阅读说明：本技术 一种富氧高温脱除可燃固废气化焦油的装置和方法 (Device and method for removing combustible solid waste gasification tar at high temperature by oxygen enrichment ) 是由 金保昇 丁琪枫 黄亚继 于 2020-06-28 设计创作，主要内容包括：本发明公开了一种富氧高温脱除可燃固废气化焦油的装置和方法,其中,该装置包括依次连接的流化床气化反应器、旋风分离器和高温富氧气化炉,流化床气化反应器用于将可燃固废气化转化为粗制可燃气,包括气化区域及其底部的风室,其中,气化区域设置可燃固废进料口,风室侧面设置气化剂进气口,气化剂为空气和富氧气体的混合气体；高温富氧气化炉炉壁上开设有富氧气体进气口,用于通过焦油与富氧气体的氧化反应及氧化反应放热后的焦油裂解、缩聚过程脱除粗制可燃气中的焦油；该装置还包括用于提供气化剂和富氧气体的供气设备。该装置可大大降低可燃固废气化后的焦油含量,焦油脱除效率高,同时大大节约了加热成本,最终可得到比较纯净的可燃气。(The invention discloses a device and a method for removing combustible solid waste gasification tar at high temperature by oxygen enrichment, wherein the device comprises a fluidized bed gasification reactor, a cyclone separator and a high-temperature oxygen enrichment gasification furnace which are sequentially connected, the fluidized bed gasification reactor is used for converting combustible solid waste into crude combustible gas by gasification, and comprises a gasification area and an air chamber at the bottom of the gasification area, wherein the gasification area is provided with a combustible solid waste feeding hole, the side surface of the air chamber is provided with a gasification agent air inlet, and the gasification agent is mixed gas of air and oxygen enrichment gas; the furnace wall of the high-temperature oxygen-enriched gasification furnace is provided with an oxygen-enriched gas inlet used for removing tar in the crude combustible gas through the oxidation reaction of the tar and the oxygen-enriched gas and the tar cracking and polycondensation processes after the heat release of the oxidation reaction; the device also comprises a gas supply device for supplying the gasifying agent and the oxygen-enriched gas. The device can greatly reduce the tar content after the gasification of the combustible solid waste, has high tar removal efficiency, greatly saves the heating cost, and finally can obtain purer combustible gas.)

1. The device for removing combustible solid waste gasified tar at high temperature by virtue of oxygen enrichment is characterized by comprising a fluidized bed gasification reactor, a cyclone separator and a high-temperature oxygen enrichment gasification furnace which are sequentially connected, wherein the fluidized bed gasification reactor is used for gasifying and converting combustible solid waste into crude combustible gas and comprises a gasification area and an air chamber at the bottom of the gasification area, a gasification agent air inlet is arranged on the side surface of the air chamber, and the gasification agent is a mixed gas of air and oxygen enrichment gas; the furnace wall of the high-temperature oxygen-enriched gasification furnace is provided with an oxygen-enriched gas inlet used for removing tar in the crude combustible gas through the oxidation reaction of the tar and the oxygen-enriched gas and the tar cracking and polycondensation processes after the heat release of the oxidation reaction; the device also comprises a gas supply device for supplying the gasifying agent and the oxygen-enriched gas.

2. The device for removing combustible solid waste gasification tar through oxygen enrichment and high temperature according to claim 1, wherein the air supply equipment comprises an air compressor, an oxygen generator for producing oxygen-enriched gas, an air preheater and a gas mixer which are connected in sequence, wherein an air outlet of the air compressor is divided into two paths, one path is connected with an inlet of the oxygen generator, and the other path is connected with an inlet of the gas mixer; an oxygen-enriched gas outlet of the oxygen generator is connected with a gas inlet of an air preheater, the gas outlet of the air preheater is divided into two paths, one path is connected with a gas inlet of a gas mixer, and the other path is connected with an oxygen-enriched gas inlet of a high-temperature oxygen-enriched gasification furnace; and a gas outlet of the gas mixer is connected with a gasification agent gas inlet.

