RU2716165C1 - Method of producing low-sulfur diesel fuel and low-sulfur gasoline - Google Patents

Abstract

FIELD: technological processes.

SUBSTANCE: invention relates to catalytic methods of processing mixed diesel fractions of primary and mixtures of diesel and gasoline fractions of secondary origin with high content of sulfur to obtain a mixture of ultra-sulfur fractions of petrol and diesel hydrocarbons. Described is a method of producing low-sulfur diesel fuel and low-sulfur gasoline, which consists in hydrogenation treatment of a mixture of secondary diesel and secondary gasoline fractions with high content of sulfur with straight-run diesel fractions at high pressure and heating in a stream of hydrogen-containing gas in the presence of a heterogeneous catalyst which contains Mo, Co/Ni, P and S into the active component, and in the composition of the aluminum borate and γ-Al₂O₃ carrier, at temperature not higher than 340 °C, pressure not more than 7.0 MPa, mass consumption of the raw material is not less than 1.0 h^-1, volume ratio hydrogen / raw material is not more than 500 m³/m³, wherein secondary diesel fractions contained in the composite raw materials are high-sulfur diesel fractions with an end of boiling of up to 360 °C, and secondary gasoline fractions contained in the composite raw materials are high-sulfur gasoline fractions with an end of boiling of up to 200 °C, obtained by rectification from semi-synthetic oil, which is a product of catalytic steam cracking of heavy oil material, which can be natural, for example, heavy oil, bitumen, or man-made, for example fuel oil, tar.

EFFECT: performing hydrogenation processing of high-sulfur diesel and gasoline fractions of secondary origin in the form of a mixture with straight-run diesel fractions to obtain diesel and gasoline fractions containing less than 10 ppm of sulfur.

3 cl, 4 ex, 3 tbl

Description

The invention relates to catalytic methods for processing mixed diesel fractions of primary and a mixture of diesel and gasoline fractions of secondary origin with a high sulfur content, to obtain a mixture of ultrafine fractions of gasoline and diesel hydrocarbons.

Currently, the most popular type of fuel for internal combustion engines is diesel fuel. The production of low sulfur diesel fuels is one of the most important tasks of modern oil refining. In Russia, diesel fuel is produced containing not more than 10 ppm sulfur in accordance with GOST R 52368-2005. (EN 590-2004). Diesel fuel EURO. Technical conditions The increase in diesel fuel consumption is associated with an increase in the share of its export to foreign markets, an increase in the number of diesel-powered cars, and the renewal of the truck fleet, buses, and the fleet of self-propelled military equipment. At the same time, in the oil refining industry, on the one hand, the requirements for the environmental quality of the fuels used are being tightened, and on the other, there is a need to extract more and more light fractions from oil due to increased fuel consumption, which leads to an increase in the production of secondary distillates. Thus, with the growing need for transport in diesel fuel, the problem of expanding its production due to the involvement of secondary processes in the processing of middle distillates becomes particularly urgent. In addition to diesel fuel, gasoline also does not lose its high relevance for use in the transport sector.

In order to increase the volume of diesel fuel and gasoline production at a number of refineries, secondary distillates such as light gas oil and visbreaking gasoline (HV) of heavy oil raw materials (heavy fuel oil, tar), light gas oil and coking gasoline (LGK) and light gas oil are used as raw materials. and catalytic cracking gasoline (LGCC). In addition to the traditional processes of refining heavy petroleum feedstocks (HPS) based on thermal cracking or hydrocracking, studies are underway aimed at developing new refinement processes to produce secondary fractions, for example, using water (HPS cracking in a sub- and supercritical environment water, as well as water vapor). The middle distillates obtained in these processes (NK-360 ° C) do not find qualified use because of their instability due to the presence of a significant amount of unsaturated hydrocarbons, an increased content of polyaromatic hydrocarbons, as well as nitrogen and organo-sulfur compounds. Due to the above features, secondary distillates, as a rule, are processed in a mixture with straight-run diesel fractions (PDF) - distillates obtained by the stage of primary oil refining. However, hydrotreating such mixtures does not always provide an acceptable depth of hydrodesulfurization and hydrogenation of aromatic compounds. Therefore, one of the challenges facing oil refining is the development of both processes and integrated processing schemes for secondary distillates to produce ultra-low-sulfur diesel fuels.

