WO2012158064A1

WO2012158064A1 - Method for producing a coking additive by retarded coking of petroleum residues

Info

Publication number: WO2012158064A1
Application number: PCT/RU2012/000337
Authority: WO
Inventors: Геннадий Георгиевич ВАЛЯВИН; Виктор Павлович ЗАПОРИН; Сергей Витальевич СУХОВ; Михаил Владимирович МАМАЕВ; Игорь Викторович БИДИЛО; Константин Геннадьевич ВАЛЯВИН; Михаил Иванович СТУКОВ; Владимир Семенович ЗАГАЙНОВ
Original assignee: Общество С Ограниченной Отвественностью "Проминтех"
Priority date: 2011-05-19
Filing date: 2012-04-27
Publication date: 2012-11-22
Also published as: RU2469066C1; EA201200588A3; EA201200588A2

Abstract

The invention relates to the field of petroleum processing, in particular to producing a coking additive in a carbon coking charge, and is directed towards reducing the content of sulphur in the end product. The method consists in that the initial stock is fed after heating into an evaporator for mixing with heavy gas oil as recycle and for forming a secondary stock, which is heated in a reaction furnace and fed into the coking chamber where a coking additive and vapour-liquid products are formed, and the latter are fractionated in a rectification column, forming gas, gasoline, light and heavy gas oils and bottoms. According to the invention, the bottoms are mixed with a metal oxide and fed into the coking chamber simultaneously with the heated secondary stock, wherein the initial stock is heated to a temperature of 250-390°С and the secondary stock to a temperature of 450-480°С, and the recycle coefficient is a maximum of 1.2. It is expedient to use calcium oxides and/or magnesium oxides as the metal oxides.

Description

A method of obtaining a coking additive

delayed coking of oil residues The invention relates to the field of oil refining, in particular, to the production of petroleum coke delayed coking with a volatile content of more than 15% and less than 25% for use as a coking additive in a coal coking charge. A known method of producing a coking additive by delayed coking of oil residues, including the supply of raw materials to the coking chamber with a temperature of 450-470 ° C, coking it for 14-24 hours. with a recycling ratio of not more than 1.2 (RF Patent for the invention of JSTs 2400518, class C 10B 55/00, publ. 2010). The disadvantage of this method is as follows. During coking of sulfurous oil residues, a coking additive with a high sulfur content is formed, which subsequently enters metallurgical coke and, as a result, adversely affects the quality of cast iron (viscosity increases, filling of molds deteriorates), as well as the quality of steel obtained during redoxing cast iron (steel becomes a breaker). To neutralize the negative effects of organic sulfur contained in metallurgical coke, used as a fuel and a reducing agent, fluxes are added to the charge during the smelting of pig iron: calcium and magnesium oxides, which, interacting with sulfur contained in metallurgical coke, convert it to inorganic reaction form:

CaO + S + C— CaS I + CO †

slag and is displayed as slag. Moreover, the higher the sulfur content in metallurgical coke, the greater the amount of flux should be added to the mixture, since the desulfurization process is advisable to carry out with an excess of calcium oxide in the slag. And the need to introduce a large amount of flux during the smelting of cast iron overloads the blast furnace, reducing the productivity of cast iron. Closest to the claimed object is a method of producing petroleum coke by delayed coking of oil residues, which consists in the fact that the feedstock is heated to a temperature of 300-350 ° C, fed to the evaporator for mixing with the recirculate and the formation of secondary raw materials, the secondary raw materials are heated in the reaction furnace to temperature 480-505 ° C and served in a coking chamber, where coke and vapor-liquid coking products are formed, fractionation of the latter in a distillation column with the formation of gas, gasoline, light and heavy g azoyle and bottoms of coking. As the recirculate using the bottom residue of coking (RF Patent for the invention N ° 2209826, CL 10B 55/00, publ. 2003). The disadvantage of this method is to obtain the target product with a high sulfur content and a low content of volatile substances. The invention is directed to a coking additive with a low sulfur content and a high content of volatile substances. This is achieved by the fact that in the method for producing a coking additive by delayed coking of oil residues, which consists in the fact that After heating, the feedstock is fed to the evaporator for mixing with the recirculate and the formation of secondary raw materials, which are heated in the reaction furnace and fed to the coking chamber, where a coking additive and vapor-liquid coking products are formed, fractionation of the latter in the distillation column to form gas, gasoline, light and heavy gas oil and bottom residue of coking, according to the invention, the bottom residue is mixed with metal oxide and fed into the coking chamber at the same time as heated secondary s raw materials, while the feedstock is heated to a temperature of 250-390 ° C, and secondary raw materials are heated to a temperature of 450-480 ° C. The recirculation coefficient is not more than 1, 2. It is advisable to use calcium and / or magnesium oxides as metal oxides. 0 The preferred content of the metal oxide fed to mixing with the bottom residue is 0.5-1.5 of the sulfur content of the feedstock. 1 It is advisable to use heavy coking gas oil as a recirculate. 2 Known laboratory studies in stationary conditions, similar to the coking process in cubes, on the effect of alkaline additives on sulfurous coking raw materials. At the same time, most of the organic sulfur in the coking feedstock interacted with potassium hydroxide and converted it to water-soluble salt, which ensured a decrease in sulfur content. (N.S. Kazanskaya, M.E. Kazakov, E.V. Smidovich, EP Sargsyants "On the properties of petroleum coke obtained in the presence of potassium oxide hydrates." - Proceedings of the Universities "Oil and Gas", 1974, N ° 6, p. 55-58). In this case, a significant amount of potassium hydroxide was introduced, which required subsequent washing of the obtained coke with water to remove excess alkali. 3 The supply of metal oxide in the still bottom with the subsequent introduction of the resulting mixture directly into the coking chamber simultaneously with the supply of secondary raw materials to it, as is the case in the present method, will provide, in comparison with the prototype, a decrease in sulfur content in the resulting coking additive due to the interaction contained in the raw material sulfur with metal oxide and the formation of an inorganic inactive form of sulfur compounds. Moreover, the addition of metal oxide less than 0.5 of the sulfur content in the feedstock is impractical due to a slight decrease in the sulfur content of the coking additive, and the addition of metal oxide more than 1.5 of sulfur content in the feedstock is impractical due to the increase in ash content in the resulting coking additive. 4 The drawing shows the installation diagram illustrating the method. 5 The proposed method is as follows. 6 The source of sulfur (primary) raw materials is heated in a furnace 1 to a temperature of 250-390 ° C and served in the evaporator 2, which serves recycle - heavy coking gas oil from the distillation column 3. As a result of mixing the primary raw materials with the recycle, secondary raw materials are formed, which are heated in the reaction furnace 4 to a temperature of 450-480 ° C and fed into the coking chamber 5, where a coking additive, as well as vapor-liquid coking products, which from the upper part of the chamber 5 through a helmet tube enter a distillation column 3, where they are fractionated to produce gas, gasoline, light and heavy gas oils, and still bottoms. The bottom residue is removed from the bottom of the distillation column 3 and fed into the mixing tank 6, which serves powdered metal oxide, for example, calcium oxide in a controlled amount: 0.5 - 1, 5 of the sulfur content in the feedstock. The resulting mixture is fed directly to the coking chamber 5 simultaneously with the supply of secondary raw materials to it, where a coking additive and vapor-liquid coking products are formed. 7 The method is illustrated by the following examples. 8 Example 1 (by the proposed method).

