RU2374298C1 - Method of producing heavy fuel oil - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to oil refining, specifically to a method of producing heavy fuel oil from oil residues, involving distillation of mazut in a vacuum column, extracting heavy fuel material - tar from the bottom of the said vacuum column and taking the said heavy fuel material or its mixture with a re-circulating viscosity breaking residue to a heating furnace, after which the material is fed into a reaction chamber, where the viscosity breaking reaction takes place at high temperature, with subsequent separation of thermal processing products, coming out from the top of the reaction chamber, in a distillation column to gas, distillate fractions and primary viscosity breaking residue, which is subjected to further thermal action by feeding it into the bottom of the vacuum column for mazut distillation or into the initial viscosity breaking material before feeding into the heating furnace in mass ratio residue: initial viscosity breaking material equal to (over 0.06-0.40):1, with extraction of a secondary viscosity breaking residue from the bottom of the distillation column, which is heavy oil fuel, where part of it is re-circulated into the bottom of the vacuum column for mazut distillation or into the material before feeding into the heating furnace.

EFFECT: increased efficiency of the method, which increases output of distillate fractions.

2 cl, 1 tbl

Description

The invention relates to the refining industry, in particular, relates to methods for producing heavy oil fuel from oil residues, intended for stationary boiler houses and technological installations.

Heavy petroleum fuels (heating oil) are traditionally obtained by mixing the residues of the primary oil refining - straight-run fuel oils, tars, semi-tars, extracts of selective oil refining, asphalt-resinous and other heavy primary oil products involving secondary heavy products - cracking residues, thermal gas oils, etc. [ one. Fuels, lubricants, technical fluids. Assortment and application. Handbook Ed. V.M.Shkolnikov. Ed. 2nd rev. and add. - M .: Publishing center "Techinform", p.100]. To reduce the viscosity and pour point of fuels, diluents are used - medium distillate fractions, especially in cases when there is a significant amount of heavy oil residues in the heating oil.

A known method of producing marine or boiler fuel by visbreaking a mixture of 10% fuel oil obtained by atmospheric distillation of oil and tar obtained by vacuum distillation of 90% of the above fuel oil, in which the cracking residue of visbreaking with a boiling range of 360 ° C, is mixed with 1-5 wt.% heavy gas oil of catalytic cracking, up to 2 wt.% of the residual component of the deasphalting of oils with propane and 0.5-2.5 wt.% slop-wax [2. RF patent No. 2185415, 2001, publ. July 20, 2002 Bull. No. 20].

The method uses several components that differ in chemical and fractional composition from different oil refining processes, which complicates the process of preparing heavy fuel and leads to the formation of unstable aggregate systems and additional capital and energy costs.

There is a method of producing boiler fuel by distillation of fuel oil in a vacuum column to obtain vacuum distillate fractions and the residue - tar, followed by its thermo-destructive processing in a furnace at a temperature of 450-490 ° C and separation of the mixture in a distillation column into a thermal residue and heavy thermal gas, of which after mixing with 0.5-2.5 wt.% metallized fraction withdrawn from the vacuum column, get boiler fuel [3. RF patent No. 2144057, publ. 2000.01.10].

The disadvantage of this method is that during thermo-destructive processing of tar in the reaction coil of the furnace, the temperature reaches 490 ° C, in connection with which the coking of the equipment occurs quickly, the duration of overhaul runs decreases, and energy and capital costs increase.

The closest in technical essence and the achieved result to the proposed one is a method for producing heavy oil fuel (heating oil) from heavy oil raw materials in the process of visbreaking with a reaction chamber.

[four. Varfolomeev D.F., Fryazinov V.V., Valyavin G.G. Visbreaking of oil residues. Thematic review, M .: TsNIITEneftekhim, 1982, p. 26-33].

According to the known method, the feedstock is heated in a tubular furnace, fed into the reaction chamber and taken out of it, cooling the reaction mixture with a quenching product, and then sent to a fractionation column, where the products of thermal processing of heavy oil feed are separated into visbreaking into gas, distillate fractions and visbreaking balance.

The known method has the disadvantages associated with obtaining a visbreaking residue with a high viscosity (16000 cSt at 50 ° C, above 2000 ° W according to Engler), which makes it impossible to use it as a commercial product, and an increase in the process temperature leads to the rapid formation of coke. In addition, the total yield of distillate fractions that are used as components of various fuels due to their low viscosity is only 17.5% of the feed.

An object of the invention is to increase the efficiency of the method for producing heavy oil fuel, which allows to increase the yield of distillate fractions.

“The problem is solved in that in the proposed method for the production of heavy oil fuel, including distillation of fuel oil in a vacuum column, separation of heavy oil feed oil - tar from a cube of a vacuum column for distillation of heavy fuel oil, and supplying it or its mixture with a recycling visbreaking residue to a heating furnace, after which the raw materials are sent to the reaction chamber, where the visbreaking process proceeds at an elevated temperature, followed by separation of the thermal processing products emerging from the top of the reaction chamber, in a distillation column for gas, distillate fractions, and the initial visbreaking residue, the primary residue is subjected to additional thermal treatment by introducing it into the cube of the vacuum distillation column of fuel oil or into visbreaking feedstock before feeding the residue: feedstock of visbreaking in a weight ratio (more than 0, 06-40): 1, with the subsequent separation from the cube of the distillation column of the secondary residue of visbreaking, which is heavy oil fuel, while part of it is recycled into a vacuum cube Olona oil or distillation in the feed before it is fed into the heating furnace. In the method, distillate fractions isolated from visbreaking products are obtained, which are used as components of various petroleum fuels (furnace, diesel, motor, etc.).