Various methods for hydrotreating straight-run diesel fuel mixed with light gas oils or diesel fractions of secondary processes are known from the patent literature, however, the main disadvantage for them is the high residual sulfur content in the resulting products, due to the low activity of the used catalysts. In addition, the hydrotreatment of secondary fractions obtained in the process of refining HPS in the presence of water vapor and / or supercritical water is currently unknown. Also used for the hydrogenation treatment of PDF and gas oil secondary processes usually contain no more than 2.0 wt. % sulfur.

A known method of processing distillates of secondary origin to produce purified diesel fuel and gasoline [RF No. 2135548, C10G 59/02, 08/27/1999], in which distillates of secondary origin (coking gasoline - sulfur content of 0.65 wt.%; Coking gas oil - content sulfur (1.4 wt.%), boiling in the temperature range 21 - 205 and / or 140 - 360 ° C, in a mixture with a straight-run fraction (PDF, sulfur content 1.4 wt.%) is subjected to two-stage hydrotreating in the presence of aluminum-cobalt-molybdenum or aluminum-nickel-molybdenum catalyst at 200 - 320 ° C per the second stage and 280 - 380 ° C on the second. The ratio of secondary to straight-run fractions varies in the range (5 - 95): (95 - 5). The disadvantage of this method is the multi-stage hydrogenation processing, as well as a very high sulfur content in the final diesel fraction (350 - 500 ppm).

A known method of processing distillates of secondary origin to produce purified diesel fuel and gasoline [RF, No. 2316580, C10G 59/06, 02/10/2008], a mixture of secondary and straight-run distillates is also subjected to two-stage hydrotreatment at 200 - 320 ° C in the first stage and 280 - 380 ° C on the second. Visbreaking gasoline (sulfur content 1.2 wt.%) And light visbreaking gas oil (sulfur content 2.0 wt.%) Are used as secondary distillates. At the first stage, aluminum-nickel-molybdenum or aluminum-nickel-tungsten catalyst is used, the volumetric feed rate of the feedstock (ISPS) is 5-10 h ^-1 , the ratio of hydrogen to feedstock depends on the iodine number of the feedstock and varies from 100 to 230 nm ³ / m ³ . At the second stage, aluminum-nickel or aluminum-cobalt-molybdenum catalyst is used, the ratio of hydrogen to feed is 150 - 300 nm ³ / m ³ . The disadvantages of this method are the multi-stage process and the high sulfur content in the final diesel fraction (50 - 1800 ppm).

A common drawback for all of the above hydroprocessing processes is that they cannot achieve a residual sulfur content in diesel fuels below 10 ppm, and used PDF and secondary raw materials (diesel fractions, light gas oils) can contain no more than 2.0 wt. % sulfur.

Closest to the proposed technical solution is the method described in [RF, No. 2609834, C10G 65/04, 02/06/2017] for hydrofining diesel distillates to obtain purified ultrafine sulfur fuel in the presence of NiMo catalysts using a carrier based on silicoaluminophosphate SAPO-31. The refinement is carried out under the following conditions:

T = 340-380 ° C, ISPS = 1.0-1.5 h ^-1 , PH ₂ = 5.5-7.0 MPa, H / C = 215-600. The raw material used is a mixture of light catalytic cracking gas oil (LGCC) with PDF in the mass ratio of LGCC / PDF = 5 - 30: 95 - 70. The sulfur content is given only for mixed raw materials - 0.754 wt. % The sulfur content in the diesel fractions obtained as a result of hydroprocessing varies in the range of 1.6 - 22.6 ppm, depending on the process conditions.

The main disadvantage of the known method of hydroprocessing is that it can be used to process only light fractions with a relatively low sulfur content.

The present invention solves the problem of creating a method for producing ultrafine diesel fuel and gasoline from high sulfur secondary diesel fractions (VDF) (sulfur content up to 3.6 wt.%) In a mixture with secondary gasoline (WBF) (sulfur content up to 2.5 wt.%) and the secondary light fractions (WSF) used in the process were obtained as products of a new process for the processing of heavy petroleum feedstocks (HPS) - catalytic steam cracking (CPC) (cracking in the presence of water vapor) as a part of liquid HPS processing products - semi inteticheskoy oil (SPE).

