C4烷烃裂解制低碳烯烃应用研究进展

本文详细介绍了C4烷烃蒸汽裂解和催化裂解技术;与蒸汽裂解技术相比,催化裂解具备降耗增产的同时降低对原料油的苛刻、减少对设备的腐蚀等优点,C4烷烃催化裂解技术在国内外已取得了一些实验室的研究成果,并出现以KBR公司的ACO技术为例的成熟的催化剂体系和催化裂解工艺。     

稠油开采水热裂解技术研究进展

随着常规原油的产量逐渐下降,稠油的开采技术得到了人们的重视并不断发展。本文简单介绍了目前稠油开采的技术手段,同时详细介绍了稠油水热裂解技术的发展、水热裂解催化剂的分类及存在的问题、供氢剂研究进展、对水热裂解降粘机理进行了解释。最后指出了稠油水热裂解技术目前存在的问题及未来发展方向。     

催化裂解碳四烃综合利用

介绍了我国Ｃ＿４烃资源的概况，国内外Ｃ＿４烃化工利用的现状、特点及以催化裂解Ｃ＿４烃为原料合成的主要产品。     

混合C4作乙烯原料的研究及经济性分析

以混合C₄作乙烯裂解原料,通过GK-Ⅵ型蒸汽裂解炉分别进行了4个不同稀释比(水和物料的质量比)及裂解温度评价试验,并进行未加氢混合C₄与加氢混合C₄裂解性能对比评价实验。结果表明,在裂解温度为838℃、反应压力为0.085 MPa、稀释比为0.55的条件下,加氢混合C₄三烯收率大于50%,并且经济效益达到最大,为最佳裂解条件。加氢混合C₄可以作为原料蒸汽裂解制烯烃的有效补充。     

国外裂解C5资源的利用途径

国外裂解C5资源的利用始于20世纪40年代，各国、各公司根据裂解C5的来源和市场需求的不同采取了多种利用途径，并取得了很好的效益。目前，美国裂解C5的综合利用率已经达到70％左右，日本的达到50％以上，而且C5分离装置规模大，技术先进，其     

裂解C9综合利用现状分析

综述了乙烯裂解C9来源、组成、性质及其国内外综合利用情况;重点介绍了C9石油树脂的合成情况,并对芳烃溶剂油及裂解C9加氢催化剂进行了阐述。从而体现了裂解C9资源发展的趋势以及展望。     

C4馏分综合利用技术的进展

重点介绍了国外裂解和催化裂化副产C_4馏分中丁二烯、丁烯,异丁烯、异丁烷等组分的分离及其利用技术的进展,以及C_4馏分综合利用方案的选择。     

裂解C9综合利用现状及发展展望

随着乙烯工业的飞速发展,作为乙烯副产品的C9资源也呈现出了快速增长的趋势。实现乙烯裂解副产C9馏分的综合利用,提升产品的附加值,对提升我国石油化工产业的国际竞争力具有十分重要的意义。本文介绍了国内外裂解C9资源的应用现状,从裂解C9加氢工艺、生产芳烃石油树脂和提取精细化学品及其衍生物等方面详细阐述了裂解C9馏分的深加工技术及进展。文章还对裂解C9产业的发展进行了展望,应根据不同的原料特性,采用分级分质的方法,有针对性地生产高附加值的化学品及其衍生物、高端氢化石油树脂及高品质溶剂油等产品,促进裂解C9资源的综合利用,推动裂解C9资源向精细化、功能化和多元化的高质量发展。     

裂解C5组分中异戊二烯的利用及生产异戊橡胶的前景分析

介绍了我国裂解C5资源量及利用状况,以及异戊橡胶市场供需现状,分析了异戊橡胶生产的技术经济性及存在的问题,提出了加快发展我国异戊橡胶的建议。     

裂解技术进展

介绍了裂解制乙烯技术的发展趋势，着重从裂解炉型，大型化，原料灵活性，急冷技术，抑制结焦技术和控制技术等方面，介绍了裂解制乙烯技术的最新发展情况及国内的裂解制乙烯技术的现状，提出了我国裂解技术的发展方向。     

