CN112538377B

CN112538377B - Method and device for coproducing synthesis gas by heavy oil contact lightening

Info

Publication number: CN112538377B
Application number: CN201910901503.9A
Authority: CN
Inventors: 张玉明; 蓝兴英; 李大鹏; 高金森; 王明峰; 王宁波; 姚晓虹; 王汝成; 黄勇; 黄传峰; 杨会民; 王成秀; 石孝刚; 蒋中山; 吴升潇; 任健
Original assignee: Nanjing Zhonghui Energy Technology Research And Development Center; China University of Petroleum Beijing
Current assignee: Nanjing Zhonghui Energy Technology Research And Development Center; China University of Petroleum Beijing
Priority date: 2019-09-23
Filing date: 2019-09-23
Publication date: 2022-02-22
Anticipated expiration: 2039-09-23
Also published as: CN112538377A

Abstract

The invention provides a method and a device for coproducing synthesis gas by heavy oil contact lightening. The method utilizes a coupling reactor as a reactor, wherein the coupling reactor comprises an upper gasification section and a lower cracking section; the method comprises the following steps: introducing a heavy oil raw material into a cracking section at the lower part of the coupling reactor, and contacting the heavy oil raw material with a contact agent to crack so as to obtain light oil gas and a carbon deposit contact agent; the carbon deposit contact agent enters the gasification section and is regenerated by gasification reaction with the gasification agent to obtain a regenerated contact agent and synthesis gas; the regenerated contact agent returns to the cracking section for recycling after heat exchange and temperature reduction; after the synthesis gas is discharged from the top of the gasification section, part of the synthesis gas enters the cracking section from the bottom, and part of the synthesis gas is taken as a synthesis gas product to be led out; the light oil gas and the synthetic gas merged from the bottom of the cracking section are subjected to gas-solid separation, the carbon deposit contact agent carried in the light oil gas is separated and returned to the cracking section for cyclic utilization, and meanwhile, purified oil gas is obtained.

Description

Method and device for coproducing synthesis gas by heavy oil contact lightening

Technical Field

The invention relates to a heavy oil lightening processing technology, in particular to a method and a device for coproducing synthesis gas by heavy oil contact lightening.

Background

The heavy oil is the residue left after the crude oil is fractionated to extract gasoline, kerosene and diesel oil; in addition, the stratum is also rich in heavy oil resources. Heavy oil has the characteristics of heavy components, low hydrogen-carbon ratio and the like, and generally has higher contents of sulfur, nitrogen elements, heavy metals, carbon residue and the like. With continuous exploitation of crude oil, the problems of heavy oil and poor oil are more and more serious, and environmental regulations are increasingly strict, so that how to process heavy oil into light oil and convert heavy oil into qualified clean oil products such as gasoline, diesel oil and liquefied gas is a major challenge for petroleum processing enterprises at present.

At present, the processing route of heavy oil can be roughly divided into hydrogenation and decarburization. Wherein, the hydrogenation treatment is to increase the hydrogen-carbon ratio by the reaction of heavy oil and hydrogen. Because the carbon residue value, the heavy metal content and the heteroatom content of the heavy oil are high, a hydrocracking mode is directly adopted, a large amount of hydrogen is usually needed, the hydrocracking mode is usually carried out under the conditions of high pressure and high-efficiency catalysts, and the process implementation difficulty is relatively high. And because the heavy oil has a lower hydrogen-carbon ratio, the problem of hydrogen deficiency in the heavy oil lightening process is more prominent.

The decarbonization process is generally a redistribution of the hydrocarbon resources in the feedstock into products. At present, the more common decarburization technologies at home and abroad mainly comprise catalytic cracking and delayed coking processes. The catalytic cracking means is adopted, the catalyst is usually subjected to rapid carbon deposition or poisoning inactivation, the coke formation amount in the heavy oil catalytic cracking process is large, if the catalyst is regenerated by adopting the traditional coke burning mode, a large amount of external heat extraction is often needed, and meanwhile, the carbon resource is greatly wasted to a certain extent. The delayed coking process has no catalyst involved and thus has high material adaptability. However, a large amount of solid coke is produced as a byproduct in the delayed coking process, and the latest environmental protection requirement requires that factory-limiting measures be taken for high-sulfur coke with the sulfur content of more than 3 percent, so that the application of the delayed coking process is limited.

In view of the advantages and disadvantages of hydrogenation and decarburization, cracking heavy oil into light oil, and then hydrotreating the light oil to obtain qualified products become the choice of many petroleum processing enterprises.

CN1504404A discloses a process combining oil refining and gasification. Petroleum hydrocarbon is firstly contacted with a coke transfer agent in a reactor for reaction, oil gas enters a subsequent product separation system, the coke transfer agent with carbon deposit is sent to a gasification furnace and reacts with steam, oxygen-containing gas and the like to generate synthesis gas, and the regeneration of the coke transfer agent with carbon deposit is realized. The regenerated coke transfer agent returns to the cracking section for recycling. The invention realizes the combination of two technological processes of oil refining and gasification, the technological process is close to the catalytic cracking process, and the traditional coke burning regeneration process is replaced by the coke gasification process.

CN102234534A discloses a method for processing inferior heavy oil, which comprises the steps of selecting a low-activity contact agent to carry out heavy oil cracking reaction, conveying the carbon deposit contact agent after reaction to different reaction areas of a gasification section to carry out combustion or gasification regeneration, respectively obtaining semi-regenerants and secondary regenerants with different coke contents, and increasing the operation difficulty of the process to a certain extent through multi-section regeneration reaction in a reactor.

CN102115675A discloses a heavy oil lightening processing method and device. Raw oil firstly reacts with a solid heat carrier in a thermal cracking reactor to obtain a light oil gas product. Heavy coke is attached to the surface of the solid heat carrier and enters a combustion (gasification) reactor through a material returning valve to remove the surface coke, and the regenerated high-temperature solid heat carrier returns to the thermal cracking reactor through a distribution valve part to be used as a reaction bed material.

