Efficient gas-solid reaction process and integrated industrial system

Abstract

The invention relates to an efficient gas-solid reaction process and an integrated industrial system, and belongs to the technical field of gas-solid reaction in chemical production. The process flow comprises the following steps: crushing and drying coke by a pulverizing unit, preheating the coke and sulfur steam to be greater than or equal to 550 DEG C, and jointly entering a gas-solid reaction unit; and the product enters a gas-solid separation unit, is subjected to two-stage gas-solid separation at a high temperature of 450-680 DEG C and a low temperature of less than or equal to 200 DEG C, and then is The integrated industrial system based on the efficient gas-solid reaction process is applied to carbon disulfide production through a coke method, the problems of external heat supply and byproduct generation control in the reaction process of coke and sulfur are solved, and the system is simple in process chain, easy and convenient to operate, compact in structure and suitable for continuous and closed carbon disulfide production requirements through the coke method.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of gas-solid reaction in chemical production, and relates to a high-efficiency gas-solid reaction process and an integrated industrial system. BACKGROUND

[0002] High-efficiency gas-solid reaction is always one of the themes in the field of chemical production, and fixed bed reactors and fluidized bed reactors are the mainstream implementation manners; when the gas-solid reaction is overall exothermic, it is easy to achieve high-efficiency reaction, and only a cooling structure needs to be arranged on the outer wall of the reaction equipment or the reaction product needs to be cooled at the outlet of the reactor; however, when the gas-solid reaction needs to be overall endothermic, the difficulty of maintaining high-efficiency reaction is greatly increased, and the bottleneck is how to uniformly and timely provide heat to the reaction area. Patent CN204429254U arranges a plurality of heating rod groups in the reactor so as to supplement heat during the gas-solid reaction process; however, these heating rods are a serious interference to the gas-solid fluidization, and the heating rods themselves also bear high-speed abrasion, and thus need to be frequently replaced and repaired. In patent CN101318652A, solid materials with strong heat storage capacity are preheated, and then the solid materials preheated to high temperature are introduced into a reaction area, and the heat stored by the solid materials is used to maintain the endothermic of the gas-solid reaction; this manner has a relatively complex equipment scheme, needs high skills for starting and stopping, and the heat storage capacity of the solid materials becomes a core index for process implementation and equipment capacity, and the process and equipment have low universality.

[0003] The "coke method" for producing carbon disulfide originated from 1796, and initially used charcoal, and then coconut shell carbon, bamboo charcoal and the like; around 2000, the domestic began to try to use coke and semi-coke to replace charcoal, and gradually developed into the well-known "coke method" for producing carbon disulfide, and became one of the two mainstream processes for large-scale industrial production of carbon disulfide along with the natural gas method. However, due to the long-term failure to solve the problems of system sealing and continuous production of the "coke method", the intermittent coke method process was forced to be eliminated by the national policy from 2013 to 2015, and since then, the periodic fluctuations in the prices of raw materials for the natural gas method and the carbon disulfide capacity gap have prompted all parties to compete to research the coke method process with a sealed system and continuous production, and the process routes are mainly fixed bed and fluidized bed processes. Patent CN101318652A is a fluidized bed "coke method" process, and although it reaches the pilot level, due to the high requirement for the operation level of the equipment and the process of supplying oxygen to "burn carbon", it is easy to introduce too many external components into the reaction of "carbon + sulfur", resulting in many and complex by-products of the final product, which becomes the bottleneck of the process in product quality; and the fixed bed method has a problem in heat supply. SUMMARY

[0004] The technical problem solved by the present application is to overcome the deficiencies of the prior art, and the present application provides a high-efficiency gas-solid reaction process and an integrated industrial system.

[0005] The technical scheme of the present application is: a high-efficiency gas-solid reaction process, which comprises grinding and screening pretreatment of blocky solid materials to screen out solid material particles; sufficient drying and temporary storage of the solid material particles;

[0006] The preheated solid material particles and gaseous materials are introduced into an external heating vertical fluidized reactor for reaction;

[0007] The reaction products are introduced from the external heating vertical fluidized reactor for gas-solid separation and gas component separation;

[0008] One or more gas components in the products are returned together with nitrogen into the external heating vertical fluidized reactor, the returned gas components are used for controlling the reaction direction, and the nitrogen is used as inert gas to control the reaction speed and preheat in the initial stage;

[0009] The change of the gas components in the reaction products is monitored, and when the dew point temperature of one or more components is higher than the set dew point temperature, the solid material feed amount is adjusted to reduce the component proportion.

[0010] Further, the average particle size of the solid material particles is ≤5 mm, and the water content after drying is less than 1.0%.

