CN110420603B

CN110420603B - Composite heat exchange combined fixed bed reaction system for preparing hydrocarbon from methanol

Info

Publication number: CN110420603B
Application number: CN201910741017.5A
Authority: CN
Inventors: 马延春
Original assignee: Jinan Longkai Energy Technology Co ltd
Current assignee: Jinan Longkai Energy Technology Co ltd
Priority date: 2019-08-12
Filing date: 2019-08-12
Publication date: 2024-01-16
Anticipated expiration: 2039-08-12
Also published as: CN110420603A

Abstract

The invention relates to a composite heat exchange combined fixed bed methanol-to-hydrocarbon reaction system, which is characterized in that a main catalyst bed layer and a supplementary catalyst bed layer are arranged in a main reactor to form a combined fixed bed, a solid heat conducting piece heat exchange structure is arranged in a radial flow main catalyst bed layer, and an ejector system is used for directly mixing and exchanging heat to form a composite heat exchange mode, so that efficient heat exchange between products and raw materials is realized, and the temperature of the reactor bed layer is controlled. The device has low manufacturing cost, small occupied area, low running cost and high safety. The reaction device is energy-saving and environment-friendly, and is suitable for coal chemical industry, petroleum and petrochemical industry, thermoelectric industry and the like.

Description

Composite heat exchange combined fixed bed reaction system for preparing hydrocarbon from methanol

Technical Field

The invention belongs to a reaction device for preparing hydrocarbon products by converting methanol. In particular to a reaction system for producing fuel components such as mixed hydrocarbon and hydrocarbon products such as olefin, aromatic hydrocarbon and the like by taking methanol or crude methanol as raw materials, belonging to the field of coal chemical industry or natural gas chemical industry.

Background

The disclosure of this background section is only intended to increase the understanding of the general background of the invention and is not necessarily to be construed as an admission or any form of suggestion that this information forms the prior art already known to those of ordinary skill in the art.

Methanol can be converted to water and various hydrocarbon products such as olefins, paraffins, aromatics, and mixtures of such hydrocarbon products by suitable catalytic processes. According to different target products, the existing methanol-to-hydrocarbon process comprises processes of preparing gasoline from methanol, preparing olefin from methanol, preparing aromatic hydrocarbon from methanol and the like.

The source of the raw materials of the methanol is wide, and coal, petroleum, natural gas, biomass and the like can be used for producing the methanol, and the methanol is used for replacing petroleum to produce fuel components such as gasoline and diesel oil and petrochemical raw materials such as olefin aromatic hydrocarbon and the like, so that the method has important significance for world petroleum supply safety.

Methanol To Gasoline (MTG) technology is a typical methanol to hydrocarbon technology, invented by Mobil company. Since 1974, the company has filed several patents on the conversion of methanol to gasoline.

The process of preparing olefin (MTO, MTP) from methanol, preparing aromatic hydrocarbon (MTA) from methanol and the like has been industrialized.

The methanol to hydrocarbon process is an exothermic process, and how to control the reaction temperature is a focus of this process. Around the problem of temperature control, various processes and reaction systems thereof have been developed, and the forms of existing reaction systems include adiabatic fixed beds, multitubular fixed beds, multistage cold shock fixed beds, moving beds, fluidized beds, and the like.

Us patent 3931349 is a patent for preparing hydrocarbons by converting methanol, which was published earlier by Mobil company, and adopts a fixed bed two-stage conversion process, wherein the first stage reaction is to dehydrate methanol to prepare dimethyl ether, and the first stage outlet material, comprising a mixture of methanol, dimethyl ether and water, enters a two-stage reactor to prepare a gasoline fraction stage product under the action of a molecular sieve catalyst.

U.S. patent 4579999 discloses another technique for preparing fractional hydrocarbon products of gasoline fraction by two-stage methanol conversion, wherein a molecular sieve catalyst is filled in a first stage reactor to convert methanol into lower olefins and partial hydrocarbons, and C5 ⁺ After cooling and separating, the low-carbon olefin enters a two-stage reactor, and is further converted into a gasoline fraction stage product under the action of an olefin polymerization catalyst.

U.S. patent 4689205 discloses a technique for preparing hydrocarbons by multistage conversion of methanol. The technology disclosed in this patent is substantially similar to that of U.S. patent 4579999 in that methanol is converted to C2-C4 olefins and a portion of C5 in a one-stage reactor under certain temperature and pressure conditions ⁺ Hydrocarbons, C5 ⁺ After the hydrocarbon is separated, the rest part enters a second-stage reactor, and the olefin polymerization catalyst is adopted to further polymerize the low-carbon olefin produced by the first-stage reaction into a hydrocarbon product of gasoline fraction. In contrast, in the technique disclosed in this patent, a fluidized bed reactor is used in the first stage.

The Chinese patent 200610048298.9 discloses a process for preparing hydrocarbon products by a methanol one-step method, which is characterized in that three stages are completed in one reactor, and compared with a two-step method, the process has the advantage of short process flow. The reaction system has simple structure, gas phase hydrocarbon circulation to control the reaction temperature, great circulation ratio, great investment in heat exchange system and separating system and great power consumption. The products are gasoline, liquefied gas, heavy gasoline, etc.

The patent of 200720101511.8 proposes a cold shock type reactor for preparing gasoline from methanol, which adopts a mode of adding cooling gas such as nitrogen gas and the like between stages to control the reaction temperature, and the products are gasoline, liquefied gas and fuel gas, and does not mention a power source for circulating the cooling gas.

