乙烷裂解制乙苯/苯乙烯项目粗分离装置工艺流程探讨

为充分利用炼厂干气,采用小型裂解炉将炼厂干气中的乙烷进行热裂解,然后对裂解气进行粗分离,再用稀乙烯气制乙苯技术生产乙苯,进而生产苯乙烯,不仅能利用炼厂干气中的乙烷和乙烯资源,同时能推动炼油企业向化工转型,提高企业经济效益。对于稀乙烯法制乙苯/苯乙烯项目中的粗分离装置,以某装置乙烯年产量120 kt的裂解气原料为基础,通过模拟对比苯吸收流程和中冷分离流程的能耗,探讨较优的工艺路线。     

以稀乙烯为原料可降低苯乙烯生产成本

据Nexant ChemSystems咨询公司称，苯乙烯生产厂商可采用稀乙烯为原料，以大幅度降低生产成本，使得西欧苯乙烯生产商可与中东生产商一样获得成本优势。     

湛江东兴稀乙烯法制乙苯催化剂活性的影响因素和保持措施

文章介绍了中石化湛江东兴苯乙烯装置稀乙烯法制乙苯催化剂活性的影响因素,并对如何防止不良影响因素影响、保持烷基化催化剂活性提出一些建议和措施。     

苯乙烯生产最新技术

乙苯脱氢技术是苯乙烯的主要生产方法。简要介绍了3种主要的乙苯生产工艺:气相法烷基化工艺、液相法烷基化工艺、稀乙烯原料制乙苯工艺的工艺特点、原理及国内外研究进展。在此基础上,对苯乙烯生产技术,如绝热负压脱氢技术、苯乙烯与环氧丙烷联产工艺的研究状况和主要技术指标进行了论述,并指出了苯乙烯生产技术的发展方向。     

苯乙烯装置脱氢系统能量优化

基于苯乙烯技术和发展现状,以稀乙烯制乙苯/苯乙烯联合装置为分析方向,着重分析装置如何在低负荷下进行能量优化。分析了东方石化乙苯/苯乙烯装置能耗高的主要原因。结合装置现目前的负荷,针对装置存在的问题,采取了蒸汽过热炉热效率提升、外购原料乙苯、投用热乙苯、优化脱氢压缩机蒸汽用量等节能降耗措施,改造后单位综合能耗在高负荷时能够低于设计值,达到了很好的节能降耗的目的。     

国内干气制乙苯技术开发进展

干气制乙苯技术可以充分利用干气中的稀乙烯资源,提高石油资源的利用率,缓解国内乙苯/苯乙烯的短缺现状。本文综述了国内几种典型的干气制乙苯技术的工艺指标及开发现状,并对气相法和相法两种技术做了简单的对比分析。     

在线色谱仪在苯乙烯测量中的改造应用

某乙烯装置的汽油加氢反应器出口物流中,苯乙烯的含量是由在线色谱仪AT-2201测定,由于AT-2201的色谱柱影响苯乙烯和背景组分的分离,使其无法精确定位苯乙烯的峰值。通过对乙烯装置工艺参数的进一步分析,将AT-2201在线色谱仪的分离系统重新进行配置后,在苯乙烯含量的测定中,在线分析结果与化验室所测数值达到了一致。     

r-PET/SEEPS共混体系流变行为及相容性

采用苯乙烯-[乙烯-(乙烯-丙烯)]-苯乙烯嵌段共聚物(SEEPS),通过熔融共混技术对回收聚对苯二甲酸乙二醇酯(r-PET)进行了增韧改性,采用动态流变分析和DMA等手段研究了SEEPS用量对r-PET/SEEPS共混物流变行为和相容性的影响。结果表明:r-PET与SEEPS共混体系的相容性较差;随着SEEPS用量增加,r-PET/SEEPS共混物的复数黏度增加,表现出明显的剪切变稀行为,r-PET和SEEPS分子链间存在相互缠结作用,共混物的内耗峰减小,弹性模量增加;力学性能分析结果表明:含20%SEEPS的r-PET/SEEPS共混物缺口冲击强度比纯r-PET提高了107.04%,柔韧性明显增强,弯曲强度有所下降。     

利用干气中稀乙烯制乙苯工艺路线的选取

在调研近几年国内外利用干气中稀乙烯制备乙苯工艺路线的基础上,分析了安庆石化干气资源及利用途径,初步探讨了利用炼油干气中稀乙烯合成乙苯工艺路线的选取.     

