1,1-二氟乙烷的生产与应用

介绍了1,1-二氟乙烷(HFC-152a)的性质,并对现有HFC-152a的生产方法及其应用领域进行了总结介绍,认为开发高效新型催化剂及配套优化工艺将是提高HFC-152a 生产能力、提升HFC-152a品质的重要途径;HFC-152a在多元体系的应用及其他新领域的开发将是未来HFC-152a应用领域的新的增长点.     

1,1-二氟乙烷生产中氯乙烯脱除技术研究进展

介绍了以氯乙烯为原料生产1,1-二氟乙烷中,脱除氯乙烯的必要性。在净化、精 馏2个阶段采用不同的方法,可将氯乙烯体积分数降至10×10-6以下。     

联产1,1-二氟乙烷和氯乙烯的方法研究

采用联产1,1-二氟乙烷(HFC-152a)和氯乙烯(VCM)的方法,将二氯乙烷和氟化氢汽化后进入反应器进行催化反应得到1,1-二氟乙烷和氯乙烯。结果表明,HFC-152a市场较好的情况下,反应温度330℃,空速2 500 h^-1,HF与二氯乙烷的摩尔比15∶1为优化的反应条件;VCM市场较好的情况下,反应温度200℃,空速2 000 h^-1,HF与二氯乙烷的摩尔比为1∶1为优化的反应条件。为了解决反应过程中未完全转化的烯烃与目标产品易形成共沸难分离的问题,在精馏过程中引入了饱和有机溶剂,得到HFC-152a的质量分数可达99.9%以上。通过1套装置同时联产HFC-152a和VCM这2种产品,具有原料单程转化率高、绿色环保、可连续化操作的特点。     

活性炭负载金属氯化物催化1-氯-1,1-二氟乙烷裂解制备偏氟乙烯

在裂解温度为400~630℃、空时为32 s条件下研究了活性炭负载金属氯化物催化剂(Fe Cl3/C、Cu Cl2/C和Ni Cl2/C)催化1-氯-1,1-二氟乙烷(HCFC-142b)裂解制备偏氟乙烯(VDF)的过程。考察了反应温度和催化剂种类对原料转化率和VDF含量及选择性的影响。结果表明:Fe Cl3/C和Cu Cl2/C的催化活性较高,Ni Cl2/C无明显催化作用。反应温度为400~500℃时,Fe Cl3/C使HCFC-142b转化率提高约10%~20%,VDF含量增加约3%~8%,选择性下降约10%~14%。反应温度为400~480℃时,Cu Cl2/C使HCFC-142b转化率和VDF含量提高50%以上,选择性也明显提高。推测Fe Cl3/C和Cu Cl2/C的催化机理为碳正离子机理。     

2-氯-1,1-二氟乙烷的制备与应用研究进展

介绍了2-氯-1,1-二氟乙烷的多种制备方法及应用研究进展,并对各种制备方法进行了分析,认为以2-氯-1,1-二氟乙烯为原料的催化加氢法,具有生产条件简单、转化率及收率高等优点,工业化价值高。并讨论了它在农药、医药等领域的应用。     

1,1—二氟乙烷

前言1,1-二氟乙烷(difluoroethane)是一种重要的有机氟化工产品,在氟碳烃系列中称为HFC-152a,过去只是作为一种中间产品。它不含氯、溴原子,所以不会破坏大气臭氧层。随着蒙特利尔协议的生效,世界上将逐渐限制 CFC_s 的生产和使用。HFC-152a在 CFC_s 替代品及各种新的用途方面,将作为最终产品使用。它的作用和地位将日趋重要,并受到较多的重视。联合国环境保护署和美国环保局的专家来华时曾多次提出希望我国开展 HFC-152a 的应用研究工作。本文简要介绍 HFC-152a 的性质、用途、前景、制造方法及国内情况。     

1,1-二氟乙烷项目通过验收

杭州富时特化工有限公司承担的2000吨／年1,1-二氟乙烷浙江省创新资金项目，日前通过了专家组验收。该装置所用的主要原材料氯乙烯转化率、氯乙烯单耗、成品主含量等主要技术指标均达蓟或超过合同要求。     

1-氯-1,1-二氟乙烷裂解制备偏氟乙烯的研究进展

偏氟乙烯是氟化工行业重要的单体,主要由1-氯-1,1-二氟乙烷（HCFC-142b）裂解制备,本文介绍了HCFC-142b裂解制备偏氟乙烯反应机理的研究进展,对HCFC-142b催化裂解工艺进行了评述和展望,综述了HCFC-142b裂解管结构改进的研究进展,对偏氟乙烯精馏分离工艺进行了评述。提出应深入研究HCFC-142b裂解机理,进一步研究裂解管材质和结构对HCFC-142b裂解过程的影响,并借鉴烃类裂解制乙烯的研究进展解决HCFC-142b裂解过程中面临的高能耗、催化剂流失、结焦等难题。     

