JP2015203112A - Production method (modification) of reforming coking additive by delayed coking of residue oil - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing oil coke with 15 to 25% of volatile components, using delayed coking, which can be used as a coking additive with a low content of organic sulfur compound, to be added into a feed for oil coking.SOLUTION: A primary feed is heated and charged into a remote stripper of a rectification column, so as to be mixed with heavy gas oil as a recycling material therein. After production of a secondary feed, the feed is then heated at 450 to 490°C in a reaction/heating furnace and transferred to a coking chamber, where a coking additive of calcium oxide and/or calcium hydroxide and vapour/liquid coking products are produced. The liquid coking products are fractionated in the rectification column, so as to form a gas, benzene, light gas oil, heavy gas oil, and coking bottom products. The oil coke is thus produced.

Description

  This patent application series relates to oil processing, and in particular, to the production of oil coke with volatiles greater than 15% and less than 25% using delayed coking for use as a coking additive to coal coking raw materials. .

  There are oil coke production methods that use delayed coking of oil residues, which differ in the following respects. The feed is heated to 300-350 ° C. and charged into the remote stripper of the rectification column where it is mixed with the recycle to prepare the secondary feed; the secondary feed is 480 to 480 in the reaction / heating furnace. Heated to 505 ° C. and charged into a coking chamber to produce coke and vapor / liquid coking products; the latter is fractionated in a rectification column, gas, benzene, light gas oil and heavy gas oil As well as a coking bottom product. The coking bottom product is used as a recycle (Patent Document 1).

  The disadvantage of this method is that the low concentration of volatile products of the target product and the high concentration of sulfur make it unsuitable as a coking additive to coal coking feeds in blast furnace coke production. .

  The method closest to the present invention is to produce coking additive by delayed coking of residual oil, charging the feed into the coking chamber at 450-470 ° C. and coking for 14-24 hours. Producing a coking additive and a vapor / liquid coking product, and fractionating the liquid coking product in a rectification column, wherein a gas is recycled. , Benzene and light and heavy gas oils, and coking bottom products are produced. In a patent similar to the above patent, the original coking feed is heated to 300-350 ° C. and charged into the remote stripper of the rectification column where it is mixed with recycle to produce a secondary feed (Patent Literature). 2).

  The disadvantage of this method is that the organic sulfur of the coking additive produced by coking high sulfur oil is high. This type of additive mixed with metallurgical coke negatively affects the quality of cast iron and cast steel produced by conversion of cast iron containing sulfur (steel becomes red deficient).

A flux containing calcium oxide in the form of lime is included in the feed to counteract the negative effects of organic sulfur used in the blast furnace as a fuel or reducing agent in ores and in metallurgical coke. . Calcium oxide reacts with sulfur in metallurgical coke to convert it to a non-organic form:
CaO + S + C → CaS ↓ (Slag) + CO ↑
And it is removed together with the slag. The higher the sulfur content of the coke, the greater the amount of flux that must be added in the form of calcium oxide. If a large amount of flux is produced in cast iron production, the blast furnace is overloaded and the output of cast iron is reduced.

  Laboratory test data on the effect of alkaline additives on coking raw materials containing sulfur under fixed conditions (similar to coking in containers) are published. A lot of organic sulfur in the raw material reacts with potassium hydroxide and is converted into a water-soluble salt, so that the sulfur content decreases (Non-patent Document 1). A considerable amount of potassium hydroxide is introduced, which means that the coke produced must be washed with water in order to remove excess alkali.

Published in 2003, Russian Federation Patent No. 2209826 with classification C10B55 / 00 Published in 2010, Russian Federation Patent No. 2400518 with classification C10B55 / 00

N. S. Kazanskaya, E .; P. Smidovich and E.M. P. Sarkisants “Properties of Oil Cockes, Produced in the Presence of Hydrate of Potassium Oxide”; Izvestiya VUZov “Neft I Gas” (Oil and Gas. 19). 6: 55-58

  The purpose of this patent application series is to produce a coke additive with a low content of organic sulfur compounds using delayed coking.

According to the first method of the present invention, the goal is achieved by producing the coking additive by delayed coking of residual oil using the following sequence of operations: the feed is heated and the remote of the rectification column Charged in stripper and mixed with heavy gas oil. A secondary feed is produced that is used as a recycle and the secondary feed is heated in a reaction-heating furnace and fed into a coking chamber where coking additives and vapor / liquid products are produced, and the liquid product is Fractionation in a rectification column produces gas, benzene, light and heavy gas oils and coking bottom products. According to the present invention, the secondary feed is mixed with modifying additives: calcium oxide (CaO) and / or calcium hydroxide (Ca (OH) ₂ ) before being introduced into the coking chamber, This may be before or after the secondary feed is heated in the reaction / heating furnace. The amount of modifying additive introduced into the coking chamber constitutes 0.5-10.0 (mass)% of the primary feed. The modifying additive is premixed with heavy gas oil in a ratio of (25-35) :( 65-75). The reforming additive is mixed with the secondary feed before and / or after the reaction / heating furnace.

