四氯乙烷脱氯化氢制三氯乙烯所用催化剂的影响因素

探讨了四氯乙烷脱氯化氢制三氯乙烯所用催化剂的制备方法、反应器材质、氯化铁、原料四氯乙烷中的杂质1,1,2-三氯乙烷和高沸物及操作条件对催化剂的影响,从而指导四氯乙烷脱氯化氢制三氯乙烯的工业生产,提高催化剂的效率,延长催化剂的寿命,消除不利的影响因素,提高产品质量,降低生产成本,确保三氯乙烯生产的长期、稳定运行.     

顶空-气相色谱法测定废水中偏二氯乙烯、1,1,1-三氯乙烷、三氯乙烯、1,1,2-三氯乙烷、1,1,2,2-四氯乙烷

建立了顶空——气相色谱法测定化工废水中偏二氯乙烯、1,1,1-三氯乙烷、三氯乙烯、1,1,2-三氯乙烷、1,1,2,2-四氯乙烷的分析方法。化工废水中偏二氯乙烯、1,1,1-三氯乙烷、三氯乙烯、1,1,2-三氯乙烷、1,1,2,2-四氯乙烷经DB-624(30m×320μm×1.80μm)毛细管柱气相分离,用保留时间定性,外标法定量。实验结果表明,几种物质在其测量范围内与对应的峰面积呈良好的线性关系,检出限分别为0.08、0.006、0.009、0.50、0.004μg/L。该方法的精密度和准确度较高,相对标准偏差小于2%,加标回收率在95.0%~102.4%之间。     

Fe/ZrO2催化剂气相催化裂解1,1,2-三氯乙烷脱氯化氢性能

采用浸渍法制备系列不同负载量的Fe/ZrO2催化剂,用于气相催化裂解1,1,2-三氯乙烷脱氯化氢性能的研究。结果表明,反应温度为350℃时,负载Fe质量分数为1%的1Fe/ZrO2催化剂催化活性最好,1,1,2-三氯乙烷转化率约95.0%,顺式1,2-二氯乙烯选择性为91.0%,反应50h性能稳定不失活,1,1,2-三氯乙烷转化率约92.0%,顺式1,2-二氯乙烯选择性约90.0%。单一ZrO2载体上的脱氯反应初始转化率为90.0%,经过1h反应即快速失活。ZrO2催化剂失活归因于ZrO2表面酸性较强导致积炭。对于Fe/ZrO2催化剂,Fe物种不但提供新的活性位点,而且降低了催化剂的表面强酸性中心,使催化剂催化活性更高,稳定性更好。     

一种1,2-二溴-1,1-二氯-2,2-二氟乙烷的制备新方法

以偏氟乙烯为原料,经光氯化、脱氯化氢、溴化加成3步反应合成1,2-二溴-1,1-二氯-2,2-二氟乙烷,试验了各种因素对反应的影响.光氯化反应时温度低有利于2,2-二氟-1,1,2-三氯乙烷选择性的提高,相转移催化剂四丁基溴化铵能加快反应脱氯化氢的速率,溴加成的合适温度为15～20℃.结果表明此合成路线是可行的.     

国内专利精选

<正>一种乙炔与二氯甲烷耦合反应制备氯乙烯联产二氯乙烯及1,1,2-三氯乙烷的方法:C N 104672054A∥徐云鹏(中国科学院大连化学物理研究所),公开日期:2015-06-03该发明涉及一种乙炔与二氯甲烷耦合反应制备氯乙烯联产二氯乙烯及1,1,2-三氯乙烷的方法,其特征在于:乙炔与二氯甲烷混合后通过反应器,其中装填有催化剂,在催化剂作用下乙炔与二氯甲烷同时发生二氯甲烷偶联反应以及乙炔氢氯化反应,乙炔与二氯甲烷的摩尔比为(0.5~     

