国内信息

国内信息二甲基二氯硅烷恒沸酸水解工艺技术开发成功吉化集团公司研究院开发成功的二甲基二氯硅烷恒沸酸水解工艺技术成果，日前正式通过专家验收。二甲基二氯硅烷恒沸酸水解技术经全面系统的小试工艺研究和百吨级中试，确定了有关参数，完成了１８ｋｔ／ａ有机硅生产装置...     

二甲基二氯硅烷水解工艺研究进展

综述了二甲基二氯硅烷水解工艺的研究进展,包括恒沸酸水解工艺、饱和酸水解工艺和浓酸水解工艺.着重介绍了各种水解工艺在氯化氢回收利用上的改进,通过对各水解工艺优缺点的探讨,展望了二甲基二氯硅烷水解工艺的发展方向.     

二甲基二氯硅烷浓酸与恒沸酸水解方法比较

聚二甲基硅氧烷主要由二甲基二氯硅烷水解制得,介绍了二甲基二氯硅烷水解的两种方法,即浓酸水解法与恒沸酸水解法,以60 kt/a二甲基二氯硅烷水解为例,对两种水解工艺过程的用能、设备投资、占地投资等进行了计算分析。结果表明,浓酸水解方法具有成本低、能耗低、流程短等优点,将逐渐取代恒沸酸水解方法成为聚硅氧烷生产的新的发展趋势。     

二甲基二氯硅烷恒沸酸水解工艺技术开发成功

由吉化集团公司研究院开发成功的二甲基 二氯硅烷恒沸酸水解工艺技术成果,日前正式通过专家验收。     

对氨基-β-苯乙醇的制备研究

研究了苯乙醇用乙酸酯化、用混酸硝化、水解和催化氢化还原制备对氨基-β-苯乙醇的工艺。50g苯乙醇与30g乙酸、0．5mL浓硫酸和50g苯恒沸脱水酯化，用50g混酸(硝酸／浓硫酸=1：1)在-5～0℃硝化4h，用20％NaOH水解，然后催化氢比还原并分离出对氨基-β-苯乙醇26．7g，总收率48．2％．纯度98．4％。     

燃料乙醇热泵恒沸精馏新工艺的研究

为解决传统燃料乙醇生产过程中能耗大的问题，将热泵技术与传统恒沸精馏工艺相结合，开发出热泵恒沸精馏生产新工艺。在分析传统恒沸精馏生产无水酒精工艺方法的基础上，重点分析了燃料乙醇热泵恒沸精馏新工艺的原理、优点和能耗问题。结果表明，热泵恒沸精馏技术节约生产过程能耗56％，显著优于传统恒沸精馏生产工艺。     

脱除二甲基二氯硅烷恒沸盐酸水解副产物盐酸中的硅氧烷的方法

概述了脱除二甲基二氯硅烷恒沸盐酸水解副产物盐酸中的硅氧烷的基本方法——活性炭吸附法、聚苯乙烯基树脂吸附法和膜分离法，比较了活性炭吸附法与聚苯乙烯基树脂吸附法的效果，并对如何更好地处理二甲基二氯硅烷恒沸盐酸水解副产物盐酸中的硅氧烷提出了建议。     

棕榈酸异丙酯的合成

以SO42-/ZrO2作催化剂,环己烷作恒沸带水剂,经过回流、恒沸脱水、常压蒸馏、过滤和减压蒸馏等工艺,棕榈酸与异丙醇直接酯化合成了棕榈酸异丙酯。合适的工艺条件是 90±5℃、5h、n(异丙醇)∶n(棕榈酸)=1.5、m(环己烷)∶ m(异丙醇)=0.3、m(催化剂)∶ m(棕榈酸)=0.005。酯化率>98%,产率>96%。     

其他

中油吉林石化公司重点产业化项目 氯化氢循环利用技术通过验收 一项具有国内领先水平的科研新成果——有机硅恒沸酸水解氯化氢回收产业化项目,由吉林石化公司研究院开发成功,并在国内万吨级生产装置上首先实现了产业化,不久前正式通过专家鉴定验收。     

氯化氢循环利用技术通过验收

吉林石化公司研究院开发成功的有机硅恒沸酸水解氯化氢回收技术,在万吨级生产装置上实现了产业化,日前正式通过专家鉴定验收。 　　在有机硅生产过程中,能够有效地实现氯资源的循环利用,不仅能解决氯资源紧张问题,而且还能解决环保问题。这对于降低有机硅产品的成本,减轻环境污染,提高有机硅工业整体技术水平和经济效益有着重要意义。 　　吉化电石厂根据有机硅生产装置废酸量过多,达不到环保要求,氯资源未能很好利用等问题,与吉化研究院协作,开发出利用加热加速析出硅氧烷的创新技术,结合传统的沉降分离工艺,有效地去除出了浓酸中的硅氧烷;实现了恒沸酸水解产生浓酸、浓酸解吸产生氯化氢、氯化氢循环使用的工艺。每年可利用废酸21 kt,有效地解决了环保问题,同时又解决了厂内氯平衡问题。 　　该工艺路线的硅氧烷脱除率在80%以上;其解吸的氯化氢用于合成氯甲烷,对选择性、甲醇利用率等指标无影响,形成了氯化氢闭合循环。该项目投资少、见效快,在吉化电石厂万吨级有机硅生产装置上使用后,较彻底地解决了有机硅装置的稀酸排放问题,大大改善了环境,每年减少了15 kt的废酸排废量,且可回收1 500 t的氯化氢,年创效益可达150万元以上,具有显著的经济效益和社会效益。 　　 (张晓君)     

