甲烷制卤代甲烷研究进展

甲烷的化学性质很不活泼,需经中间体才能将其转变成高附加值的化工产品。以卤代甲烷为中间体具有能耗低的优势,是一种潜在的甲烷活化方式。综述国内外甲烷制卤代甲烷研究进展,主要介绍不同卤素源条件下的反应机理及催化剂性质、反应条件对单卤代甲烷选择性的影响。甲烷经氯代甲烷活化时,产物中一氯甲烷选择性与催化剂性质密切相关,亲电型催化剂能高选择性生成一氯甲烷;甲烷经溴代甲烷活化时,贵金属和非贵金属均可作为催化剂活性中心,且该反应可以根据后续产物的需要,调节产物组成和比例。甲烷溴代反应单卤代产物选择性高于甲烷氯代反应,但溴代反应需在较高温度进行。     

三氯乙醛尾气回收的探讨

近来有些资料发表了从三氯乙醛尾气中回收一氯甲烷的方法,这里做一些讨论。 工业一氯甲烷除甲烷氯化法和甲醇氯化氢化法合成外,国内很多企业采用了回收法。(1)从敌百虫副产尾气中回收;(2)天然气氯化法生产四氯化碳副产;(3)膦胺的副产物。回收法既保护了环境不受污染,又得到了经济效益,可谓两全齐美。目前,市场上销售的一氯甲烷,用回收法制得的产品占很大比例。但从三氯乙醛尾氯中回收一氯甲烷值得商酌。     

甲醇气相法联产氯代甲烷工艺特点

论述了甲醇气相催化法生产一氯甲烷以及一氯甲烷液相催化法生产二氯甲烷、氯仿和四氯化碳的工艺特点。     

甲醇法三氯甲烷装置开发设计简介

一、前言目前我国甲烷氯化物的生产方法很多,按所用的原料分,约有以下七种,即甲烷热氯化法、甲醇法、农药副产一氯甲烷氯化法、乙醛法、氯油法、二硫化碳法及废氯代烃高温氯化法等。其中除了引进的废氯代烃高温氯化法工艺技术比较先进外,国内各生产装置的工艺技术水平、设备、管道的耐腐蚀性能及生产管理     

以甲醇为原料生产甲烷氯化物的可行性

甲烷氯化物(包括—氯甲烷、二氯甲烷、氯仿、四氯化碳)是基本有机化工原料,可以生产一系列的化工产品。我国目前的甲烷氯化物总产量只有四万吨左右,远远满足不了需要。为了发展我国的氯碱工业,研究甲烷氯化物的生产是很有必要的。甲烷氯化物的生产方法主要为甲烷热氯化法和甲醇氯化法。按生产原料比例来看,甲醇法所占的比例是很大的,见下表。从表上可看出,生产一氯甲烷、二氯甲烷和三氯甲烷,在美国几乎全部以甲醇为原料,而西欧则以甲醇为主(占40～70%)甲烷为辅(占30～40%);日本甲烷为主,占50%以     

氯甲烷生产技术进展

简要介绍了甲醇氢氯化法制备氯甲烷的 3种技术路线 :气 -液相非催化法、气 -液相催化法和气 -固相催化法。分析了国内氯甲烷的生产状况并认为气 -液相催化法和气 -固相催化法是开发的重点     

用甲醇和氯气制备甲烷氯化物

用甲醇和氯气生产的甲烷氯化物,其数量是很大的。由于甲醇的利用率高、价格低廉、易于运输、生产工艺简单以及在生产中能全部或部分地平衡氯气,所以该法占有重要地位。近年来,继日本德山曹达公司的一氯甲烷液相氯化法之后,该生产工艺得到了进一步的发展。本生产工艺,包括甲醇氢氯化制取一氯     

甲醇法甲烷氯化物生产装置腐蚀机理及防腐措施

分析了在甲醇法甲烷氯化物生产过程中粗甲烷氯化液再循环系统腐蚀的机理。从一氯甲烷酸度、水分的工艺控制等角度进行了阐述,提出了防腐蚀措施。     

我国甲烷氯化物发展设想及需求预测

甲烷氯化物亦称氯甲烷,系一氯甲烷、二氯甲烷、三氯甲烷、四氯化碳的统称。甲烷氯化物用途极为广泛,除直接作溶剂、萃取剂、推进剂、致冷剂、杀虫剂、灭火剂等外,还是有机合成工业和其它工业不可缺少的原料,进一步加工还可制取合成橡胶、合成纤维、塑料、医药、农药、香料、染料、有机硅及有机氟系列产品。一氯甲烷是生产硅氧烷和其它化合物的原料(硅氧烷用一氯甲烷     

