RU2260616C2 - Process of manufacturing liquid products in delayed coking plants - Google Patents

Abstract

FIELD: petroleum processing.

SUBSTANCE: invention relates to technology of processing heavy petroleum residues, in particular to coking process, which can be used in delayed coking plants. Processing of sulfur-containing raw material in delayed coking plants comprises preheating raw material and treating it with supplied hydrogen, said raw material being heavy petroleum residues or petrochemical by-products. Coking process is carried out in one step in presence of hydrogen supplied in quality 10 to 200 m³ per 1 m³ raw material.

EFFECT: increased yield of liquid products, reduced sulfur level in products, and reduced material and power consumption.

2 cl, 2 tbl

Description

The invention relates to a technology for processing heavy oil residues, namely to the coking process, and can be used in delayed coking plants.

The raw materials for processing at delayed coking plants are various oil residues - fuel oil obtained by atmospheric distillation of oil; tars obtained by vacuum distillation of fuel oil; asphalt; oil by-products; heavy catalytic cracking gas oil; heavy pyrolysis resin. The target products of the process are: gasoline, light and heavy gas oils, petroleum coke, unsaturated and hydrogen sulfide-containing gases.

Despite the fact that heavy gas oil is used as a component of heating oil, petroleum coke is used in various industries, unsaturated gas is used as raw material for gas fractionation plants and fuel gas, and hydrogen sulfide-containing gas is used for the production of sulfuric acid; it is considered economically feasible to obtain the maximum amount liquid products (gasoline, light and heavy gas oil). An increase in the yield of the latter is also preferable due to the fact that at present the cost of gasoline, diesel fuels and heating oil is 1.5-3 times higher than the cost of petroleum coke and gas. In addition, there is an urgent need to reduce the sulfur content in the obtained coking products, since the main component of the raw materials in delayed coking units (UZK) are straight-run oil residues - tars.

Practice has shown that the yield of coking products and their quality depend on the composition and quality of the used individual oil residues or mixtures thereof. Therefore, at all UZKs, the task of increasing the yield of target products and improving their quality is solved by selecting the optimal composition of coking raw materials and regulating the technological parameters of the process.

In the works (D.F. Varfolomeev, A.I. Stekhun. Raw materials of coking and the effectiveness of its use. M., TSNIITENEFTEKHIM, 1987, p. 28-33 and N.T. Porodenko, B.I. Bronds. Receiving and processing petroleum coke. M., \ Chemistry \, 1986, p.67) the possibility of controlling the yield of coking products by changing the depth of tar concentration in the process of vacuum distillation at ABT installations is shown. The coking process is carried out at a heating temperature of 470-482 ° C and a pressure of 3.5-3.8 kgf / cm ³ .

Common features of the known technical solutions and the claimed is that the tar is used as a raw material, and the coking process is carried out at high temperature.

However, these technical solutions have the following disadvantages:

- High gas output, low selection of vacuum shoulder straps and, as a result, low production of liquid products (oils and high-octane gasolines) while reducing the concentration of tar;

- Low quality petroleum coke (including the low mechanical strength of coke and, as a result, a large amount of coke breeze);

- Fast coking of the furnace coils due to weighting of tar;

- Overloading of technological equipment.

It is known (R. A. Kerimov, P. D. Shikhalizade, N. A. Salimova, T. F. Ganiev, M. Dakakni. Oil refining and petrochemicals, 1983, No. 12, p. 3, 4) a technical solution in which the composition of the raw material, in addition to tar, includes an extract of selective purification of oils.

Common features of the known technical solution and the claimed are the composition of the raw materials and the temperature regime of coking.

The disadvantages of the known technical solutions are:

- Use of a scarce component - an extract of selective oil purification;

- Insufficiently high yield of light petroleum products;

- An increase in the sulfur content in coking products due to its increased content in the extract of selective oil purification.

A known process for processing sulfur raw materials, including its heating to a coking temperature (475-480 ° C) (Patent RU No. 2210585). The process is carried out under a pressure of 3.2-3.5 kgf / cm ² . An increase in the yield of target coking products and an improvement in their quality was obtained by adding heavy pyrolysis resin (2-20 wt%) and heavy catalytic cracking gas oil to the tar.

Common features of the known technical solution and the present invention are the technological parameters of the coking process (pressure, sulfur feed, temperature).

The disadvantages of this method are:

- Insufficiently high yield of liquid products;

- Limited resources of heavy pyrolysis resin;

- The content of sulfur in the target products to the extent that adversely affects their further use.

The closest (prototype) in technical essence is the process of processing sulfur raw materials, which includes the following stages:

- the raw material is heated to a coking temperature, and then served in a delayed coking chamber with hydrogen,

- after coking, the resulting coke is treated with hydrogen at a temperature of 490-550 ° C and a pressure of 0.6-5.0 MPa for 8-24 hours, with hydrogen being supplied in an amount of 10-100 nm ³ / m ³ . The implementation of the invention allows to reduce the sulfur content in the coke.

The disadvantages of the prototype are:

- A significant duration of the coking process due to the introduction of an additional stage of the treatment of coke with hydrogen,

- Increased hydrogen consumption,

- Deterioration of the coke oven chamber due to the supply of high pressure hydrogen to the post-treatment step.

An object of the invention is to obtain in the process of coking of heavy sulfur-containing oil residues and petrochemical by-products in delayed coking plants of the maximum possible amount of liquid products with a low sulfur content, to obtain petroleum coke and other substances with improved environmental properties.