The fluidized bed process is characterized in that three stages of the reaction process for preparing gasoline from methanol are completed in a fluidized bed reactor. The fluidized bed mode can effectively solve the cooling problem, but the fluidized bed has the advantages of complex structure, high manufacturing cost, large catalyst abrasion, difficult separation of catalyst powder and high operation cost.

The existing multitube reactor takes molten salt as a heat transfer medium to absorb reaction heat and produce steam, but a molten salt heat exchange system has a complex structure, difficult system start and stop and large equipment investment.

The adiabatic fixed bed reactor has simple structure, is easy to amplify and is popularized and applied. In order to control the catalyst bed temperature, the existing adiabatic fixed bed reactors all adopt a mode of mixing and feeding recycled hydrocarbon and methanol raw materials. The reaction product is cooled by a heat exchanger and then sent to an oil-water separator, and after dry gas, oil and water are separated, the liquid-phase oil product is further separated into products, byproducts, circulating hydrocarbon and the like by a rectifying system. The circulating hydrocarbon needs to be pressurized and heated by a compressor and then returned to the inlet of the reactor. The circulation ratio can reach 5-20 times, so in the whole device, the material treatment capacity including the circulating hydrocarbon is about 10 times of the raw material methanol, about 20 times of the product gasoline, the methanol-to-gasoline device for annual production of 10 ten thousand tons of gasoline is realized in the whole treatment process including reaction, heat exchange, separation and refining, and the specification investment of the separation and refining equipment is equivalent to a megaton of petroleum-based refinery. The device has the advantages of high power consumption, high heat exchange capacity and high equipment manufacturing cost. The product outlet of the reactor is connected with the product heat exchanger through a large-caliber high-pressure high-temperature valve, a flange and the like, and the temperature and pressure change range is large, the leakage risk of high-temperature high-pressure inflammable and explosive gas is large, and the safety and sealing maintenance workload is large in the processes of stopping, starting, running, regenerating and the like.

In order to reduce the power consumption and equipment investment of the methanol-to-hydrocarbon device, the inventor provides a methanol-to-hydrocarbon method and device with the stepwise adjustment of the injection circulation classification reaction in the invention patent of the invention (patent number: 201610438258.9), and the invention has the characteristics of high yield of target products, low power consumption and low equipment investment. The invention comprises a 3-section reactor, a high-temperature product heat exchanger and 5 sets of ejector systems. Engineering practice and further research find that compared with the traditional fixed bed reaction device, the device has the advantages that the power consumption is greatly reduced, the product yield is improved, but the two problems still exist, and firstly, the device has the problem of difficult debugging, wherein a plurality of sets of ejectors are adopted as main reasons. The maintenance workload is large mainly because a multi-stage reactor, a high-temperature product heat exchanger and a plurality of sets of ejectors are adopted, and a plurality of high-temperature and high-pressure valves, flanges and other parts with higher price are needed, and the number is increased although the caliber is reduced compared with that of the traditional device, and under different working conditions of device starting, running, stopping, regeneration and the like, the temperature change range of the high-temperature and high-pressure parts can be from normal temperature to 550 ℃, the pressure can be from normal pressure to above 3.0 megapascals, the temperature and pressure change range is large, the sealing requirement is high, and the maintenance workload is large.

In summary, the hydrocarbon production from methanol is a relatively strong exothermic reaction, and the control of the reaction temperature is a problem that must be considered in the hydrocarbon production process from methanol. The fixed bed reactor is a widely used hydrocarbon production device from methanol. The existing reaction systems for preparing hydrocarbon from methanol, such as a fluidized bed, a fixed bed and the like, have the problems of high power consumption, high equipment investment and the like.

Disclosure of Invention

In order to overcome the problems, the invention provides a composite heat exchange combined fixed bed methanol-to-hydrocarbon reaction system. The combined fixed bed methanol-to-hydrocarbon reaction system adopting the composite heat exchange mode solves the problems of high power consumption and high equipment investment existing in the existing methanol-to-hydrocarbon reaction system of the existing methanol-to-hydrocarbon process.

In order to achieve the technical purpose, the invention adopts the following technical scheme:

a composite heat exchange combined fixed bed reaction system for preparing hydrocarbon from methanol comprises: the fixed bed and rectifying tower 8, the fixed bed shell 17 is internally provided with a first buffer chamber 3, a catalyst bed layer 5, a second buffer chamber 20, an intermediate chamber 19 and a supplementary catalyst bed layer 18 from top to bottom in sequence; the catalyst bed 5 is symmetrically arranged relative to the nozzle 4 at the outlet of the first buffer chamber 3, a heat conducting piece 22 is further arranged between the inlet of the catalyst bed 5 and the second buffer chamber 20, the material outlet at the bottom of the fixed bed is sequentially connected with the reboiler 14 at the bottom of the rectifying tower 8 and the oil-water separator 12, and the oil-water separator 12 is respectively connected with the dry gas buffer utilization system 11 and the water treatment system 13.

It is found that in the existing reaction process of preparing hydrocarbon from methanol in a fixed bed, the process of etherification and low-carbon olefin generation is firstly carried out on the HZSM-5 catalyst, the process can be carried out at a higher space velocity when the temperature exceeds 200 ℃ and most of reaction heat is discharged, and the process can be completed in a catalyst bed with a thinner inlet end of the catalyst bed. The latter half of the catalyst bed layer is mainly used for ensuring the continuous reaction of unreacted methanol and the like, and has smaller heat release. The aromatization process is completed under conditions of aromatic hydrocarbon products or temperature and catalyst and the like.