巨化集团公司年产3万吨甲烷氯化物装置的自动化水平

0引言甲烷氯化物装置最终产品是四氯化碳和氯仿，该二种产品分别是生产氟致冷剂（F22、E11、F12）的主要原料之一。该装置引进日本德山曾达技术，采用甲醇和氯为原料，甲醇气相催化氢氯化，一氯甲烷液相催化氨化的生产工艺，年产三氯甲烷16000t，四氯化碳14000t，同时每年副产纯度大于99．9％的干氯化氢10350t作为其它产品的原料。整套装置包括了氢氯化单元、氯化单元、精馏单元、制冷单元、废物处理单元等及其辅助设施，工艺流程较长，操作要求较高。为了保证产品质量、降低成本，严格控制环境污染，因此必须有相应的生产过程自动化来配…     

Liquid phase methanol and dimethyl ether synthesis from syngas

The Liquid Phase Methanol Synthesis (LPMeOH^TM) process has been investigated in our laboratories since 1982The reaction chemistry of liquid phase methanol synthesis over commercial Cu/ZnO/Al₂O₃ catalysts, established for diverse feed gas conditions including H₂-rich, CO-rich, CO₂-rich, and CO-free environments, is predominantly based on the CO₂ hydrogenation reaction and the forward water-gas shift reactionImportant aspects of the liquid phase methanol synthesis investigated in this in-depth study include global kinetic rate expressions, external mass transfer mechanisms and rates, correlation for the overall gas-to-liquid mass transfer rate coefficient, computation of the multicomponent phase equilibrium and prediction of the ultimate and isolated chemical equilibrium compositions, thermal stability analysis of the liquid phase methanol synthesis reactor, investigation of pore diffusion in the methanol catalyst, and elucidation of catalyst deactivation/regenerationThese studies were conducted in a mechanically agitated slurry reactor as well as in a liquid entrained reactorA novel liquid phase process for co-production of dimethyl ether (DME) and methanol has also been developedThe process is based on dual-catalytic synthesis in a single reactor stage, where the methanol synthesis and water gas shift reactions takes place over Cu/ZnO/Al₂O₃ catalysts and the in-situ methanol dehydration reaction takes place over -Al₂O₃ catalystCo-production of DME and methanol can increase the single-stage reactor productivity by as much as 80%. By varying the mass ratios of methanol synthesis catalyst to methanol dehydration catalyst, it is possible to co-produce DME and methanol in any fixed proportion, from 5% DME to 95% DMEAlso, dual catalysts exhibit higher activity, and more importantly these activities are sustained for a longer catalyst on-stream life by alleviating catalyst deactivation.     

以合成气合成甲醇催化剂及其进展

本文概念了甲醇合成催化剂以及新型催化剂的研究开发状况,介绍了各类甲醇合成催化剂,锌铬催化剂,铜基催化剂,耐硫催化以及目前国际上研究最热的液相甲醇合成催化剂,并论述了常用催化剂优缺点。     

混酸催化甲醇液相合成二甲醚研究

研究了硫酸和磷酸混酸催化甲醇液相合成二甲醚过程。考察了混酸催化剂、反应温度、原料进料速率和催化剂寿命等对二甲醚收率的影响。实验结果表明,混酸催化剂能较好地催化甲醇液相脱水制二甲醚反应并可长期使用,当混酸催化剂的配比为w(硫酸)∶w(磷酸)=1.2∶1,反应温度为140℃,甲醇进料速度为1.00 mL/min时,二甲醚收率可达到84%。     

二氧化碳和甲醇直接合成碳酸二甲酯研究进展

从均相及多相催化剂体系和反应条件等方面,综述了近年来二氧化碳和甲醇直接合成碳酸二甲酯的研究开发最新进展。介绍了均相催化剂体系包括有机金属烷氧基化合物、碱土金属烷氧基化合物、碱性催化剂和乙酸盐催化剂;多相催化剂体系包括负载型金属催化剂、负载型固体碱催化剂和氧化物催化剂。对催化剂及反应体系的设计、光催化剂、杂多酸催化剂、离子液体体系、助催化剂及吸水剂的使用、微波加热、膜反应器以及超临界二氧化碳溶剂体系进行了评述。     