国外动态

由苯和乙烯直接合成苯乙烯日本理化学研究所开发了由苯和乙烯为原料一步反应直接合成苯乙烯的新的反应过程。它是采用铑金属粒做催化剂,在少量一氧化碳的存在下,通入苯和乙烯在200℃下,加热加压反应,得到苯乙烯和二乙基酮。此过程与过去的苯乙烯制造工程相比,有流程     

混合醇醇解RPET制备不饱和聚酯树脂的研究

本文以醋酸锌为催化剂,利用混合醇取代二元醇作为醇解剂对回收聚对苯二甲酸乙二醇酯塑料降解,得到的醇解产物与酸酐进一步缩合聚合,以苯乙烯作为稀释剂,制得不饱和聚酯树脂。该方法具有工艺简单、成本低廉、操作简便、绿色环保、经济效益好等特点,得到的不饱和聚酯树脂性能稳定,使用性能良好。     

Toughening and Compatibilization of Acrylonitrile–Butadiene–Styrene/Poly (Ethylene Terephthalate) Blends Using an Oxazoline-Functionalized Impact Modifier

An oxazoline-functionalized core–shell impact modifier was synthesized between aminoethanol and acrylonitrile/butadiene/styrene high rubber powder. According to the Fourier transform infrared spectroscopy test, the nitrile groups were partially converted into oxazoline groups successfully. The oxazoline-functionalized acrylonitrile/butadiene/styrene high rubber powder was used as an impact modifier for acrylonitrile–butadiene–styrene/poly(ethylene terephthalate) blends. The differential scanning calorimeter and rheological tests demonstrated that poly(ethylene terephthalate) was partially miscible with acrylonitrile–butadiene–styrene, because the oxazoline groups of oxazoline-functionalized acrylonitrile/butadiene/styrene high rubber powder reacted with the end groups of poly(ethylene terephthalate). The results of scanning electron microscopy indicated that the morphology of acrylonitrile–butadiene–styrene/poly(ethylene terephthalate) blends with proper oxazoline-functionalized acrylonitrile/butadiene/styrene high rubber powder content was improved significantly. The best mechanical properties were achieved, When 6 wt% oxazoline-functionalized acrylonitrile/butadiene/styrene high rubber powder was added into acrylonitrile–butadiene–styrene/poly(ethylene terephthalate) blends.     

Elastomeric block polymers from ethylene sulphide

Block polymers of ethylene sulphide with butadiene, isoprene and styrene have been prepared by anionic synthesis, and their properties have been examined. The ABA polymers from ethylene sulphide and isoprene are elastomers with good thermal stability but unless of low molecular weight are difficult to process except at high temperatures, when they are prone to degradation. ABC block polymers from styrene, isoprene or butadiene and ethylene sulphide are strong resilient elastomers with improved thermal stability compared with the conventional styrene/butadiene block polymers. Good properties are obtained with small amounts (2–4%) of low molecular weight (～4000), highly crystalline poly(ethylene sulphide) blocks. X-ray, differential scanning calorimetry, and gel permeation chromatography data show the ethylene sulphide blocks to be anisotropic, extended-chain crystallites which aggregate large numbers of the attached diene/styrene chains. These aggregates persist at temperatures above the softening point of the polystyrene domains, and in solution. The polymers possess unusual flow characteristics which are not well understood. Electron micrographs of stained, cast or microtomed films show the elastomers to have a two-phase morphology. It has not been possible to identify the structure of the small poly(ethylene sulphide) domains. The ABC polymers can be oil extended and compounded with carbon black. Vulcanizates using accelerated sulphur systems have good physical properties.     

Ethylene/styrene copolymerisation by homogeneous metallocene catalysts: experimental and molecular simulations using rac-ethylenebis(tetrahydroindenyl)MCl2 [M=Ti,Zr] systems

Styrene was copolymerised with ethylene using the catalyst systems [rac-Et(H₄Ind)₂TiCl₂]/MAO and [rac-Et(H₄Ind)₂ZrCl₂]/MAO. Keeping other experimental variables under control, we tested different styrene/ethylene ratios in the reactor feed. It was found that the titanium-based catalyst showed very low activity even for ethylene homopolymerisation. In contrast, the zirconium system achieved monomer polymerisation, incorporating small amounts of styrene. When the styrene/ethylene ratio was increased, both catalyst activity and the molecular weight of the resulting copolymers decreased. However, styrene incorporation into the copolymer increased as the styrene/ethylene ratio rose. To gain insight into the copolymerisation mechanisms at play, we undertook a computational study using a high-level hybrid DFT method (B3LYP). Agreement between the experimental and theoretical results was generally good, indicating the usefulness of combined experimental/theoretical studies for clarifying mechanisms of -olefin copolymerisation using organometallic systems.     

