WO2016197476A1

WO2016197476A1 - Wax oil circulating hydrogenation method, design method therefor, and use thereof

Info

Publication number: WO2016197476A1
Application number: PCT/CN2015/089854
Authority: WO
Inventors: 李苏安; 邓清宇; 王坤朋
Original assignee: 北京中科诚毅科技发展有限公司
Priority date: 2015-06-12
Filing date: 2015-09-17
Publication date: 2016-12-15
Also published as: CN104946299A

Abstract

A wax oil circulating hydrogenation method, a design method therefor, and a use thereof. The hydrogenation method comprises: mixing the wax oil produced by a slurry bed hydrogenation reactor with some or all raw materials to be hydrogenated or one or two catalysts to obtain raw material slurry having reduced viscosity, the raw material slurry entering the slurry bed hydrogenation reactor for circulating hydrogenation. The mass fraction of wax oil for circulating hydrogenation accounts for 4-30wt% of the raw materials to be hydrogenated, such that the kinematic viscosity of the raw material slurry is less than or equal to 750 cSt at the temperature being less than or equal to 60°C. The method is simple and convenient to operate, facilitates automated control, improves the light oil yield, improves the stability of apparatus operation, and prolongs the repair cycle of a hydrogenation-series apparatus.

Description

Wax oil cycle hydrogenation method, design method and use thereof

Technical field

The invention relates to a wax oil circulating hydrogenation method, a design method thereof and a use thereof, and belongs to the fields of petrochemical industry and coal chemical industry.

Background technique

In recent years, the world's oil resources are increasingly in short supply, and the problem of heavy and inferior oil resources is becoming more and more obvious. However, with the rapid economic growth, the demand for petroleum products in the society is increasing. Heavy oil deep processing technology can not only effectively use petroleum resources, but also improve the economic benefits of petroleum processing enterprises. At present, heavy oil processing mainly includes processes such as delayed coking, heavy oil catalytic cracking and residue hydrogenation. The quality of the liquid product of the delayed coker is poor and the coke yield is high. Heavy oil catalytic cracking has high requirements on raw materials and cannot handle inferior residual oil. Residue hydrogenation can treat high-sulfur, high-carbon, high-metal inferior residual oil, while improving liquid yield and quality of liquid products. Residue fixed bed hydrogenation requires high content of heavy metals in the residue, and slurry slurry bed hydrogenation can effectively remove sulfur, nitrogen and heavy metals from the residue.

At the same time, China is a country rich in coal and oil. In order to cope with the contradiction between oil supply and demand and implement energy conservation and emission reduction policies, adequate and clean utilization of coal resources is an important choice to ensure energy security. Using coal liquefaction technology and oil-coal mixing technology, refining coal and inferior residual oil are important methods to solve China's energy dilemma. The slurry bed hydrogenation process is the core of direct coal liquefaction and oil-coal mixing.

In addition to producing light oil, the slurry bed hydrogenation reactor produces heavy wax oil that has not been completely cracked. Some documents and patents mention the practice of feeding all of the wax oil into the hydroprocessing unit of the next stage, which does not increase the operating load of the slurry bed reactor. However, the actual situation is that in the heavy oil hydrogenation, oil-coal mixing or direct coal liquefaction process, the fluidity of the treated raw materials is relatively poor, and the raw materials are easily retained in the pipeline or the reactor inlet to affect the progress of the reaction.

Summary of the invention

Based on the problems in the prior art, the present invention provides a process for the cyclic hydrogenation of wax oil. The self-produced wax oil is used to prepare a raw material or a catalyst to be hydrogenated, and the viscosity of the raw material is reduced, and the cyclic hydrotreating of the wax oil is realized.

The technical solution of the invention:

A method for cyclic hydrogenation of a wax oil, characterized in that a self-produced wax oil in a slurry bed hydrogenation reaction is mixed with a part or all of a raw material and/or a catalyst to be hydrogenated to obtain a raw material slurry having a reduced viscosity, the raw material slurry Into the slurry bed hydrogenation reactor for cyclic hydrogenation.

Preferably, the wax oil accounts for 4 to 30% by weight of the raw material to be hydrogenated.

When the temperature of the raw material slurry is not higher than 60 ° C, the kinematic viscosity is not higher than 750 cSt.

Preferably, a part of the self-produced wax oil of the slurry bed hydrogenation reaction is mixed with one or both of the raw materials or catalysts to be partially or completely hydrogenated to obtain a raw material slurry having a reduced viscosity, and the raw material slurry enters the The slurry bed hydrogenation reactor is cyclically hydrogenated; the other part flows to the equipment or pipe or interface blocked by coking or intermittent flow in the slurry bed hydrogenation reaction process for backwashing the plug.

