An integrated process of oxidative coupling of methane and pyrolysis of naphtha in a scaled‐up unit

A heat‐effective ‘integrated’ process of C₂H₄ production, incorporating exothermic oxidative coupling of methane (OCM) carried out in the catalytic section of a flow tubular reactor, and endothermic pyrolysis of naphtha carried out in the postcatalytic section of the same reactor, studied earlier in a small silica reactor, was examined now in a scaled‐up unit with a stainless‐steel (1H18N9T) reactor (volume 400 cm³, Li/MgO catalyst bed 165 cm³). It was demonstrated that depending on the operating conditions, such an integrated process could be realized over a wide range of the relative contribution of the two component processes, leading always to an increase in the C₂H₄ yield, as compared with OCM or pyrolysis alone. A high degree of additivity of the yields of all products was observed in all cases, independently of the relative contribution of OCM and pyrolysis. Such results indicated that in the scaled‐up unit with a stainless‐steel reactor, the interactions between the component processes and products were only negligible under experimental conditions. The overall balance of CH₄, being consumed in OCM and formed in pyrolysis, was negative, equal to zero, or positive, depending on the relative contribution of the component processes. The integrated process could be based, therefore, either on CH₄ and naphtha as raw materials or exclusively on naphtha, with the recirculation of the excess of CH₄ to the OCM section. Copyright © 2004 Society of Chemical Industry     

甲烷氧化偶联反应制乙烯的研究进展

介绍了近年来甲烷氧化偶联制乙烯(OCM)过程的催化剂、反应机理、动力学及工程放大涉及的反应工艺、反应器等方面的研究进展,对甲烷氧化偶联法和传统裂解法的经济性进行了对比,指出目前甲烷氧化偶联制乙烯工艺的选择性和转化率还较低,因此成本上比裂解制乙烯要高。最后,对催化剂、工程放大、生产流程和分离方案等方面的研究中存在的问题进行了分析。     

石脑油芳烃抽提工艺改造与参数优化

大庆联谊石化股份有限公司50kt·a~(-1)芳烃抽提装置以常压石脑油为原料,在开工及生产过程中出现了芳烃混浊发泡、颜色发黄、抽余油芳烃含量不合格等问题,通过技术改造,解决了这些问题,优化了常压石脑油芳烃抽提工艺操作参数,取得了很好的经济效益。     

Techno-economic evaluation of a biogas-based oxidative coupling of methane process for ethylene production

This contribution is a preliminary techno-economic assessment of a biogas-based oxidative coupling of methane (OCM) process. Biogas is frequently utilized as a renewable energy source within small scale combined heat and power plants or as a natural gas substitute. The activation of methane also enables its utilization as a feedstock to produce chemicals. In this sense, the OCM process allows for the direct conversion of methane into ethylene, which is a major building block for the chemical and polymer industries. Biogas resulting from the anaerobic digestion of vinasse, a liquid effluent from bioethanol industry, is treated for contaminant removal and its methane content is converted into ethylene, which is then purified as the main product. The biogas cleaning process is assessed based on literature data, while an experimentally validated simulation model is used to assess the OCM process. A techno-economic evaluation is then performed through a Monte Carlo simulation, wherein uncertain parameters take random values between reasonable bounds. The net present value results positive in 74% of the cases, indicating that the project is profitable under a wide range of scenarios. Some performance improvement opportunities have been identified and highlighted to guide future studies in the topic.

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煤制乙二醇生产PET的研究

简要阐述了煤制乙二醇生产聚对苯二甲酸乙二醇酯(PET)的必要性,并以煤制乙二醇为原料制备PET,研究了催化剂、反应时间对PET性质的影响,说明了煤制乙二醇生产PET的可行性。     

基于集成建模方法的乙二醇全流程模拟

乙二醇生产流程是一个包含十几个精馏塔和固定床催化反应器的长流程。由于流程长且反应催化剂影响不易确定等因素,乙二醇生产过程的全流程模拟十分困难。基于ASPEN PLUS软件平台,集成支持向量机、优化算法、机理建模等多种方法,建立了乙二醇的全流程模型。通过采集并处理实际生产的工业数据,采用优化算法进行模型的智能校正,进一步完善了模型的性能。乙二醇全流程模型模拟结果与实际工业过程数据相符,能够满足工业建模的要求。     

