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Determination of stability of high-viscosity marine fuel from the point of colloid chemistry concept of oil disperse systems and the need for inclusion of this parameter in the current requirements are expounded. High-viscosity marine fuels produced from residual fuel oil, visbreaking residue, and catcracking light gas oil were taken as the objects of the study. The stability of the obtained samples was determined via xylene equivalent. Also determined was the effect of dispersing additives based on hydroxyethylated amines and alkyl naphthalenes on the stability of the obtained samples of high-viscosity marine fuels.

Diesel oil component and aromatized extract with a high sulfur content have been obtained by extraction purification of mixtures of catcracking and visbreaking light gas oils using N,N-dimethyl formamide in the presence of hexane. The extract can be used for production of technical-grade carbon.

The drawbacks of the planned version of the product separation block are examined on the example of a visbreaking unit at a Russian oil refinery. The causes of its inefficient operation and rapid coking of the equipment are determined. The process solutions to improve the operation of this block which were developed and implemented are presented.

Different aspects of visbreaking with a soaker and coil were examined. The advantages and disadvantages of different methods of turbulization and chilling and different types of heat-exchange equipment were analyzed. The possibility of totally stripping hydrogen sulfide was established. The effect of different factors on the stability of the visbreaking residue was examined. Ways of efficiently utilizing visbreaking residue were demonstrated.

A new visbreaking unit with output of 1.5 million tons a year in vacuum resid was started up at Salavatnefteorgsintez Co. A separate reaction chamber (soaker) is provided in the unit for increasing the degree of feedstock conversion and reducing coking of furnace coil tubes. To increase takeoff of gasoil cuts, the unit is equipped with a vacuum block. Heavy and light vacuum gasoils are used for preparation of type M-100 atmospheric resid.

The possibility of converting a combined delayed-coking unit to operating in conditions of mild thermal cracking (visbreaking) of petroleum resids is examined. Major technical and process solutions that ensure the maximally efficient use of the existing equipment are proposed. The possibility of obtaining boiler fuel with a maximum residual hydrogen sulfide content of 2 ppm is demonstrated. Cost effectiveness is ensured by a significant increase in the volume of refined petroleum resids.

The causes and consequences of development of thermal decomposition of petroleum residues are examined. The results of theoretical, laboratory, and industrial tests of different process schemes are investigated. As a function of the problem solved, thermal cracking and visbreaking prevailed in different stages. The results of using these processes are reported.

Comprehensive studies of the effect of the dose characteristics of an active electron beam on conversion of the components of ozonized and straight-run atmospheric resid were conducted for the first time. It was shown that preliminary ozonation totally alters the mechanism and paths of radiolysis reactions. The structure of the heavy crude oil feedstock changed and the concentration of vanadylporphyrins decreased by 1.3 times.

Sources of hydrogen sulfide in the components of atmospheric resid produced at Kuibyshevsk Refinery Co. are examined. The dependence of its content in atmospheric resid on the process parameters of operation of AVT and visbreaking plants is demonstrated. Possible ways of reducing the hydrogen sulfide content in commercial atmospheric resid are reported. SNPKh–1004 and SNPKh–1050 M neutralizers added to the atmospheric resid bind hydrogen sulfide. They allow producing grade 100 atmospheric resid with a hydrogen sulfide content of less than 2 ppm.

The chief types of hydrogen sulfide absorbers available in the Russian market are examined. The action of hydrogen sulfide absorbers differing in chemical composition is analyzed with reference to two components of commercial residual fuel oil, namely straight-run fuel oil and visbreaking gas oil. The absorbers (absorbents) are effective in almost all cases. They are found to have an adverse effect on the content of water-soluble acids and alkalis.

Secondary processes, visbreaking in particular, are the primary sources of hydrogen sulfide in commercial residual fuel oil, whose content is subject to stiff restrictions in Russia and abroad. The hydrogen sulfide content in residual fuel oil can be reduced by using special reagents, namely, hydrogen sulfide sorbents, which are water-soluble for light petroleum products and crude oil-soluble for dark products. The problems related to use of oil-soluble sorbents are examined.

A crude-oil residue visbreaking unit has been operating for a long time at the Moscow Refinery [1]; it solves the problem of boiler fuel production in the winter. In the summer, it does not run due to the difficulties of utilizing visbreaking residue (VR), although year-round operation is economically expedient. A rational way to use the residue could be in production of asphalt, for which the demand is very high in the summer construction season.

Technical and production solutions ensuring a commercial boiler fuel with a hydrogen sulfide content of no more than 2 ppm are developed as a result of the basic design of a unit for stripping hydrogen sulfide from visbreaking resid. The potential exists for a further increase in the output of the visbreaking plant to 2 million tons/year, where the actual output achieved is 1.4 million tons/year.

In this article we will describe experience in startup and on-line correction of process elements, as well as the mechanical design of the visbreaker. All of the work was aimed at achieving the operating indexes specified in the design, improving the equipment reliability, and extending the length of the runs between maintenance shutdowns.