Polymeric proton conducting systems based on commercial elastomers. II. Synthesis and microstructural characterization of films based on HSBR/EPDM/PP/PS/silica

This article reports on the synthesis and structural characterization of films containing hydrogenated poly(butadiene‐styrene) block copolymer/ethylene‐propylene terpolymer/polypropylene, hydrogenated poly(butadiene‐styrene) block copolymer/ethylene‐propylene terpolymer/polystyrene, and hydrogenated poly(butadiene‐styrene block copolymer/ethylene‐propylene terpolymer/silica) crosslinked with peroxides and heterogeneously sulfonated. Sulfonation of the different polymeric systems gives rise to materials with high proton conductivity and great dimensional stability, suited for application in a variety of electronic devices. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 2394–2402, 2004     

自苯乙烯合成β-苯乙醇

本文叙述自苯乙烯合成β-苯乙醇的方法。先将苯乙烯转为2-溴代-1-苯乙醇,然后脱去溴化氢而成环氧苯乙烷,继之接触加氢而得β-苯乙醇。以105克NaClO_3溶于225克水的溶液,同时和由360克NaBr溶于750克水的溶液与稀硫酸组成的混合液,在3.5～4小时内加入于210克苯乙烯中。反应在90—95℃时进行,并予以剧烈搅拌。反应完成后,分出油层,用温水和稀纯碱液洗滌,然后减压蒸馏,得80—85％（理论计）的2-溴代-1-苯乙醇,沸点106—111℃/2—3毫米,n_D~（23.5）1.5770。以此用稍过量的稀烧碱溶液在60—65℃时处理3—4小时,得80—85％环氧苯乙烷,沸点60—65℃/3—4毫米,n_D~（22）1.5350,d_（16）~（16）1.055。将100克环氧苯乙烷溶于200毫升乙醇中,内含3.3克NaOH,在Raney镍存在下加氢,压力为3大气压,温度为室温,β-苯乙醇得率为75％,n_D~（20）1.530,d~（22）1.0206。     

Catalytic processes and catalyst production at OAO Nizhnekamskneftekhim: State of the art and future prospects

The production and use of catalysts at OAO Nizhnekamskneftekhim are analyzed. The problems and prospects of further development of catalysts for the following processes are discussed: production of rubbers (BK, SKEPT, SKI, SKD-N brands), α-olefins, ethylene and propylene glycols, propylene and styrene oxides, ethylene oxide, ethylene, and aromatic hydrocarbon concentrate (from propane); dehydrogenation of isoparaffins (isoprene and isobutylene synthesis) and ethylbenzene; methyl phenyl carbinol dehydration into styrene. The ways of improving the efficiency of the enterprise are by organizing in-house catalyst production with the help of R&;D institutions for import substitution and by reducing the catalytic problems in the petrochemical industry.     

Copolymerization of ethylene with aromatic vinyl monomers using metallocenes

Copolymerization of ethylene with styrene, allyl benzene and 4‐phenyl‐1‐butene was examined using different metallocene catalysts. We separated the bulky phenyl group of styrene from its double bond using methylene spacers and studied the effect on its copolymerization behaviour with ethylene. The extent of incorporation of the comonomer is in the order 4‐phenyl‐1‐butene > allyl benzene > styrene for all catalysts. The comonomer incorporation was found to be less than 10 mol% under the experimental conditions employed in the present study. © 2001 Society of Chemical Industry     

Crystallization analysis fractionation of poly(ethylene-co-styrene) produced by metallocene catalysts

Ethylene homo polymer and ethylene–styrene copolymers were synthesized using Cp₂ZrCl₂ (1)/methyl aluminoxane (MAO) and rac-silylene-bis (indenyl) zirconium dichloride (2)/MAO catalyst systems by varying styrene concentration and reaction conditions. Crystallization analysis fractionation (CRYSTAF), DSC, FTIR and ¹H NMR spectroscopy were used for characterizing the synthesized polymers. Interestingly, styrene was able to increase the activity of 1/MAO and 2/MAO catalyst systems at low concentrations, but at higher concentrations the activity decreases. The 1/MAO system at low and high pressure was unable to incorporate styrene, and the final product was pure polyethylene. On the other hand, with 2/MAO polymerization of ethylene and styrene yielded copolymer containing both styrene and ethylene. Results obtained from CRYSTAF and DSC reveal that on using 1/MAO system at high pressure, the resulting polymer in the presence of styrene has similar crystallinity as the polymer produced without styrene. Using both 1/MAO at low pressure and 2/MAO leads to decrease in crystallinity with increase in styrene concentration, even though the former does not incorporate styrene.