三相床中合成气一步法制二甲醚

在反应温度 2 30～ 2 70℃、压力 2～ 5MPa下 ,以医药用石蜡油为惰性液相介质 ,使用C30 2铜基催化剂和CM - 3- 1改性分子筛组成的复合催化剂 ,在三相搅拌釜中研究了合成气 (CO、CO2 、H2 )一步法合成二甲醚的反应。结果表明随着温度的升高 ,碳的转化率增加 ,二甲醚的选择性提高 ,甲醇的选择性降低 ;随着压力的增加 ,碳的转化率升高 ,二甲醚的选择性提高 ,甲醇的选择性降低     

液相法甲醇合成过程中机械搅拌反应器的模拟

本文对C301及C302两种不同催化剂条件下机械搅拌反应器内液相法甲醇过程进行了模拟,模拟中节气液之间的传质过程及催化剂气固相本征反应动力学,主要模拟条件：温度483K－528K,压力2．0MPa-6．0MPa,原料气中CO浓度0．06－0．45。模拟结果表明,在C301与C302催化剂条件,隆成总体速率的模拟计算与实测值相吻合,平均偏差分别为7．98％和11．92％,可以认为,气固相本征动力学模型应用于液相甲醇合成过程的工程设计与过程分析是适用和可靠的。     

液相合成甲醇催化剂活性的研究

The effects of reduction procedure, reaction temperature and composition of feed gas on the activity of a CuO-ZnO-Al2O3 catalyst for liquid phase methanol synthesis were studied. An optimized procedure different from conventional ones was developed to obtain higher activity and better stability of the catalyst. Both CO and CO2 in the feed gas were found to be necessary to maintain the activity of catalyst in the synthesis process. Reaction temperature was limited up to 523K, otherwise the catalyst will be deactivated rapidly. Experimental results show that the catalyst deactivation is caused by sintering and fouling, and the effects of CO and CO2 on the catalyst activity are also investigated. The experimental results indicate that the formation of water in the methanol synthesis is negligible when the feed gas contains both CO and CO2. The mechanism for liquid-phase methanol synthesis was discussed and it differed slightly from that for gas-phase synthesis.     

Slurry Phase Hydrogenation of CO2 to Methanol Using Supported In2O3 Catalysts as Promising Approach for Chemical Energy Storage

A promising approach for chemical energy storage from fluctuating renewable electricity is methanol synthesis from CO₂ and hydrogen in a slurry reactor concept, due to efficient heat storage and easy reactor control. In combination with a promising In₂O₃/ZrO₂ catalyst and mineral oil as carrier liquid, efficient methanol production under a wide range of changing process conditions is shown for the first time. A maximum methanol productivity of 2.1 g_MeOHg_In⁻¹h⁻¹ and multiple recycling stability of the catalyst and the carrier liquid was achieved, showing no significant decrease in methanol yields.     

Effect of water on liquid phase DME synthesis from syngas over hybrid catalysts composed of Cu/ZnO/Al2O3 and γ-Al2O3

DME synthesis from syngas via methanol has been carried out in a single-stage liquid phase reactor. Cu/ ZnO/Al₂O₃ and γ-Al₂O₃ were used together as methanol synthesis catalyst and dehydration catalyst, respectively. The influence of water on the catalytic system was investigated mainly. Water affected the activity of methanol dehydration catalyst as well as methanol synthesis catalyst. Thus, removal of water from the reaction system, by adding a dehydrating agent or controlling methanol formation rate by the reaction parameters, was efficient in maintaining the high catalytic activity and stability. Presented at the Int’l Symp. on Chem. Eng. (Cheju, Feb. 8-10, 2001), dedicated to Prof. H. S. Chun on the occasion of his retirement from Korea University.     

新型联醇催化剂的研究

联醇生产长期以来存在生产周期短、副反应严重的问题,其中主要是催化剂寿命短和结蜡严重。该专题开发的新型联醇催化剂采用较低的Cu/Zn比,添加稀土组分,制备工艺采用两步法代替传统联醇催化剂的一步沉淀法,并将膜分离技术用于原料液除杂质。其选择性、低温活性、耐热性、耐硫性、抗压强度以及使用寿命均优于传统的联醇催化剂。该催化剂的经济、社会效益显著,具有广阔的推广前景。