1,1-二氟-1,2-二氯乙烷的应用

本文介绍了1,1-二氟-1,2-二氯乙烷的应用。     

二氟二氯甲烷—1,1—二氟乙烷二元系恒温汽液平衡的研究

用带观察窗的静态平衡器测定了二氟二氯甲烷、１，１－二氟乙烷在常沸点以上的蒸汽压以及该二元系在２９．８１℃、３９．９０℃和４９．８６℃下的加压汽车平衡，获得了温度Ｔ、总蒸汽压ｐ、系统总组成Ｚ、系统总量ｎＴ以及汽相体积Ｖ＾ｇ的数据。以物料衡算与由Ｔ、ｐ、ｘ推算ｙ的方法相结合，求得了平衡相组成ｘ、ｙ。并进一步用修正的ＰＲ及修正的ＳＲＫ状态方程成功地关联了数据。     

光催化膜对水中腐植酸的去除及积垢机理

利用湿式相转化方法制备TiO₂/聚苯砜（polyphenylsulfone,PPSU）/聚醚亚硫胺（polyetherimide,PEI）催化膜应用于水中腐植酸（humic acid,HAs）的去除及积垢机理研究。结果表明,随着亲水性PEI比例增加,光催化膜的纯水通量和HAs的过滤通量越大,去除效率越低;且随着光照时间的延长去除效率越趋于稳定,且有回复的现象。在0.2MPa操作压力下,制备的TiO₂/PPSU/PEI （1%/50%/50%）膜具有最佳的可逆阻抗力比例（R_c/R_t=48.24%）;其渗透通量、HAs去除效率及反洗后通量分别为34.0L/（m²·h）、63.2%及22.5L/（m²·h）,具有较佳的通量及HAs去除效率。     

High pressure isothermal vapor-liquid equilibria of carbon dioxide+1,1-difluoroethane

Vapor-liquid equilibrium data for the binary mixture of carbon dioxide (CO₂)+1,1-difluoroethane (HFC-152a) were measured at five evenly spaced temperatures of (273.15, 283.15, 293.15, 303.15 and 313.15) K by using a circulation-type equilibrium apparatus in which both vapor and liquid phases were recirculated. The experimental data were correlated with the Peng-Robinson equation of state (PR-EoS) using the Wong-Sandler mixing rules combined with the NRTL excess Gibbs free energy model and the Carnahan-Starling-DeSantis equation of state (CSD EoS). Almost all the calculated values with these two models showed good agreement with the experimental data.     

Permeability of poly-L-methionine membrane and its oxidized membrane to water vapor

The permeability of poly-L -methionine (PLM) membrane and its oxidized form to water vapor was studied. Permeability coefficients of the PLM membrane were large, of the order of 10^?7 cm³ (S.T.P.)·cm/cm²·sec·cm Hg. The sorption and permeation behavior of the PLM membrane was hydrophobic. The oxidized membrane was prepared by treating one or both sides of the PLM membrane with an aqueous solution of hydrogen peroxide. The membrane oxidized from one side is probably not layered but has a gradient of composition from one surface to the other. The amounts of water sorbed by the modified membrane increased with increase in oxidation time. The permeability coefficients of water vapor through the modified membrane were of the order of 10^?6 cm³ (S.T.P.)·cm/cm²·sec·cm Hg.     

气相抽提法去除土壤中的苯和乙苯

土壤气相抽提技术（SVE）是一种安全、经济、高效的土壤治理技术,广泛应用于不饱和土壤中挥发性有机污染物的去除。以红壤为实验土样,北京潮土和吉林黑土为对照土样,选用最常见的挥发性有机污染物苯作为单一污染物,采用一维土柱通风模拟SVE过程,研究了不同土质对苯污染土壤去污过程的影响。同时选用苯与乙苯作为二元混合污染物,研究了土壤含水率对苯与乙苯污染红壤去污过程的影响。结果表明,对于二元混合物实验,在通风流量600 ml.min^-1、含水率16.8%时,苯与乙苯的净化时间分别降至最低36 h和84 h。不同类型土壤的对照实验表明,土壤质地与有机质含量也是SVE去污过程的重要影响因素。     

Measurement of VLE data for propane+1,1-difluoroethane at various temperatures from 268.15 to 333.15 K