  According to the proposed second method of the invention, by producing coking additive by delayed coking of the residual oil, i.e. the primary feed is heated and fed into the remote stripper of the rectification column and recycled. Mixed with heavy gas oil used as a secondary feed to produce a secondary feed that is heated in a reaction / heating furnace and transferred into a coking chamber where it produces coking additives and vapor / liquid coking products The goal is achieved by delayed coking, which involves fractionating the liquid coking product in a rectification column, where gas, benzene, light gas oil and heavy gas oil and coking bottom product are produced. According to this method, calcium oxide and / or calcium hydroxide is premixed as a modifying additive with heavy gas oil in a ratio of (25-35) :( 65-75); Either mixed with the secondary feed and then charged into the coking chamber or introduced directly into the coking chamber with the modifying additive comprising 0.5-10.0 (mass)% of the primary feed Either.

  In both these methods, the secondary feed is heated at 450-490 ° C. in a reaction / heating furnace.

  In both of the proposed methods, the quality of heavy coking gas oil withdrawn from the rectification column and the coking bottom product is controlled by circulating ligation at the bottom of the column containing heavy gas oil and on the column plate. By varying the amount of irrigation gas oil into the oil, the quality and amount of heavy gas oil and coking bottom product are controlled.

  In both methods, an antifoaming dopant can be sprayed on top of the coking chamber to reduce foaming during coking in the presence of calcium oxide and / or calcium hydroxide.

  Introducing the modifying additive into the caulking material along with the secondary feed and / or coking bottom product ensures that the amount of sulfur in the organic form in the modified coking additive produced is reduced. . This is due to the fact that organic sulfur compounds contained in the primary feed react with calcium oxide and / or calcium hydroxide to form non-organic, non-active sulfur compounds. It is not appropriate to add less than 0.5% by weight of calcium oxide and / or calcium hydroxide with respect to the weight of the primary feed. This is because this will not significantly reduce the sulfur content in the coking additive. On the other hand, it is not appropriate to add more than 10% metal oxide with respect to the primary feed. This will increase the ash content in the coking additive produced.

  Cyclic irrigation at the bottom of the rectification column can control the final quality of heavy gas oil and coking bottom products, in particular the starting and final temperature of these boiling, and consequently control their viscosity And ensure that the heavy gas oil suspension of calcium oxide and / or calcium hydroxide is at a concentration suitable for pumping. Therefore, when the boiling point of heavy gas oil coming out of the column is high, its viscosity is also high, and when the calcium concentration in the suspension exceeds 35%, pumping becomes difficult. Increasing circulation irrigation at the bottom of the column ensures concentration of the high boiling components of heavy gas oil and transfer into these coking bottom products. This lowers the viscosity of both heavy gas oil and coking bottom product.

  By introducing an antifoaming dopant into the top of the coking column, coke foam enters the rectification column and by vigorous foaming during the coking process of petroleum raw materials in the presence of calcium oxide and / or calcium hydroxide. Caulking up is prevented. When the feed is mixed with calcium oxide, foaming does not occur up to 300 ° C during heating of the modified heavy gas oil suspension, but when the feed is mixed with calcium hydroxide, the foam is only 80 ° C in temperature. Even just exceeding

FIG. 2 shows a diagram of the present invention according to Method 1. FIG. 3 shows the present invention according to method 2.

  The present invention functions (in the first or second method) as follows.

  The input (primary) feed containing sulfur is heated in the furnace 1 to 250-390 ° C. and introduced into the remote stripper 2 of the rectification column 3 where it is recycled: heavy coking from the rectification column. Gas oil is also introduced. The primary feed is mixed with the recycle to produce a secondary feed that is heated to 450-490 ° C. in the reaction / heating furnace 4 and introduced into the coking chamber 5 where the coking additives and vapor / liquid A coking product is produced and transferred via a slum pipe into a rectification column where it is fractionated to produce gas, benzene, light and heavy gas oil, and a coking bottom product.

  In Method 1, the secondary feed is mixed with the reforming additive (calcium oxide and / or calcium hydroxide) before or after the reaction / heating furnace 4 before being charged into the furnace 5. The reforming additive is premixed with heavy gas oil at a ratio of (25-35) :( 65-75) to produce a heavy gas oil suspension of the reforming additive (used by mixer 6 or disintegrator) ).

  According to the second method of the proposed method, calcium oxide and / or calcium hydroxide premixed with heavy gas oil in a ratio of (25-35) :( 65-75) is used as the modifying additive. Introduced into the coking bottom product results in a heavy gas oil suspension of the reforming additive (eg, mixer 6 or disintegrator is used). The coking bottom product is then either mixed with the secondary feed and then charged into the coking chamber or directly into the coking chamber.