CN102965138A discloses a pyrolysis gasification coupling process of a heavy oil double-reaction-tube semicoke circulating bed, and proposes that a descending reaction tube is used for heavy oil cracking to obtain a light oil gas product. After coking, semicoke enters a riser gasification reactor to perform gasification reaction with oxidant and steam to generate synthesis gas, and the reacted high-temperature semicoke flows into a material returning device to continue circulation to provide heat required by heavy oil reaction.

In the method, different types of reactors such as a fluidized bed, a lifting pipe and a downer are adopted for heavy oil cracking reaction, but the generated heavy coke needs to be conveyed to another reactor for gasification, combustion and other regeneration reactions, so that materials need to be subjected to circulating material returning operation among a plurality of reactors, and not only is the occupied area of equipment in actual production larger, but also the energy consumption is higher.

Disclosure of Invention

Aiming at the defects, the invention provides a method for coproducing synthesis gas by heavy oil contact and lightening, which can realize mutual material supply and heat complementation of two reaction processes of heavy oil cracking and coke gasification, reduce energy consumption in the heavy oil lightening processing process and save equipment floor area.

The invention also provides a device for co-producing the synthesis gas by heavy oil contact lightening, and the device is used for processing the heavy oil, so that the energy consumption in the heavy oil lightening processing process can be reduced, and the occupied area of equipment can be saved.

In order to achieve the above object, the present invention provides a method for co-producing synthesis gas by heavy oil contact lightening, which uses a coupling reactor as a reactor, wherein the coupling reactor comprises an upper gasification section and a lower cracking section, and the cracking section and the gasification section are communicated with each other; the method comprises the following steps:

introducing a heavy oil raw material into a cracking section at the lower part of the coupling reactor, and contacting the heavy oil raw material with a contact agent to crack so as to obtain light oil gas and a carbon deposit contact agent;

the carbon deposit contact agent enters the gasification section and is regenerated by gasification reaction with the gasification agent to obtain a regenerated contact agent and synthesis gas; the regenerated contact agent returns to the cracking section for recycling after heat exchange and temperature reduction; after the synthesis gas is discharged from the top of the gasification section, part of the synthesis gas enters the cracking section from the bottom, and part of the synthesis gas is taken as a synthesis gas product to be led out;

the light oil gas and the synthetic gas merged from the bottom of the cracking section are subjected to gas-solid separation, the carbon deposit contact agent carried in the light oil gas is separated and returned to the cracking section for cyclic utilization, and meanwhile, purified oil gas is obtained.

The heavy oil raw material enters a cracking section at the lower part of a coupling reactor and contacts with a contact agent to carry out a lightening reaction to obtain light oil gas and coke. The coke is attached to the surface of the contact agent, namely the carbon deposit contact agent. The carbon deposit contact agent enters a gasification section at the upper part of the coupling reactor, so that the coke on the surface of the contact agent and the gasification agent introduced into the gasification section are subjected to gasification reaction to obtain the synthesis gas and realize the regeneration of the contact agent.

After the high-temperature synthesis gas is discharged from the top of the gasification section, part of the synthesis gas enters the cracking section from the bottom, so that not only is heat required for cracking reaction provided and the contact agent is ensured to be fully fluidized, but also the synthesis gas is rich in active micromolecules such as hydrogen, carbon monoxide and the like, so that coking can be inhibited to a certain extent, the yield and the quality of light oil gas are improved, and the product distribution of heavy oil cracking is improved; and part of the synthesis gas is led out and collected to be used as a synthesis gas product, so that the hydrogen source of a refinery can be enriched or the synthesis gas can be applied to other petroleum processing links. The proportion of the synthesis gas fed into the cracking section and the synthesis gas extracted as a product can be reasonably determined according to the actual energy consumption requirement, so that the heat can be fully utilized.

The high-temperature regeneration contact agent can exchange heat with a heat taking medium such as low-temperature steam and the like firstly, so that the temperature of the regeneration contact agent is reduced to a proper temperature and then returns to the cracking section for recycling, and in addition, the regeneration contact agent can also provide partial heat and catalytic activity required by heavy oil cracking for the cracking section.

High-temperature light oil gas and synthesis gas merged from the bottom of the cracking section are led out of the coupling reactor and then subjected to gas-solid separation to remove carried carbon deposit contact agent. The carbon deposit contact agent can return to the cracking section to be used as bed material for heavy oil cracking, and the obtained purified oil gas can be subjected to oil gas fractionation and other means to obtain gas products such as synthesis gas, dry gas, liquefied gas and the like, light oil products and possibly heavy oil products. Wherein the light oil product can be further cut to obtain liquid products with different distillation ranges, the heavy oil product can be returned to the cracking section for recycling processing, and the synthetic gas can enrich the hydrogen source of refineries or be applied to other petroleum processing links.

Therefore, the cracking section and the gasification section are integrated in the same coupling reactor, so that mutual supply and heat complementation of materials in the heavy oil cracking reaction process and the coke gasification reaction process are realized, and compared with a process method for transporting and circulating the materials among a plurality of reactors in the heavy oil lightening process at the present stage, the method provided by the invention not only can obviously reduce the energy consumption in the heavy oil lightening process and improve the light oil gas yield, but also solves the problem of high difficulty in material circulating operation at the present stage, and also solves the problems of large occupied area and high equipment investment of the current heavy oil lightening process device.

The heavy oil raw material is not particularly limited, and may be one or a mixture of several of heavy oil, super heavy oil, oil sand bitumen, atmospheric heavy oil, vacuum residual oil, catalytic cracking slurry oil, solvent deoiled bitumen, and the like, or one or a mixture of several of heavy tar and residual oil generated in a coal pyrolysis or liquefaction process, heavy oil generated in an oil shale dry distillation process, and heavy oil derived from a biomass medium-low temperature pyrolysis liquid product.

The inventor researches and discovers that the method provided by the invention has a good treatment effect on heavy oil raw materials with the Conradson carbon residue value of more than 8 wt%, and even on heavy oil raw materials with the Conradson carbon residue value of more than 15 wt%, the method still has a good treatment effect, and a large amount of light oil gas can be obtained.