By utilizing the characteristic of the reaction of preparing hydrocarbon from methanol, the invention divides the catalyst bed layer of the reaction system of preparing hydrocarbon from methanol in a fixed bed into two parts: the main catalyst bed layer and the supplementary reaction catalyst bed layer form a combined fixed bed methanol-to-hydrocarbon reaction system together. Wherein, the main catalyst bed mainly completes the rapid exothermic reaction, and the bed can be properly thinned without considering the problem caused by ensuring the methanol conversion rate, thereby being beneficial to simplifying the structure of the temperature control device. The lower reaction temperature is controlled to slow down coking. The supplementary catalyst bed layer mainly ensures the conversion rate of methanol, and because the heat release amount is small, an additional temperature control device is not required to be arranged, so that the structure is simplified.

In some embodiments, the thermally conductive member 22 is located inside the main catalyst bed 5 and on the inlet side.

The invention sets up solid heat-accumulating heat-conducting member in the inside of the main catalyst bed and at the inlet side, the reaction heat partly absorbed by the catalyst particles is conducted by the contact heat and solid heat conduction of the solid heat-conducting member, and the heat of the catalyst particles is led to the solid heat-accumulating heat-conducting member at the inlet; the heat of reaction partially absorbed by the reaction product is conducted by contact heat and solid heat conduction to the solid heat transfer member within the catalyst bed, and also directed to the solid heat storage and conduction member of the inlet. Raw material methanol flowing through the inside of the main catalyst bed and the solid heat storage and conduction piece at the inlet side is heated to the reaction temperature and then enters the catalyst bed to start reaction and release heat. The product and catalyst particles rise in temperature, transferring heat to the heat transfer element, which in turn transfers heat to the feed methanol.

In some embodiments, a heat exchanger 23 is arranged between the feed pipe of the methanol feedstock and the first buffer chamber 3. The methanol raw material from the raw material pump 1 is heated by a feed valve 2 through a heat exchanger 23 arranged in a first buffer chamber 3, is sprayed out through a raw material nozzle 4 to form high-speed air flow, and is injected with high-temperature product gas in the first buffer chamber 3, enters a second buffer chamber 20 at the inlet side of a main catalyst bed after mixed heat exchange, then enters the main catalyst bed after being heated by a heat conducting piece 22, the reaction releases heat, and part of reaction heat is used for heating reactants through catalyst particles and the heat conducting piece 22 of the main catalyst bed. And the other part of the reaction heat is carried out of the main catalyst bed by the product. The primary catalyst bed outlet product, a portion of which enters the first buffer chamber 3 via an outer thermally conductive passage 21 between the outside of the primary catalyst bed and the inner wall of the reactor shell 17. The other part of the water enters a supplementary catalyst bed through an intermediate chamber 19 to react and then is discharged out of a reactor shell 17, enters a rectifying tower bottom reboiler through a product valve 16 to exchange heat and cool, enters an oil-water separator 12, enters a water treatment system 13 after being separated, and enters a dry gas recycling system 11 and C3 after dry gas below C2 enters ⁺ The fractions enter a rectifying tower through a liquid hydrocarbon pump 10, the separated products enter a product tank 6, liquefied gas enters a liquefied gas tank 7, dry gas 9 at the top of the tower enters a dry gas recycling system 9, and heavy hydrocarbon at the bottom of the tower enters a heavy hydrocarbon tank 15.

In some embodiments, an outer heat conducting channel 21 (i.e., a gas channel) is provided between the outside of the main catalyst bed 5 and the inner wall of the reactor shell 17. The invention adopts radial flow to arrange the main catalyst bed layer so as to shorten the solid heat conduction path and reduce the thermal resistance. The reaction raw materials enter the catalyst bed layer from the inner side of the catalyst bed layer, and flow out from the outer side of the catalyst bed layer after reacting. The flowing reaction product is divided into two paths, one path of reaction product is discharged out of the reaction system carrying part of reaction heat after the reaction is completed by the supplementary catalyst bed layer, and enters the separation system, and the rest of reaction heat is lost in a small amount. The other path enters the buffer chamber at the inlet end of the ejector through a channel between the outer side of the main catalyst bed and the reactor shell, exchanges heat with raw material methanol through the heat exchanger of the ejector, is further ejected by the ejector, exchanges heat with the raw material methanol from the nozzle of the ejector, and enters the main catalyst bed for reaction after being heated to the reaction temperature through the solid heat storage and conduction piece at the inlet side of the main catalyst bed.

In some embodiments, a liquid hydrocarbon pump 10 is disposed between the liquid hydrocarbon outlet of the oil-water separator 12 and the feed inlet of the rectifying tower 8.

In some embodiments, the rectifying column 8 discharge port is connected to the product tank 6. C3C 3 ⁺ The above fractions are pumped via liquid hydrocarbon pump 10 into a rectifying column, from which the product (about 80% of the total hydrocarbon product) is separated and fed into product tank 6.

In some embodiments, the gas outlet at the top of the rectifying tower 8 is connected with the gas inlet of the dry gas buffer utilization system 11. Dry gas below C2 (about 1% of the total hydrocarbon product) enters the dry gas recovery system 11.

In some embodiments, the bottom drain of rectifying column 8 is connected to the feed of heavy hydrocarbon tank 15. The bottom heavy hydrocarbons (about 5% of the total hydrocarbon product) enter the heavy hydrocarbon tank 15.

In some embodiments, the material of the heat conductive member 22 includes, but is not limited to, ceramic ball filler, carbon steel, stainless steel, aluminum. Preferably, the aluminum material with high heat conductivity and moderate price is adopted.

The invention also provides application of any of the composite heat exchange combined fixed bed methanol-to-hydrocarbon reaction systems in the preparation of hydrocarbon from methanol.

The invention has the beneficial effects that:

(1) The invention has the advantages of low power consumption and low equipment investment.