  In any case, the concentration of calcium oxide or calcium hydroxide reaches 0.5-10.0 (mass)% of the primary feed.

In both methods, foaming can be prevented by introducing a heavy gas oil mixture of reforming additive into the coking bottom product and the outlet of a pump (not shown) that pumps the secondary feed to the coking chamber.
In addition, both methods of the present invention provide heavy gas oil circulation irrigation. The amount and quality of heavy gas oil and coking bottom product exiting the rectification column is controlled by varying the amount of circulating ligation supplied to the first plate below the rectification column accumulator.

  Also, in both methods, an antifoam additive is sprayed on the top of the coking chamber (not shown).

  The following examples illustrate the application of each method of the present invention.

Example 1 (Method 1)
Primary feed (tar consisting of a mixture of West-Siberian and Arlan oils) (1.025 g / cm ³ density, 24 maa Conradson caking, 3.21% sulfur content) Caulked in delayed coking units as follows:
The primary feed was heated in a tubular furnace at 310 ° C. and then charged into the remote stripper of the rectification column where it was mixed with heavy coking gas oil (10% of the primary feed) as recycle. The secondary feed was calcium oxide, which was premixed with heavy gas oil at a ratio of 25:75 to form a heavy gas oil suspension of calcium oxide and mixed with calcium oxide. After the calcium oxide reached 2.5% by weight with respect to the primary feed, it was heated in a furnace at 470 ° C. and charged into the coking chamber where coking additives and vapor / liquid coking products were produced. The liquid coking product was charged to the bottom of the rectification column via a slum pipe where it fractionated to yield gas, benzene, light and heavy gas oils and a coking bottom product.

  The coking conditions, material balance and the quality of the coking additive produced in Example 1 are shown in the table.

  Method 1 was performed in Examples 2-5. The coking conditions and coking results are shown in the table.

Example 6 (Method 2)
The same primary feed as in Example 1 was heated in a tubular furnace at 310 ° C. and then charged into the remote stripper of the rectification column, where heavy coking gas oil as recycle (10% by weight of primary feed). ). The produced secondary feed was heated in a furnace at 485 ° C. and transferred to a coking chamber where coking additives and vapor / liquid coking products were produced. The liquid coking product was charged via a slum pipe into the bottom of the rectification column where it fractionated to yield gas, benzene, light and heavy gas oils and a coking bottom product. The produced coking bottom product is calcium oxide, premixed with heavy caulking gas oil at 30:70 to form a heavy gas oil suspension of calcium oxide, mixed with calcium oxide, and directly coked. Charged into the chamber. The calcium oxide concentration was 5% by weight of the primary feed.

  Two or more examples of coking using Method 2 are shown in Examples 7 and 8. The process input data and coking additive quality in Examples 6-8 are also shown in the table.

  In order to compare the two proposed methods, coking additives were produced using a prototype method.

Example 9 (using a prototype method)
The same feed as in Example 1 was heated in an oven to 320 ° C. and then transferred to the remote stripper of the rectification column where it was mixed with heavy coking gas oil (10% of the primary feed) as recycle. This secondary feed was heated in a furnace at 470 ° C. and transferred into a coking chamber where coking additives and vapor / liquid coking products were produced. The liquid coking product was charged via a slum pipe into the lower part of the rectification chamber where it fractionated to yield gas, benzene, light and heavy gas oils and a coking bottom product. Data related to Example 9 are shown in the table.

  As can be seen from the data presented, coking with the modified additive has reduced the sulfur content in the produced coking additive (down to 0.65 to 2.87% while the prototype was The content was 3.62%). This occurs because some sulfur combines with calcium to form calcium sulfide (CaS). The greater the amount of modifying additive mixed with the primary coking feed, the greater the reduction in organic sulfur concentration in the coking additive, but at the same time the ash content in the coking additive increases. Ash is present in the form of calcium sulfide, which in the future enters the blast furnace as part of metallurgical coke in the form of fuel or reducing agent and is incorporated into slag to desulfurize sulfur contained in ore and fuel. Reduce the amount of flux required for the introduction: or exist in the form of calcium oxide and / or calcium hydroxide (the main flux component), ie it does not react with sulfur, thus reducing the amount of flux required Assists further reduction of sulfur in cast iron.