The contact agent used in the invention can be a decarburization modification contact agent which is commonly used at present, for example, the decarburization modification contact agent can be a silicon-aluminum material such as quartz sand, kaolin, argil, alumina, silica sol, montmorillonite, illite and the like, and also can be one or more of a catalytic cracking (FCC) industrial balancing agent or a waste catalyst, red mud, steel slag, blast furnace ash, coal ash and other solid particles.

The inventor finds that it is preferable to select a contact agent with relatively low cracking activity, for example, a contact agent with a micro-reaction activity index of 5-30, so as to ensure high cracking efficiency and light oil yield in the heavy oil cracking process. In the specific implementation process of the invention, the micro-reaction activity index of the used contact agent is 10-20, such as kaolin, clay, alumina, silica sol, industrial equilibrium agent or waste catalyst in the catalytic cracking process, and the like.

Furthermore, the contact agent is preferably in a microspherical shape, and the particle size of the contact agent is distributed in a range of 10-500 mu m, so that the contact agent has better fluidization performance; in the specific implementation process of the invention, the particle size distribution of the used contact agent is 20-200 μm.

In the invention, in the heavy oil cracking process, the surface of the carbon deposit contact agent preferably forms high-content coke, namely the carbon deposit contact agent with high coke content enters the gasification section for gasification reaction, so that the temperature rise and the temperature decrease of a large amount of contact agents in the cracking reaction and the gasification reaction process can be prevented, the energy consumed in the temperature rise process is mainly used for the gasification reaction of the coke, and the overall energy efficiency in the whole heavy oil processing process is improved. Specifically, it is desirable to maintain the contact agent surface coke mass content above 10% during the cracking process, for example, by using a smaller weight ratio of contact agent to heavy oil (i.e., the agent-to-oil ratio) to ensure that the heavy oil cracking process forms a higher coke content on the contact agent surface.

In the practice of the present invention, the reaction in the cleavage stage is typically: the reaction temperature is 450-700 ℃, the reaction pressure is 0.1-3.0 Mpa, the reaction time is 1-20 seconds, the apparent gas velocity is 1-20 m/s, and the weight ratio of the contact agent to the heavy oil is 0.1-1.0. Preferably, the temperature of the cracking reaction is 480-580 ℃, the reaction pressure is 0.1-1.0 Mpa, such as normal pressure, the reaction time is 3-20 seconds, the apparent gas velocity is 1-20 m/s, and the agent-oil ratio is 0.2-0.6.

In the present stage, the catalyst-to-oil ratio in the heavy oil catalytic cracking process is usually greater than 1, and the coke content on the surface of the catalyst (contact agent) is usually less than 5%, so that a large amount of heat needs to be consumed in the gasification regeneration process to heat the catalyst for regeneration and provide heat for the cracking reaction, resulting in higher energy consumption but lower efficiency in the heavy oil upgrading process. Compared with the prior art, the method has the advantages that the catalyst-oil ratio is low and can be controlled below 1.0, such as 0.2-0.6, so that a large amount of heat is not needed to regenerate the contact agent, and the synthesis gas and the regenerated contact agent generated in the regeneration process of the contact agent provide heat for the cracking reaction, so that the method has very low energy consumption, remarkably reduces the production cost in the heavy oil processing process, and improves the heavy oil processing efficiency.

The gasification agent introduced into the gasification stage is not particularly limited in the present invention, and may be, for example, steam, an oxygen-containing gas, or a mixed gas of steam and an oxygen-containing gas. Wherein the oxygen-containing gas may be, for example, air, oxygen-enriched air, oxygen, or the like.

In the specific implementation process of the invention, the reaction temperature in the gasification section is generally controlled to be 850-1200 ℃, the reaction pressure is generally controlled to be 0.1-6.0 Mpa, the apparent gas velocity is generally controlled to be 0.1-5 m/s, and the retention time of the carbon deposit contact agent is generally controlled to be 1-20 min. By carrying out the gasification reaction under the above conditions, it is possible to ensure sufficient regeneration of the coke on the surface of the contact agent, and to obtain a high-quality synthesis gas.

In the invention, before entering the gasification section for regeneration, the carbon deposit contact agent is preferably subjected to steam stripping to fully remove a small amount of light oil gas remained on the surface and in the pores of the carbon deposit contact agent, thereby being beneficial to the smooth operation of the gasification reaction.

In the specific implementation process of the invention, when the steam stripping is carried out, the mass ratio of the steam to the heavy oil raw material is controlled to be 0.03-0.3: 1, the temperature of the water vapor is 200-400 ℃, and the apparent gas velocity of the water vapor is 0.5-5.0 m/s. Wherein the water vapor can be obtained by low-temperature water vapor or water and a regeneration contact agent through heat exchange.

After the carbon deposit contact agent is regenerated in the gasification section, the obtained regenerated contact agent can go down to enter the cracking section after heat exchange and temperature reduction of a heat collector arranged in the gasification section; alternatively, the regenerated contact agent can also be returned to the cracking section after being subjected to heat exchange and temperature reduction by a heat exchanger arranged outside the coupled reactor. Compared with a built-in heat collector, the external heat collector is more beneficial to flexibly controlling the parameters such as the temperature of the regenerated contact agent after heat exchange, the rate when the regenerated contact agent returns to the cracking section and the like, and is more beneficial to industrial implementation.

In the invention, before gas-solid separation, the light oil gas and the synthesis gas merged from the bottom of the cracking section are preferably subjected to temperature reduction treatment, for example, a temperature reduction washing section is arranged in the cracking section, so that the light oil gas and the synthesis gas exchange heat with low-temperature liquid oil products such as heavy oil raw materials in the temperature reduction washing section, and the light oil gas and the synthesis gas not only can be used as a superheat removing section of high-temperature oil gas to inhibit excessive cracking and coking, but also can be used for removing a small amount of carbon deposit contact agent small particles (carbon deposit contact agent fine powder) carried in the high-temperature oil gas.