3. The device for removing combustible solid waste gasification tar through oxygen enrichment and high temperature according to claim 1, wherein the oxygen concentration in the oxygen-enriched gas is 30-95%.

4. The apparatus for removing combustible solid waste gasification tar through oxygen enrichment and high temperature according to claim 1, wherein a heater is arranged on the outer wall of the high temperature oxygen enrichment gasification furnace for providing initial reaction heat for the oxidation reaction of tar and oxygen-enriched gas.

5. The device for removing combustible solid waste gasification tar through oxygen enrichment at high temperature according to claim 1, characterized in that three oxygen-enriched gas inlets are arranged at the upper part of the high-temperature oxygen-enriched gasification furnace, and the three oxygen-enriched gas inlets are uniformly distributed at the upper part of the furnace wall of the high-temperature oxygen-enriched gasification furnace.

6. The method for removing combustible solid waste gasification tar by oxygen enrichment and high temperature based on the device of claim 1 is characterized by comprising the following steps:

(1) sending the combustible solid waste into a gasification area of a fluidized bed gasification reactor, introducing a gasification agent into an air chamber by adopting air supply equipment, controlling the temperature of the gasification area to be 500-800 ℃, sending crude combustible gas generated by the gasification reaction of the combustible solid waste into a cyclone separator, and sending the crude combustible gas into a high-temperature oxygen-enriched gasification furnace after fly ash is separated by cyclone;

(2) introducing oxygen-enriched gas into the high-temperature oxygen-enriched gasification furnace by using a gas supply device, controlling the oxygen concentration of the oxygen-enriched gas to be 30-95%, heating the high-temperature oxygen-enriched gasification furnace to 1000-1250 ℃, wherein the crude combustible gas comprises combustible gas, tar and gasified residual carbon, wherein the tar, a small part of the combustible gas and the oxygen-enriched gas are subjected to oxidation reaction at high temperature, and the rest of the combustible gas stays in the high-temperature oxygen-enriched gasification furnace for 1-2 s from top to bottom and then leaves; meanwhile, the heat released by the oxidation reaction provides the required temperature for cracking and polycondensation of tar, and the incompletely converted tar, carbon black formed by polycondensation of the tar and gasified residual carbon are discharged out of the high-temperature oxygen-enriched gasification furnace together.

7. The method for removing combustible solid waste gasification tar through oxygen enrichment at high temperature according to claim 6, characterized in that in the step (2), after the oxidation reaction of the tar and the oxygen-enriched gas is started, the heating of the high-temperature oxygen-enriched gasification furnace is stopped.

Technical Field

The invention relates to a combustible solid waste gasification device and a method, in particular to a device and a method for removing combustible solid waste gasification tar at high temperature by oxygen enrichment.

Background

In recent years, global economy has rapidly developed, and with the increase of industrialization and energy consumption levels, the reserves of traditional fossil fuels such as petroleum, coal, natural gas and the like are increasingly reduced. To realize sustainable generation of energyAt present, broad scholars are actively developing renewable energy sources for replacing fossil fuels, and among the numerous alternative energy sources, biomass combustible solid wastes are the most abundant renewable resources, and the global annual yield is about 1.1 × 10¹¹Ton. Through the development of many years, combustible solid waste fuel has become an important fossil fuel alternative energy source nowadays.

The combustible solid waste gasification technology is one of the main modes for converting the chemical energy of the combustible solid waste, the combustible solid waste is processed by a specific technology, the carbohydrate in the combustible solid waste is converted into gas fuel with high grade, easy transportation and high utilization efficiency, and the gas can be further upgraded into renewable fuel and chemicals if the gasified gas is clean enough. Specifically, the combustible solid waste gasification is a process of taking combustible solid waste as a raw material, taking oxygen (air), water vapor and the like as gasifying agents, and converting combustible solid waste into combustible gas through thermochemical reaction under high temperature conditions; the main products of the gasification of the combustible solid waste are hydrogen, carbon monoxide, methane, acetylene and other combustible gases.

