70％H2SO4回硫酸生产系统提浓的操作与控制

稀硫酸腐蚀性强,硫酸法—浓硝酸工艺采用98%H2SO4脱除硝酸中的水,产生了大量的稀硫酸须予以处理。介绍了用稀硫酸作为硫酸生产装置干吸工序补充水,在提浓的同时又提高了装置的硫酸产量,提出了使用稀硫酸时的操作程序和应注意的问题。     

70%H2SO4回硫酸生产系统提浓的操作与控制

稀硫酸腐蚀性强,硫酸法-浓硝酸工艺采用98%H2SO4脱除硝酸中的水,产生了大量的稀硫酸须予以处理.介绍了用稀硫酸作为硫酸生产装置干吸工序补充水,在提浓的同时又提高了装置的硫酸产量,提出了使用稀硫酸时的操作程序和应注意的问题.     

浓硝酸氧化处理烷基化废硫酸再生研究

采用浓硝酸氧化处理烷基化废硫酸,考察反应温度、浓硝酸投加量及投加方式等因素对烷基化废硫酸溶液色度、COD去除率、再生硫酸含量和硫酸回收率等指标的影响。结果表明,加入浓硝酸对废硫酸色度值和COD去除率影响显著,在250℃条件下,按0.1 m L/次加入体积分数为2%的浓硝酸,反应2 h后,废硫酸溶液的色度值降到1度,COD去除率达到99.0%,得到无色透明的再生硫酸,质量百分含量达97.5%,回收率为76.8%。通过该方法回收得到高浓度的再生硫酸,可回用到烷基化装置或其他工业。     

浓硝酸氧化处理烷基化废硫酸再生研究

采用浓硝酸氧化处理烷基化废硫酸,考察反应温度、浓硝酸投加量及投加方式等因素对烷基化废硫酸溶液色度、COD去除率、再生硫酸含量和硫酸回收率等指标的影响。结果表明,加入浓硝酸对废硫酸色度值和COD去除率影响显著,在250℃条件下,按0.1 m L/次加入体积分数为2%的浓硝酸,反应2 h后,废硫酸溶液的色度值降到1度,COD去除率达到99.0%,得到无色透明的再生硫酸,质量百分含量达97.5%,回收率为76.8%。通过该方法回收得到高浓度的再生硫酸,可回用到烷基化装置或其他工业。     

浓硝酸生产中稀硝酸与浓硝酸镁比例的调节

浓硝酸生产中稀硝酸与浓硝酸镁比例的调节余一心（济南化肥厂山东济南市２５０１０１）济南化肥厂于１９９１年建成两套年产万吨浓硝酸装置，采用硝镁法生产浓硝酸。投产后产品质量不稳定，浓度在９７％上下波动，产量达不到设计要求，且稀硝酸镁中含硝高，造成稀硝酸消耗...     

硝酸镁法浓硝酸工艺技术及装置大型化探讨

比较了浓硝酸生产的几种方法,介绍了浓硝酸主流工艺硝酸镁法制浓硝酸三元相图的实际应用情况及技术革新成果。提出了浓硝酸装置大型化的思路,建议先建设5万t/a的示范装置,并对其工艺技术、设备材质以及规格选型和计算,进行认真分析研究,为建设10万t/a、15万t/a大型装置奠定基础,以提升我国浓硝酸生产水平。     

浓硝酸、硝盐生产中废水处理方法探讨

探讨了硝法浓硝酸、硝酸铵、硝酸钠和亚硝酸钠工业生产废水的处理方法:①利用间硝法浓硝酸生产中排出的2.5%酸水代替浓度为30%的盐酸用于450 t/h一级除盐水装置;②采用膜分离法,将硝铵废水经膜分离处理,浓水回收返回生产系统,淡水作为锅炉用水或循环水的补充水。通过生产运行数据总结了废水处理效果。结果表明,把废水处理与回收利用、产品回收相结合的废水处理方法,可以达到节能和零排放的目的。     

浓硝酸生产中酸性水的回收利用

在硝镁法浓硝酸生产过程中会产生大量酸性水,其中大部分排入中和池,用碱中和达标后排放,损耗较大.针对这一问题,对装置进行了优化,合理回收利用酸性水代替吸收塔塔顶的工艺水.优化改造后,年节约工艺水10.64 kt,增产稀硝酸1 290.20 t(折质量分数100％硝酸819.28 t),同时降低了中和碱耗量,尾气中氮氧化物...     

反渗透浓水回收利用技术的改造

<正>1反渗透装置现状安徽晋煤中能化工股份有限公司(以下简称中能公司)现有1套300 t/h脱盐水装置,工艺采用预处理+反渗透+EDI,反渗透为100 m3/h×3组合,系统回收率75%,单套反渗透系统产纯脱盐水量100 m3/h,浓水排放量为33～34 m3/h,整套反渗透系统浓水排放量约为102 m3/h。每套反渗透系统的浓水在浓水排放阀截流之前压力达     

浓硝酸高产、优质、降耗经验总结

0前言 浓硝酸的工业生产方法有直接法和间接法。而间接法中以硝酸镁为脱水剂的镁法生产是当今生产浓硝酸最经济、安全的方法。我厂浓硝酸生产即采用该方法。在我厂近40a的浓硝酸生产过程中，经过不断摸索、总结和对生产装置的改进以及对工艺参数的调整，使浓硝酸产品浓度完全符合甚至超过了国家标准（≥98．0％），产品中的亚硝酸含量只有国家标准（0．5％）的1／10左右，灼烧固体残渣含量远远低于国家标准（0．02％），     

Fatty acid monoesters of 1-ascorbic acid and d-isoascorbic acid

Summary Fat-soluble fatty acid monoesters of 1-ascorbic acid (vitamin C) and d-isoascorbic acid have been prepared from lauric, myristic, palmitic, and stearic acids in 40–50 per cent yields. Evidence has been presented to show that only the primary hydroxyl group of each of the ascorbic acids has been esterified. Antioxidant properties of these esters are being studied. Preliminary tests on the esters have indicated that they may have useful properties as interfacial modifiers.     