1,1,2-三氯乙烷催化裂解制偏二氯乙烯工艺开发

利用浸渍法制备了γ-Al_2O_3负载金属盐催化剂,考察了活性组分、温度、负载率对1,1,2-三氯乙烷脱氯化氢反应的影响。在γ-Al_2O_3负载2%Cs F、180℃、0.5 MPa优化条件下,1,1,2-三氯乙烷转化率达30%,偏二氯乙烯选择性达90%。用气-液-固三相反应器考察了沸腾鼓泡状态、添加阻聚剂苯醌对不同温度下Cs F-γ-Al_2O_3液相催化1,1,2-三氯乙烷制偏二氯乙烯的寿命的影响。结果表明,在113℃、0.1 MPa下,Cs F-γ-Al_2O_3对偏二氯乙烯的选择性高达85%,寿命长达230 h。用高温凝胶色谱(GPC)和红外光谱(IR)对Cs F-γ-Al_2O_3表面吸附物种进行表征,结果显示,苯醌由于其对偏二氯乙烯的阻聚作用而能延长催化剂寿命。     

溶剂解吸气相色谱法测定空气中21种挥发性卤代烃的方法改进

改进了利用活性炭吸附-二硫化碳解吸-气相色谱/电子捕获检测器(GC/ECD)测定环境空气中反式-1,2-二氯乙烯、1,1-二氯乙烷、顺式-1,2-二氯乙烯、三氯甲烷、1,1,1-三氯乙烷、四氯化碳、1,2-二氯乙烷、三氯乙烯、1,2-二氯丙烷、1-溴-2-氯乙烷、1,1,2-三氯乙烷、四氯乙烯、氯苯、三溴甲烷、1,1,2,2-四氯乙烷、1,2,3-三氯丙烷、1,3-二氯苯、1,4-二氯苯、苄基苯、1,2-二氯苯、六氯乙烷这21种挥发性卤代烃的分析方法。所建立的方法在一定浓度范围内工作曲线线性良好,相关系数均在0.995 7~0.999 9之间,加标回收率在80.4%~113.3%之间,RSD为1.0%~6.6%,检出限为6.17~29.25μg/m3。所建立的方法操作简便、分析快速、灵敏度高,且具有较好的精密度与准确性。     

美国将氯乙烷类作为致癌物处理

美国癌协会最近的研究表明:从统计学上看有四种氯乙烷在动物中引起严重致癌,这四种化合物是:1,2-二氯乙烷、1,1,2-三氯乙烷、1,1,2,2-四氯乙烷和六氯乙烷,美国国家职业安全卫生协(NIOSH)根据美国癌协会的这一研究,建议工厂车间将这四种氯乙烷作为致癌物处理,NIOSH还建议严格     

1,1,2-三氯乙烷生产工艺的研究进展

1,1,2-三氯乙烷在化学工业中十分重要,可以用来作溶剂、萃取剂、杀虫剂,并且可以用于医学领域起麻醉作用,也可以是制作修正液的原料以及用来生成1,1-二氯乙烷。综述了氯乙烯氯化法、塔式合成法、1,2-二氯乙烷反应精馏法、利用烯烃混合废气法、共沸精馏法等1,1,2-三氯乙烷的生产方法。     

1,2-二氯乙烷反应精馏制备1,1,2-三氯乙烷

以1,2-氯乙烷和氯气为原料,用反应精馏法制备1,1,2-三氯乙烷,并考察了反应温度,1,2-氯乙烷进料位置、填料类型和空塔气速对反应的影响。结果表明,较好的条件为1,2-氯乙烷进料位置在塔的中上段,反应段温度为105-110℃,增大空塔气速和使用规整填料能明显提高1,1,2-三氯乙烷的选择性和生成速率。     