[0011] Further, the main component of the returned gas is hydrogen sulfide, and the total amount of hydrogen sulfide and nitrogen accounts for no more than 15.0 mol% of the gas phase reactant.

[0012] Further, the set dew point temperature range is 200-400℃; when the dew point temperatures of multiple components are all in the range, the highest value is taken for the control of the solid material feeding.

[0013] An integrated industrial system based on the high-efficiency gas-solid reaction process, which produces carbon disulfide by the "coke method", comprises a powder preparation unit, a gas-solid reaction unit, and a gas-solid separation unit;

[0014] The powder preparation unit grinds and screens blocky coke into coke particles, and introduces the coke particles into the gas-solid reaction unit after sufficient drying and preheating treatment;

[0015] The gas-solid separation unit introduces liquid sulfur into the gas-solid reaction unit after vaporization and temperature rise, and performs high-temperature gas-solid separation, preheater heat exchange, low-temperature gas-solid separation, and gas phase component monitoring on the reaction products from the gas-solid reaction unit;

[0016] The gas-solid reaction unit is fluidized with the coke particles after the secondary heating of the vaporized sulfur, and one or more gas components in the reaction product are returned to the gas-solid reaction unit together with nitrogen, the gas components are used to control the reaction direction, and the nitrogen is used as an inert gas to control the reaction speed and preheat in the initial stage; the hot flue gas generated by the gas-solid reaction unit is transported to the pulverizing unit to provide a heat source and pneumatic conveying.

[0017] Further, the temperature of the vaporized sulfur after the secondary heating is greater than or equal to 550 DEG C.

[0018] Further, the hot flue gas generated by the gas-solid reaction unit is low-oxygen-concentration hot flue gas, the oxygen content is controlled to be less than 5.0 mol%, and the temperature ranges from 110 DEG C to 300 DEG C.

[0019] Further, the pulverizing unit comprises grinding and screening devices, a drying storage bin, a buffer and feeding device, a feeding pressurizing equipment, and a hot flue gas induced draft fan; the grinding and screening devices grind and screen the blocky coke to be coke particles; the coke particles are dried and temporarily stored in the drying storage bin; the fine coke particles after drying are pneumatically conveyed to the buffer and feeding device by the inert gas through the hot flue gas induced draft fan; the buffer and feeding device are used for dust removal and emptying of the coke particles, and the feeding pressurizing equipment is used for pressurizing the coke particles and providing the coke particles to the gas-solid reaction unit.

[0020] Further, the gas-solid separation unit comprises high-temperature gas-solid separation devices, a liquid sulfur preheater, low-temperature gas-solid separation devices, a gas phase component monitoring device, and a supporting device; the high-temperature gas-solid separation devices complete high-temperature gas-solid separation at 450 DEG C to 680 DEG C; the liquid sulfur preheater is a tube-shell heat exchanger, which completes liquid sulfur heat exchange and temperature rise at 130 DEG C to 150 DEG C and heat exchange and temperature drop of the 450 DEG C to 680 DEG C high-temperature gas mixture; the low-temperature gas-solid separation devices complete low-temperature gas-solid separation at less than or equal to 200 DEG C; the gas phase component monitoring device is used for monitoring sulfur vapor; and the supporting device is used for collecting ash.

[0021] Further, the high-temperature gas-solid separation devices are composed of one or more high-temperature cyclone separators; and the low-temperature gas-solid separation devices are composed of one or more low-temperature cyclone separators or are filter-type low-temperature separators.

[0022] Compared with the prior art, the present application has the following beneficial effects:

[0023] (1) The present application proposes a high-efficiency gas-solid reaction process with certain universal effect, solves the inherent problems that the existing fixed bed and fluidized bed are difficult to continuously and stably provide heat and accurately control the reaction degree in the gas-solid reaction process, and greatly improves the reaction efficiency.

[0024] (2) The application is based on a new integrated industrial system for producing carbon disulfide by the "coke method" formed by a high-efficiency gas-solid reaction process, which solves the problems of external heat supply and by-product generation control in the reaction process of coke and sulfur, and has a simple process chain, compact device and reduced operation difficulty compared with similar systems. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 A high-efficiency gas-solid reaction process flowchart of the application;

[0026] Figure 2 A working flowchart of the integrated industrial system for producing carbon disulfide by the coke method of the application. DETAILED DESCRIPTION

[0027] The application will be further explained and described below in conjunction with the drawings and specific embodiments of the specification.