Electrosynthesis of 2,3-dimethyltartaric acid from pyruvic acid in acid medium

This study reports the electrohydrodimerization of pyruvic acid to 2,3-dimethyltartaric acid in sulphuric acid medium (0.5 M H₂SO₄) on a lead cathode. The main products detected were lactic acid and 2,3-dimethyltartaric acid. The selectivity towards the formation of 2,3-dimethyltartaric acid was studied vs. pyruvic acid concentration in sulphuric acid solution, at −1.1 V vs. MSE. The best selectivity of 2,3-dimethyltartaric acid reached 69% for an initial concentration of 1.7 M pyruvic acid. The yield of pyruvic acid was 84%.     

Conjugated linoleic acid production from linoleic acid by lactic acid bacteria

After screening 14 genera of lactic acid bacteria, Lactobacillus plantarum AKU 1009a was selected as a potential strain for CLA production from linoleic acid. Washed cells of L. plantarum with high levels of CLA production were obtained by cultivation in a nutrient medium with 0.06% (wt/vol) linoleic acid (cis-9,cis-12-octadecadienoic acid). Under the optimal reaction conditions with the free form of linoleic acid as the substrate, washed cells of L. plantarum produced 40 mg CLA/mL reaction mixture (33% molar yield) from 12% (wt/vol) linoleic acid in 108 h. The resulting CLA was a mixture of two CLA isomers, cis-9,trans-11 (or trans-9,cis-11)-octadecadienoic acid (CLA1, 38% of total CLA) and trans-9,trans-11-octadecadienoic acid (CLA2, 62% of total CLA), and accounted for 50% of the total FA obtained. A higher yield (80% molar yield to linoleic acid) was attained with 2.6% (wt/vol) linoleic acid as the substrate in 96 h, resulting in CLA production of 20 mg/mL reaction mixture [consisting of CLA1 (2%) and CLA2 (98%)] and accounting for 80% of total FA obtained. Most of the CLA produced was associated with the cells (ca. 380 mg CLA/g dry cells), mainly as FFA.     

乳酸催化制备丙烯酸反应液中乳酸和丙烯酸含量的联合测定

以正丁醇为内标,氢火焰离子化检测器测定,建立了气相色谱法直接进样测定乳酸催化制备丙烯酸反应液中乳酸和丙烯酸含量的方法。在载气（N2）流速为30mL·min^-1,氢气流速为88mL·min^-1,空气流速为300mL·min^-1,进样器和离子室温度为160℃,柱温为150℃的10％PEG-20M（3m×3mml填充柱上能实现很好的分离。乳酸和丙烯酸测定方法的线性相关系数分别为0．9994和0．9996,相对标准偏差分别为O．74％和0．56％,平均回收率分别为97．35％-1197．60％,检出限分别为8．62mg·L^-1和1．21mg·L^-1方法简便、快速、准确。     

由氯乙酸副产盐酸精制高纯盐酸

开发研究了氯乙酸副产盐酸的精制工艺及盐酸中有机杂质的紫外分光光度分析方法。副产盐酸经酸洗、吸收、蒸馏得高纯盐酸。中试结果表明 ,工艺合理 ,精制盐酸达到GB 32 0 - 93规定的工业用合成盐酸标准     

炼厂酸性气制取硫酸生产总结

介绍炼厂酸性气制硫酸装置的工艺过程。由于实供气源与设计值有较大出入,二氧化碳浓度偏高, 并且夹带烃类物质较多,使装置无法正常运行。通过对酸性气进行预处理后,一次开车成功,各项工艺指标均达到设计要求,遇酸性气流量突降时可补充适量硫磺,维持正常生产。     

The performic acid oxidation of linoleic acid

The performic acid oxidation of linoleic acid has been shown to form 9,12-dihydroxy-trans-10,11-methylene-heptadecanoic acid (I) after hydrolysis of the formate ester. A sequence of reactions led to the identification of dimethyl-trans-1,2-cyclopropanedicarboxylate by gas liquid chromatography. Spectroscopic evidence is presented for thetrans geometry in I. Failure of the monoepoxide of linoleic acid to give the formate ester of I suggests the alternative that a homoallylic carbonium ion is formed directly upon attack of the peroxide reagent.     

Electrosynthesis of iminodiacetic acid from nitrilotriacetic acid

The electrosynthesis of iminodiacetic acid by electrooxidation of nitrilotriacetic acid in undivided cells has been studied using Zn, Cu, PbO₂, DSA^®O₂, DSA^®Cl₂, C, Ni and porous carbon as anodes. Results show that the synthesis is possible in both acid and basic mediums. The best results were obtained in aqueous 40% w/w sulphuric acid with porous carbon RVC-4000 as anode and SUS 316 as cathode, at 60 °C, 400 mA cm^-2 and charge 95% of theoretical. Under these conditions, nitrilotriacetic acid conversion was 92%, current efficiency 80% and selectivity 85%. Loss of selectivity was due to chemical side reaction between iminodiacetic acid and HCHO electrogenerated in the electrolysis.     

液相色谱法测定氯乙酸中乙酸、二氯乙酸的含量

提出了液相色谱法测定氯乙酸中乙酸和二氯乙酸含量的分析方法,计算出氯乙酸的含量,并与现行工业氯乙酸国标分析方法进行了比较,证明液相色谱分析方法简洁、快速,分析结果准确,在氯碱行业具有推广运用的价值。