Combustible solid waste gasification has numerous advantages: (1) the size and the type of the raw materials are not strictly required; (2) compared with other combustible solid waste treatment technologies, the combustible solid waste gasification has less environmental pollution; (3) the further processed gasified gas can be utilized in a plurality of fields. However, the development of combustible solid waste gasification technology is faced with a series of challenges, and gasification efficiency, gas calorific value and tar are three major obstacles for hindering the development of the combustible solid waste gasification technology, wherein the tar problem is the most serious. Excessive tar can cause a series of problems such as pipeline blockage, scaling and corrosion of gas-using equipment, energy waste caused by incomplete combustion and the like, and the presence of tar can severely limit the use of the production gas due to engine wear and high maintenance cost.

The mechanical method can play a role in removing tar, about 40-99% of tar can be removed by different mechanical methods such as a water scrubber, a cyclone dust collector and a Venturi scrubber, however, the mechanical method can only remove or capture tar in the produced gas, but cannot perform resource utilization on the tar, the energy of the tar is wasted, and secondary pollution such as water pollution and the like can be brought at the same time. Thermal and catalytic crackingAlthough the conversion is high, they all have some respective disadvantages: in order to improve the tar conversion rate, the thermal cracking needs very high temperature, usually exceeding 1300 ℃, and needs to continuously supply heat for the thermal cracking reaction, so the operation cost is high; the catalytic cracking improves the problem of thermal cracking, can improve gas production components at low temperature, but is easy to deposit carbon and H due to the existence of nickel-based and alkali metal catalysts₂S poisoning and other reasons cause easy deactivation of the catalyst, while the dolomite catalyst is low in price but easy to break, and the service life of the catalyst is short.

Disclosure of Invention

The purpose of the invention is as follows: aiming at the tar problem in the existing combustible solid waste gasification technology, the invention provides a device for removing combustible solid waste gasification tar at an oxygen-enriched high temperature and also provides a method for removing combustible solid waste gasification tar at an oxygen-enriched high temperature based on the device.

The technical scheme is as follows: the invention relates to a device for removing combustible solid waste gasification tar at high temperature by virtue of oxygen enrichment, which comprises a fluidized bed gasification reactor, a cyclone separator and a high-temperature oxygen enrichment gasification furnace which are sequentially connected, wherein the fluidized bed gasification reactor is used for gasifying and converting combustible solid waste into crude combustible gas and comprises a gasification area and an air chamber at the bottom of the gasification area, the gasification area is provided with a combustible solid waste feeding hole, the side surface of the air chamber is provided with a gasification agent air inlet, and the gasification agent is mixed gas of air and oxygen enrichment gas; the cyclone separator is used for centrifugally separating fly ash particles in the crude combustible gas; the furnace wall of the high-temperature oxygen-enriched gasification furnace is provided with an oxygen-enriched gas inlet used for removing tar in the crude combustible gas through the oxidation reaction of the tar and the oxygen-enriched gas and the tar cracking and polycondensation processes after the heat release of the oxidation reaction; the device also comprises a gas supply device for supplying the gasifying agent and the oxygen-enriched gas.

Preferably, the air supply device comprises an air compressor, an oxygen generator for producing oxygen-enriched gas, an air preheater and a gas mixer which are sequentially connected, wherein an air outlet of the air compressor is divided into two paths, one path is connected with an inlet of the oxygen generator, and the other path is connected with an inlet of the gas mixer; an oxygen-enriched gas outlet of the oxygen generator is connected with a gas inlet of the air preheater, the gas outlet of the air preheater is divided into two paths, one path is connected with the gas inlet of the gas mixer, and the other path is connected with an oxygen-enriched gas inlet of the high-temperature oxygen-enriched gasification furnace; the gas outlet of the gas mixer is connected with the gasifying agent inlet.