(2) The invention cancels the gas compressor with larger power consumption of the prior methanol-to-hydrocarbon device, adopts the ejector to pressurize the circulating gas, pressurizes the methanol liquid phase and greatly reduces the power consumption.

(3) The invention eliminates the external circulating hydrocarbon system and its heat exchange system, separating system, refining system, circulating system and greatly reduces the equipment investment.

(4) The invention adopts a set of built-in ejector system, and the reaction system works stably and reliably and is easy to debug.

(5) Compared with the ejector installed outside the reactor, the ejector is small in pressure difference between the inside and the outside, low in requirement on strength, rigidity and tightness, convenient to manufacture, easy to install and free from an insulating layer. The gas flow resistance is small and the distribution is uniform.

(6) The circulating gas required by the invention circularly flows in and out of the front-stage main catalyst bed layer in the reactor, the flow rate of the rear-stage catalyst bed layer is far smaller than that of the existing reaction system, and the catalyst utilization efficiency is high.

(7) Compared with the existing reaction technology, the circulating gas required by the invention circularly flows inside and outside the front section catalyst bed layer inside the reactor, the flow of the oil-water separation system outside the reactor, the rectifying system and the circulating hydrocarbon evaporation and overheating system are greatly reduced, the equipment investment is greatly reduced, and the energy power consumption is greatly reduced.

(8) According to the invention, the high-temperature devices such as the high-temperature heat exchanger, the two sections of catalyst beds and the ejector system are arranged in the reactor shell, so that the problems of high sealing requirement and large maintenance workload caused by the requirement of a large-caliber high-temperature high-pressure valve and a high-temperature high-pressure flange in the prior art are solved, and the safety of the device is improved.

(9) The system has the advantages of simple structure, low running cost, universality and easy mass production.

Drawings

The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this application, illustrate embodiments of the application and together with the description serve to explain the application and do not constitute an undue limitation to the application.

FIG. 1 is a composite heat exchange combined fixed bed methanol to hydrocarbon reaction system of example 1.

The device comprises a raw material pump 1, a feeding valve 2, a first buffer chamber 3, a heat exchanger 23, a raw material nozzle 4, a catalyst bed layer 5, a product tank 6, a liquefied gas storage tank 7, a rectifying tower 8, a rectifying tower top dry gas 9, a liquid hydrocarbon pump 10, a dry gas buffer utilization system 11, an oil-water separator 12, a water treatment system 13, a heat exchanger 14, heavy hydrocarbon 15, a product valve 16, a reactor shell 17, a supplementary catalyst bed layer 18, an intermediate chamber 19, a catalyst bed layer inlet side second buffer chamber 20, an outer heat conducting channel 21, a heat conducting piece 22 and an inner heat conducting channel 45.

Detailed Description

It should be noted that the following detailed description is illustrative and is intended to provide further explanation of the present application. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments in accordance with the present application. As used herein, the singular is also intended to include the plural unless the context clearly indicates otherwise, and furthermore, it is to be understood that the terms "comprises" and/or "comprising" when used in this specification are taken to specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof.

As introduced by the background technology, the problems of high power consumption, high equipment investment and the like of the existing fluidized bed, fixed bed and other methanol-to-hydrocarbon reaction systems are solved. Therefore, the invention provides a composite heat exchange combined fixed bed methanol-to-hydrocarbon reaction system.

It was found that the reaction heat of the hydrocarbon production from methanol was about 1.7 to 1.8MJ/kg, and the heat required to evaporate methanol gas overheated from 25 ℃ to 300 ℃ was about 1.7MJ/kg. The methanol gas starts to react and release heat on the HZSM-5 catalyst at the temperature below 200 ℃, and the reaction rate is higher at the temperature above 300 ℃. The hot spot temperature of the catalyst bed is generally controlled below 480 ℃. Typical data for existing adiabatic fixed beds for methanol to hydrocarbon: the inlet temperature of the catalyst bed is 340 ℃, the circulation ratio is 10, and the outlet temperature is 400 ℃. The reaction heat of the methanol to hydrocarbon can also evaporate and overheat the liquid phase methanol to the reaction temperature or above.

Therefore, the heat of the reaction for preparing hydrocarbon from methanol can be utilized to evaporate and overheat the methanol to the reaction temperature; alternatively, the heat required to superheat the methanol to the reaction temperature may be achieved by absorbing the heat of the methanol-to-hydrocarbon reaction.

In the process of preparing hydrocarbon from methanol, raw material methanol firstly absorbs heating heat Q1 provided by a heating device before entering a reaction system, absorbs heat from normal temperature (for example, 25 ℃) and is evaporated and overheated to a reaction temperature (for example, 300 ℃), then enters a catalyst bed layer, starts to react and emit heat in the catalyst bed layer, the temperature rises, and after the reaction is completed, a reaction product leaves the reaction system at a higher temperature. Under the stable working condition, the temperature of the catalyst bed layer is basically kept stable, and the reaction heat Q2 and the heating heat Q1 are removed from the system to maintain the stable operation of the system.

The reaction heat Q2 of the methanol to hydrocarbon is larger, and simulation calculation shows that the adiabatic temperature rise exceeds 600K, and on the existing methanol to hydrocarbon catalyst, the temperature is too high, side reactions such as methanol decomposition reaction and the like occur, the temperature is generally controlled below 480 ℃, and circulating hydrocarbon is needed to be doped to control the temperature rise. At the outlet of the existing reactor, the recycle hydrocarbon and the newly added reaction product are brought together again with Q1 and Q2.

