四氟化硫的提纯精馏工艺

本发明涉及一种四氟化硫的提纯精馏工艺,由五氟化碘与硫磺在四氟化硫反应器中反应合成,制得四氟化硫粗气,在经冷却器、冷凝分离器以及冷凝捕集器获得纯度为≥95%的液态初级四氟化硫产品,再经由精馏过程获得纯度为≥99.9%的液态四氟化硫产品,连续充入钢瓶。本发     

四氟甲烷的合成与开发

介绍了四氟甲烷的性质、用途,叙述了烷烃直接氟化法、氟氯甲烷氟化法、氢氟甲烷氟化法和氟碳直接合成法等制备四氟甲烷的方法,并以具体实例说明。认为应进一步开发氢氟烃直接氟化法和氟碳直接合成法工艺,使其早日实现工业化生产。     

中国无机氟化工五十年发展进程

回顾了中国无机氟化工近50 a的发展历程,包括氟资源储量、生产工艺技术水平,以及产品品种、产量和质量。介绍了目前中国生产无机氟化工产品现状,主要包括无水氟化氢、氟化铝、氟化钠等产品,以及六氟磷酸锂、四氟硼酸锂、高纯氟气、六氟化硫、三氟化氮、四氟化碳、六氟化钨、五氟化碘、五氟化磷、三氟化硼、四氟化硫等产品,阐述了这些产品的产量、生产工艺技术水平、供需情况。指出目前中国无机氟化工存在的问题和今后的发展方向。     

α-三氟甲基乙胺合成工艺研究

以L-丙氨酸和四氟化硫为原料,压力下经一步氟化反应制得α-三氟甲基乙胺。实验研究获得的最佳工艺条件为：以100 g L-丙氨酸为原料,n（L-丙氨酸）∶n（四氟化硫）为1∶2,55℃及18-19 kgf/cm^2压力下保温反应12 h,产品收率在55%以上,产品盐酸盐熔点在218.5℃以上。     

氢氟醚的合成和应用研究进展

第三代氯氟烃替代品之一——氢氟醚类化合物（HFEs）的合成方法分为两类,第一类是醚类化合物的氟化,包括直接氟化法和电化学氟化法;第二类是通过含氟化合物与其他化合物的反应制备氢氟醚,反应类型主要包括不饱和烃与醇的加成反应、含氟羰基化合物的烷基化反应和卤代烷与醇的分子间消除反应。其中,碱催化不饱和烃与醇加成制备氢氟醚操作简便,反应条件相对温和,产物易分离提纯,是一具有工业化前景的氢氟醚合成方法。氢氟醚物化性能优良,且环境友好,在制冷、清洗等行业有着广阔的应用前景。     

氟化工专利精选

2,3,3,3-四氟丙烯的制备方法 1种2,3,3,3-四氟丙烯（HFC-1234yf）的制备方法：1）在氟化催化剂存在下,氟化氢和1,1,2,3-四氯丙烯进入第1反应器反应;2）在氟化催化剂存在下,2-氯-3,3,3三氟丙烯、2-氯-1,1,1,2-四氟丙烷、1,1,1,2,2-五氟丙烷（HFC-245cb）和氟化氢进入第2反应器反应;     

1，1，1，3-四氟丙烯合成方法研究进展

介绍了1,1,1,3-四氟丙烯的特性、用途,叙述了1-氯-3,3,3-三氟丙烯氟化法、1,1,1,3,3-五氯丙烷气相催化氟化法、CX4与CH2=CX2加成法和以三氟丙烯为原料合成法合成1,1,1,3-四氟丙烯的方法,评叙了各种方法的优缺点。     

氟代碳酸乙烯酯的合成方法综述

综述了氟代碳酸乙烯酯的制备方法。其制备方法主要有两种:一、直接氟化法:以氟气、氮气和碳酸乙烯酯为原料在高温高压条件下的一步合成法;二、卤素交换法:碳酸乙烯酯先经过氯代反应生成氯代碳酸乙烯酯,然后与氟化试剂进行卤素取代反应制备氟代碳酸乙烯酯。并重点介绍了卤素取代反应中使用不同的催化剂用来合成氟代碳酸乙烯酯。     

氟代碳酸乙烯酯的制备和精制工艺最新进展

总结了氟代碳酸乙烯酯（FEC）的制备方法,主要包括电化学氟化法、直接氟化法和氟–卤交换法等,比较了不同方法的优缺点。同时介绍了FEC的精制工艺,详细介绍了几种高纯FEC的制备工艺,并对FEC的研究前景进行了展望。     