Wherein the oxygen concentration in the oxygen-enriched gas is preferably 30-95%.

Optionally, a heater is arranged on the outer wall of the high-temperature oxygen-enriched gasification furnace and used for providing initial reaction heat for the oxidation reaction of the tar and the oxygen-enriched gas. Furthermore, three oxygen-enriched gas inlets can be opened on the upper part of the high-temperature oxygen-enriched gasification furnace, and are uniformly distributed on the upper part of the furnace wall of the high-temperature oxygen-enriched gasification furnace, so that the oxygen distribution in the furnace is more uniform, the contact area of the oxygen and the tar is increased, the exothermic distribution of the oxidation reaction in the furnace is more uniform, and the tar removal efficiency is increased.

The invention discloses a method for removing combustible solid waste gasification tar by oxygen enrichment and high temperature based on the device, which comprises the following steps:

(1) sending the combustible solid waste into a gasification area of a fluidized bed gasification reactor, introducing a gasification agent into an air chamber by adopting air supply equipment, controlling the temperature of the gasification area to be 500-800 ℃, sending crude combustible gas generated by the gasification reaction of the combustible solid waste into a cyclone separator, and sending the crude combustible gas into a high-temperature oxygen-enriched gasification furnace after cyclone separation;

(2) oxygen-enriched gas is introduced into the high-temperature oxygen-enriched gasification furnace by adopting a gas supply device, the oxygen concentration in the oxygen-enriched gas is controlled to be 30-95%, the high-temperature oxygen-enriched gasification furnace is heated to 1000-1250 ℃, the rough combustible gas comprises micromolecule gas, tar and gasified residual carbon, the micromolecule gas mainly comprises combustible gas such as methane, hydrogen, carbon monoxide and other micromolecule gas such as carbon dioxide, nitrogen and the like, wherein the tar and a small part of the combustible gas and the oxygen-enriched gas are subjected to oxidation reaction at high temperature, the rest of the combustible gas stays in the high-temperature oxygen-enriched gasification furnace for 1-2 s from top to bottom and leaves, meanwhile, the heat released by the oxidation reaction provides required temperature for cracking and polycondensation of the tar, and the tar which is not completely converted after the reaction, carbon black formed by polycondensation of the tar and the gasified residual carbon are discharged.

Preferably, in the step (2), after the oxidation reaction of the tar and the oxygen-enriched gas is started, the high-temperature oxygen-enriched gasification furnace is stopped being heated, and the temperature of the reaction furnace can be maintained at a high level by the heat released by the oxidation reaction without providing an external heat source.

Has the advantages that: compared with the prior art, the invention has the advantages that: (1) the device adopts a mode of removing tar by oxygen-enriched gasified crude combustible gas, the activation energy of the reaction of tar and oxygen-containing groups is lower than that of the thermal cracking reaction of tar, the addition of oxygen-enriched gas provides oxygen-containing groups for the reaction of tar, the oxidation reaction of tar is promoted, a large amount of heat is released by the oxidation reaction, the temperature in a reaction space is increased, the thermal cracking and the polycondensation of tar are promoted, the tar content is greatly reduced through the reaction processes of oxidation, cracking, polycondensation and the like of tar at high temperature, the tar removal efficiency is higher, and meanwhile, part of carbon particles can be removed; (2) moreover, the exothermic heat of the oxidation reaction directly provides a reaction temperature condition for the thermal cracking and polycondensation of tar, so that only the initial reaction temperature is needed to be provided for the gasification furnace, heat is not needed to be continuously provided after the oxidation reaction starts, and compared with the existing thermal cracking process that the reaction speed is slow and heat needs to be continuously provided, the device provided by the invention has the advantages that the tar removal rate is obviously improved, and the heating cost is greatly saved; (3) the invention adopts air and oxygen-enriched gas as gasifying agent, the combination of the air and the oxygen-enriched gas can reduce the nitrogen content of combustible gas, thereby improving the heat value of the gas produced by low-temperature gasification of the fluidized bed, and combining with oxygen-enriched high-temperature gasification of tar, the purer combustible gas can be obtained finally.

