DEPOSIT FORMATION DUE TO INSTABILITY AND CONTAMINATION OF RAW MATERIALS IN ALKALI-TREATED LIGHT DISTILLATES

ABSTRACT

Alkali treating of petroleum distillates is carried out to obtain the advantages of the product purity and to improve performance. The use and quality of alkaline solutions must be controlled since metal ions present as impurities can catalyze low temperature oxidation and polymerization of olefinic compounds; leading to formation of heavy emulsions which tend to deposit in hydrocarbon phases and eventually to block the handling systems. The effects of the variable factors “time, temperature, antioxidant and anticorrosion additives” were studied. The addition of a small amount of methanol was found to retard the deposit formation. This can be ascribed to ion-molecule reactions of methoxide ions with aryl and heavy thiols present in the light distillates. The promoting effects of light and the surrounding air on the stability of final treated product have been investigated.     

MIP装置回炼轻汽油馏分增产丙烯的实施方案及效果

为降低成品油产量、增产丙烯,可将高烯烃含量轻汽油馏分送回MIP装置进行回炼。轻汽油回炼方式有4种：轻汽油走单独增设的回炼提升管回炼,轻汽油走急冷油线进MIP反应器变径提升管回炼,轻汽油进MIP提升管预提升段底部回炼,轻汽油进单独增设回炼喷嘴（在重油喷嘴下方）回炼。经对比分析发现：在重油喷嘴下方单独增设轻汽油回炼喷嘴回炼,可以调控反应时间和反应深度;在尽量多产丙烯的前提下,轻汽油回炼产物分布合理、对MIP产品性质负面影响小、装置经济效益好,是优选的轻汽油回炼方式。     

DETERMINATION OF ORGANIC SULFUR COMPOUND TYPES IN VACUUM GAS OILS USING GC-FID-SCD METHOD

The analyses of individual organic sulfur compounds in petroleum distillates are the key to understanding the kinetics of the chemistry involved in hydrodesulfurization, HDS. A sample of vacuum gas oil (VGO) produced commercially by distillation of treated atmospheric residue was analyzed by GC-FID-SCD method for individual organic sulfur compounds characterization and quantification. Dibenzothiophene and benzonaphthothiophene and their alkyl derivatives were found to constitute almost the entire organic sulfur compound range present in the VGO. Using a relationship between the total sulfur determined by “X-ray” and “Coulomax” methods and the composition of individual sulfur compounds determined by SCD, the quantity of those organic sulfur compounds present in VGO was estimated. Despite the limit in temperature raise (325°C) in the capillary column and that the range studied (346-555°C) is higher than those limits, optimum conditions were chosen to overcome those obstacles. From the analyses the behavior of refractory and unrefractory sulfur compounds in the VGO region can now be followed easily.     

Delayed coking — Innovations and trends: 1993 update

Delayed coking has an increasingly important role to play in the integration of modem petroleum refineries because of its ability to convert heavy vacuum residues to lighter distillates and petroleum coke. The flexibility of operation inherent in delayed coking permits refiners to process a wide variety of crude oils including those containing heavy, high sulfur residues. These crudes are frequently bought at a discount and if economically convertible to light distillates by Delayed Coking can be a substantial factor in the refiner's cash flow development. The purpose of this article is to provide a perspective on the considerations that go into the specification of new Delayed Cokers and provide complementary operating insights.Published in Khimiya i Tekhnologiya Topliv i Masel, No. 2, pp. 9–17, February, 1995.     

原油中氯化物的来源分布及脱除技术研究进展

原油中的无机氯化物主要以碱金属和碱土金属盐形式存在,利用电脱盐装置可以有效地脱除这些氯化物.有机氯化物来自采油过程中使用的含氯助剂,早期研究认为有机氯主要分布在原油轻馏分中,近年研究表明有机氯的分布较为复杂,在原油的重馏分中也含有较大量的氯化物,且现有的电脱盐装置并不能有效地脱除原油中的有机氯化物,因此需要开发新的脱除有机氯化物的方法.     

多产低碳烯烃工艺参数的变化对产品选择性的影响

针对中国石化荆门分公司现有两套催化裂化装置（一催和二催）的目的产品不同（一催多产低碳烯烃,二催保持较高额度液体收率和汽油产率）,希望通过调整工艺参数满足要求的情况,通过实验考察了反应时间、剂油比和再生温度对产物分布和选择性的影响。结果表明：延长反应时间,热裂化反应深度会显著增加,干气选择性和氢气产率明显增加,热裂化指数明显上升;增加剂油比是保持丙烯收率、增加总液体收率的优选方案;较高的初始油剂接触温度有利于低碳烯烃的生成,但如果以汽油、柴油为目的产物,则应该适当降低再生温度和初始接触温度,而不是降低反应温度。     

LONG TERM STORAGE STABILITY OF MIDDLE DISTILLATE FUELS FROM A CHEMICAL MECHANISTIC POINT OP VIEW. PART 1.

The objective of this review is to (i) articulate the current level of understanding of the types of “reactive molecules” intimately involved in the long term oxidative storage instability of middle distillates, (ii) review the types of chemical reaction mechanisms most likely involved in the “oxidative phase” of insoluble formation, (iii) review the postulated chemical mechanisms of stabilizer (additive) operation, and (iv) discuss future research areas that must be explored if a greater understanding and control of middle distillate instability is to be realized.     

LONG TERM STORAGE STABILITY OF MIDDLE DISTILLATE FUELS FROM A CHEMICAL MECHANISTIC POINT OF VIEW. PART 2.

The objective of this review is to (i) articulate the current level of understanding of the types of “reactive molecules” intimately involved in the long term oxidative storage instability of middle distillates, (11) review the types of chemical reaction mechanisms most likely involved in the “oxidative phase” of insoluble formation, (iii) review the postulated chemical mechanisms of stabilizer (additive) operation, and (iv) discuss future research areas that must be explored if a greater understanding and control of middle distillate instability is to be realized.     

KINETIC PARAMETERS OF HYDROPROCESSING REACTIONS IN A FLOW REACTOR

ABSTRACT

The change in distillation properties of a blend of light and heavy distillates over a commercial hydrotreating catalyst was studied using a small packed bed reactor. The results were interpreted assuming a pseudo-component model that took into account the physical and chemical complexity of the system. A first order series-parallel reaction mechanism was found to be valid for the operating conditions involved. Pore diffusion effects were also taken into consideration.     

THE PRELIMINARY STUDY ABOUT THE COMPOSITION OF DAQING HEAVY FRACTION OIL

ABSTRACT

The family composition of Daqing heavy fraction oil and the latent content of lubricating oil by mass spectrography and slovent dewaxing methods were determined, and then compared with document data.The change of Daqing heavy distillate is discussed.The results show Daqing crude oil and its distillates have the trend to be heavier,but its heavy distillates are still suitable for catalytic stocks of heavy catalytic cracking and its residuum can be also used for the feed stocks and other wide uses. We hope the analysis results can provide scientific basis for refineries.