RU2255958C1 - Heavy petroleum fraction processing method - Google Patents

Abstract

FIELD: petroleum processing and petrochemistry.

SUBSTANCE: heavy petroleum fractions are processed via catalytic and thermal cracking of feedstock in presence of activating additive obtained by treatment of petroleum products with ozone-containing gas, said petroleum products containing at least 0.65% sulfur-containing compounds (as sulfur equivalent) and at least 3,5% polyarene compounds. Processing is accomplished by stepwise introduction of activating additive into processed heavy petroleum fractions.

EFFECT: increased output of light products.

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Description

The invention relates to the field of oil refining, in particular to methods for the secondary processing of heavy oil feedstocks, and can be used in catalytic and thermal cracking processes, including visbreaking.

A known method of processing vacuum gas oil by catalytic cracking, in which oxyalkylated alkyl phenol or block copolymers of ethylene and propylene oxides are introduced into the feedstock [SU 1474168]. This technique allows you to slightly increase the yield of gasoline (from 27.8 to 28.9 wt.%), But the high cost of additives and a slight increase in yield make it ineffective.

A known method of processing heavy raw materials, according to which part of the source of heavy oil and / or raw materials that are different in composition from the source, is modified by treating with air at a temperature of 200-300 ° C and a mass ratio of air: raw materials of 0.2: (0 , 6-1). After separation and removal of the gas phase, the liquid product is subjected to vacuum distillation with the release of distillate, boiling to a temperature of 540 ° C. The distillate is then mixed with the feedstock to an additive concentration of 2.0-25 wt.% [WO 9319139]. The method increases the yield of light oil products, without reducing the duration of operation of the catalyst.

The main disadvantages of this method is the two-stage process for producing an activating additive using high temperature in the first stage and vacuum distillation of the oxidant in the second.

The closest analogue of this method is a method for processing heavy oil fractions by catalytic cracking in the presence of an activating additive obtained by treating petroleum products containing at least 0.65% sulfur-containing compounds in terms of sulfur and at least 3.5% polyarene compounds using ozone in an amount based on the content of 0.5-13 g of ozone absorbed by the additive per 1 kg of the mixture [RU 2123026].

The main disadvantages of this method is the relatively low yield of light fractions.

The objective of the invention is to increase the yield of light fractions during catalytic and thermal cracking.

The problem is achieved by the method of processing heavy oil fractions by heating them in the presence of an activating additive obtained by processing petroleum products containing at least 0.65% sulfur-containing compounds in terms of sulfur and at least 3.5% polyarene compounds, with an ozone-containing gas, followed by separation of products into fractions in which the refining process is carried out with a fractional supply of an activating additive in the processed heavy oil fractions. At the same time, for example, vacuum gas oil of various origins, as well as mixtures thereof with fuel oil, can be used as heavy petroleum feedstock for catalytic cracking, and for thermal cracking there are practically no restrictions on the nature and composition of the feedstock. It may consist entirely of fuel oil, oil and / or natural tar and mixtures thereof.

An activating additive is obtained according to the procedure described in RU 2123026, by bubbling ozone-containing gas through a layer of oil products at 20-60 ° C until the oil products are saturated with ozone. At the same time, petroleum products must contain at least 0.5% sulfur-containing compounds in terms of sulfur and at least 3.5% polyarene compounds to obtain an additive. To obtain an activating additive, you can use oil products, which are the feedstock for processing. Usually, the amount of additive introduced into the feedstock is determined on the basis of ensuring the content of 0.5-13 g of bound ozone per 1 kg of the mixture supplied for processing. Moreover, the content of bound ozone in the feedstock in an amount of less than 0.5 g / kg does not give a noticeable increase in the yield of light oil products, and an increase above 13 g O ₃ per kg of feedstock leads to additional energy costs that are not offset by a corresponding increase in the yield of target products.

Cracking is carried out in traditional conditions, for example, catalytic - at a temperature of 500-530 ° C. During thermal cracking, it is possible to reduce the pressure to atmospheric and temperature to 350 ° C.