In the existing methanol-to-hydrocarbon process device, for a reaction system, heat required for evaporating and superheating raw material methanol from normal temperature liquid phase to a reaction temperature is firstly added through a divided wall type heat exchanger, and then products and circulating hydrocarbon are carried out. Q2 is the heat of reaction and must be carried out of the reaction system to maintain the temperature of the reaction system stable, typically also after conversion from product and recycle hydrocarbons through a dividing wall heat exchanger.

The heat exchange mode of the existing methanol-to-hydrocarbon process mainly adopts a liquid phase and gas phase fluid medium dividing wall type heat exchanger for heat exchange, a large amount of fluid circulates, and the processes of pressure boosting, pressure reducing, temperature rising, temperature reducing, evaporating, superheating, condensing, mixing, separating, refining and the like are repeatedly completed, so that the power consumption is high, and the investment on power equipment and heat exchange equipment is high.

The invention adopts a composite heat exchange mode, and solves the problems of large power consumption and large equipment investment caused by heat transfer mainly depending on fluid media in the prior art by increasing the contact heat conduction share of solid media.

The solid phase medium of the present invention includes, but is not limited to, solid phase components such as catalysts, packed porcelain spheres, internals, reactor shell, heat transfer components, and the like. The direction of heat flow is always directed from the high temperature point to the low temperature region inside the solid phase members and between the solid phase members in contact with each other. Heat transfer from the high temperature point of the catalyst particles themselves to the low temperature region is included in the methanol-to-hydrocarbon reactor; transferring heat from the high temperature catalyst particles to the directly contacted low temperature catalyst particles; heat transfer from the catalyst particles to the packed ceramic spheres, heat transfer from the ceramic spheres to the internals, and heat transfer to the reactor shell. The overall heat transfer effect includes heat transfer from the catalyst bed against the gas flow direction at the inlet end of the catalyst bed, further heat transfer to the inlet end packing, screen, platen, and heat transfer to the methanol feed gas flowing therethrough. This phenomenon is present in the existing hydrocarbon reactor for methanol production, but the heat flow strength is weak and is not known to be utilized. The invention increases the share of heat transfer of the solid medium in the flow direction of the reverse reaction fluid by adopting a mode of enhancing the contact heat transfer intensity of the solid medium, and achieves the aim of controlling the reaction temperature by combining a temperature control mode of gas-solid combined heat exchange such as injection circulation in the reactor.

The solid phase medium contact heat conduction mode almost does not need power, and solves the problems of large power consumption and large equipment investment caused by heat transfer of a large amount of gas circulation hydrocarbon inside and outside the existing reactor.

The solid phase medium is mutually insoluble with liquid phase methanol, gas phase methanol and reaction products, and can be in direct contact with heat conduction, so that the heat exchange coefficient is large, and the problem of large equipment investment caused by the existing circulating hydrocarbon temperature control mode is solved.

It has been found that in a reaction system for producing hydrocarbons from methanol, the volume specific heat of solid phase components such as a catalyst, a ceramic filler, an internal component, and a reactor shell is hundreds to thousands times or more than the volume specific heat of a gas phase methanol gas, water, and a mixed hydrocarbon. This shows that the gas phase product passes through the catalyst bed once, and the catalyst bed does not have obvious temperature rise, and meanwhile, the temperature rise of the gas phase product is also inhibited because the gas phase product exchanges heat with the solid phase structure such as the catalyst and the like. The product passes through the catalyst bed layer once, the temperature of the product and the catalyst is slightly raised, and the temperature rise is not great. When inert recycle gas is mixed in the product, the reaction heat is transferred to and from the product, the recycle gas and the catalyst bed layer at different positions, and is redistributed. At the outlet of the catalyst bed, the mixed gas of the product and the recycle gas leaves the catalyst bed at a state higher than the inlet temperature, and the smaller the recycle ratio is, the higher the temperature rise is. When the cold car starts, the outlet temperature of the catalyst bed layer gradually rises, and under the stable working condition, the outlet temperature of the catalyst bed layer also rises compared with the inlet, and the outlet temperature is kept stable.

The invention sets up solid heat-accumulating heat-conducting member in the inside of the main catalyst bed and at the inlet side, the reaction heat partly absorbed by the catalyst particles is conducted by the contact heat and solid heat conduction of the solid heat-conducting member, and the heat of the catalyst particles is led to the solid heat-accumulating heat-conducting member at the inlet; the heat of reaction partially absorbed by the reaction products is conducted by contact heat and solid heat conduction through solid heat transfer elements within the catalyst bed, and also directed to the inlet solid heat storage and conducting elements. Raw material methanol flowing through the inside of the main catalyst bed and the solid heat storage and conduction piece at the inlet side is heated to the reaction temperature and then enters the catalyst bed to start reaction and release heat. The product and catalyst particles rise in temperature, transferring heat to the heat transfer element, which in turn transfers heat to the feed methanol.

The solid heat accumulating and conducting member is made of ceramic ball stuffing, carbon steel, stainless steel, aluminum material, etc. and has high heat conducting coefficient and moderate cost.

The invention adopts radial flow to arrange the main catalyst bed layer so as to shorten the solid heat conduction path and reduce the thermal resistance. The reaction raw materials enter the catalyst bed layer from the inner side of the catalyst bed layer, and flow out from the outer side of the catalyst bed layer after reacting. The flowing reaction product is divided into two paths, one path of reaction product is discharged out of the reaction system carrying part of reaction heat after the reaction is completed by the supplementary catalyst bed layer, and enters the separation system, and the rest of reaction heat is lost in a small amount. The other path enters the buffer chamber at the inlet end of the ejector through a channel between the outer side of the main catalyst bed and the reactor shell, exchanges heat with raw material methanol through the heat exchanger of the ejector, is further ejected by the ejector, exchanges heat with the raw material methanol from the nozzle of the ejector, and enters the main catalyst bed for reaction after being heated to the reaction temperature through the solid heat storage and conduction piece at the inlet side of the main catalyst bed.