The invention also provides a device for coproducing synthesis gas by heavy oil contact lightening, which is used for realizing the method and at least comprises a coupling reactor, a heat remover and a first gas-solid separator, wherein:

the coupling reactor comprises a cracking section at the lower part and a gasification section at the upper part, and the cracking section and the gasification section are communicated with each other; the cracking section is provided with a heavy oil raw material inlet, a carbon deposit contact agent discharge port, an oil gas discharge port, a carbon deposit contact agent return port, a synthesis gas inlet and a regeneration contact agent return port; the gasification section is provided with a carbon deposit contact agent inlet, a gasification agent inlet, a synthetic gas outlet and a regeneration contact agent outlet; a carbon deposit contact agent discharge port of the cracking section is connected with a carbon deposit contact agent inlet of the gasification section, a synthetic gas discharge port of the gasification section is connected with a synthetic gas inlet of the cracking section, and a regeneration contact agent discharge port of the gasification section is connected with a regeneration contact agent return port of the cracking section;

the heat collector is arranged in the coupling reactor, or the heat collector is arranged outside the coupling reactor, and the regeneration contact agent discharge port of the gasification section is connected with the regeneration contact agent return port of the cracking section through the heat collector;

the first gas-solid separator is provided with an inlet, a gas outlet and a solid outlet, the inlet of the first gas-solid separator is connected with the oil gas outlet of the cracking section, and the solid outlet of the first gas-solid separator is connected with the carbon deposit contact agent return port of the cracking section.

Furthermore, a steam stripping section is arranged at the lower part in the cracking section. The carbon deposit contact agent generated in the cracking section descends, and steam stripping is carried out in the steam stripping section to remove the light oil gas product remained on the surface or in the pores of the carbon deposit contact agent, so that subsequent gasification and regeneration are facilitated.

Furthermore, a cooling washing section is arranged at the upper part in the cracking section. Light oil gas generated in the cracking section and synthesis gas entering from the bottom of the cracking section go upwards to pass through the cooling washing section for washing and cooling so as to inhibit excessive cracking and coking and remove a small amount of carbon deposit contact agent small particles carried in high-temperature oil gas.

In the invention, the heat collector can be an internal heat collector or an external heat collector. For the built-in heat collector, namely the heat collector is arranged in the coupling reactor and can be arranged at the lower part in the gasification section, the regenerated contact agent outlet is arranged at the bottom of the gasification section, and the regenerated contact agent return opening is arranged at the top of the cracking section; and a material dropping pipe is also arranged in the coupling reactor, one end of the material dropping pipe is connected with the regenerated contact agent discharge port, and the other end of the material dropping pipe passes through the regenerated contact agent return port and enters the cracking section. The regenerated contact agent generated in the gasification section flows downwards to enter a heat collector, and after heat removal and temperature reduction, the regenerated contact agent enters a material descending pipe from a regenerated contact agent outlet at the bottom of the gasification section, and flows downwards in the material descending pipe to enter the cracking section.

The method for coproducing the synthesis gas by heavy oil contact and lightening realizes the lightening of the heavy oil and obtains the high-quality synthesis gas by coupling the two reaction processes of heavy oil cracking and coke gasification and realizing the synergistic effects of material mutual supply, heat complementation and the like of the two reaction processes in the gasification section and the cracking section which are communicated up and down. Particularly, the matching of material flow and energy flow in the heavy oil processing process can be further realized by adjusting the flow rate of the synthesis gas, the type of the gasifying agent and other conditions, the stability in the whole heavy oil processing process is ensured, and the overall energy efficiency is improved.

By selecting a proper contact agent and adjusting reaction conditions such as the agent-oil ratio of the cracking reaction, the oil yield in the heavy oil cracking process can be maximized, the higher coke content can ensure that most heat in the gasification process is used for coke heating and reaction gasification, and the heating and cooling of an inert upgrading contact agent in the conventional upgrading contact agent combustion or gasification regeneration process under the condition of large agent-oil ratio are avoided, so that the energy consumption in the heavy oil lightening processing process is further reduced, and the method has stronger economical efficiency and competitiveness.

Therefore, compared with the process method that materials are transported and circulated among a plurality of reactors in the process of heavy oil catalytic cracking and coke gasification at the present stage, the method provided by the invention not only can obviously reduce the energy consumption in the process of heavy oil processing, improve the yield of light oil gas and reduce the difficulty of material circulation operation, but also can reduce the occupied area of a heavy oil processing device and reduce the equipment investment cost.

The device for coproducing the synthesis gas by heavy oil contact and lightening can realize mutual supply and heat complementation of materials in the two reaction processes of heavy oil cracking and coke gasification, reduce energy consumption and material circulation operation difficulty in the heavy oil lightening processing process and improve the yield of light oil gas. In addition, the device has smaller occupied area and lower investment cost.

Drawings

FIG. 1 is a schematic diagram of an apparatus for co-producing syngas by heavy oil contacting and lightening according to an embodiment of the present invention;

fig. 2 is a schematic diagram of an apparatus for co-producing synthesis gas by heavy oil contact lightening according to another embodiment of the present invention.

Description of reference numerals:

100-coupled reactor; 110-a cleavage section;

120-a gasification stage; 130-cooling washing section;

140-steam stripping section; 150-material dropping pipe;

200-a heat collector; 300-a first gas-solid separator;

400-second gas-solid separator.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example one

The embodiment provides a method for coproducing synthesis gas by heavy oil contact and lightening, which utilizes a coupling reactor as a reactor, wherein the coupling reactor comprises an upper gasification section and a lower cracking section, and the cracking section and the gasification section are communicated with each other; the method comprises the following steps:

Specifically, the heavy oil raw material may be one or a mixture of several of heavy oil, super heavy oil, oil sand bitumen, atmospheric pressure heavy oil, vacuum residue oil, catalytic cracking slurry oil, solvent deoiled bitumen, and the like, or one or a mixture of several of heavy tar and residue oil generated in a coal pyrolysis or liquefaction process, heavy oil generated in an oil shale dry distillation process, low temperature pyrolysis liquid products in biomass, and the like.

In some examples of the present invention, the heavy oil feedstock has a conradson carbon residue value of 8 wt% or more, and further, the heavy oil feedstock has a conradson carbon residue value of 15 wt% or more.

The contact agent used in the cracking process of the heavy oil raw material is preferably a contact agent with relatively low cracking activity, such as a contact agent with a micro-reaction activity index of 5-30. In some examples of the present invention, the micro-reactivity index of the contact agent is 10-20, such as kaolin, clay, alumina, silica sol, industrial balancing agent or waste catalyst in the catalytic cracking process, etc.