氯化物对乙烯三聚合制1-己烯的影响

选择了多种氯化物作促进剂进行乙烯三聚合制1-己烯,考察了氯化物的氯原子数目、空间效应、对称结构对聚合的影响以及用卤代芳香族化合物作促进剂时的聚合规律。结果表明,含有偶效氯原子、具有对称结构的卤代烷烃有较高的反应活性;以卤代芳香族化合物为促进剂时,乙烯三聚合活性及催化剂效率较高,1-己烯选择性在86％以上。     

Adsorption and desorption of halogenated hydrocarbons using activated carbon

Environmental hazards caused by halogenated hydrocarbons and increasingly stringent regulations for limiting their emission require comprehensive investigations of these substances. The present work deals with the adsorption and desorption of halogenated hydrocarbons on activated carbon. The results could be useful in the utilization of landfill gases because halogenated hydrocarbons must be removed in order to avoid pollution and the loaded activated carbons have to be regenerated. Activated carbons are well suited to removal and recovery of halogenated hydrocarbons from gas flows.     

Oligomerization pathways of dichlorodifluoromethane hydrodechlorination catalyzed by activated carbon supported Pt-Cu, Pt-Ag, Pt-Fe, and Pt-Co

Activated carbon-supported Pt-Cu, Pt-Ag, Pt-Co, Pt-Fe, and Pt catalyze the formation of oligomerization products from CF₂Cl₂ and H₂ mixture (1:1 ratio) at 523 K. All catalysts deactivate with time on stream. The Pt-Co/C catalyst exhibits the highest selectivity toward C₂–C₃ hydrocarbons (50%), whereas Pt-Cu/C is the most selective toward tetrafluoroethylene (20%). The other catalysts (Pt, Pt-Ag, Pt-Fe) exhibit negligible oligomerization activity, CH₄ and partially halogenated C₁ molecules are the main products. The performance of each catalyst is understood in terms of the difference in the stability of bimetallic particles toward segregation under dechlorination conditions.     

Secondary Cracking of C4 Hydrocarbons from Heavy Oil Catalytic Pyrolysis

For C4 hydrocarbons from heavy oil catalytic pyrolysis, the cracking behaviours on catalyst CEP‐1 and quartz sand were investigated in a confined fluidized bed reactor. C4 hydrocarbons show a good cracking ability on CEP‐1, and butene is easier to convert than butane. Only at high reaction temperatures can butane present a good cracking ability. On catalyst CEP‐1, C4 hydrocarbons can undergo not only cracking reactions, but also such reactions as hydrogen transfer, polymerization and aromatization. The conversion of C4 hydrocarbons thermal pyrolysis is high, indicating that free radical reactions play an important part in the secondary cracking of C4 hydrocarbons. The product yields of C4 hydrocarbons pyrolysis on quartz sand are usually lower than those on catalyst CEP‐1. For both catalytic pyrolysis and thermal pyrolysis of C4 hydrocarbons, the selectivity of propene is higher than that of ethene.     

卤代烷烃lgS和lgK_(ow)的拓扑学研究

应用半经验量子化学AM1法得到了36种卤代烷烃分子的优化构像,利用量子化学算法和分子图形学技术获得K ier指数、Kappa形状指数及连接性指数,将这些参数与卤代烷烃的性质关联,它们与36种卤代烷烃的辛醇/水分配系数的多元回归方程为:lgKow=-0.3400L 0.1771L 0.4440X-0.0982X 0.2794X 0.126K2 0.920;与其溶解度的多元回归方程为:lgSw=-0.4470L 0.1681L 1.7470X-1.0621X-0.8322X 0.5586X 0.269K2-0.684。两个方程的相关系数均在0.94以上。     

水中挥发性卤代烃测定的不确定度评定

污水中挥发性卤代烃为国标优先检测项目之一,是污水检测的一个重要参考指标。为了提高挥发性卤代烃测量的准确度,对污水中4种挥发性卤代烃:三氯甲烷、四氯化碳、三氯乙烯、四氯乙烯进行测定,结果表明:不确定度主要来源于系统误差,建议尽量选用不确定度较小的标准溶液,误差较小的移液管和容量瓶,从而减小系统误差;且尽可能的进行多次重复测定,提高测量的精密度、准确度。     