The invention adopts a composite solid heat conduction mode of the injector arranged in the reactor to ensure the heat exchange capacity. The ejector is fluid machinery and mixed reaction equipment for mass transfer and energy transfer by utilizing jet turbulence diffusion. The high-pressure air flow is sprayed out from the nozzle at high speed, the low-pressure air around the nozzle is ejected, the two air flows are mixed and pressurized in the mixing chamber and the diffuser, and the pressure of the low-pressure air entering the ejector from the suction inlet is improved under the condition that a certain high-pressure working air is consumed. The working fluid exits the nozzle at a high velocity into the receiving chamber of the eductor and carries away the relatively low pressure medium prior to the eductor. The fluid to be taken away is ejection fluid, so that the pressure of the ejection fluid is increased without directly consuming mechanical energy, which is the most important performance of the ejector. With this property, in many cases, the use of ejectors is simpler and more reliable than the use of mechanical supercharging devices (compressors, pumps, blowers, induced fans, etc.). Besides the special simple structure, the method for connecting the ejector with various devices is simple, the manufacture is not complex, and the method can be widely applied to engineering.

The methanol raw material from the raw material pump 1 is heated by a feed valve 2 through a heat exchanger 23 arranged in a first buffer chamber 3, is sprayed out through a raw material nozzle 4 to form high-speed air flow, and is injected with high-temperature product gas in the first buffer chamber 3, enters a second buffer chamber 20 at the inlet side of a main catalyst bed after mixed heat exchange, then enters the main catalyst bed after being heated by a heat conducting piece 22, the reaction releases heat, and part of reaction heat is used for heating reactants through catalyst particles and the heat conducting piece 22 of the main catalyst bed. And the other part of the reaction heat is carried out of the main catalyst bed by the product. The primary catalyst bed outlet product, a portion of which enters the first buffer chamber 3 via an outer thermally conductive passage 21 between the outside of the primary catalyst bed and the inner wall of the reactor shell 17. The other part of the water enters a supplementary catalyst bed through an intermediate chamber 19 to react and then is discharged out of a reactor shell 17, enters a rectifying tower bottom reboiler through a product valve 16 to exchange heat and cool, enters an oil-water separator 12, enters a water treatment system 13 after being separated, and enters a dry gas recycling system 11 and C3 after dry gas below C2 enters ⁺ The fractions enter a rectifying tower through a liquid hydrocarbon pump 10, the separated products enter a product tank 6, liquefied gas enters a liquefied gas tank 7, dry gas 9 at the top of the tower enters a dry gas recycling system 9, and heavy hydrocarbon at the bottom of the tower enters a heavy hydrocarbon tank 15.

The heat conductive member 22 may be formed of a ceramic filler, a metal material, or the like, preferably a metal material, including a screen, a plate, a tube, or the like, in combination with the manufacture and installation of the internal member. A laminated structure is formed between the heat conducting piece and the catalyst, and the catalyst bed is internally mixed with the structural forms of inert filler porcelain balls, metal wires, metal sheets and the like.

The technical scheme of the present application is described below by means of specific examples.

Example 1, methanol to gasoline component, liquefied gas and heavy gasoline component.

Regarding the solid heat conduction system, the embodiment of the heat conductive member 22: the outer and inner vertical surfaces of the main catalyst bed are metal screens to protect the catalyst bed and reduce gas flow resistance. The top and bottom surfaces are closed with metal plates and a reinforcing structure is attached to the reactor shell. The annular carbon steel plate or the aluminum disc is used as a main heat conducting piece, the catalyst bed layer and the annular aluminum disc are alternately laminated, and the temperature field distribution meeting the requirement can be obtained by adjusting the thickness of the catalyst bed layer and the distribution along the radial direction, the thickness and the radius of the aluminum disc and other factors.

Regarding the selection design of the injection heat exchange system, the high-temperature gas in the first buffer chamber 3 transfers heat to the raw material methanol of the working fluid in the injector system through the heat exchanger 23, so that the raw material methanol is heated, the working capacity of the injector is also increased, and the injector is cooled by the high-temperature gas to be cooled, so that the injection coefficient of the injector is also improved. By increasing the heat exchange capacity of the heat exchanger 23, the injection ratio of the injector can be increased, but the cost of the heat exchanger 23 is increased. The heat conducting piece structure is optimized, the proportion of solid heat conduction is increased, the requirement on the heat exchanging capacity of the heat exchanger 23 can be reduced, and the manufacturing cost is reduced.

The methanol raw material heated and warmed is sprayed out through the raw material nozzle 4 to form high-speed air flow, the high-speed air flow enters the horn mouth type channel to be accelerated and pressurized, then enters the catalyst bed 5 from the inner heat conducting channel 45 at the inlet side of the catalyst bed 5, meanwhile, after the heat conducting piece 22 at the inlet side of the catalyst bed 5 absorbs reaction heat, part of heat is transferred to the air flow at the inlet side, then the air flow passes through the main body part of the catalyst bed 5 through the inner heat conducting channel 45 to react, and finally, the air flow is discharged from the outlet side of the catalyst bed 5.

The heat conducting member 22 is subjected to sealing treatment, so that the gas can only pass through the main body of the catalyst bed 5 and then be discharged from the outlet side of the catalyst bed 5.

The center of the catalyst bed 5 is a bell-mouth-shaped channel (the diameter is gradually changed from small to large), the side wall of the bell-mouth-shaped channel is the inlet side of the catalyst bed 5, and the outermost side (the side close to the fixed bed shell) of the catalyst bed is the outlet side of the catalyst bed 5.