Further, the contact agent is preferably in the form of microspheres, and the particle size thereof is preferably in the range of 10 to 500 μm, more preferably 20 to 200 μm.

During the cracking reaction, the coke content on the surface of the contact agent is preferably maintained at more than 10% by mass. In some embodiments of the invention, the reaction conditions within the cleavage section are: the reaction temperature is 450-700 ℃, the reaction pressure is 0.1-3.0 Mpa, the reaction time is 1-20 seconds, the apparent gas velocity is 1-20 m/s, and the weight ratio of the contact agent to the heavy oil (namely, the agent-oil ratio) is 0.1-1.0. Preferably, the temperature of the cracking reaction is 480-580 ℃, the reaction pressure is 0.1-1.0 Mpa, such as normal pressure, the reaction time is 3-20 seconds, the apparent gas velocity is 1-20 m/s, and the agent-oil ratio is 0.2-0.6.

The reaction temperature of the gasification reaction is generally controlled to be 850-1200 ℃, the reaction pressure is generally controlled to be 0.1-6.0 Mpa, the apparent gas velocity is generally controlled to be 0.1-5 m/s, and the retention time of the carbon deposit contact agent is generally controlled to be 1-20 min. The gasifying agent used may be, for example, steam, an oxygen-containing gas, or a mixed gas of steam and an oxygen-containing gas. Wherein the oxygen-containing gas may be, for example, air, oxygen-enriched air, oxygen, or the like.

Furthermore, before entering the gasification section for regeneration, the carbon deposit contact agent is preferably subjected to steam stripping to fully remove a small amount of light oil gas remained on the surface of the carbon deposit contact agent and in pores, thereby being beneficial to the smooth operation of the gasification reaction. Specifically, during steam stripping, the mass ratio of steam to the heavy oil raw material is generally controlled to be 0.03-0.30: 1, the temperature of the water vapor is 200-400 ℃, and the apparent gas velocity of the water vapor is 0.5-5.0 m/s.

Example two

As shown in fig. 1 and fig. 2, the present embodiment provides an apparatus for co-producing synthesis gas by heavy oil contact lightening, which is used for implementing the method described in the first embodiment, and comprises at least a coupling reactor 100, a heat remover 200 and a first gas-solid separator 300, wherein:

the coupling reactor 100 comprises a cracking section 110 at the lower part and a gasification section 120 at the upper part, and the cracking section 110 and the gasification section 120 are communicated with each other; the cracking section 110 is provided with a heavy oil raw material inlet, a carbon deposit contact agent discharge port, an oil gas discharge port, a carbon deposit contact agent return port, a synthesis gas inlet and a regeneration contact agent return port; the gasification section 120 has a carbon deposit contact agent inlet, a gasification agent inlet, a syngas discharge outlet and a regeneration contact agent discharge outlet; the accumulated carbon contact agent discharge port of the cracking section 110 is connected with the accumulated carbon contact agent inlet of the gasification section 120, the synthetic gas discharge port of the gasification section 120 is connected with the synthetic gas inlet of the cracking section 110, and the regeneration contact agent discharge port of the gasification section 120 is connected with the regeneration contact agent return port of the cracking section 110;

the heat collector 200 is arranged in the coupling reactor 100, or the heat collector 200 is arranged outside the coupling reactor 100, and the regenerated contact agent discharge port of the gasification section 120 is connected with the regenerated contact agent return port of the cracking section 110 through the heat collector 200;

the first gas-solid separator 300 is provided with an inlet, a gas discharge port and a solid discharge port, the inlet of the first gas-solid separator 300 is connected with the oil gas discharge port of the cracking section 110, and the solid discharge port of the first gas-solid separator 300 is connected with the deposited carbon contact agent return port of the cracking section 110.

In particular, the coupling reactor 100 may be obtained by appropriately modifying and assembling a cracking reactor and a gasification reactor commonly used in the art, wherein the cracking reactor may be, for example, a fluidized bed reactor, and the top end of the cracking reactor is communicated with the bottom end of the gasification reactor. The cracking reactor and the gasification reactor are preferably arranged coaxially, so that the transportation and circulation of materials are facilitated, the difficulty in circulating operation among a plurality of reactors in the technical processes of catalytic cracking, gasification and the like is reduced, and the occupied area of the device is further reduced.

Further, the aforementioned apparatus may further include an atomizer (not shown). The atomizer may be disposed outside of the coupling reactor 100 and connected to the cracking section 110 through a heavy oil feedstock inlet. Thus, after being sufficiently preheated, the heavy oil feedstock can be first atomized in an atomizer and then introduced into the cracking section 110. The atomizer can also be disposed in the coupling reactor 100 as an atomized feeding section of the coupling reactor 100, and the atomized feeding section can be specifically disposed in the cracking section 110 and corresponds to the heavy oil feedstock inlet, so that after the preheated heavy oil feedstock enters the cracking section 110 through the heavy oil feedstock inlet, the atomization is first achieved in the atomized feeding section, and then the cracking reaction is performed.

With further reference to fig. 1 and 2, the coupling reactor 100 may further include a temperature-reducing washing section 130. The reduced temperature washing stage 130 may be specifically disposed in an upper portion of the pyrolysis stage 110. Specifically, the cooling washing section 130 may adopt the structure of the washing section (or desuperheating section) in the currently conventional coking fractionating tower or catalytic fractionating tower, and generally 8 layers or 10 layers of herringbone baffles or tongue-shaped tower plates are used, aiming at enabling the upward high-temperature oil gas (i.e. light oil gas and synthesis gas) and the downward low-temperature liquid to generate countercurrent contact and exchange heat in the cooling washing section 130, so as to inhibit excessive cracking and coking, and remove a small amount of carbon deposit contact agent small particles carried in the high-temperature oil gas.

The cryogenic liquid may be, for example, a heavy oil feedstock. Because the amount of the heavy oil raw material after heat exchange is not large and the heavy oil raw material is fully dispersed in the heat exchange process with the high-temperature oil gas, the heavy oil raw material which is generally used as low-temperature liquid can be directly subjected to cracking reaction in the cracking section 110 after heat exchange and temperature rise.