The problem is solved by a method for producing low-sulfur diesel fuel and low-sulfur gasoline, which consists in the hydrogenation processing of a mixture of secondary diesel and secondary gasoline fractions with a high sulfur content with straight-run diesel fractions at elevated pressure and heating in a stream of hydrogen-containing gas in the presence of a heterogeneous catalyst comprising the active component Mo, Co / Ni, P and S, and the composition of the carrier is aluminum borate and γ-Al ₂ O ₃ , at a temperature not exceeding 340 ° C, a pressure of not more than 7.0 MPa, wt the total consumption of raw materials is not less than 1.0 h ^-1 , the volumetric ratio of hydrogen / raw materials is not more than 500 m ³ / m ³ , high-sulfur diesel fractions with a boiling end up to 360 ° С are used as secondary diesel fractions included in the mixture raw material high sulfur gasoline fractions with a boiling point up to 200 ° С obtained by distillation from semi-synthetic oil, which is a product of catalytic steam cracking of heavy oil feed, which can be dnym, such as heavy oil, bitumen or man-made, such as heavy oil, tar.

The sulfur content in the secondary diesel fractions can vary from 0 to 3.6 wt. %;

The sulfur content in the secondary gasoline fractions can vary from 0 to 2.5 wt. %

EFFECT: hydrogenation processing of high-sulfur diesel and gasoline fractions of secondary origin (sulfur content is higher than in the prototype) in the form of a mixture with PDF to produce diesel and gasoline fractions containing less than 10 ppm sulfur. Used VDF obtained as a result of CPC TNS with their subsequent isolation from the products (PSN) by distillation.

The problem is solved by the method of hydrogenation processing of VSF with a high sulfur content (up to 3.6 wt.%), In the form of mixed raw materials with PDF. The content of VDF can reach 25 wt. %, WBF content - 5 wt. % The process of hydroprocessing straight-run or mixed raw materials with a high sulfur content is carried out at 340 ° C, a pressure of 7.0 MPa, a mass flow rate of 1.0 h ^-1 , a volume ratio of hydrogen / feedstock of 500 nm ³ / m ³ in the presence of a catalyst containing, by weight . %: Mo - 10.0 - 16.0; Co / Ni - 2.7 - 4.5; P - 0.8 - 1.8; S 6.7-10.8; the carrier is the rest; wherein the carrier contains, by weight. %: aluminum borate Al ₃ BO ₆ with norbergite structure - 5.0 - 25.0; γ-Al ₂ O ₃ - the rest. The catalyst has a specific surface area of 120 - 190 m ² / g, a pore volume of 0.35 - 0.65 cm ³ / g, an average pore diameter of 7 - 12 nm, and is a particle with a cross-section in the form of a circle, trefoil or four-leaf with the diameter described circles 1.0 - 1.6 mm and a length of up to 20 mm.

The main distinguishing feature of the proposed method for processing a mixture of VDF and VBF compared with the prototype is that fractions of secondary origin obtained from HPS by CPC are used in hydrotreating.

The second distinguishing feature of the proposed method compared to the prototype is that it can be used to process WDF and WBF with a very high sulfur content (up to 3.6 and 2.5 wt.%, Respectively), mixed with WBF.

Description of the proposed technical solution.

Hydrogenation processing of a mixture of PDF and VDF (VDF content up to 25%, WBF content up to 5%) is carried out at a temperature of 340 ° C, a pressure of 7.0 MPa, a mass flow rate of 1.0 h ^-1 , a volume ratio of hydrogen / raw material 500 m ³ / m ³ in the presence of a catalyst containing, by weight. %: Mo - 10.0 - 16.0; Co - 2.7 - 4.5; P - 0.8 - 1.8; S 6.7-10.8; the carrier is the rest; wherein the carrier contains, by weight. %: aluminum borate Al ₃ BO ₆ with norbergite structure - 5.0 - 25.0; γ-Al ₂ O ₃ - the rest. The used catalyst has a specific surface area of 120 - 190 m ² / g, a pore volume of 0.35 - 0.65 cm ³ / g, an average pore diameter of 7 - 12 nm, and is a particle with a cross-section in the form of a circle, trefoil or four-leaf with a diameter the circumference described is 1.0 - 1.6 mm and a length of up to 20 mm.

The invention is illustrated by the following examples.

Example 1

For hydroprocessing, mixed raw materials are used, consisting of 70% straight-run diesel fraction PDF, 25% secondary diesel fraction VDF and 5% secondary gasoline fraction WBF obtained from liquid products of catalytic steam cracking of Tatar heavy sulfur heavy oil (TN) with a sulfur content of 4.3 mass . % Secondary diesel and gasoline fractions are isolated from semi-synthetic oil (CPC product of heavy oil) by distillation. The sulfur content in the VDF is 3.6 wt. %, in WBF - 2.5 wt. % in PDF - 0.2 wt. %, in mixed raw materials - 1.2 wt. %

For hydrogenation processing, a catalyst composition of Co-Mo / Al ₂ O ₃ with an active phase in sulfide form is used. Physico-chemical characteristics of the source medium and the catalyst used are shown in table 1.