[0028] A high-efficiency gas-solid reaction process includes the following processes:

[0029] 1) The solid material is ground and sieved for pretreatment, and particles with an average particle size of ≤5 mm are screened out to ensure the efficiency of the gas-solid reaction. Excessive particles can cause ash to wrap the reactants, reducing the reaction efficiency. The screened particles are fully dried and temporarily stored to ensure that the moisture content is less than 1.0%. Excessive moisture content can increase by-products, causing difficulties in subsequent product refining for users;

[0030] 2) The preheated solid material and gaseous material are introduced into an externally heated vertical fluidized reactor for reaction to generate a reaction product;

[0031] 3) The reaction product is introduced from the upper part of the externally heated vertical fluidized reactor for gas-solid separation and gas component separation. The outer diameter of the externally heated vertical fluidized reactor is not more than 700 mm to ensure the efficiency of heat exchange and the sensitivity of parameter control;

[0032] 4) One or more components of the reaction product gas component in step 3) are returned together with nitrogen into the externally heated vertical fluidized reactor to control the reaction process. The returned gas components are used to control the reaction direction, and nitrogen is used as an inert gas to control the reaction speed and preheat during the initial start-up. Under normal operating conditions, the total amount of returned gas components and nitrogen accounts for no more than 15.0 mol% of the gas phase reactant.

[0033] 5) On-line or periodic monitoring of the dew point temperature of the reaction product, and then controlling the feeding amount of the solid reactant. The specific implementation is to monitor the dew point temperature of one or several components with the highest dew point temperature in the product, and obtain the dew point temperature by on-line calculation. When the dew point temperature is higher than the set value, the component ratio is reduced by adjusting the feeding amount of the solid material. Generally, the set value of the dew point temperature of the gas product is between 200-400℃; when the dew point temperatures of multiple components are all within this range, the highest value is used for solid material feeding control.

[0034] The external heating vertical fluidized reactor in the process includes a radiation chamber, a convection chamber, a lining, a burner, and a furnace tube system including a reaction section and a preheating section. The radiation chamber and the convection chamber are in communication with each other, the inner surfaces of both are lined, and the burner is installed on the side wall or the bottom of the radiation chamber. The reaction section is located inside the radiation chamber, the top of the reaction section is provided with a solid material inlet, the upper side is provided with a reaction product outlet, and the bottom is provided with a slag removal port. The preheating section is located inside the convection chamber, one end of the preheating section is provided with a continuous phase material inlet, and the other end is connected with the lower inlet of the reaction section through an in-furnace or out-furnace adapter.

[0035] Based on the above-mentioned efficient gas-solid reaction process, an integrated industrial system for producing carbon disulfide by "coke method" is designed. A process system for producing carbon disulfide from solid carbon particles and sulfur, comprising: a powder preparation unit 1, a gas-solid reaction unit 2, and a gas-solid separation unit 3.

[0036] The powder preparation unit 1 grinds and sieves large pieces of coke into coke particles, and performs sufficient drying and preheating treatment, and then introduces the coke particles into the gas-solid reaction unit 2. The liquid sulfur is heated to ≥550℃ after vaporization and introduced into the gas-solid reaction unit 2. The coke particles and gaseous sulfur are fluidized and reacted in the gas-solid reaction unit 2, and the reaction product is introduced into the gas-solid separation unit 3, and sequentially completes high-temperature gas-solid separation at 450-680℃, gaseous component sulfur monitoring, liquid sulfur preheater heat exchange, and low-temperature gas-solid separation at ≤200℃, and then is sent out from the gas-solid separation unit 3 to the downstream user gas phase separation and refining system, i.e. the product refining system of the existing methane method.

[0037] The powder preparation unit 1 includes grinding and sieving device 101, drying silo 102, buffer and feeding device 103, feeding and pressurizing equipment 104, and hot flue gas induced draft fan 105.

[0038] The large coke is ground into coke particles by a grinding and screening device 101 and pre-treated by screening, and coke particles with a particle size of ≤5 mm are screened out and enter a drying silo 102 for drying and temporary storage. At the bottom of the drying silo 102, the dried fine coke particles are pneumatically conveyed by inert gas through a hot flue gas induced draft fan 105 to a buffer and feeding device 103. After the buffer and feeding device 103 is dedusted and emptied, the coke particles are pressurized by a feeding and pressurizing equipment 104 and provided to an externally heated vertical fluidized reactor 201 of a gas-solid reaction unit 2. The heat source of the drying silo 102 and the inert gas for pneumatic conveying are both low-oxygen-concentration hot flue gas from the gas-solid reaction unit 2, wherein the hot flue gas mainly comprises CO2, H2O, N2 and O2, the oxygen content of the flue gas is controlled to be less than 5.0 mol%, and the temperature is 110-300°C.