国外三氟化氮制备技术研究开发进展

介绍了国外各有关公司近年来三氟化氮(NF_3)生产发展概况;介绍了三氟化氮主要制备方法——氟氨直接化合法和氟化氢铵熔融盐电解法的基本原理、工艺技术以及研究开发进展;介绍了高纯三氟化氮典型质量指标及精制提纯方法研究进展。主要介绍国外专利技术。     

Infrared identification of carboxylic acids formed in polymer photooxidation

Several low molecular weight carboxylic acids with different substitutions were introduced into various polymer matrices: polypropylene, polystyrene, poly(butylene terephthalate), MDI-based polyurethane, and poly(vinyl chloride). These acids were then submitted to chemical treatments by sulfur tetrafluoride and ammonia. Derivatization reactions by SF₄ and NH₃ gave, respectively, acyl fluorides and carboxylate ions. The wavenumbers corresponding to the v?_c?o maxima of the carboxylic acids, acyl fluorides, and carboxylate ions were determined. For each one of these species, noticeable shifts were recorded that depended on the nature of the substitutents as well as on the nature of the polymer matrix. In addition, samples of the chosen polymers were exposed to photoaging. Photooxidized samples were reacted with SF₄ and NH₃. Their IR characteristics were determined before and after the treatments. Comparison with the results obtained with the molecular acids permitted us to specify the chemical structure of the acids formed by photooxidation and then to determine the oxidation sites on the macromolecular chains of the different polymers. © 1994 John Wiley & Sons, Inc.     

Pd催化的有机氟化反应研究进展

近几年来,Pd催化的有机反应是有机合成领域的热点,Pd化合物在催化氟化反应中具有高活性、高选择性,引起研究者们的极大关注。本文综述了近年来Pd催化的氟化反应进展,分别从亲核氟化、亲电氟化以及不对称氟化反应三个方面综述了近年来Pd催化形成C—F键的研究进展,并对各类反应的反应条件、反应选择性、产率以及机理的研究进行了讨论和总结。特别是对合成含氟芳香化合物的研究,从反应机理、反应条件和催化配体等方面做了详细的介绍,对脂肪族含氟化合物进行了简要的概述。在此基础上,展望了Pd催化在氟化反应中的一些应用前景,指出反应机理的深入探讨和催化配体的选择是今后的研究重点和主要方向。     

室温固相研磨法合成邻氨基苯甲酸类芳醛席夫碱的研究

为了寻找清洁而方便的有机席夫碱制备方法,我们以邻氨基苯甲酸和各种芳醛的物质的量之比为1∶1的比例,采用室温固相研磨合成法,在常温下合成了10种邻氨基苯甲酸类芳醛席夫碱化合物,反应几乎定量完成。用熔点测定和元素分析法对其进行表征。重结晶产率达70%～82%,该法具有反应条件温和,反应时间短,产率高和分离提纯容易等特点,是实验室合成邻氨基苯甲酸类席夫碱的一种快捷而实用的方法。     

Influence of organic sulfur compounds and metals on mesophase formation

The influence of organic sulfur compounds and metals on the texture of the mesophase formed in pitch during the carbonization process was investigated by the addition of organic sulfur compounds and organometallic compounds to the cracked oil obtained from Khafji asphalt and polyvinyl chloride (PVC) pitch. These pitches, containing sulfur and metals, have been examined by polarised light microscopy, and quinoline insolubles (QI), sulfur and metal contents were determined. The existence of either organic sulfur compounds or organometallic compounds in the pitch has no effect on mesophase texture. However, the coexistence of sulfur and metals (such as vanadium or nickel) has a great effect on mesophase texture. From these results, sulfur and metals coexisting in the pitch have a catalytic effect which activates the thermal decomposition and the thermal polymerization reactions of the pitch. Furthermore, the precursors of mesophase (β resin) are formed abundantly in the pitch by these reactions. These precursors promote the nucleation of mesophase spherules, and a large number of mesophase spherules are formed in the pitch at the same time. Therefore, these spherules coalesce with each other before growing to large spheres and lead to a fine mosaic texture.     