With further reference to FIG. 1, a steam stripping section 140 may also be provided in the lower portion of the cracking section 110. In particular, the steam stripping section 140 can include a multi-layer stripping structure that can be formed using a combination of one or more of chevron baffles, annular baffles, conical baffles, grated baffles, loose fill, or structured fill, among other stripping structures. The carbon deposit contact agent generated in the cracking section 110 descends and is subjected to steam stripping in the steam stripping section 140 to remove the light oil gas product remained on the surface or in the pores of the carbon deposit contact agent, thereby facilitating the subsequent gasification regeneration.

Correspondingly, the aforementioned apparatus may further comprise a steam supply device (not shown) for supplying steam at a suitable temperature and flow rate into the cracking section 110, thereby forming a steam stripping section 140 at a lower portion of the cracking section 110.

With further reference to FIG. 1, the apparatus may further comprise a return feeder (not shown) for connecting the coke contact agent discharge of the pyrolysis section 110 and the coke contact agent inlet of the gasification section 120. Namely, the carbon deposit contact agent is discharged from the carbon deposit contact agent outlet at the lower part of the cracking section 110 and then is transported into the gasification section 120 through the material returning device.

As previously described, regeneration of the char-forming contact agent occurs in the gasification stage 120, resulting in a regenerated contact agent and syngas. Due to the high heavy metal content and high ash content of the inferior heavy oil, part of the contact agent is easy to be permanently inactivated in the heavy oil processing process. In addition, the higher metals and ash content of the heavy oil feedstock also tends to accumulate on the contact agent, forming ash components that are difficult to convert, and therefore an ash discharge port (not shown) may also be provided in the lower portion of the gasification stage 120. The discharged ash contains high heavy metal content, and heavy metals such as Ni, V and the like in the discharged ash can be recovered through a subsequent treatment device.

In this embodiment, the heat collector 200 is used to cool the regenerated contact agent from the gasification stage 120 to a suitable temperature after heat exchange, and may be a heat collecting and exchanging device commonly used in the field of petroleum processing.

Referring further to fig. 1, the heat collector 200 may be built-in, that is, the heat collector 200 is disposed in the coupling reactor 100, and may be disposed in the lower portion of the gasification section 120. The regeneration contact agent discharge port is arranged at the bottom of the gasification section 120, and the regeneration contact agent return port is arranged at the top of the cracking section 110; a descending pipe 150 is further arranged in the coupling reactor 100, one end of the descending pipe 150 is connected with the regenerated contact agent discharge port, and the other end of the descending pipe 150 passes through the regenerated contact agent return port and enters the cracking section 110. Thus, the regenerated contact agent generated in the gasification section 120 flows downwards to enter the heat collector 200, enters the material descending pipe 150 from the regenerated contact agent outlet at the bottom of the gasification section 120 after being heated and cooled, and flows downwards to enter the cracking section 110 in the material descending pipe 150.

Referring further to fig. 2, the heat collector 200 may be disposed externally, i.e. the heat collector 200 is disposed outside the coupling reactor 100. Specifically, two ends of the heat collector 200 may be respectively connected to the gasification section 120 and the cracking section 110 through external transportation pipes (not shown), so that the regenerated contact agent from the gasification section 110 enters the heat collector 200 through the external transportation pipes for heat exchange and temperature reduction, and then returns to the cracking section 110 through the external transportation pipes for recycling.

As shown in fig. 1 and fig. 2, the light oil gas and the synthesis gas discharged from the oil gas discharge port of the cracking section 110 are led out of the coupling reactor 100 and then enter the first gas-solid separator 300, the carbon deposit contact agent carried in the light oil gas and the synthesis gas is separated to obtain purified oil gas, and the separated carbon deposit contact agent can be returned to the cracking section 110 for recycling.

In this embodiment, the first gas-solid separator 300 may be a gas-solid separation device commonly used in the petroleum processing field, such as a cyclone separator. In practical use, the light oil gas and the synthesis gas carrying the carbon deposit contact agent are introduced into the cyclone separator from the upper inlet, the carbon deposit contact agent is separated from the airflow of the light oil gas and the synthesis gas by utilizing the centrifugal force generated when the gas-solid mixture rotates at high speed and can be collected at the solid discharge port at the bottom of the cyclone separator, and the purified oil gas is discharged from the gas discharge port at the top of the cyclone separator and then is further processed and utilized.

With further reference to fig. 1 and 2, a second gas-solid separator 400 may be further disposed in the gasification stage 120 to perform gas-solid separation on the syngas in the gasification stage 120 to obtain purified syngas, and a small amount of contact agent particles entrained in the syngas are separated and returned to the gasification stage 120.

Further, the apparatus may further include a gasifying agent supply device (not shown). The gasifying agent supply device is connected to the gasifying section 120 and is used for supplying a gasifying agent, so that the gasifying agent is introduced into the gasifying section 120 from a gasifying agent inlet.

In order to illustrate the practical effects of the present invention, the following embodiments will be further described with reference to specific application examples:

application example 1

As shown in fig. 1, the low-quality heavy oil is preheated and then atomized through a heavy oil raw material inlet to enter a cracking section 110 at the lower part of a coupling reactor 100, and the atomized heavy oil droplets contact with a fluidized contact agent to undergo a lightening reaction to obtain light oil gas and coke respectively. The coke is attached to the surface of the contact agent, namely the carbon deposit contact agent.

The carbon deposit contact agent falls under the action of gravity, passes through the steam stripping section 140 to remove the light oil gas product remained on the surface of the carbon deposit contact agent, and then is discharged from the carbon deposit contact agent discharge port at the lower part of the cracking section 110 and conveyed into the gasification section 120 through the material returning device.