钛液水解工艺对偏钛酸性能的影响

采用外加晶种常压水解法制备偏钛酸,使用激光粒度仪分析偏钛酸的粒度分布,通过沉降高度和洗涤时间判断偏钛酸的过滤性能。考察了晶种加入量、变灰点时间、钛液浓度、二次沸腾保温时间对偏钛酸粒度分布及其过滤性能的影响。结果表明：晶种加入量、钛液浓度和二次沸腾保温时间对偏钛酸性能有显著影响,晶种加入量越大、钛液浓度越低、水解速度就越快,变灰时间越短,得到的偏钛酸的粒度分布也越宽,过滤性能越差。延长二次沸腾保温时间可以使偏钛酸粒度分布更窄,粒子更均匀。     

水解偏钛酸粒度分布影响因素分析

以攀枝花某钛白粉厂的工业硫酸氧钛浓钛液为原料,采用外加晶种水解工艺制备水解偏钛酸,通过检测钛液水解过程中浆料透过率的变化间接检测水解过程反应速率的变化,通过分析水解过程不同时间段的偏钛酸粒度分布,确定了影响偏钛酸粒度分布的主要因素。在此基础上考察了钛液浓度、F值、铁钛比、水解晶种加量、熟化搅拌时间对偏钛酸粒度分布的影响。结果表明钛液沸腾后快速水解,再随钛液浓度降低水解速率逐渐降低,浆料粒度逐渐长大,二次沸腾20 min后,浆料的粒度分布逐渐稳定,后期保温过程对粒度分布影响不大;钛液浓度、铁钛比、F值、晶种加量和熟化期间搅拌时间均对偏钛酸粒度分布有影响,D50随着钛液浓度的增加而减小,随F值和铁钛比的增大而增加,随着晶种加量的增加而减小,随熟化期搅拌时间的延长而降低。     

Process alternatives for methyl acetate conversion using reactive distillation. 1. Hydrolysis

In a polyvinyl alcohol (PVA) plant, reaction stoichiometry indicates that equal molar of methyl acetate is generated for every mole of PVA produced. This work explores an alternative to convert methyl acetate back to acetic acid (raw materials of PVA plant), methyl acetate (MeAc) hydrolysis. The design and control of methyl acetate hydrolysis using reactive distillation is studied. Because of the small chemical equilibrium constant (∼0.013) and unfavorable boiling point ranking (MeAc being the lightest boiler), the reactive distillation exhibits the following characteristics: (1) total reflux operation and (2) excess reactant (water) design. The proposed flowsheet consists of one reactive distillation column with a reactive reflux drum, two separation columns, and one water-rich recycle stream. A systematic design procedure is used to generate the flowsheet based on the total annual cost (TAC). Two dominate design variables are: recycle flow rate (for the degree of excess in water) and the overhead impurity level of acetic acid in the product column (to avoid tangent pinch). Finally, the operability of the hydrolysis plant is evaluated. A plantwide control structure is developed followed by process identification and controller tuning. The results show that reasonable control performance can be achieved using simple temperature control for feed flow and feed composition disturbances.     

多晶单斜氧化锆颗粒的水解法合成

利用透射电子显微镜研究了在一密闭容器内恒沸条件下氧氯化锆溶液中所形成的产物的聚合长大过程。结果发现：在不同浓度的氧氯化锆溶液中于恒沸过程先形成微细的子晶核，子晶核再通过聚合作用长大成具有一定大小、一定形状的单斜氧化锆颗粒。尿素的添加对产物的聚合长大过程起了促进作用。     

玉米芯水解制备木糖的研究

文章对玉米芯酸性水解制备木糖的工艺条件进行了研究。以硫酸作为催化剂,考察了不同的反应温度、酸浓度、反应时间、固液物料比及浓缩次数对木糖产率的影响。得出最佳的制备木糖的工艺条件为:酸浓度为3%、反应时间3小时、物料比1∶8、沸腾浓缩3次,该条件下木糖收率可达49.74%。     