The feedstock (tar mixture of West Siberian and Arlan oil), having a density of 1.025 g / cm, Conradson coking capacity of 24% by weight, sulfur content of 3.21% was coked in a delayed coking unit as follows: 9 The feedstock was heated in a tube furnace to temperature of 295 ° C, after which it was fed to the evaporator, where it was mixed with heavy coking gas oil as recycle in an amount of 20% for raw materials. The resulting secondary raw materials were heated in a furnace to a temperature of 460 ° C and fed into a coking chamber, where a coking additive and vapor-liquid coking products were formed. The latter were fed through the helmet pipe to the bottom of the distillation chamber, where they were fractionated to form gas, gasoline, light and heavy gas oil and bottoms, which was removed from the distillation column with a temperature of 390 ° C into the mixing tank, which was also fed calcium oxide in the form of lime in an amount of 0.62 of the sulfur content in the feedstock, which is 2.0% for coking feedstock . The resulting mixture was fed into the coking chamber simultaneously with the supply of secondary raw materials to it. 0 As a result of coking, the yield of coke was 33.1%, the sulfur content in coke was 2.84%. Compared with coke obtained by the prototype method, the decrease in sulfur content in coke amounted to 0, 78% abs. 1 Example 2 (by the proposed method).

Coking was carried out analogously to example 1, with the only difference being that 0.93 of the sulfur content of the powdered calcium oxide feedstock in the form of lime (or 3% for coking feedstock) was added and mixed into the bottom residue. 2 Example 3 (by the proposed method).

Coking was carried out analogously to example 1, with the difference that magnesium oxide was used as an additive in an amount of 1.55 of the sulfur content in the feedstock (or 5% of the feedstock). 3 For comparison, coke was obtained by the prototype method. 4 Example 4 (prototype).

The same raw materials as in example 1 were heated in a tube furnace to a temperature of 320 ° C, after which they were fed to an evaporator, where it was mixed with heavy coking gas oil as 20% recirculate to the raw material. The resulting secondary raw materials were heated in a furnace to a temperature of 490 ° C and fed into the coking chamber, where coke and vapor-liquid coking products were formed. The latter were fed through the helmet pipe to the lower part of the distillation chamber, where they were fractionated to form gas, gasoline, and light and heavy gas oils. 5 The material balance of coking and quality indicators of raw materials and coking products in examples 1 to 4 are summarized in table.

Volatile matter in

coking additive,% 16.8 16.1 15.5 10.1

Ash content in coking

% 2.80 3.80 6.50 0.74 6 As can be seen from the table, the proposed method in comparison with the prototype provides a decrease in sulfur in the obtained coking additive to 1.53-2.84% (in the method according to the prototype, the sulfur content in the target product is 3.62%), however, the addition of calcium oxide is more 1.5 of the sulfur content in the feedstock increases the ash content of the coking additive. 7 In this case, the introduction of a coking additive obtained by the proposed method with sulfur already partially bound to an inorganic form into the charge of coking will eliminate overloading the blast furnace for smelting cast iron and, accordingly, reducing the productivity of the target product (cast iron), as is the case with the introduction of flux directly in the smelting process cast iron.

Claims

The claims 1. A method of producing a coking additive by delayed coking of oil residues, which consists in the fact that the raw material after heating is fed to the evaporator for mixing with the recirculate and the formation of secondary raw materials, which are heated in the reaction furnace and fed into the coking chamber, where the coking additive is formed and vapor-liquid coking products, fractionation of the latter in a distillation column with the formation of gas, gasoline, light and heavy gas oil and bottoms coking residue, characterized in that the bottom residue is mixed with metal oxide and fed into the coking chamber simultaneously with the supply of heated secondary raw materials, while the feed is heated to a temperature of 250-390 ° C, the secondary to a temperature of 450-480 ° C, and the recirculation coefficient is not more than 1.2 . 2. The method according to p. 1, characterized in that as the metal oxides using oxides of calcium and / or magnesium. 3. The method according to p. 1 or 2, characterized in that the content of the metal oxide supplied for mixing with the bottom residue is preferably 0.5-1.5 of the sulfur content in the feedstock. 4. The method according to p. 1, characterized in that the recirculate use heavy coking gas oil.