[0039] The gas-solid reaction unit 2 comprises the externally heated vertical fluidized reactor 201, a preheating and vaporizer 202, an economizer 203 and structures inherent to general industrial furnaces such as a burner, a lining, a flue gas and air system and the like.

[0040] The externally heated vertical fluidized reactor 201 has a diameter of not more than 700 mm. Liquid sulfur is vaporized and heated to ≥550°C by a built-in coil in the preheating and vaporizer 202, enters from the lower part of the externally heated vertical fluidized reactor 201 and is subjected to fluidized reaction with coke particles entering from the upper part of the externally heated vertical fluidized reactor 201. At the same time, a return gas mainly comprising hydrogen sulfide produced by a downstream gas phase separation and refining system and nitrogen provided from an external system are also mixed into the reaction material sulfur vapor and enter the externally heated vertical fluidized reactor 201 together, and the total amount of hydrogen sulfide and nitrogen accounts for not more than 15.0 mol% of the gas phase reactants.

[0041] The burners arranged in a matrix on both sides of the tubular fluidized reactor provide heat required for fluidized reaction of the externally heated vertical fluidized reactor 201. The high-temperature flue gas produced by fuel combustion is indirectly heat-exchanged with cooling water in the economizer 203 and cooled to 110-300°C, and the cooled hot flue gas is pressurized by a hot flue gas induced draft fan 105 and sent to a powder preparation unit 1 for drying and conveying of solid particles.

[0042] The product after the reaction of coke particles with gaseous sulfur is led out from the upper part of the externally heated vertical fluidized reactor 201 to a gas-solid separation unit 3. The gas-solid separation unit 3 comprises a high-temperature gas-solid separation device 301, a liquid sulfur preheater 302, a low-temperature gas-solid separation device 303 and a supporting ash collection device and the like. The liquid sulfur preheater 302 is located between the high-temperature gas-solid separation device 301 and the low-temperature gas-solid separation device 303.

[0043] The reaction product is subjected to the following operations in the gas-solid separation unit 3 in sequence: high-temperature gas-solid separation at 450-680℃; monitoring of the gaseous component sulfur; heat exchange in the liquid sulfur preheater; low-temperature gas-solid separation at ≤200℃, and then sent out of the gas-solid separation unit 3 to the downstream user gaseous phase separation and refining system; in the process, when the gaseous component sulfur is monitored to be too high, the excess proportion of the coke particles supplied to the gas-solid reaction unit 2 is increased.

[0044] The liquid sulfur at a temperature of 130-150℃ is heated and raised in temperature by the liquid sulfur preheater 302, enters the gas-solid reaction unit 2, is subjected to preheating and vaporization in the vaporizer 202 in the gas-solid reaction unit 2, and is raised in temperature to ≥550℃, and then enters the outer-heated vertical fluidized reactor 201 for reaction. At the same time, the high-temperature gas mixture at 450-680℃ produced by the high-temperature gas-solid separation device 301 is cooled to ≤200℃ after heat exchange in the liquid sulfur preheater 302, and then enters the low-temperature gas-solid separation device 303. The liquid sulfur preheater 302 is a tube-in-shell heat exchanger, which functions to cool the reaction product outside the tube by using the liquid sulfur inside the tube; the high-temperature gas-solid separation device 301 is an inertial separation device, which is composed of one or more high-temperature cyclone separators; and the low-temperature gas-solid separation device 303 is also an inertial separation device, which is composed of one or more low-temperature cyclone separators. The high-temperature cyclone separator is adapted to 450-680℃, and the low-temperature cyclone separator is adapted to ≤200℃. The main difference between the two is that the materials selected and the number of levels set are different due to the influence of temperature. In addition, the low-temperature separator can also be a filtering low-temperature separator to realize the low-temperature gas-solid separation process.

[0045] The target component monitored by the gas-solid separation unit 3 is sulfur vapor, i.e. the monitoring of the highest dew point temperature is converted into the monitoring of the elemental sulfur vapor, so as to realize the simplification and low cost of the monitoring mode.

[0046] Although the present application has been disclosed with reference to the preferred embodiments as above, it is not intended to limit the present application, and any person skilled in the art can make possible changes and modifications to the technical solutions of the present application by using the disclosed methods and technical contents without departing from the spirit and scope of the present application. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present application, which does not depart from the technical solutions of the present application, shall fall within the protection scope of the technical solutions of the present application.