Isothermal vapor-liquid equilibrium data for the binary systems of propane (R-290) (1)+1,1-difluoroethane (HFC-152a) (2) were measured at eight temperatures of (268.15, 273.15, 283.15, 293.15, 303.15, 313.15, 323.15 and 333.15 K), respectively. The experiments were performed with a circulation-type equilibrium apparatus to measure temperature, pressure, and the compositions of the liquid and vapor phases. The experimental data were correlated with the Peng-Robinson equation of state (PR-EoS) using the Wong-Sandler mixing rules and the Carnahan-Starling-DeSantis equation of state (CSD EoS). Calculated results showed good agreement with experimental data. It was found that this system has very strong positive azeotropes for all the temperature ranges studied here. This article is dedicated to Professor Chul Soo Lee in commemoration of his retirement from Department of Chemical and Biological Engineering of Korea University.     

Review: membrane materials for the removal of water from industrial solvents by pervaporation and vapor permeation

Organic solvents are widely used in a variety of industrial sectors. Reclaiming and reusing the solvents may be the most economically and environmentally beneficial option for managing spent solvents. Purifying the solvents to meet reuse specifications can be challenging. For hydrophilic solvents, water must be removed prior to reuse, yet many hydrophilic solvents form hard-to-separate azeotropic mixtures with water. Such mixtures make separation processes energy-intensive and cause economic challenges. The membrane processes pervaporation (PV) and vapor permeation (VP) can be less energy-intensive than distillation-based processes and have proven to be very effective in removing water from azeotropic mixtures. In PV/VP, separation is based on the solution–diffusion interaction between the dense permselective layer of the membrane and the solvent/water mixture. This review provides a state-of-the-science analysis of materials used as the selective layer(s) of PV/VP membranes in removing water from organic solvents. A variety of membrane materials, such as polymeric, inorganic, mixed matrix, and hybrid, have been reported in the literature. A small subset of these is commercially available and highlighted here: poly (vinyl alcohol), polyimides, amorphous perfluoro polymers, NaA zeolites, chabazite zeolites, T-type zeolites, and hybrid silicas. The typical performance characteristics and operating limits of these membranes are discussed. Solvents targeted by the United States Environmental Protection Agency for reclamation are emphasized and ten common solvents are chosen for analysis: acetonitrile, 1-butanol, N,N-dimethyl formamide, ethanol, methanol, methyl isobutyl ketone, methyl tert-butyl ether, tetrahydrofuran, acetone, and 2-propanol. Published 2018. This article is a U.S. Government work and is in the public domain in the USA.     

改性聚吡咯材料去除水中氟离子的性能

通过控制合成条件和在聚合过程中分别引入酸性红G（ARG）、甲基橙（MO）、α-环糊精（α-CD）和甲基橙等掺杂剂合成了表面带有毛刺的纤维、不同直径纳米纤维编织成的微米片状特殊微形貌的改性聚吡咯（PPy）材料。通过场发射扫描电子显微镜（SEM）、透射电子显微镜（TEM）、傅里叶变换红外光谱分析（FTIR）、氮气吸脱附分析（BET）、zeta电位分析等方法对其物理化学性能进行了表征,并将其应用于水体低浓度氟离子的吸附去除,比较了改性聚吡咯材料与传统方法合成的颗粒状聚吡咯对氟离子吸附的性能。结果表明：改性的特殊微形貌PPy的比表面积比传统颗粒状PPy提高了7~10倍;在常温和pH=5的条件下,F^-初始浓度在3~5mg/L,投加量为2g/L时,改性的特殊微形貌PPy可在10min之内达到吸附平衡,并将F^-的浓度降低到国家《生活引用水卫生标准》（GB 5749—2006）规定的1mg/L以下,说明特殊微形貌的控制对PPy吸附F^-具有很大影响。另外,该吸附行为是自发的放热过程,Langmiur模型可以很好地拟合该吸附过程,PPy对F^-的去除主要涉及离子交换作用。     

膜生物反应器对水源水中微量二氯酚的去除

通过实验室小试,研究了一体式膜生物反应器（MBR）对微污染湖水中的微量2,4-二氯酚（2,4-DCP）的去除效果。64 d的连续试验证实,当进水2,4-DCP浓度在2～200 μg·L-1时,MBR对2,4-DCP的平均去除率达936%。出水2,4-DCP浓度平均为428 μg·L-1,满足《城市供水水质标准》的要求。同时采用间歇试验对MBR去除2,4-DCP的机理进行了研究,证实生物作用在2,4-DCP的去除中起主要作用,MBR对2,4-DCP的去除符合零级动力学过程,降解速率常数为106 μg·L-1·min-1。此外,试验证实MBR对DCP的去除是基于二级基质原理,而向反应器内投加葡萄糖并不能促进MBR对2,4-DCP的去除。