水合物法分离低浓度煤层气中的甲烷

向模拟煤层气(13.11vol% CH4+86.89vol% N2)中添加5.8mol%四氢呋喃(THF)?0.03mol%十二烷基硫酸钠(SDS)促进剂溶液分离提纯煤层气,考察了压力、温度、反应时间对气体消耗量、反应速率、分解气中甲烷浓度、甲烷回收率和甲烷分离因子的影响,采用色谱分析法分别测定了CH4在剩余气相和分解气相中的浓度。结果表明,压力增加,CH4回收率增大,CH4分离因子增大,CH4分离效果越好;温度是影响甲烷分离因子的关键因素,温度降低,氮气和甲烷竞争进入水合物晶体中,导致水合物相中甲烷浓度降低;温度升高有利于提高水合物对甲烷的选择性。甲烷回收效率最高可达98.65%,分离因子最大为14.83。随反应时间增加,分解气中CH4浓度升高。     

冷凝法回收石脑油卸车尾气的工艺改进

对吉林石化公司乙烯厂石脑油卸车栈台卸车尾气进行了治理,使多年来直排大气、污染环境、造成资源浪费的尾气排放问题得以改善,并取得了较好的经济效益和环境效益。     

炼化一体化企业中乙烯原料的优化利用

为降低乙烯生产成本,中国石化天津分公司通过优化整合内部资源,拓宽裂解原料来源,将重整液化气、加氢液化气、抽余油、加氢裂化尾油、加氢裂化柴油作为裂解乙烯原料,实现了裂解乙烯原料的自给自足。详细分析了各种原料的性质和裂解收率情况,对于同类装置增加裂解原料来源具有很重要的借鉴意义。     

水解酸化工艺在高盐乙烯污水预处理中的应用

为提高污水处理效果,将水解酸化工艺引入高盐乙烯污水预处理阶段。针对水解酸化工艺对污水可生化性、有机污染物处理效果,以及对后续好氧生化处理和硫酸盐浓度的影响进行了研究。经工业应用后表明,高盐污水经过水解酸化工艺处理后,m(BOD5)/m(CODCr)值提高了27.8%,CODCr的去除率为20.8%,后续生化处理的CODCr去除率较水解酸化池投用前提高了12.9%,污水中部分硫酸盐被还原为硫化物,硫酸盐的质量浓度降低了9.5%。     

The conversion of methane to ethylene and ethane with near total selectivity by low temperature (< 610 ° C) oxydehydrogenation over a calcium-nickel-potassium oxide catalyst

The catalytic oxidative coupling of methane to C₂, C₃ and C₄ paraffins and olefins has been accomplished with close to 100% selectivity at methane conversions of about 10% per pass. Essentially no carbon oxides are formed and the mechanism appears to be a surface catalyzed reaction. Temperatures of < 600 ° C are used and the presence of steam is important. The catalyst comprises a ternary mixture of calcium, nickel and potassium oxides. Method of preparation and composition of the catalyst are critical for its performance. Presence of a carbidic carbon on the catalyst surface may be important.     

乙烯法VCM工艺技术进展及创新研究

阐述了乙烯法VCM工艺技术研究应用进展，比较了三井东压及赫斯特技术的特点，改进并创新了高温氯化工艺，指出赫斯特的氧氯化技术是目前最先进的工艺，国外二氯乙烷精制单元采用在回收塔加抑焦剂的方法。提出把回收塔的真空精馏塔改为汽提塔、在VCM精制工艺中增加气液分离器和减压分离器，将VCM2^#塔设计成垂直筛板结构。     

Steady-state conversion of methane to C4+ aliphatic products in high yields using an integrated recycle reactor system

Conversion of methane in high yields to C₄₊ nonaromatic hydrocarbons was demonstrated in a recycle system. The principal components of the recycle system included an oxidative coupling reactor with a Mn/Na₂WO₄/SiO₂ catalyst at 800°C for conversion of methane to ethylene, and a reactor with an H-ZSM-5 zeolite at 275°C for subsequent conversion of ethylene to higher hydrocarbons. Total yields of C₄₊ products were in the range of 60–80%, and yields of C₄₊ nonaromatic hydrocarbons were in the range of 50–60%. This revised version was published online in July 2006 with corrections to the Cover Date.     