The ejector in this application means: the structure of the nozzle 4 and the bell mouth type channel.

The solid heat conduction of the application is not limited to the heat conduction member 22 of the catalyst bed, and all the parts forming the internal heat conduction channels, the partition plates and the rib plates of the catalyst bed and corresponding solid connection of the fixed bed shell, the buffer chamber and the like can be used as the extension of the heat conduction member 22 to promote the export of reaction heat.

The hollow design of the inner heat conducting channel 45 can effectively ensure the heat exchange efficiency between the reaction heat and the heat conducting piece 22, thereby achieving the purposes of controlling the reaction temperature and slowing down coking.

The solid heat conduction and injector system compound heat conduction mode is adopted, so that the requirement of catalyst bed temperature control of the methanol-to-hydrocarbon device can be met. The heat exchange proportion of the mixed heat exchange of the solid heat conduction and the ejector can be properly adjusted. Increasing the fraction of solid heat conduction can reduce the heat exchange area of the heat exchanger 23 and even eliminate the heat exchanger 23.

Methanol raw material from a raw material pump 1, the pressure is 1.3-1.5Mpa, the temperature is 25-30 ℃, the methanol raw material is heated by a feeding valve 2 through a heat exchanger 23 arranged in a first buffer chamber 3 to be heated to 150-160 ℃, then is sprayed out by a raw material nozzle 4 at the pressure of 1.2-1.4Mpa to form high-speed airflow, high-temperature product gas with the pressure of 0.9-1.0Mpa and the temperature of 300-310 ℃ in the first buffer chamber 3 is ejected, mixed gas with the pressure of 1.1-1.3Mpa and the temperature of 200-250 ℃ is formed after mixed heat exchange, the mixed gas enters a second buffer chamber 20 at the inlet side of a main catalyst bed layer, and then enters the main catalyst bed layer 5 after being heated by a heat conducting member 22 to be heated to 300-320 ℃, the reaction is exothermic, and part of reaction heat (10-15%) passes through catalyst particles and a guide of the main catalyst bed layer 5 The heat element 22 is used to heat the reactants. The other part of the reaction heat (80% -90%) is carried out of the main catalyst bed by the product. The outlet product of the main catalyst bed is high-temperature product gas with the pressure of 0.9-1.0Mpa and the temperature of 350-450 ℃, and part (80-90%) enters the first buffer chamber 3 through an external heat conducting channel 21 between the outer side of the main catalyst bed and the inner wall of the reactor shell 17. The other part (10% -20%) enters the supplementary catalyst bed 18 through the intermediate chamber 19 to react and then is discharged out of the reactor shell 17, the reaction heat is partially transferred to the reactor shell 17, the pressure of the reaction product is 0.9-1.0Mpa, the temperature is 380-460 ℃, the high-temperature product gas enters the bottom reboiler of the rectifying tower (namely the heat exchanger 14) to exchange heat and cool, then enters the oil-water separator 12, the separated water enters the water treatment system 13, the dry gas below C2 (about 1% of the total hydrocarbon product) enters the dry gas recycling system 11, C3 ⁺ The fractions are pumped into a rectifying tower through a liquid hydrocarbon pump 10, the separated product (accounting for about 80 percent of the total hydrocarbon product) enters a product tank 6, liquefied gas (accounting for about 13 percent of the total hydrocarbon product) enters a liquefied gas tank 7, overhead dry gas 9 (accounting for about 1 percent of the total hydrocarbon product) enters a dry gas recycling system 9, and heavy hydrocarbon at the bottom (accounting for about 5 percent of the total hydrocarbon product) enters a heavy hydrocarbon tank 15.

Compared with the existing fixed bed methanol to gasoline process device, the device omits a high-power circulating gas compressor, and greatly reduces the power consumption. The number of heat exchangers and the total heat exchange area are greatly reduced, and the equipment investment is greatly reduced.

Example 2

Methanol to prepare mixed aromatic hydrocarbon. Referring to fig. 1, methanol is reacted with light aromatic hydrocarbons to produce polyalkyl aromatic hydrocarbons, such as trimethylbenzene, durene, and the like. As chemical raw material, the added value is higher than that of gasoline. Increasing the density of the heat transfer member 22 distributed in the main catalyst bed and increasing the fraction of solid heat transfer can simplify the heat exchanger 23.