In the gasification stage 120, the carbon deposit contact agent and the steam and/or oxygen-containing gas flowing in from the gasification agent supply device are subjected to high-temperature gasification reaction, so that high-quality synthesis gas is obtained, and the regeneration of the contact agent is realized at the same time. The synthesis gas generated in the gasification section 120 is discharged from the oil gas outlet at the top of the gasification section 120, and a part of the synthesis gas and the steam provided by the steam supply device enter the cracking section 110 from the synthesis gas inlet at the bottom of the cracking section 110, so as to provide heat and hydrogen atmosphere for the decarburization and upgrading of the heavy oil. Another portion of the syngas can be used to supplement a refinery hydrogen source or for other uses.

The regenerated contact agent obtained by regeneration in the gasification section 120 enters the heat collector 200 under the action of gravity, exchanges heat with heat-taking media such as low-temperature steam and the like in the heat collector 200 to reduce the temperature of the regenerated contact agent to a proper temperature, and then falls into the cracking section 110 through the falling pipe 150 to provide heat and catalytic activity required by the heavy oil cracking reaction.

The high-temperature light oil gas and the synthesis gas merged upwards pass through a cooling washing section, are cooled and remove part of carbon deposit contact agent fine powder carried in the high-temperature light oil gas and the synthesis gas, then enter a first gas-solid separator 300, such as a cyclone separator, for further gas-solid separation, and remove the residual carbon deposit contact agent in the high-temperature light oil gas and the synthesis gas, so that purified oil gas is obtained. The collected carbon deposit contact agent is returned to the cracking section 110 as reaction bed material to form the carbon deposit contact agent particle circulation of the cracking section 110 and provide partial heat required by the cracking process and a gas-solid catalytic cracking reaction site.

The purified oil gas obtained by the purification of the cyclone separator can further pass through a gas-liquid fractionating tower, an oil gas absorption stabilizing tower and other systems to respectively obtain gas products such as synthesis gas, dry gas, liquefied gas and the like and light oil products. Of course, the resulting oil can be further cut and separated to obtain liquid products of different boiling range components, wherein the heavy oil (possibly including a portion of the contact agent solid particles) can be mixed with the heavy oil feedstock for recycling processing.

In the embodiment of the present application, the cracking section 110 and the gasification section 120 are vertically communicated, so that the raw material mutual supply and heat complementation between the cracking reaction and the gasification reaction are formed in the coupling reactor 100, and the technical advantages of the reaction synergistic coupling and the synthesis gas co-production are realized. On the other hand, the cracking section 110 and the gasification section 120 are effectively isolated by the material dropping pipe 150, the heat collector 200 and the like, so that the oil gas yield is improved, the problems of coking, blockage and the like of large-size coke particles are effectively solved, the two reactions can be relatively independently carried out, and the safety and the operation stability of the heavy oil lightening process are improved.

By arranging the heat collector 200 between the gasification section 120 and the cracking section 110, the regenerated contact agent after coke removal can further recover part of heat through the heat collector 200, and the regenerated contact agent with a proper temperature enters the cracking section 110 to provide heat and catalytic activity required by heavy oil cracking reaction.

And moreover, the energy efficiency of the process is improved through a smaller agent-oil ratio, so that the technology has stronger economical efficiency and competitiveness.

The process flow of the application example 1 is used for processing domestic vacuum residue of a certain refinery, and the properties of the raw oil are shown in Table 1.

As can be seen from Table 1, the feedstock oil has high density, high carbon residue value, and high asphaltene content, and contains high sulfur, nitrogen, and heavy metal components. The coke formation tendency is serious by adopting the traditional catalytic cracking process, and the rapid carbon deposition inactivation or heavy metal poisoning inactivation of the catalyst is easily caused.

TABLE 1

Item	Data of
		Density (20 ℃), kg m^-3	993.8
Viscosity (80 ℃ C.), mm²·s^-1	5357.85
		Kang's carbon residue, wt.%	17.82
Group composition, wt%
		Saturated hydrocarbons	21.13
Aromatic hydrocarbons	35.33
		Glue	37.51
Asphaltenes	6.03
		Sulfur, wt.%	1.10
Nitrogen, wt%	1.03
		Ni，μg·g^-1	79.4
V，μg·g^-1	88.1

In the process, a self-made decarbonization modification contact agent with certain micro-reverse activity is adopted, and a cheap kaolin material is adopted for modification to obtain a macroporous structure with a high proportion, a large specific surface area and low acidity. The particle size distribution range of the contact agent is mainly 20 to 100 μm, and the bulk density is 0.78 to 1.03 g/cm^-3Abrasion index<1 wt%, and a microreflective index of about 20.

The cracking reaction conditions are as follows: the reaction temperature is 510 ℃, the pressure is 0.1Mpa, the mass ratio of the catalyst to the oil is 0.6, the reaction time is about 16 seconds, and the apparent gas velocity is about 4.5 m/s.

The gasification reaction conditions are as follows: the gasifying agent is water vapor and oxygen according to the ratio of 1: 1 volume ratio of mixed gas, reaction temperature of 900 ℃, reaction pressure of 0.1Mpa, apparent gas velocity of about 0.6m/s, and residence time of carbon deposition contact agent of about 10 min.

The steam stripping conditions were: the mass ratio of the steam to the heavy oil raw material is 0.20, the temperature of the steam is 350 ℃, and the superficial gas velocity of stripping steam is 2.5 m/s.

The light oil gas obtained by the cracking reaction and the synthesis gas from the gasification section are purified by gas-solid separation to obtain the final oil gas product, and the product distribution is shown in table 2. Table 3 shows the composition of the synthesis gas obtained by carrying out the gasification reaction under the above conditions with the char-forming contact agent as the gasification reaction mass.

TABLE 2

Product distribution, wt%	Numerical value
		Dry gas	2.32
Liquefied gas	2.84
		Gasoline (gasoline)	13.89
Diesel oil	21.03
		Wax oil	33.19
＞500℃	10.84
		C₃～500℃	70.95
C₅～500℃	67.21
		Total liquid yield	78.95
Coke	15.89

As can be seen from table 2, compared with the initial carbon residue value of the raw material, the ratio of the coke yield to the carbon residue is about 0.8-0.9, which is much smaller than the ratio of coke/carbon residue 1.4-1.6 in delayed coking, which indicates that the economic index of the device in this embodiment is much higher than that of the heavy oil processing device in the prior art; the total liquid yield of heavy oil cracking is close to 80%, wherein most of the total liquid yield is light oil fraction of less than 500 ℃, which shows that the process of the embodiment can realize the lightening of heavy oil, obtain a large amount of oil products with higher added values and has very high processing efficiency; in addition, heavy oil components greater than 500 ℃ can be further processed by means of recycling.