Drawings

FIG. 1 is a schematic structural diagram of a device for removing combustible solid waste gasification tar at high temperature by oxygen enrichment.

Detailed Description

The technical solution of the present invention is further explained with reference to the drawings and the embodiments.

The invention relates to a device for removing combustible solid waste gasification tar at high temperature by oxygen enrichment, which mainly comprises a fluidized bed gasification reactor 1, a cyclone separator 2, a high-temperature oxygen enrichment gasification furnace 3 and an air supply device consisting of an air compressor 4, an oxygen generator 5, an air preheater 6 and a gas mixer 7, as shown in figure 1.

The fluidized bed gasification reactor 1 is used for gasifying and converting combustible solid waste into crude combustible gas. The gasification furnace comprises a gasification area 11 and an air chamber 12 which are arranged from top to bottom, wherein the bottom of the air chamber 12 is provided with a slag discharge port 13; wherein, the gasification area 11 is provided with a combustible solid waste feed inlet 14, and the combustible solid waste feed inlet 14 can be connected with a feeder; the side surface of the wind chamber 12 is provided with a gasification agent inlet 15, the gasification agent adopts mixed gas of air and oxygen-enriched gas, and the gasification agent is provided by a gas supply device.

A gas outlet of the fluidized bed gasification reactor 1 can be connected with an air inlet of the cyclone separator 2 through a pipeline, an air outlet of the cyclone separator 2 can be connected with a gas inlet of the high-temperature oxygen-enriched gasification furnace 3 through a conduit, and the bottom of the cyclone separator 2 is provided with a slag discharge port 21; the rough combustible gas generated by the gasification reaction of the fluidized bed comprises combustible gas, tar and gasified carbon residue, and fly ash particles in the rough combustible gas are removed by cyclone separation after entering the cyclone separator 2, and then the rough combustible gas is sent to the high-temperature oxygen-enriched gasification furnace 3 for further removing the tar.

An oxygen-enriched gas inlet 31 is formed in the wall of the high-temperature oxygen-enriched gasification furnace 3, and the oxygen-enriched gas inlet 31 is also connected with a gas supply device; the oxygen-enriched gas enters the high-temperature oxygen-enriched gasification furnace 3 and is subjected to oxidation reaction with tar in the rough combustible gas, the oxidation reaction releases a large amount of heat, thermal cracking and polycondensation of the tar at high temperature are further realized, and finally the tar content is greatly reduced. The oxygen-enriched gas inlets 31 can be three, and are uniformly distributed on the upper part of the furnace wall of the high-temperature oxygen-enriched gasification furnace, so that oxygen in the furnace is more uniformly distributed, the contact area of oxygen and tar is increased, the exothermic distribution of the oxidation reaction in the furnace is more uniform, and the tar removal efficiency is improved. The outer wall of the high-temperature oxygen-enriched gasification furnace 3 is also provided with a heater 32 for providing temperature conditions for the oxidation reaction of tar; because oxidation reaction releases a large amount of heat, the heat directly provides reaction temperature conditions for thermal cracking and polycondensation of tar, therefore, the heater 32 only needs to provide initial reaction temperature for the high-temperature oxygen-enriched gasification furnace 3, heat does not need to be continuously provided after the oxidation reaction starts, and heating cost can be greatly saved. The bottom of the high-temperature oxygen-enriched gasification furnace 3 is also provided with an outlet 33, the crude combustible gas enters the high-temperature oxygen-enriched gasification furnace 3, flows from top to bottom and leaves the gasification furnace from the outlet 33, and simultaneously, tar which is not completely converted after the reaction with the oxygen-enriched gas, carbon black formed by condensation polymerization of the tar and residual carbon in the crude combustible gas are discharged out of the high-temperature oxygen-enriched gasification furnace 3 from the outlet 33.