Methanol raw material from a raw material pump 1, the pressure is 2.5-2.6Mpa, the temperature is 25-30 ℃, high-speed methanol aerosol flow is formed by spraying the methanol raw material at the pressure of 2.5-2.6Mpa through a raw material nozzle 4 through a feeding valve 2, the pressure in a first buffer chamber 3 is injected at 1.0-1.2Mpa, and the temperature is 380-450 DEG CThe temperature product gas is mixed and subjected to heat exchange to form mixed gas with the pressure of 1.2-1.4Mpa and the temperature of 150-200 ℃ and enters the second buffer chamber 20 at the inlet side of the main catalyst bed, then the mixed gas is heated by the heat conducting piece 20 to be heated to 310-350 ℃ and then enters the main catalyst bed, the reaction releases heat, and part of the reaction heat (10-15%) is used for heating reactants through catalyst particles of the main catalyst bed and the heat conducting piece 22. The other part of the reaction heat (80% -90%) is carried out of the main catalyst bed by the product. The outlet product of the main catalyst bed is high-temperature product gas with the pressure of 1.1-1.3Mpa and the temperature of 360-460 ℃, and part (80-90%) enters the first buffer chamber 3 through an outer heat conducting channel 21 between the outer side of the main catalyst bed and the inner wall of the reactor shell 17. The other part (10% -20%) enters a supplementary catalyst bed through an intermediate chamber 19 to react and then is discharged out of a reactor shell 17, the reaction heat is partially transferred to the reactor shell 17, the pressure of the reaction product is 1.0-1.1Mpa, the temperature of the high-temperature product gas is 380-480 ℃, the high-temperature product gas enters a rectifying tower bottom reboiler (namely a heat exchanger 14) to exchange heat and cool, then enters an oil-water separator 12, the separated water enters a water treatment system 13, the dry gas (about 1% of total hydrocarbon products) below C2 enters a dry gas recycling system 11, and C3 ⁺ The fractions are pumped into a rectifying tower through a liquid hydrocarbon pump 10, mixed light aromatic hydrocarbon products (accounting for about 60 percent of total hydrocarbon products) are separated and enter a product tank 6, mixed light hydrocarbon (accounting for about 12 percent of total hydrocarbon products) enters a liquefied gas tank 7, overhead dry gas 9 (accounting for about 2 percent of total hydrocarbon products) enters a dry gas recycling system 9, and mixed heavy aromatic hydrocarbon at the bottom (accounting for about 25 percent of total hydrocarbon products) enters a heavy hydrocarbon tank 15.

Compared with the existing fixed bed methanol to aromatics process device, the device omits a high-power circulating gas compressor, and greatly reduces the power consumption. The number of heat exchangers and the total heat exchange area are greatly reduced, and the equipment investment is greatly reduced.

Example 3

Example 4

The heat conducting member 22 is located inside the main catalyst bed 5 and on the inlet side.

Example 5

A heat exchanger 23 is arranged between the feeding pipeline of the methanol raw material and the first buffer chamber 3.

Example 6

An outer heat conducting channel 21 is arranged between the outer side of the main catalyst bed 5 and the inner wall of the reactor shell 17.

Example 7

A liquid hydrocarbon pump 10 is arranged between the liquid hydrocarbon outlet of the oil-water separator 12 and the feed inlet of the rectifying tower 8.

Example 8

And a discharge hole of the rectifying tower 8 is connected with the product tank 6.

Example 9

The exhaust port at the top of the rectifying tower 8 is connected with the air inlet of the dry gas cache utilization system 11. Dry gas below C2 (about 1% of the total hydrocarbon product) enters the dry gas recovery system 11.

Example 10

The liquid outlet at the bottom of the rectifying tower 8 is connected with the liquid inlet of the heavy hydrocarbon tank 15. The bottom heavy hydrocarbons (about 5% of the total hydrocarbon product) enter the heavy hydrocarbon tank 15.

Example 11

The material of the heat conductive member 22 includes, but is not limited to, ceramic ball filler, carbon steel, stainless steel, aluminum material. Preferably, the aluminum material with high heat conductivity and moderate price is adopted.

Finally, it should be noted that the above-mentioned embodiments are only preferred embodiments of the present invention, and the present invention is not limited to the above-mentioned embodiments, but may be modified or substituted for some of them by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention. While the foregoing describes the embodiments of the present invention, it should be understood that the present invention is not limited to the embodiments, and that various modifications and changes can be made by those skilled in the art without any inventive effort.

Claims

1. A composite heat exchange combined fixed bed methanol-to-hydrocarbon reaction system is characterized by comprising: the device comprises a fixed bed and a rectifying tower, wherein a first buffer chamber, a catalyst bed layer, a second buffer chamber, a middle chamber and a supplementary catalyst bed layer are sequentially arranged in a fixed bed shell from top to bottom; the catalyst bed is symmetrically arranged relative to the nozzle at the outlet of the first buffer chamber, a heat conducting piece is arranged between the inlet of the catalyst bed and the second buffer chamber, the material outlet at the bottom of the fixed bed is sequentially connected with a reboiler at the bottom of the rectifying tower and an oil-water separator, and the oil-water separator is respectively connected with a dry gas buffer utilization system and a water treatment system;

An outer heat conduction channel is arranged between the outer side of the catalyst bed and the inner wall of the reactor shell.

2. The composite heat exchange combined fixed bed methanol-to-hydrocarbon reaction system of claim 1, wherein said heat conducting member is located inside the catalyst bed and at the inlet side.

3. The composite heat exchange combined fixed bed methanol-to-hydrocarbon reaction system of claim 1, wherein a heat exchanger is arranged between the feed pipe of the methanol feedstock and the first buffer chamber.

4. The composite heat exchange combined fixed bed methanol-to-hydrocarbon reaction system of claim 1, wherein a liquid hydrocarbon pump is arranged between a liquid hydrocarbon outlet of the oil-water separator and a feed inlet of the rectifying tower.

5. The composite heat exchange combined fixed bed methanol-to-hydrocarbon reaction system of claim 1, wherein the rectifying column discharge port is connected with a product tank.

6. The composite heat exchange combined fixed bed methanol-to-hydrocarbon reaction system of claim 1, wherein the gas outlet at the top of the rectifying tower is connected with the gas inlet of the dry gas buffer utilization system.

7. The composite heat exchange combined fixed bed methanol-to-hydrocarbon reaction system of claim 1, wherein the rectifying column bottom drain port is connected with the heavy hydrocarbon tank liquid inlet.

8. The composite heat exchange combined fixed bed methanol-to-hydrocarbon reaction system of claim 1, wherein the material of the heat conducting member includes, but is not limited to, ceramic ball filler, carbon steel, stainless steel, aluminum.

9. Use of the composite heat exchange combined fixed bed methanol-to-hydrocarbon reaction system of any one of claims 1-8 in the production of hydrocarbons from methanol.