Production of steam cracking feedstocks by mild cracking of plastic wastes

In this work the utility of new possible petrochemical feedstocks obtained by plastic waste cracking has been studied. The cracking process of polyethylene (PE), polyethylene-polypropylene (PEPP) and polyethylene-polystyrene (PEPS) has been carried out in a pilot scale tubular reactor. In this process mild reaction parameters has been applied, with the temperature of 530 °C and the residence time of 15 min. The produced hydrocarbon fractions as light- and middle distillates were tested by using a laboratory steam cracking unit.It was concluded that the products of the mild cracking of plastic wastes could be applied as petrochemical feedstocks. Based on the analytical data it was determined that these liquid products contained in significant concentration (25-50 wt.%) of olefin hydrocarbons. Moreover the cracking of polystyrene containing raw material resulted in liquid products with significant amounts of aromatic hydrocarbons too. The steam cracking experiments proved that the products obtained by PE and PEPP cracking resulted in similar or better ethylene and propylene yields than the reference samples, however the aromatic content of PEPS products reduced the ethylene and propylene yields.     

Biofuel potential production from cottonseed oil: A comparison of non-catalytic and catalytic pyrolysis on fixed-fluidized bed reactor

Conversion of vegetable oils predominantly composed of triglycerides using pyrolysis type reactions represents a promising option for the production of renewable fuels and chemicals. The purpose of this article was to compare catalytic cracking with thermal cracking on production of gaseous hydrocarbon and gasoline conversion by cottonseed oil, and to discuss the difference on composition of products from catalytic cracking and thermal cracking. Reaction products are heavily dependant on the catalyst type (catalyst activation) and reaction conditions. They can range from dry gas to light distillate, such as dry gas, liquefied petroleum gas and gasoline. When the temperature of catalytic cracking is over 460 °C, the effects of thermal cracking must be considerable.     

废旧轮胎催化裂解研究进展

废旧轮胎因产量高、难降解、污染环境,被称为最难处理的“黑色垃圾”之一。催化裂解是一种处理废旧轮胎的重要手段,可以实现其高效转化与资源化利用,同时得到高附加值的化学产品,如单环芳烃、低碳烯烃与柠檬烯等。本文基于轮胎的物理结构与化学组成、催化裂解过程与裂解产物特征、反应器类型与特征、催化剂类型与作用原理、工艺条件等问题综述了废旧轮胎的催化裂解产物分布规律。通过对比反应器、催化剂与工艺条件对产物分布的影响,进一步分析了当前实现废旧轮胎催化裂解工业化的问题,并基于当前废旧轮胎催化裂解的研究现状,提出应集中设计适应于大规模处理的反应器与配套工艺,同时开发高稳定性与对特定产物高选择性的催化剂,从而实现对废旧轮胎以低能耗、高转化、高价值为特点的资源化利用。     

炼油产乙烯裂解原料的优化利用及经济分析

炼油厂的一次、二次加工油品及副产气体是乙烯裂解炉的主要原料来源。主要对炼油产乙烯裂解原料进行优化利用,分析不同优质裂解原料对三烯收率影响及其经济性,为乙烯装置原料选择,优化降本,根据市场需求生产乙烯、丙烯或丁二烯产品,提高经济效益提供参考。     

Studying the Influence of Alumina Catalysts Doped with Tin and Zinc Oxides in the Soybean Oil Pyrolysis Reaction

The pyrolysis of vegetable oils consists of cracking triglycerides to produce smaller molecules. A mixture of hydrocarbons and oxygenated compounds, such as carboxylic acids and aldehydes, is obtained as the product and which can be separated by fractional distillation. When the reaction is carried out in the absence of catalysts (thermal cracking), a great quantity of these oxygenated compounds is obtained. Thus, the presence of those oxygenated compounds in the products results in a high level of acidity, which can be a problem when using them as fuels in combustion engines. The aim of this work was to study the composition of the products obtained by cracking of vegetable oils assisted by γ-alumina doped with zinc and tin oxides. The products were analyzed by FT-IR, GC-MS and GC-FID and the acid number was determined by titration with alcoholic KOH solution. The acid number, infrared spectra and chromatograms of the resulting hydrocarbon mixtures indicated a significant reduction in oxygenated compounds when compared with the mixtures obtained by the thermal cracking process, thus decreasing the acidity of the mixture.     

The products of cumene cracking on an amorphous silica alumina

A detailed analytical study of the products of cumene cracking over amorphous silica alumina shows that the mechanism of cracking over these catalysts is identical to that observed over crystalline LaY and HY at various levels of exchange. Additional analytical details are developed in this work and are used to elaborate on the previously proposed reaction network for this reaction. In particular we find that hydrogen and propane appear as secondary products in the cracking reaction network. We also find that within the limits of our measurement all the observed coke is formed from product propylene.     