The gas supply equipment is used for providing a gasification agent and oxygen-enriched gas for the device. In the air supply equipment, an air outlet of an air compressor 4 is divided into two paths, one path is connected with an air inlet of an oxygen generator 5, and the other path is connected with an air inlet of an air mixer 7; an oxygen-enriched gas outlet of the oxygen generator 5 is connected with a cold gas inlet of an air preheater 6, a hot gas outlet of the air preheater 6 is divided into two paths, one path is connected with a gas inlet of a gas mixer 7, the prepared oxygen-enriched gas is preheated and then mixed with air in the gas mixer 7 to obtain a gasification agent, and the gasification agent is sent into the fluidized bed gasification reactor 1 for use; the other path of the oxygen-enriched gas outlet of the air preheater 6 is connected with an oxygen-enriched gas inlet 31 of the high-temperature oxygen-enriched gasification furnace 3 to provide oxygen-enriched gas required by the reaction for the high-temperature oxygen-enriched gasification furnace 3. Controlling the oxygen concentration in the oxygen-enriched gas to be 30-95%; the proportion of air and oxygen-enriched gas in the gasifying agent is configured according to the actual working condition.

The method for removing combustible solid waste gasification tar by adopting the device in oxygen enrichment and high temperature comprises the following steps:

(1) combustible solid waste is sent into a gasification area 11 of a fluidized bed gasification reactor 1 from a combustible solid waste feed inlet 14, an air compressor 4, an oxygen generator 5, an air preheater 6 and a gas mixer 7 are opened, the oxygen concentration of oxygen-enriched gas produced by the oxygen generator 5 is 30-95%, the oxygen-enriched gas and the air produced by the air compressor 4 are preheated to 200-300 ℃ by the air preheater 6 and then are introduced into the gas mixer 7 to be mixed to obtain a gasification agent, the gasification agent is sent into an air chamber 12 of the fluidized bed gasification reactor 1 through a gasification agent air inlet 15, and the flow and the oxygen content of the gasification agent can be controlled by a flow meter; controlling the temperature of the fluidized bed at 500-800 ℃, sending the generated rough combustible gas into a cyclone separator 2, and sending the rough combustible gas into a high-temperature oxygen-enriched gasification furnace 3 after cyclone separation; the crude combustible gas comprises combustible gas, tar and gasified residual carbon;

(2) after the rough combustible gas enters the high-temperature oxygen-enriched gasification furnace 3, the oxygen-enriched gas produced by the oxygen generator 5 is preheated by the air preheater 6 and then is vertically introduced into the high-temperature oxygen-enriched gasification furnace 3 through the oxygen-enriched gas inlet 31, the high-temperature oxygen-enriched gasification furnace 3 is heated to 1000-1250 ℃ by the heater 32, most of the combustible gas stays in the high-temperature oxygen-enriched gasification furnace 3 from top to bottom for 1-2 s and then leaves, the tar, a small part of the combustible gas and the oxygen-enriched gas are subjected to oxidation reaction at high temperature, the heater 32 is closed after the oxidation reaction, a large amount of heat is released by the oxidation reaction, the tar is cracked and polycondensed, most of the tar is removed through the oxidation reaction, the tar which is not completely converted after the reaction, carbon black formed by.

Application example

The temperature of the fluidized bed in the fluidized bed gasification reactor 1 is 676 ℃, the oxygen concentration in the gasification agent is 32.5 percent, and the flow rate of the gasification agent is 12Nm³H, the temperature of the high-temperature oxygen-enriched gasification furnace 3 is 1250 ℃, and the flow of oxygen-enriched gas is 2Nm³H, under the working condition that the oxygen concentration of the oxygen-enriched gas is 90 percent, the biomass gas production rate is 1.3Nm³Per kg, the heat value of gas produced by gasification after two-stage gasification is 10MJ/Nm³The tar content is about 20mg/m³The tar conversion rate reaches about 99 percent, and the tar generated by the gasification of the biomass fluidized bed is almost completely removed.