The following examples illustrate the method.

Example 1

As a feedstock for thermal cracking, oil tar with a density of 1.01 is used, having the following elemental composition (wt.%): C - 85.4; H - 10.52; S is 1.88; N is 0.4 and O is the rest. The content of paraffin-naphthenic hydrocarbons is 15.7%, arene - 56.1%, resins and asphaltenes - the rest. An activating additive is obtained by treating part of the initial oil tar with an ozone-air mixture at 30 ° C. Half of the obtained additive is mixed with the original oil tar, while obtaining a mixture containing 5.5 g of absorbed ozone per 1 kg of the mixture. Cracking is carried out in a rotating liter autoclave for 50 min at a temperature of 450 ° C. After that, the autoclave is cooled, gas is separated, the second half of the additive is introduced and heating is continued at 450 ° С for 40 minutes. After completion of the process, the autoclave is cooled, gas is separated, liquid products are unloaded and their distillation is carried out with the selection of the gasoline fraction from t _bales to 200 ° C and diesel distillate to 340 ° C. In parallel, a comparative experiment is carried out with the supply of the entire additive to the initial oil tar, while the content of bound ozone in the initial mixture is 11 g / kg. The results of the comparative experiment are shown in parentheses. The yield of products on the feedstock (wt.%): Fractions from t _bales to 200 ° C - 20.3 (16.4)%; fractions with t _bales = 200-340 ° C - 45.4 (44.7)%. The total yield of light fractions from t _bales to 340 ° C was 65.7 (61.1)%.

Examples 2-4

The process of thermal cracking of the tar is carried out under the conditions of example 1, varying only the total specific content of absorbed ozone supplied with the additive, and dividing the total (total) amount of activating additive into 2, 3 and 4 equal parts. The results of three experiments are shown in table 1.

Table 1 The results of examples 2-4 Example No. The total content of bound ozone, g / kg Servings Per Container The yield of light fractions, wt.% The output of light fractions when you enter the total amount of additives (prototype), wt.% 2 4.1 2 43,4 38.1 3 7.4 3 52,5 47.3 4 14.9 4 68.3 59.7

Examples 5-9

Vacuum gas oil of a combined West Siberian oil is subjected to processing with a sulfur content of 1.34 wt.%, A density of 0.89, a viscosity of 28.4 cSt, having the following composition (wt.%): Saturated hydrocarbons 50.9; Arenas 48.1.

An activating additive is obtained by treating part of the initial gas oil with an ozone-air mixture at room temperature. The process is carried out in a flow-through installation consisting of two catalytic cracking units connected in series at 500 ° C and a mixture feed rate of 2.0 h ^-1 in the presence of a microspherical aluminosilicate catalyst. Half of the activating additive is mixed with the feedstock and fed to the inlet of the first catalytic cracking reactor, and the remaining half of the additive is mixed with cracking products leaving the first reactor, and fed to the inlet of the second catalytic cracking reactor. The results of the examples are shown in table 2.

table 2 The results of examples 5-9 Example No. The total content of bound ozone, g / kg The yield of light fractions, wt.% The output of light fractions when you enter the total amount of additives (prototype), wt.% 5 3.8 70.1 66,4 6 1.9 58.2 55,4 7 5,0 71.0 67.9 8 8.2 74.3 69.7 nine 9.3 75.8 69.9

Thus, the thermal cracking of tar with a fractional feed of an activating additive allows to increase the yield of light oil products to 68.3%. When processing vacuum gas oil by catalytic cracking, the yield of light oil products increases to 75.8 wt.%.

Claims (1)

A method of processing heavy oil fractions by catalytic and thermal cracking in the presence of an activating additive obtained by treating petroleum products containing at least 0.65% sulfur-containing compounds in terms of sulfur and at least 3.5% polyarene compounds with an ozone-containing gas, followed by separation of the products into fractions, characterized in that the refining process is carried out with a fractional supply of an activating additive in the processed heavy oil fractions.