Preferred equipment for backwashing includes a slurry bed hydrogenation reactor, a vacuum furnace and/or a separator.

Wherein the slurry bed hydrogenation reactor comprises a reactor column body, a feed distributor and a circulating blister, the backwashing point comprising a deck of the distribution plate of the feed distributor and the circulating blister. The circulating blister is flushed through a flushing conduit located on the reactor tower, the conduit height being greater than or equal to the circulating blister height.

Wherein the vacuum furnace is a vertical tubular structure, and the backwashing point is set at the inlet of the vacuum furnace to flush the coking in the pressure reducing furnace tube.

Wherein the separator comprises an upper gas phase outlet and a bottom liquid phase outlet, and the bottom portion is tapered, and the backwashing point is an inclined surface of the gas phase outlet side and the tapered structure.

Preferred interfaces and conduits for backwashing include conduits for the dead zone due to coking or intermittent use, sampling ports and instrumentation interfaces, and secondary lines for regulating valves, pumps, and the like.

The use of the above wax oil cyclic hydrogenation method is applied to a heavy oil hydrogenation process, a coal direct liquefaction process and a coal-oil mixing process, the heavy oil including heavy crude oil, residual oil, catalytic oil slurry, deoiled asphalt and coal tar In one or more combinations, the coal includes one or more combinations of lignite, bituminous coal, non-sticky coal, and the ratio of oil to coal in the oil-coal mixing process ranges from 97:3 to 40:60.

Also included is a method of designing the above-described wax oil cycle hydrogenation process.

Technical effects of the present invention:

The method for circulating hydrogenation of wax oil of the invention utilizes the characteristics of good fluidity of the wax oil to mix part or all of the wax oil produced by the hydrogenation process with part or all of the raw material or catalyst with poor flowability to form The flowability of the raw material slurry is remarkably improved, and the viscosity is lowered, which solves the problem of poor material flowability in the prior art of oil-coal mixing, heavy oil hydrogenation, and direct coal liquefaction process. The prepared raw material slurry is used for cyclic hydrogenation, and the wax oil is further reacted, hydrogenated, and cracked together with the raw material to improve the light oil yield.

When the wax oil is added in an amount of 5 to 20% by weight, the total viscosity of the raw material can be reduced by 5 to 25 times. The fluidity of the raw material is remarkably improved, and the problem that the raw material is easily retained in the pipeline or the inlet of the reactor and affects the progress of the reaction is solved.

DRAWINGS

1 is a schematic diagram of cyclic hydrogenation of a wax oil according to Example 1 of the present invention;

2 is a schematic view showing the backwashing of the wax oil of the vacuum furnace of Example 2.

Reference number:

1-catalyst; 2-pulverized coal; 3-residue oil; 4-cycle wax oil; 5-base catalyst configuration system; 6-pressure reduction tower; 7-wax oil circulation pump; 8-decompression furnace; Furnace rinse point.

detailed description

In order to further illustrate the specific features of the invention, it will be described in conjunction with the specific embodiments.

Example 1

The wax oil of the present embodiment is a product of a slurry bed oil coal mixing process, as shown in FIG. 1, the slurry bed hydrogenation self-produced circulating wax oil 4 is taken out from the bottom of the vacuum decompression tower 6 through a wax oil circulation pump 7 to The raw material catalyst arrangement system 5 is mixed with the pulverized coal 2 to be hydrogenated, the residue 3 and the catalyst 1 to form a raw material slurry. The raw material slurry is mixed with hydrogen gas to be heated in the raw material heating furnace, and is repeatedly introduced into the above-mentioned slurry bed hydrogenation reaction series device to carry out a cyclic hydrogenation reaction.

In addition to the purpose of re-cracking, the wax oil can also reduce the viscosity of the heavy oil and solid coal raw materials in the oil-coal mixing, improve the fluidity of the raw materials, and smoothly pass the raw materials through various pipes and devices. Compared with the raw materials not added with the self-produced wax oil, the total viscosity is reduced to less than 500 cSt, which is about 5-15 times lower, so that the hydrogenation reaction proceeds smoothly and the reaction progress is accelerated.

Example 2

The wax oil of this example is of the same source as in Example 1, wherein 80% of the wax oil is subjected to cyclic hydrogenation as in the process of Example 1, and another 20% of the wax oil is used for backwashing, as shown in FIG. Schematic diagram of wax oil backwashing, set the decompression furnace at the inlet of the decompression furnace 8 to introduce the backwashing oil. The coking occurs mainly in the decompression furnace tube. When the coke in the furnace tube needs to be flushed, the wax oil is started. Flush the system and the status is intermittent. The backwashed wax oil is rinsed from the bottom up, and the pressure for flushing the wax oil comes from the circulation pump, and there is no need to separately set the backwash pump.