OXIDATIVE CRACKING OF LINEAR HYDROCARBONS AT LOW TEMPERATURES

This work describes the oxidative cracking of n-alkanes with molecular oxygen at low temperatures (below 473 K) in an autoclave reactor. An increase of the oxygen consumption rate with increasing hydrocarbon size was observed. Data for n-hexadecane indicate that oxidative cracking is an autocatalytic reaction. The oxidation rate increased with the progress of the reaction. Low molecular weight compounds were formed as the main products. CG and CG-MS analyses of the liquid products found homologous series of oxygen compounds (acids, ketones, and ethers) and short-chain n-alkanes. Our results strongly suggest that oxidative cracking can be employed for processing heavy materials such as polymers and petroleum residues.     

油脂催化裂解制备可再生烃类燃料研究进展

非食用油脂作为一种生产可再生烃类燃料的原料,受到了全世界的关注。相对于常规的裂解非食用油脂生产烃类燃料的方法中存在的脱羧选择性较差、产物中饱和烃类少、含氧有机物多等问题,微波辅助裂解具有选择性、脱羧过程中微波具有促进作用、烃类得率高等优点。本文简述了目前常用的油脂催化裂解的方法,着重介绍了不同催化剂的催化裂解、微波辅助裂解制备液体燃料。通过比较,得出了微波催化裂解在燃料性能及处理成本上的优势,为制备低成本、高效能的可再生烃类燃料提供了新方法,具有广阔的应用前景。     

Acid-catalyzed cracking of polystyrene

The effects of catalyst acidity and the restricted reaction volume afforded by HZSM-5 on the volatile cracking products derived from poly(styrene) are investigated. Three catalysts: silica/alumina, HZSM-5, and sulfated zirconia, were employed as cracking catalysts. Styrene, which is the principal radical depolymerization product from poly(styrene), is a minor catalytic cracking product. The most abundant volatile product generated by catalytic cracking is benzene. Alkyl benzenes and indanes are also detected in significant yields. Various thermal analysis techniques are employed to obtain volatilization activation energies for polymer-catalyst samples and to elucidate probable reaction pathways. Detected products are explained by reaction mechanisms that begin with protonation of poly(styrene) aromatic rings. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 63: 1287–1298, 1997     

Solid-acid-catalyzed alkane cracking mechanisms: evidence from reactions of small probe molecules

This review is a summary of the mechanisms of catalytic cracking of small (C₃-C₆) alkanes. Most of the evidence has arisen from product distributions and kinetics of cracking of these alkanes, interpreted on the basis of solution carbocation chemistry and theoretical chemistry. Cracking of small alkanes catalyzed by solid acids such as the zeolite HZSM-5 proceeds by two mechanisms: (1) The unimolecular (protolytic cracking) mechanism, which proceeds via an alkanium ion formed by protonation of the alkane by the catalyst. This supposed transition state collapses to give either H₂ and a carbenium ion or an alkane and a carbenium ion; the carbenium ions give up protons to the catalyst to form alkenes. The cracking products include methane and ethane as well as H₂. (2) The classical (bimolecular) cracking mechanism, which involves carbenium ion chain carriers that react with the alkane reactant to abstract hydrides and generate carbenium ions that undergo β-scission. The products include alkanes and alkenes, but not methane, ethane, or H₂. Because protolytic cracking gives alkene products, which are much stronger bases than alkanes, the alkenes become the predominant proton acceptors as conversions increase, and thus bimolecular cracking prevails at all but the lowest conversions. Protolytic cracking in the near absence of secondary reactions has been observed only for propane and n-butane at low conversions; secondary reactions appear to be generally significant for other alkanes. Although the product distributions are qualitatively understood, there are still inconsistencies in the literature of quantitative product distributions and kinetics, and more experimental work is needed with standard catalysts such as HZSM-5. Theoretical chemistry is leading to deeper understanding of the transition states, showing that cracking mechanisms involving bare carbocations are oversimplified. Rather, the catalyst surface must be included, and it has been simulated by clusters that are zeolite fragments. Surface alkoxides are more stable than surface carbenium ions, and cracking takes place by concerted bond breaking and formation. Theoretical activation energies for protolytic cracking of alkanes are close to experimental activation energies that have been corrected for the adsorption energy of the reactant, but it appears that more theoretical work (as well as better data) is required for satisfactory agreement of theory and experiment. This revised version was published online in June 2006 with corrections to the Cover Date.