Hydrogenation processing of mixed raw materials is carried out in a flow reactor with a fixed catalyst bed under the following conditions: temperature 340 ° C, bulk feed rate (ISPS) - 1 hour ^-1 , hydrogen / feed ratio - 500, hydrogen pressure - 7 MPa. Gasoline fractions are isolated from a mixture with diesel by distillation.

The properties of the obtained diesel fractions are shown in table 2, gasoline in table 3.

Example 2

It differs from example 1 in that the composition of the mixture of diesel and gasoline fractions sent for hydroprocessing includes 85% of PDF, 10% of VDF and 5% of WBF. Example 3

It differs from Example 1 in that nickel is included in the composition of the catalyst instead of cobalt (Table 1).

Example 4

It differs from Example 3 in that diesel and gasoline fractions obtained from semisynthetic oil, a product of CPC tar, are used as VDF and VBF. The sulfur content in the VDF is 1.9 mass. %, WBF - 0.5 wt. %, in PDF - 0.2 mass. %, in mixed raw materials - 0.6 mass. %

Table 1

Physicochemical Characteristics of the Initial γ-Al ₂ O ₃ Carrier and Used Catalysts

Parameter Carrier γ-Al ₂ O ₃ Active ingredient catalyst Nimo S _beats , m ² / g 258 143 150 V _then cm ³ / g 0.65 0.38 0.41 D _then Å 101 110 104 B, wt. % 0.8 0.50 0.49 Co, wt. % - 3.95 - Ni, wt. % - - 4.04 Mo, wt. % - 12,4 12.8 P, wt. % - 1.24 1.23

Hydrotreating results are shown in tables 2-3.

table 2

Properties of the obtained diesel fraction

Characterization of diesel fractions after hydrotreatment Example 1 Example 2 Example 3 Example 4 Residual sulfur content, ppm 8.45 6.02 8.22 7.89 The nitrogen content, ppm 1.86 1.14 1.73 1.22 Cetane index 47.7 46.8 45.8 47.7 Pour point, ° C -16.2 -15.0 -20.1 -13.1

Table 3

Properties of the resulting gasoline fraction

Characterization of gasoline fractions after hydrotreating Example 1 Example 2 Example 2 Example 3 Residual sulfur content, ppm 1.01 0.89 0.98 0.94 The nitrogen content, ppm 0.28 0.14 0.21 0.15 Octane number (research method) 82 83 79 72

Thus, as can be seen from the above examples, the proposed method for the hydrogenation processing of secondary diesel and gasoline fractions allows the processing of high-sulfur VDF and VBF, with a sulfur content greater than in the prototype, in the form of mixtures with PDF.

In addition, the proposed method allows the use of VDF and WBF obtained from liquid products of catalytic steam cracking of various heavy oil feedstocks, including high sulfur. The resulting diesel fuels, in this case, have a sulfur content of less than 10 ppm.

Claims (3)

1. The method of producing low-sulfur diesel fuel and low-sulfur gasoline, which consists in the hydrogenation processing of a mixture of secondary diesel and secondary gasoline fractions with a high sulfur content with straight-run diesel fractions at elevated pressure and heating in a stream of hydrogen-containing gas in the presence of a heterogeneous catalyst comprising the active component Mo , Co / Ni, P and S, and the composition of the carrier is aluminum borate and γ-Al ₂ O ₃ , at a temperature not exceeding 340 ° C, a pressure of not more than 7.0 MPa, mass flow of raw materials not m less than 1.0 h ^-1 , the volumetric ratio of hydrogen / raw materials is not more than 500 m ³ / m ³ , characterized in that high-sulfur diesel fractions with a boiling end up to 360 ° C are used as secondary diesel fractions included in the mixed raw materials and as the secondary gasoline fractions that make up the mixture of raw materials, high-sulfur gasoline fractions with a boiling point up to 200 ° C obtained by distillation from semi-synthetic oil, which is the product of catalytic steam cracking of heavy oil feed, which can be used, are used nym, such as heavy oil, bitumen or man-made, such as heavy oil, tar. 2. The method according to p. 1, characterized in that the sulfur content in the secondary diesel fractions can vary from 0 to 3.6 wt.%. 3. The method according to p. 1, characterized in that the sulfur content in the secondary gasoline fractions can vary from 0 to 2.5 wt.%.