The rinse oil wax oil of Example 2 can also be replaced by diesel or a mixture of wax oil and diesel oil. Only diesel is a refined oil, and the washing cost is high. In addition to the vacuum furnace, it can also be used for heavy oil hydrogenation process, coal direct liquefaction process and other equipment or pipelines or interfaces used in the oil-coal mixing process, according to the actual situation, continuous flush operation or intermittent operation.

in conclusion:

It can be seen from the above embodiment that the wax oil cyclic hydrogenation method of the present invention is applied to the hydrogenation reaction process of the slurry bed reactor in the heavy oil hydrogenation process, the coal direct liquefaction process and the oil coal kneading process, The cyclic hydrogenation of the wax oil produced by the hydrogenation reaction serves the dual purpose of reducing the viscosity of the solid raw material and re-hydrocracking. The method is easy to operate and convenient for automatic control System, increased light oil yield. In addition, for the heavy crude oil with high solid content in the reaction material, which is more likely to coke and block, heavy oil, inferior residue hydrogenation or oil coal mixing or direct coal liquefaction process, a part of the wax oil can also be transported through the circulation pump. Backwashing at a location that is prone to coking or clogging not only allows for more complete reuse of the self-produced wax, but also solves the problem of coking and clogging.

The above description is only a preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily think of changes or substitutions within the technical scope of the present disclosure. For example, it should be covered by the scope of the present invention. Therefore, the scope of the invention should be determined by the scope of the claims.

Claims

A wax oil cyclic hydrogenation process characterized in that a self-produced wax oil in a slurry bed hydrogenation reaction is mixed with a part or all of a raw material to be hydrogenated or a mixture of a raw material and a catalyst to obtain a raw material slurry having a reduced viscosity, the raw material The slurry enters a slurry bed hydrogenation reactor for cyclic hydrogenation.
The method for cyclic hydrogenation of a wax oil according to claim 1, wherein the wax oil accounts for 4 to 30% by weight of the raw material to be hydrogenated.
A method for cyclic hydrogenation of a wax oil according to claim 1, wherein the raw material slurry has a kinematic viscosity of not higher than 750 cSt at a temperature not higher than 60 °C.
The use of a wax oil cycle hydrogenation process according to any one of claims 1 to 3, characterized in that it is used in a heavy oil hydrogenation process, a coal direct liquefaction process and a oil coal kneading process, the heavy oil comprising heavy crude oil One or more combinations of residual oil, catalytic oil slurry, deoiled asphalt and coal tar, the coal including one or more combinations of lignite, bituminous coal and non-stick coal, the oil coal mixing process The ratio of medium oil to coal ranges from 97:3 to 40:60.
A wax oil cyclic hydrogenation process characterized in that a part of a self-produced wax oil of a slurry bed hydrogenation reaction is mixed with one or both of a part or all of a raw material or a catalyst to be hydrogenated to obtain a raw material slurry having a reduced viscosity. The feedstock slurry enters the slurry bed hydrogenation reactor for cyclic hydrogenation; the other portion flows to a plugged device or conduit or interface in the slurry bed hydrogenation reaction process for backwashing the plug.
The method of claim 5 wherein the means for backwashing comprises a slurry bed hydrogenation reactor, a reduced pressure furnace and a separator.
The method of claim 6 wherein said slurry bed hydrogenation reactor comprises a reactor column, a feed distributor and a circulating blister, said backwashing point comprising a distribution plate of said feed distributor The deck and the circulating blisters.
A slurry bed backwashing method according to claim 6, wherein the pressure reducing furnace is a vertical tubular structure, and the backwashing point is perpendicular to the bottom of the pressure reducing furnace, and the furnace body is flushed. Tubular structure.
A slurry bed backwashing method according to claim 6, wherein said separator comprises an upper gas phase outlet and a bottom heavy component discharge port, and a bottom portion thereof has a tapered structure, and a backwashing point is said gas phase. An inclined surface on both sides of the outlet and on both sides of the tapered structure.
A wax oil cyclic hydrogenation design method, characterized in that a self-produced wax oil for designing a slurry bed hydrogenation reaction is mixed with a part or all of a raw material to be hydrogenated or a mixture of a raw material and a catalyst to obtain a raw material slurry having a reduced viscosity. The raw material slurry enters a slurry bed hydrogenation reactor for cyclic hydrogenation.