SC-1型裂解炉中重烃-石脑油混合裂解性能优化

通过模拟实验,对大庆石化重烃-石脑油混合原料裂解性能进行了优化研究,考察了在SC-1型裂解炉中重烃质量分数分别为30%、35%的条件下,工艺参数对目的产物收率的影响。实验结果表明,重烃(质量分数30%、35%)-石脑油原料在SC-1型裂解炉中裂解,适宜的裂解温度均为850℃,水油质量稀释比为0.5时,三烯收率分别为53.78%、54.39%,重烃-石脑油混合裂解性能与石脑油单独裂解性能相近。重烃(质量分数35%)-石脑油原料裂解的模拟实验数据已应用于工业裂解炉中,使乙烯收率提高0.48%,三烯收率提高0.15%。     

世界乙二醇供求现状及三菱化学新工艺

叙述了世界乙二醇供求和技术进展状况,预测今后需求年均增长率为6%～7%,介绍了三菱化学的EG制造新工艺,该工艺具有99%以上的高MEG选择率和接近理论量比的水用量,而且投资费用和生产费用低,将成为大型EG装置的首选。     

Characterization of surface carbon formed during the conversion of methane to benzene over Mo/H-ZSM-5 catalysts

During the conversion of methane to benzene in the absence of oxygen over a 2 wt% Mo/H-ZSM-5 catalyst at 700°C, three different types of surface carbon have been observed by X-ray photoelectron spectroscopy: adventitious or graphitic-like C (284.6 eV), carbidic-like C (282.7 eV), and hydrogen-poor sp-type C (283.2 eV), where the C 1s binding energies for the respective forms of carbon are given in parentheses. Pretreatment of the catalyst at 700°C in CO also resulted in a strong signal at 283.2 eV; thus, the species responsible for this signal appears to be different from the usual aromatic-type coke. The coke with dominantly sp hybridization is concentrated on the external surface of the zeolite and is responsible for the gradual deactivation of the catalyst. This revised version was published online in July 2006 with corrections to the Cover Date.     

Dynamic analysis and open‐loop start‐up of an integrated radiant syngas cooler and steam methane reformer

The transient performance of an integrated radiant syngas cooler (RSC) of an entrained‐bed gasifier and steam methane reformer (SMR) is investigated. Base‐case designs using either co‐current or counter‐current configurations are subjected to operating transients to evaluate the feasibility to transition to new steady states. Each system, under open loop, is subjected to changes in key variables of the SMR feed on the tube side and disturbances to variables of the coal‐derived syngas on the RSC side to determine the dynamics and stability of the integrated system. The results indicate that the co‐current configuration is flexible to move to new operating steady states and more safe than the counter‐current configuration, although it provides less cooling and has poorer methane conversion. The variables likely to violate the design limit in the event of a disturbance are identified. A start‐up procedure is also established based on industrial practices employed for entrained‐bed gasifiers and methane reformers. © 2016 American Institute of Chemical Engineers AIChE J, 63: 1602–1619, 2017     

陶瓷膜-生化组合工艺综合处理油脂废水

对采用陶瓷膜-生化组合工艺处理油脂废水进行了研究.该工艺采用陶瓷膜过滤技术对高浓度的碱炼洗涤废水进行预处理,以回收皂脚,其渗透液与其他工艺段排出的生产废水混合后,采用复合厌氧-接触氧化工艺进行生化处理.结果表明,碱炼洗涤废水流量为80 m3/d、COD 58～69 g/L、油3.6～5.3 g/L时,陶瓷膜过滤系统适宜的膜面流速为3.0 m/s、过滤压差0.15 MPa、料液温度40～70℃.在此条件下,碱炼洗涤废水的COD去除率达到97.3%.油去除率96.8%～99.0%.回收皂脚浓缩液8 m3/d.陶瓷膜预处理的采用,显著提高了后续生化处理工艺的效率,使厌氧处理和好氧处理时间均缩短了2 h,降低了运行费用.     

乙二醇脱水和精制系统先进控制与优化

在对过程机理深入分析的基础上,通过推断控制、解耦控制、专家控制等先进控制策略的开发和实施,解决了乙二醇脱水和精制系统存在的具体问题,并根据所建立的准确工业过程模型进行了操作条件优化。表明了先进控制和优化技术的实施显著提高了乙二醇脱水和精制系统操作的稳定性,有效降低系统能耗并延长了运转周期。