3-丁烯腈在盐酸催化剂溶液中的水解动力学研究

以盐酸为催化剂,通过水解3-丁烯腈合成3-丁烯酸,考察了3-丁烯腈初始浓度、反应温度、盐酸浓度对水解反应过程的影响;在此基础上,研究了3-丁烯腈水解动力学,拟合出了反应速率常数和反应活化能。结果表明,该反应为1级串连反应,同时盐酸浓度对水解反应速率常数有很大的影响:当盐酸的浓度低于5.0 mol/L时速率常数的关系为k1k2;且随着盐酸浓度的增大,腈水解反应活化能逐渐减小。     

New method for hydroxylating long-chain unsaturated fatty acids,esters, alcohols,and hydrocarbons

Summary A new method for hydroxylating long-chain unsaturated compounds is described which involves addition of formic acid at its boiling point to the double bond followed by hydrolysis of the intermediate formate esters. The addition reaction proceeds slowly in the absence of catalysts, but strongly acidic substances, such as perchloric acid, sulfuric acid, and boron fluoride-acetic acid complex, speed up the addition tremendously. Monohydroxystearic acids can be prepared in good yield by addition of 90–100% formic acid to the double bond of oleic or elaidic acids, methyl oleate, or the unreacted olefinic material separated from the hydrolyzed reaction product of oleic acid with formic acid, followed by hydrolysis. Similarly prepared are dihydroxyoctadecanes from oleyl alcohol, monohydroxyoctadecenoic and dihydroxystearic acids from linoleic acid, monohydroxyhendecanoic acids (isolated as methyl esters) from 10-hendecenoic (undecylenic) acid, and secondary hexanols from 1-hexene. Triglycerides are readily formylated if a small amount of mutual cosolvent is employed. Acetic acid in the presence of acidic catalysts also adds to the double bond at its normal boiling point, but yields are lower than with formic acid. Presented at the Fall Meeting of the American Oil Chemists’ Society, Cincinnati, O., Oct. 20–22, 1952. One of the laboratories of the Bureau of Agricultural and Industrial Chemistry, Agricultural Research Administration, U. S. Department of Agriculture.     

Effect of recycle and feeding method on batch reactive recovery system of lactic acid

Reactive batch distillation coupling esterification and hydrolysis was studied for the recovery of lactic acid. The analysis of the dynamic behavior of the system showed drastic change of esterification reaction rate in the reboiler due to the difference of volatility and component boilup rate of each species. Methanol recycle and feeding method were investigated as the factors which could control the compoent boilup rate of each species and rate of esterification reaction. The flow rate and composistion of methanol recycle stream was controlled by the temperature of the partial condenser. A temperature slightly higher than the methanol boiling point is optimum as the temperature of the partial condenser. When the temperature of the partial condenser was increased in the initial part of whole batch time and decreased in the latter part, the performance of the system was enhanced, compared with when the partial condenser temperature remained constant. Semibatch operation was compared with batch operation. Continuous feeding of methanol enhanced the recovery system performance while continuous feeding of lactic acid aqueous solution deteriorated, compared with batch operation. This paper is dedicated to Dr. Youn Yong Lee on the occasion of his retirement from Korea Institute of Science and Technology.     

Effects of operation variables on the recovery of lactic acid in a batch distillation process with chemical reactions

In this study, the feasibility of recovery of lactic acid by batch reactive distillation using cation exchange resin as a catalyst was investigated. For the recovery of lactic acid, two reactions, esterification and hydrolysis, are involved and hence, an apparatus with two distillation columns was developed and operated in a batch mode to ensure enough residence time in the reboiler and column. The effects of operation variables such as catalyst loading, reactant mole ratio, feed concentration, type of alcohols and partial condenser temperature on the yield were studied. In this study, the reaction products of the esterification (methyl lactate and water) were distilled to the hydrolysis part to be recovered into pure lactic acid. The yield of lactic acid increased as catalyst loading in the esterification part increased and reactant mole ratio and feed lactic acid concentration decreased. Methanol as a reactant gave higher yield than any other alcohols. The yield of recovered lactic acid was as high as 90%. The yield of lactic acid was closely related to the boiling temperature of the reaction mixture in the esterification part     

Model for Continual Depolymerization of Biomass Catalyzed by Dilute Sulfuric Acid

Ethanol fuel from biomass is conventionally produced via the hydrolysis of biomass catalyzed by acid. In this paper, it is understood that the degree of polymerization of cellulose is randomly distributed and that the rupture of β‐1,4‐glucosidic bonds during acidic hydrolysis of cellulose is a process of continual depolymerization. From this perception, a model is established for the continual depolymerization of cellulose catalyzed by acid. Meanwhile, analog computation resulted in the activation energy and the reaction rate constant related to the rupture of β‐1,4‐glucosidic bonds. The established model is highly validated by test runs and thus assumed as a model that can be used to describe the depolymerization route taken in acidic hydrolysis of cellulose. The calculated activation energy and rate constant for the rupture of β‐1,4‐glucosidic bonds correspond to the rule of acidic hydrolysis of cellulose. Investigation of the model is of great significance in further studies on the hydrolysis mechanism of cellulose.