助催化剂对BCZ-108催化剂聚合行为的影响研究

在铝钛物质的量比为25、50、100、150、200、300条件下,研究丙烯聚合用BCZ-108催化剂的聚合行为及聚丙烯的主要性能,并与常规应用的NA催化剂进行对比。结果表明,随着铝钛物质的量比的增大,两种催化剂的聚合反应速率的衰减越来越快,聚丙烯的立体定向性越来越低,熔点越来越低,分子量分布越来越宽;BCZ-108催化剂的聚合活性比NA催化剂高30%以上;两种催化剂的聚合活性在铝钛物质的量比为50时达到最高,此时BCZ-108催化剂的活性为1 212 g·g^-1,NA催化剂的活性为907 g·g^-1。     

Production of aromatic hydrocarbons by co-cracking of bio-oil and ethanol over Ga2O3/HZSM-5 catalysts

The catalytic cracking of bio-oil is important to produce aromatic hydrocarbons, which can partially replace gasoline or diesel to greatly reduce carbon emissions from transportation. To further promote the formation of aromatic hydrocarbons, this work studied the effects of the preparation method and the acid strength of Ga₂O₃/HZSM-5 on catalytic cracking of the bio-oil distilled fraction systematically. The preparation method of Ga₂O₃/HZSM-5 had an important effect on its catalytic activity: the Ga₂O₃/HZSM-5 prepared by physical mixing showed the low dispersion of active phases and poor pore structure, resulting in its insufficient activity and severe coke deposition; the Ga₂O₃/HZSM-5 prepared by precipitation exhibited the higher activity, while many polycyclic aromatic hydrocarbons unfavorable for the subsequent utilization were in the oil phase; the Ga₂O₃/HZSM-5 prepared by impregnation showed the highest activity and 35.5% (mass) selectivity of the oil phase, including 80.3% monocyclic aromatic hydrocarbons and 12.0% polycyclic aromatic hydrocarbons. The Brønsted acidity of Ga₂O₃/HZSM-5 decreased with Si/Al ratio, leading to the decline in reactant conversion, oil phase selectivity and quality. Meanwhile, the polymerization between monocyclic aromatic hydrocarbons and oxygenates was promoted to produce many polycyclic aromatic hydrocarbons and even coke, causing catalyst deactivation.     

Degradation of halogenated organic compounds in ground water by heterogeneous catalytic oxidation with hydrogen peroxide

summary Catalytic oxidation with hydrogen peroxide is a reliable method for the treatment of polluted water. The conversion of a wide spectrum of components including aliphatic and aromatic hydrocarbons as well as halogenated organic compounds into non-toxic or minor-toxic substances and finally into carbon dioxide and water can be achieved. The degradation of chlorobenzene, 4-chlorophenol, 4-chloroaniline and 1-nitro-4-chlorobenzene was investigated. Several catalysts can be implemented into the catalytic process. It has been demonstrated that the type of catalyst and oxidation agent as well as the reaction parameters influence the degradation rate and has to be adjusted to the concrete waste water problem to be solved.     

Low-pressure polymerization of ethylene. II

This paper presents the kinetic study of polymerization of ethylene with VOCl₃ and aluminum alkyls such as Et₃Al and Et₂AlCl. The effect of various parameters like the [Al]/[V] ratio, catalyst concentration, reaction time, temperature, solvents, and additives on rate of the reaction, yield, and molecular weight is reported. Each of these parameters has a remarkable effect on the yield and the rate of polymerization for both catalyst systems. Triethylamine is found to increase the catalyst efficiency and the rate. It is also observed that aliphatic hydrocarbons acted as a better polymerization medium than did the aromatic ones.