The technical result consists in increasing the yield of liquid products (the amount of gasoline, light and heavy gas oil), in reducing the amount of sulfur in the resulting products (in gasoline, coke, light and heavy gas oils), in reducing the duration of the coking process, material and energy costs.

The technical result in the process of processing sulfur raw materials in delayed coking plants, including its heating to the coking temperature and treatment with hydrogen supplied, is achieved due to the fact that heavy oil residues and by-products of petrochemicals are processed as raw materials, and the coking process is carried out in one stage in the presence of hydrogen, and hydrogen is supplied in an amount of 10-200 m ³ / m ^{3 of} raw materials.

A comparative analysis of the prototype and the present invention allows us to conclude that the common features are the processing of sulfur materials in delayed coking plants, including heating the raw material to a coking temperature and processing it with supplied hydrogen. A distinctive feature of the invention is that heavy oil residues and petrochemical by-products are processed as raw materials, the coking process is carried out in one stage in the presence of hydrogen, which is supplied in an amount of 10-200 m ³ / m ^{3 of} raw materials.

The possibility of achieving the claimed technical result, namely, increasing the yield of liquid products, improving the quality in terms of the "mass fraction of sulfur" of liquid products, coke and other substances obtained in the coking process, is shown in the examples below.

Examples.

The inventive method is implemented in laboratory conditions using as raw materials for coking various heavy oil residues and by-products of petrochemicals (see table. 1, 2). The laboratory facility is a batch reactor with a volume of 200 cm ³ with automatic temperature control, which is maintained in the range 470-520 ° C, a system for the removal and condensation of coking products. The loading of raw materials with a volume of 80-100 cm ^{3 is} carried out manually. Hydrogen with a purity of not less than 99.0% from a gas cylinder is supplied to the reactor under a pressure of 3.0-3.8 kgf / cm ³ in an amount of 10-200 m ³ / m ^{3 of} raw materials through a special perforated distributor located at the bottom of the reactor. The inventive method is implemented taking into account the technological parameters of the coking process (temperature and pressure in the reactor), characteristic of existing industrial installations of delayed coking. The quality of the components of the coking feed used in the tests is presented in Table 1. The technological parameters of the coking process, the composition of the raw materials, the yield and quality of the products obtained are presented in table 2.

Comparative analysis presented in table. 2 data shows:

1. When coking mixed raw materials of the prototype with the introduction of hydrogen (examples 1, 2) there is an increase in the yield of liquid products by 3.3% (mass.) And a decrease in the yield of coke and gas + losses, respectively, by 3.0 and 0.3 % (mass.).

2. When coking tar in the presence of hydrogen (examples 4, 6, 8) there is a fairly significant increase in the yield of liquid products by 3.35-6.45% (mass.) And a decrease in the yield of coke by 3.45-6.25% (mass.) when changing gas + loss of 0.2-0.3% (mass.) compared with experiments without hydrogen (see experiments 3, 5, 7).

3. When coking a mixture of tar and heavy pyrolysis resin (20% (mass.)) With the introduction of hydrogen there is an increase in the yield of liquid products by 4.2% (mass.) And a decrease in the yield of coke by 3.5% (mass.) Gas + loss of 1.7% (mass.) (see experiments 9, 10).

4. When heavy catalytic cracking (20% (mass.)) Is added to the tar with the introduction of hydrogen, an increase in the yield of liquid products by 4.9% (mass.) And a decrease in the yield of coke by 3.9% (mass.) And gas + loss of 1.0% (mass.) (see experiments 11, 12).

5. When heavy selective extract of oils is added to the tar (20% (mass.)) With the introduction of hydrogen, an increase in the yield of liquid products by 3.9% (mass.) And a decrease in the yield of coke by 3.9% (mass.) Without gas changes + losses (see experiments 13, 14).

6. Conducting experiments at a higher temperature of 520 ° C, as well as various hydrogen consumption of 10, 200 h ^-1 on light (see experiment 18), heavy tar (see experiments 15-17) and a mixture of tar and heavy pyrolysis resin ( see experiment 19) also showed an increase in the yield of liquid coking products with a decrease in the yield of coke compared with experiments without the use of hydrogen (see experiments 1, 3, 5).

7. In all experiments, the use of hydrogen during coking allowed to reduce the sulfur content in all products - coke, gasoline, light and heavy gas oils.

Thus, the proposed method for processing heavy oil residues and by-products of petrochemicals at ultrasonic testing in the presence of hydrogen can significantly increase the yield of liquid products, improve the quality of coke, gasoline, light and heavy gas oil in terms of \ mass fraction of sulfur \.

Table 1
Actual quality indicators for coking feed components The name of indicators Heavy tar Light tar Heavy pyrolysis resin Catalytic cracking heavy gas oil Selective Oil Purification Extract 1. Density at 20 ° С according to GOST 3900, g / cm ³ 0.983 0.970 1.06 1,000 0.960 2. Coking ability according to GOST 19932,% 12 10 10 1,0 2.0 3. Mass fraction of sulfur according to GOST 1437,% 1,5 1.4 0.1 * 1.3 1.7 * according to GOST R 50442

Claims (2)

1. The process of processing sulfur-containing raw materials in delayed coking plants, including heating the raw material to a coking temperature and treating it with supplied hydrogen, characterized in that heavy sulfur-containing oil residues and petrochemical by-products are processed as raw materials, the coking process is carried out in one stage in the presence of hydrogen. 2. The process according to claim 1, characterized in that hydrogen is supplied in an amount of 10-200 m ³ / m ^{3 of} raw materials.