A distinctive feature of the proposed method is that the obtained visbreaking residue is subjected to additional thermal treatment by introducing it into the cube of the vacuum column, where it is mixed with the vacuum residue - tar and then enters the visbreaking process, with the subsequent selection of a portion of the balance amount of the secondary residue as the whole product .

Also, the primary visbreaking residue can be introduced into the initial tar before it is fed from the bottom of the column into the heating furnace for additional thermal effect. Circulating the visbreaking residue, which is a product with a reduced viscosity, into a cube of a vacuum distillation column of a fuel oil or into a heating furnace is a technique unknown previously in the production of heavy fuels, which reduces coke formation by diluting highly viscous feedstock before it enters the scheme of the visbreaking process.

In addition, due to the secondary heat treatment of the visbreaking residue, the degree of conversion of the feedstock and the yield of distillate fractions used as components of petroleum fuels increase.

The method is as follows. The remainder of the atmospheric distillation of oil — fuel oil — enters the vacuum column to isolate the vacuum distillates and the remainder of the vacuum distillation of oil — tar. Tar (or its mixtures with other heavy fractions and oil refining residues, for example, oil extracts, heavy vacuum gas oil, semi-tar, etc.) is fed into a heating furnace, where the raw material is heated to a temperature of 430-450 ° C and sent upward from the bottom to the reaction chamber in which chemical reactions take place. After quenching with gas oil, the products of visbreaking emerging from the top of the chamber are separated into a distillation column, from which gas and light distillates are discharged from above, middle distillates (gas oil) from the middle part, and the primary visbreaking residue from the cube. The resulting primary residue is then subjected to additional thermal treatment at a temperature of 360-380 ° C by introducing it into the cube of the vacuum distillation column of fuel oil or into visbreaking feedstock before feeding it into the heating furnace in a weight ratio of residue: visbreaking feedstock (more than 0.06-40) : 1, after which the mixture of feedstock and heat-treated primary residue is fed to heat treatment in the above-described visbreaking mode with the reaction chamber. After the separation of visbreaking products described above, the secondary visbreaking residue is removed from the cube of the distillation column, which is the target product - heavy oil fuel (fuel oil M-100), and the primary residue is converted into a “recycling visbreaking residue” together with a portion of the secondary residue, which a predetermined ratio to the feed is fed into the vacuum column for the distillation of fuel oil or into the feedstock in front of the furnace, and the other part is removed from the installation. Distillates - gasoline fraction, gas oil (wide fraction 200-350 ° С) are removed from the plant as components of petroleum fuels.

The implementation of the method is illustrated by specific examples, the technical data of which are given in the table. In examples 1, 2, 3, a tar was used, having a conditional viscosity at 80 ° C of 118 s, a density of 995 kg / m ³ , and coking ability of 16.5 wt.%. The experiments were carried out on a pilot visbreaking unit with a reaction chamber with a capacity of up to 1.2 l / h. For comparison, under similar conditions, experiments were performed (example 4) using the known method [4] on the same pilot plant using tar with the above indicators.

The data in the table show that the additional thermal effect on the visbreaking residue introduced into the cube of the vacuum column or into the visbreaking feedstock before being fed to the heating furnace according to the proposed method for re-visbreaking the mixture of tar and residue having a reduced viscosity allows increasing the yield of light fractions by 25- 45 rel.%, Reduce coke formation by 2-3 times. Thus, the efficiency of the method for producing heavy oil fuel is increased, and the oil refining depth is also increased to 1.5-2.0% due to the receipt of marketable products from oil residues.

Table No. Name Example Number The proposed method The known method [4] one 2 3 four one Visbreaking Terms: - temperature, ° С at the exit of the furnace 440 440 450 450 at the top of the camera 420 420 430 430 - pressure, MPa 1.4 1.4 2.0 2.0 - raw material consumption, l / h 0.8 1,0 1,2 1,2 2 Balance ratio visbreaking to the original raw materials, wt. share. 0.05: 1 0.25: 1 0.4: 1 3 Yield for raw materials, wt.%: - gas 4.0 3.9 3,5 3.0 - gasoline 9,4 7.6 10.1 5.1 - wide fraction 200-350 ° C 21.1 18.3 23,4 13.9 - sum of light fractions NK - 350 ° C 30.5 25.9 33.5 19.0 - residue> 350 ° C 64.1 69.0 60.9 74.1 - losses (coke) 1.4 1,2 2.1 3.9 four The increase in the yield of light fractions, rel.% 37.7 26.6 43.3 5 Quality indicators of the whole product (M-100): - conditional viscosity at 80 ° C, degrees WU 16.1 15,2 14,4 23.0 - density at 20 ° C, kg / mg ³ 975 972 967 978 - coking ability, wt.% 14.5 13,2 12.8 15.0

Claims (2)

1. A method of producing heavy petroleum fuel, including distillation of fuel oil in a vacuum column, separation of heavy oil feedstock - tar from a cube of a vacuum distillation column of fuel oil, and feeding it or a mixture thereof with a recycled visbreaking residue into a heating furnace, after which the feed is sent to the reaction chamber, where at an elevated temperature, the process of visbreaking proceeds with the subsequent separation of the products of thermal processing, leaving the top of the reaction chamber, in a distillation column into gas, distillate fractions II and the primary visbreaking residue, which is subjected to additional thermal treatment by introducing it into the cube of the vacuum distillation column of fuel oil or into visbreaking feedstock before feeding it into the heating furnace in the mass ratio of residue: visbreaking feedstock (more than 0.06-0.40): 1 , with the separation from the cube of the distillation chamber of the secondary residue of visbreaking, which is heavy petroleum fuel, while part of it is recirculated into the cube of the vacuum column for the distillation of fuel oil or into raw materials before being fed to the heating furnace. 2. The method according to claim 1, characterized in that the distillate fractions isolated from visbreaking products are used as components of various petroleum fuels.