Claims

1. A highly efficient gas-solid reaction process, characterized in that, include: The lumpy solid materials are pre-treated by grinding and screening to remove solid particles. Solid material particles are thoroughly dried and temporarily stored; Preheated solid particles and gaseous materials are introduced into an externally heated vertical fluidized reactor for reaction; The reaction products are drawn out from the externally heated vertical fluidized reactor for gas-solid separation and gas component separation; One or more gaseous components of the product, along with nitrogen, are fed back into the externally heated vertical fluidized bed reactor. The fed-back gaseous components are used to control the direction of the reaction, while nitrogen is used as an inert gas to control the reaction rate and to preheat the reactor during the initial start-up phase. Monitor changes in the gaseous components of the reaction products. When the dew point temperature of one or more components exceeds the set dew point temperature, adjust the feed rate of solid materials to reduce their proportion.

2. The efficient gas-solid reaction process according to claim 1, characterized in that: The solid material has an average particle size of ≤5mm and a moisture content of less than 1.0% after drying.

3. The efficient gas-solid reaction process according to claim 1, characterized in that: The total amount of hydrogen sulfide and nitrogen in the returned gas does not exceed 15.0 mol% of the gaseous reactants.

4. The efficient gas-solid reaction process according to claim 1, characterized in that: The dew point temperature setting is 200-400℃; when the dew point temperatures of multiple components are all within this range, the highest value is used for solid material feeding control.

5. An integrated industrial system based on the efficient gas-solid reaction process according to any one of claims 1-5, characterized in that: The integrated industrial system uses the "coke method" to produce carbon disulfide, including a pulverizing unit (1), a gas-solid reaction unit (2), and a gas-solid separation unit (3). The pulverizing unit (1) grinds and sieves the block coke into coke particles, and after fully drying and preheating, introduces it into the gas-solid reaction unit (2). The gas-solid separation unit (3) vaporizes and heats the liquid sulfur before introducing it into the gas-solid reaction unit (2); and performs high-temperature gas-solid separation, preheater heat exchange, low-temperature gas-solid separation, and monitoring of gas phase components on the reaction products from the gas-solid reaction unit (2). After the gas-solid reaction unit (2) heats the vaporized sulfur a second time, it undergoes a fluidization reaction with the coke particles. One or more gaseous components in the product after the reaction, along with nitrogen, are fed back into the gas-solid reaction unit (2). The gaseous components are used to control the direction of the reaction, and nitrogen is used as an inert gas to control the reaction rate and to preheat the gas at the beginning of the start-up. The hot flue gas generated by the gas-solid reaction unit (2) is transported to the pulverizing unit (1) to provide a heat source and pneumatic conveying.

6. An integrated industrial system according to claim 5, characterized in that: The temperature of the vaporized sulfur after the second heating is ≥550℃.

7. An integrated industrial system according to claim 5, characterized in that: The hot flue gas generated by the gas-solid reaction unit (2) is a low oxygen concentration hot flue gas with an oxygen content controlled below 5.0 mol% and a temperature range of 110 to 300°C.

8. An integrated industrial system according to claim 5, characterized in that: The powder making unit (1) includes a grinding and screening device (101), a drying storage silo (102), a buffer and feeding device (103), a feeding pressurizing device (104), and a hot flue gas induced draft fan (105). The grinding and screening device (101) grinds and screens the lumpy coke into coke particles. The drying storage silo (102) dries and temporarily stores the coke particles. The dried fine carbon particles are pneumatically conveyed to the buffer and feeding device (103) by inert gas via the hot flue gas induced draft fan (105). The buffer and feeding device (103) removes dust from the coke particles and discharges them into the air. The feeding pressurizing device (104) pressurizes the coke particles and supplies them to the gas-solid reaction unit (2).

9. An integrated industrial system according to claim 5, characterized in that: The gas-solid separation unit (3) includes a high-temperature gas-solid separation device (301), a liquid sulfur preheater (302), a low-temperature gas-solid separation device (303), a gas phase component monitoring device, and supporting devices; the high-temperature gas-solid separation device (301) completes high-temperature gas-solid separation at 450-680℃; the liquid sulfur preheater (302) uses a shell-and-tube heat exchanger to complete heat exchange and heating of liquid sulfur at 130-150℃ and heat exchange and cooling of the high-temperature gas mixture at 450-680℃; the low-temperature gas-solid separation device (303) completes low-temperature gas-solid separation at ≤200℃; the gas phase component monitoring device is used to monitor sulfur vapor; and the supporting devices are used for ash collection.

10. An integrated industrial system according to claim 9, characterized in that: The high-temperature gas-solid separation device (301) consists of one or more stages of cyclone high-temperature separators; the low-temperature gas-solid separation device (303) consists of one or more stages of cyclone low-temperature separators or uses a filter-type low-temperature separator.

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