The modifying additive is introduced into the secondary feed or coking bottom product gas oil in the form of a heavy coking gas oil suspension of calcium oxide and / or calcium hydroxide. When the reforming additive is introduced at the reaction / heating furnace outlet, the temperature of the secondary feed at the furnace outlet may be increased to 490 ° C. because the temperature at the inlet of the coking chamber is reduced.
When preparing a heavy gas oil suspension of calcium hydroxide at temperatures above 80 ° C., severe foaming is involved. It is therefore recommended to prepare the suspension at a low (less than 80 ° C.) temperature. Also, when using calcium hydroxide as the modifying additive, a large amount of calcium (10% of the primary feed) is required to avoid having to raise the secondary feed temperature significantly at the furnace outlet ( If the modifying additive is introduced after the furnace), the suspense needs to be the highest possible concentration of calcium. However, this will make the suspension more viscous and difficult to pump. In this case, it is inevitable that the gas oil used to prepare the suspension will be as viscous as possible. In order to control the viscosity of the heavy gas oil and ensure that the suspension has the viscosity required for standard pumping operations, a circulation ligation is applied to the bottom plate of the rectification column. . Concentration and coking of the high boiling (and consequently high viscosity) fraction of heavy gas oil by feeding the cooled heavy gas oil to a circulation irrigation on the first plate below the accumulator of the rectification column The transition to the bottom product is facilitated, which pushes down the boiling end of heavy gas oil, lowers the viscosity, and at the same time lowers the boiling start point and viscosity of the coking bottom product.

  In the coking process according to Example 2 and Example 5 to Example 8, an antifoaming dopant is placed in the upper part of the coking chamber in order to reduce foaming and completely avoid the transfer of coking foam to the rectification column. added.

  When the modified additive is introduced in the form of a heavy coking gas oil suspension mixed with the coking bottom product and introduced directly into the coking chamber, the organic sulfur content in the coking additive is reduced, the coking additive Simultaneously with increased output. This is because the coking bottom product is the smallest volatile fraction formed during coking and consists of a fraction characterized by high density and cohesiveness; by using the coking bottom product in the coking process This happens because the output of the caulking additive is boosted.

  Using one of the proposed methods will produce a coking additive with a lower sulfur content in organic form than by the prototype method.

  In addition, including the coking bottom product as part of the secondary feed increases the output of the coking additive.

Input coking data, material balance and target product quality

Claims (9)

  A method of producing modified coking additive by delayed coking of residual oil, wherein the primary feed is heated, charged into a remote stripper of a rectification column, mixed with heavy gas oil as recycle, and two A secondary feed is produced and the secondary feed is heated in a reaction / heating furnace and transferred to a coking chamber to produce a coking additive and a vapor / liquid coking product, wherein the liquid coking product is Fractionated in a rectification column to produce gas, benzene, light and heavy gas oils and coking bottom product, the secondary feed being transferred to heavy gas before being transferred to the coking chamber Calcium oxide and / or pre-mixed additive with oil in a ratio of (25-35) :( 65-75) The modifying additive constitutes a 0.5 to 10.0 wt% of the primary feed, the method is mixed with calcium hydroxide, which is charged into the coking chamber.   The method of claim 1, wherein the secondary feed is to be mixed with the modifying additive before and / or after being transferred to the reaction / heating furnace.   The method of claims 1 and 2, wherein the secondary feed is heated at 450-490 ° C in the reaction / heating furnace.   Including circulatory ligation with heavy gas oil at the bottom of the rectification column, and the quality and quantity of heavy gas oil and coking bottom product obtained from the rectification column determines the amount of circulatory ligation applied to the plate of the column. 3. A method according to claim 1 and claim 2 which is controlled by changing.   The method of claims 1 and 2, wherein the top of the coking chamber is to be sprayed with an antifoam additive.   A method of producing a modified coking additive by delayed coking of petroleum residues, wherein the primary feed is heated and placed in a remote stripper of a rectification column where it is mixed with heavy gas oil as recycle. And a secondary feed is produced and then heated in a reaction / heating furnace and transferred to a coking chamber to produce a coking additive and a vapor / liquid coking product; where the liquid coking product is the rectification Reformation fractionated in the column to yield gas, benzene, light and heavy gas oil and coking bottom product, premixed with heavy gas oil in a ratio of (25-35) :( 65-75) Calcium oxide and / or calcium hydroxide as additives are added to the caulk bottom product and then the caulk The partial product is mixed with the secondary feed and then fed into the coking chamber or introduced directly into the coking chamber; the modifying additive introduced into the coking chamber comprises the primary additive The method, which is 0.5 to 10.0% by weight of the feed.   The method of claim 6, wherein the secondary feed is heated at 450-490 ° C. in the reaction / heating furnace.   Including recirculation ligation with heavy gas oil at the bottom of the rectification column, and the quality and quantity of heavy gas oil and coking bottom product obtained from the rectification column determines the amount of recirculation ligation applied to the plate of the column. The method according to claim 6 and 7, wherein the method is controlled by changing.   The quality and quantity of heavy gas oil and coking bottom product exiting the rectification column includes the amount of circulation ligation applied to the plate of the column. The method according to claim 6 and 7, wherein the method is controlled by changing.

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