Growth of Complex Oxide Single Crystals from Fluoride Melts

Single crystals of a barium magnesium tantalate, a lead tantalate, calcium niobate, and potassium germanate were synthesized by the reactions of oxides and fluorides at high temperatures. The technique is very much like the flux method, except that some of the fluoride cations combine chemically with the oxide nutrients. Starting compositions and conditions for growth are given. The most probable reactions were calculated using free energies of formation with known thermo-chemical data for an analogous system. Complex fluoride-forming reactions, hydrolysis reactions, and reactions which form fluorides and oxyfluorides are possible. The reaction products were also studied by X-ray analysis of the single crystal and polycrystalline products. Lattice parameters, space groups, and X-ray powder patterns are presented for the single crystal materials.     

Speciation and thermal transformation of sulfur forms in high-sulfur coal and its utilization in coal-blending coking process:A review

The utilization of high-sulfur coal is becoming more urgent due to the excessive utilization of low-sulfur,high-quality coal resources, and sulfur removal from high-sulfur coal is the most important issue. This paper reviews the speciation, forms and distribution of sulfur in coal, the sulfur removal from raw coal,the thermal transformation of sulfur during coal pyrolysis, and the sulfur regulation during coal-blending coking of high organic-sulfur coals. It was suggested that the proper characterization of sulfur in coal cannot be obtained only by either chemical method or instrumental characterization, which raises the need of a combination of current or newly adopted characterization methods. Different from the removal of inorganic sulfur from coal, the organic sulfur can only be partly removed by chemical technologies;and the coal structure and property, particularly high-sulfur coking coals which have caking ability,may be altered and affected by the pretreatment processes. Based on the interactions among the sulfur radicals, sulfur-containing and hydrogen-containing fragments during coal pyrolysis and the reactions with minerals or nascent char, regulating the sulfur transformation behavior in the process of thermal conversion is the most effective way to utilize high organic-sulfur coals in the coke-making industry.An in-situ regulation approach of sulfur transformation during coal-blending coking has been suggested.That is, the high volatile coals with an appropriate releasing temperature range of CH_4 overlapping well with that of H2 S from high organic-sulfur coals is blended with high organic-sulfur coals, and the C–S/C–C bonds in some sulfur forms are catalytically broken and immediately hydrogenated by the hydrogencontaining radicals generated from high volatile coals. Wherein, the effect of mass transfer on sulfur regulation during the coking process should be considered for the larger-scale coking tests through optimizing the ratios of different coals in the coal blend.     

四氟化碳中痕量气体杂质的气相色谱分析

采用配有放电离子化检测器的气相色谱仪分析高纯四氟化碳中痕量气体杂质。研究了分析四氟化碳中氧气、氮气、一氧化碳、二氧化碳和六氟化硫等气体杂质的操作参数,确定了高纯四氟化碳中痕量气体杂质的分析方法。     

Sulfur Removal from Low‐Sulfur Gasoline and Diesel Fuel by Metal‐Organic Frameworks

Several materials in the class of metal‐organic frameworks (MOF) were investigated to determine their sorption characteristics for sulfur compounds from fuels. The materials were tested using different model oils and common fuels such as low‐sulfur gasoline or diesel fuel at room temperature and ambient pressure. Thiophene and tetrahydrothiophene (THT) were chosen as model substances. Total‐sulfur concentrations in the model oils ranged from 30 mg/kg (S from thiophene) to 9 mg/kg (S from tetrahydrothiophene) as determined by elementary analysis. Initial sulfur contents of 8 mg/kg and 10 mg/kg were identified for low‐sulfur gasoline and for diesel fuel, respectively, by analysis of the common liquid fuels. Most of the MOF materials examined were not suitable for use as sulfur adsorbers. However, a high efficiency for sulfur removal from fuels and model oils was noticed for a special copper‐containing MOF (copper benzene‐1,3,5‐tricarboxylate, Cu‐BTC‐MOF). By use of this material, 78 wt % of the sulfur content was removed from thiophene containing model oils and an even higher decrease of up to 86 wt % was obtained for THT‐based model oils. Moreover, the sulfur content of low‐sulfur gasoline was reduced to 6.5 mg/kg, which represented a decrease of more than 22 %. The sulfur level in diesel fuel was reduced by an extent of 13 wt %. Time‐resolved measurements demonstrated that the sulfur‐sorption mainly occurs in the first 60 min after contact with the adsorbent, so that the total time span of the desulfurization process can be limited to 1 h. Therefore, this material seems to be highly suitable for sulfur reduction in commercial fuels in order to meet regulatory requirements and demands for automotive exhaust catalysis‐systems or exhaust gas sensors.