TABLE 3

Synthesis gas Components	H₂	CO	CO₂	CH₄Etc. other components
					Volume content (vol%)	40.7	39.5	18.7	1.1

As can be seen from Table 3, in the synthesis gas obtained by gasifying coke, H is₂The sum of the volume fraction of the CO and the high-quality synthetic gas is about 80 percent, and the high-quality synthetic gas can be used for preparing hydrogen by subsequent reforming and replenishing a hydrogen source of a refinery.

Application example 2

The heavy oil upgrading process of application example 2 is substantially the same as that of application example 1, except that in this application example, the regenerated contact agent in the gasification section 120 is led out of the coupling reactor 100, enters the external heat collector 200 for heat exchange and temperature reduction, and then returns to the cracking section 110.

According to the same reaction conditions (including the reaction conditions in the cracking section 110, the reaction conditions in the gasification section 120 and the steam stripping conditions) as those in the application example 1, the heavy oil raw material as that in the application example 1 is processed, and the result shows that compared with the initial carbon residue value of the raw material, the ratio of the coke yield to the carbon residue is about 0.8-0.9, which is far smaller than the ratio of coke/carbon residue in delayed coking 1.4-1.6; the total liquid yield is close to 80%, wherein most of the total liquid yield is light oil fraction at the temperature of less than 500 ℃, and heavy oil components at the temperature of more than 500 ℃ can be further processed by a recycling mode. And, in the synthesis gas obtained by gasification of coke, H₂The sum of the volume fraction of the CO and the high-quality synthetic gas is close to 80 percent, and the high-quality synthetic gas can be used for preparing hydrogen by subsequent reforming to supplement a refinery hydrogen source.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. The method for coproducing the synthesis gas by heavy oil contact and lightening is characterized in that a coupling reactor is used as a reactor, the coupling reactor comprises an upper gasification section and a lower cracking section, a steam stripping section is arranged at the lower part in the cracking section, a cooling washing section is arranged at the upper part in the cracking section, and the cracking section and the gasification section are communicated with each other; the method comprises the following steps:

the carbon deposit contact agent descends in the cracking section, enters the gasification section after steam stripping in the steam stripping section, and is regenerated by gasification reaction with the gasification agent to obtain a regenerated contact agent and synthesis gas; the regenerated contact agent returns to the cracking section for recycling after heat exchange and temperature reduction; after the synthesis gas is discharged from the top of the gasification section, part of the synthesis gas enters the cracking section from the bottom, and part of the synthesis gas is taken as a synthesis gas product to be led out;

the light oil gas and the synthesis gas merged from the bottom of the cracking section go upward, are subjected to cooling treatment through a cooling washing section, are discharged out of the cracking section, are subjected to gas-solid separation, and are separated from the carbon deposit contact agent carried in the light oil gas and returned to the cracking section for cyclic utilization, and meanwhile, purified oil gas is obtained.

2. The method of claim 1 wherein said heavy oil feedstock has a conradson carbon residue value of not less than 8 wt%.

3. The method according to claim 1, wherein the particle size distribution of the contact agent is 10 to 500 μm; and/or the micro-inverse activity index of the contact agent is 5-30.

4. The method of claim 1 wherein the coke mass content of the coke-depositing contact agent is above 10%.

5. The method as claimed in claim 1 or 4, wherein the reaction temperature in the cracking section is 450-700 ℃, the reaction pressure is 0.1-3.0 MPa, the reaction time is 1-20 seconds, the superficial gas velocity is 1-20 m/s, and the weight ratio of the contact agent to the heavy oil raw material is 0.1-1.0: 1.

6. the method according to claim 1 or 4, wherein the reaction temperature in the gasification section is 850-1200 ℃, the reaction pressure is 0.1-6.0 Mpa, the apparent gas velocity is 0.1-5 m/s, and the residence time of the carbon deposit contact agent is 1-20 min; the gasifying agent is water vapor and/or oxygen-containing gas.

7. The method according to claim 6, wherein the steam stripping is carried out while controlling the mass ratio of the steam to the heavy oil feedstock to be 0.03-0.3: 1, the temperature of the water vapor is 200-400 ℃, and the apparent gas velocity of the water vapor is 0.5-5.0 m/s.

8. An apparatus for co-producing synthesis gas by heavy oil contact upgrading, for carrying out the method according to any one of claims 1 to 7, wherein the apparatus comprises at least a coupling reactor, a heat remover and a first gas-solid separator, wherein:

the coupling reactor comprises a cracking section at the lower part and a gasification section at the upper part, and the cracking section and the gasification section are communicated with each other; the cracking section is provided with a heavy oil raw material inlet, a carbon deposit contact agent discharge port, an oil gas discharge port, a carbon deposit contact agent return port, a synthesis gas inlet and a regeneration contact agent return port; the gasification section is provided with a carbon deposit contact agent inlet, a gasification agent inlet, a synthetic gas outlet and a regeneration contact agent outlet; the accumulated carbon contact agent discharge port of the cracking section is connected with the accumulated carbon contact agent inlet of the gasification section, the synthetic gas discharge port of the gasification section is connected with the synthetic gas inlet of the cracking section, and the regeneration contact agent discharge port of the gasification section is connected with the regeneration contact agent return port of the cracking section;

the heat collector is arranged in the coupling reactor, or the heat collector is arranged outside the coupling reactor, and a regeneration contact agent discharge port of the gasification section is connected with a regeneration contact agent return port of the cracking section through the heat collector;

the first gas-solid separator is provided with an inlet, a gas outlet and a solid outlet, the inlet of the first gas-solid separator is connected with the oil gas outlet of the cracking section, the lower part of the solid outlet of the first gas-solid separator, which is connected with the carbon deposit contact agent return port of the cracking section, in the cracking section is provided with a steam stripping section, and the upper part in the cracking section is provided with a cooling washing section.