The quality of the high-viscosity residues changed significantly after reconstruction of the vacuum units (VU) on the AVT units at Ryazan' Oil Refinery Open Joint-Stock Company (see Table 1). A visbreaking unit based on the TK-1, type 15/5 thermal cracking unit in operation since 1961 was constructed for processing these residues. A mixture of vacuum and atmospheric resids was used as the feedstock for the TK-1.

From naphtha obtained in vacuum-resid visbreaking, oligomerization treatment has been proven successful in removing dienes and most of the ractive monoolefins.

Visbreaking heavy resids is one of the process that are used to cut deeper into the barrel of crude.

It has been five years since Tyumen’ Oil Company was formed and Ryazan’ Oil Refinery — the company’s basic refining enterprise — was incorporated in it. During this time, the refinery, advantageously located near Moscow, the largest market in Russia and the region, has passed through two stages typical of Russian enterprises called «survival» and “reconstruction.” Three years ago, few would have thought that the refinery, which was refining no more than 5 million tons of crude oil a year with a planned output of 13 million tons at that time, would not only restore the optimum load volumes but also resume reconstruction with capital investments of $260 million. This became possible due to the advent of the companies "Alpha-Group" and "Renova" in Tyumen’ Oil Company (TOC), their new management, and as a result — a partnership with AVV Co. and financing under guarantee of the American Exim-Bank. The fundamental measures instituted in this period to increase production efficiency were: * ensuring an oil refining volume of 1 million tons per month due to reactivation of AT-6, LCh-35/11-600, and LG-35/8 units, the creation of a unified industrial complex based on the AT-6 atmospheric unit and the vacuum units on the AVT-1 and AVT-2 installations; * introduction of modern domestic reforming catalysts; * organization of production of arctic and winter diesel fuels and petroleum resid; * reducing production of atmospheric resid due to introduction of visbreaking in the modernized TK-1 unit. As a result, the production volume of fundamental products increased in 1998 in comparison to 1997: * automotive gasolines: by 55%; * diesel fuel: by 87%; * aviation kerosene: by 48%; * lube oils: by 35%. In 1999, with an oil refining volume of 11.2 million tons (86% of capacity), a further increase in production volumes was obtained in comparison to the 1998 level: * automotive gasolines: by 60%, including high-octane gasolines by 77%; production of the latter increased by 48%, or 17% above the 1998 level; * lube oils: by 70%; * packaged oils: by 7 times; * asphalts: by 57%; * petroleum resid: by 3 times. Specialists at Ryazan’ OIl Refinery and the Moscow office of TOC have developed and are implementing efficient programs to further increase the production volumes of automotive gasolines, diesel fuels, and lube oils and to bring their quality up to the current international level. Complex reconstruction of the installations for hydrotreating of diesel fuel allowed beginning industrial production of this fuel with improved environmental characteristics for the first time in Russia: a sulfur content of less than 0.034%, which corresponds to European certification EN 590, i.e., the latest international requirements. On completion of reconstruction of the LCh-24-7 unit, all of the diesel fuel produced will satisfy these specifications. Technologies for isomerization of light naphtha cuts were successfully assimilated due to the use of a new catalyst developed by Russian scientists and used for the first time at the refinery. This technology will allow

Two variants for the visbreaking of petroleum resids in unheated reaction chambers were investigated: the first in which the feed enters at the top (downflow) and the second in which feed is introduced at the bottom of the chamber (upflow). The evaluations were based on reaction time for a given conversion and on product quality. Studies were carried out in a pilot unit. Feedstocks consisted of vacuum tar from a mixture is West Siberian and Ukhta crudes. Process conditions and product yields were compared. Direction of flow had a substantial influence on the visbreaking regime.

This article reports on work to determine the quality requirements for short resids and the definition of single stage cracking conditions such that standard residual fuel oil can be obtained without the use of any outside diluents. Two types of feedstock are used: short resids from Romashkino crude containing 21%, 33% and 38% by weight of fractions distilling below 500/sup 0/C, and a short resid from mixed Siberian crudes containing 10% by weight of fractions distilling below 500/sup 0/C. The higher the density of the residue above 500/sup 0/C of the original feedstock, the greater are the amounts of gasoil cuts below 500/sup 0/C that must be left in the feed in order to obtain standard fuel oil (boiler fuel).

This article compares different schemes for the processing of long resid, both by the traditional process of thermal cracking and by possible modifications and combinations of this process (e.g., visbreaking of long and short resids and thermal cracking of heavy distillates). Material balances for thermal cracking and visbreaking of resids from medium-sulfur crudes (with a predominant yield of diesel fuel cuts) are used for the calculations. It is determined that the most cost-efficient of the schemes for the thermal processing of long resid are the methods oriented toward visbreaking of the short and long resid in combination with thermal cracking of the vacuum distillate. The most effective method of long resid processing is found to be the catalytic processing of vacuum gasoil in combination with visbreaking of short resid.

As a result of experiments on the deep hydrogenation of thermally cracked gasoline from the visbreaking and delayed coking of tar from high-sulfur Arlan crude on an industrial alumo-cobalt-molybdenum catalyst it was established that to obtain a high-quality feedstock for catalytic reforming from these gasolines the purification must be done in two stages.