to less than 2 mg/g. The acid value of this material exceeded the maximum allowed for biodiesel, but was reduced to an acceptable value by a brief wash with 0.5 N NaOH.     

副产盐酸脱析工艺的应用

介绍了副产盐酸脱析原理、工艺流程及操作条件。对设备及工艺在运行中出现的问题提出了改进意见。     

无灰分散剂副产盐酸的汽提精制实验报告

以瓷质拉西环为填料,采用空塔线速度００５～０１５ｍ／ｓ,汽提温度７０～８０℃,气液（体积）比为１３０∶１～１６０∶１的操作条件下,可使无灰分散剂副产盐酸中２－氯－２－甲基丙烷等有机物杂质含量从１５×１０－４脱除到（１２±３）×１０－６,脱除率达９０％以上。     

甘草酸及甘草黄酮类物质的提取、精制和应用的研究进展

随着甘草酸和甘草黄酮类物质在药理研究中的新发现,尤其在治疗SARS方面的可能应用,使其提取和精制具有重要的意义。对甘草酸和黄酮类物质的各种提取、精制方法进行了归纳和总结,指出优缺点,并对有效物质的应用现状及发展前景进行了简述。     

Dissolution kinetics of periclase in dilute hydrochloric acid

Kinetics of the reaction between particulate sintered polycrystalline MgO and dilute hydrochloric acid were studied. The effects of process parameters, i.e., concentrations of H⁺ and Mg²⁺ ions, temperature and particle size were investigated. It was observed that the rate of chemical dissolution of MgO: (a) increased with increase in both HCl concentration (from 10^-4 to ) and temperature (from 25 to ); (b) decreased with increase in particle size (from 63 to ); (c) was not affected by Mg²⁺ ion concentration. Thorough comparison of our results with those published by other authors revealed that the “initial” stage of MgO dissolution has never been observed under the conditions of the experiments in the present work. It was concluded that the initial stage of MgO dissolution was probably too short to be detected and just the “advanced” kinetic regime was investigated. Values of the kinetic parameters were calculated, and apparent activation energy between 93 and and the reaction order for H⁺ ions from 0.41 to 0.76 were obtained. The presented values of the reaction order for H⁺ ions are consistent, allowing for experimental error, with current kinetic theories and most of other experiments. However, the rate-controlling step could not be assigned unambiguously, because the same value of the reaction order for H⁺ ions can be predicted by various theories for different rate-determining steps. The broad variety of likely rate-determining steps indicates some intrinsic diversity in current kinetic models.     

Corrosion inhibition of carbon steel in hydrochloric acid by some polyethylene glycols

The inhibition effect of some PEGs on carbon steel corrosion at 25 °C in 0.5N hydrochloric acid as corroding solution was evaluated by weight loss method and polarization and electrochemical impedance spectroscopy (EIS) techniques. In order to study the effect of polyethylene glycols’ structure on the inhibition efficiency, different molecular weights (400, 1000, 4000, and 10,000 g mol⁻¹) were selected. This work has demonstrated that polyethylene glycols have inhibition effect on corrosion process and their inhibition efficiencies are between 50 and 90%. The inhibition efficiencies are increased by increase of the inhibitors’ concentration and molecular weight.