阅读说明：本技术 一种粗燃气净化工艺 (Crude fuel gas purification process ) 是由 龚佰勋 陈洪一 黎莉 邓旺明 韦彦秀 于 2019-09-30 设计创作，主要内容包括：本发明公开了一种粗燃气净化工艺,主要适用于生活垃圾热解气化过程产生的粗燃气的净化提质。粗燃气中污染物去除的先后顺序为：灰尘、焦油、酸碱性气体、深度除尘,粗燃气净化工艺流程主要为：高温旋风除尘+换热+文丘里旋风除尘+喷淋塔+布袋除尘器。粗燃气先经高温旋风除尘器去除绝大部分灰尘,随后回收热量。换热后的粗燃气进入文丘里旋风除尘器,去除灰尘、焦油等。除尘、除焦后的粗燃气进入喷淋塔,去除HCl、H<Sub>2</Sub>S和NH<Sub>3</Sub>等酸碱性气体。布袋除尘器作为保障环节可有效控制燃气中的粉尘浓度。工艺中产生的废水进入粗燃气洗涤废水处理系统,产生的灰渣进行填埋处理。粗燃气经该工艺处理后,品质将极大提升,可满足后续内燃发电要求。该工艺具有针对性强、效果好、成本低等优点。(The invention discloses a crude fuel gas purification process which is mainly suitable for purifying and upgrading crude fuel gas generated in the process of pyrolysis and gasification of household garbage. The order of removing the pollutants in the crude fuel gas is as follows: dust, tar, acid-base gas and deep dust removal, and the process flow of crude gas purification mainly comprises the following steps: high-temperature cyclone dust removal, heat exchange, Venturi cyclone dust removal, a spray tower and a bag-type dust remover. The coarse fuel gas is firstly treated by a high-temperature cyclone dust collector to remove most of dust, and then the heat is recovered. The crude gas after heat exchange enters into a Venturi cycloneAnd the dust remover is used for removing dust, tar and the like. The crude fuel gas after dust removal and decoking enters a spray tower to remove HCl and H 2 S and NH 3 And the like. The bag-type dust collector can effectively control the dust concentration in the fuel gas as a guarantee link. Wastewater generated in the process enters a crude gas washing wastewater treatment system, and generated ash slag is subjected to landfill treatment. After the crude fuel gas is treated by the process, the quality is greatly improved, and the follow-up internal combustion power generation requirements can be met. The process has the advantages of strong pertinence, good effect, low cost and the like.)

1. A process for purifying crude fuel gas is mainly suitable for purifying and upgrading crude fuel gas generated in the process of pyrolysis and gasification of household garbage, and the order of removing pollutants in the crude fuel gas is as follows: dust, tar, acid-base gas and deep dust removal.

2. The process of the crude fuel gas purification process as claimed in claim 1 mainly comprises the following steps: high-temperature cyclone dust removal, heat exchange, Venturi cyclone dust removal, a spray tower and a bag-type dust remover.

3. The high-temperature cyclone dust collector of claim 2 is arranged at the outlet of the gasifier and used for removing dust in the crude fuel gas, the operating temperature is 800-850 ℃, and the dust separated by the high-temperature cyclone dust collector enters the ash bin of the gasifier.

4. The heat exchange link of claim 2, wherein the temperature of the dedusted crude fuel gas is high, and the gasification agent and the pyrolyzer are respectively heated to recover heat, and the temperature is reduced from about 800 ℃ to about 100 ℃.

5. The venturi cyclone dust collector of claim 2, combining the advantages of the venturi and the cyclone dust collector, mainly removing dust, tar and part of acid and alkali gases in the crude fuel gas, mixing the gas and liquid at the throat of the venturi, and then removing impurities through natural sedimentation and the cyclone dust collector.

6. The spray tower of claim 2, wherein the spray tower is provided with two stages, and one stage uses water as an absorbent; the first stage uses NaOH solution as absorbent for removing HCl and H in crude fuel gas ₂S and NH ₃And the like.

7. The bag-type dust collector of claim 2, wherein a polytetrafluoroethylene filter bag is used as a guarantee link to further reduce the dust concentration, and the generated ash is buried.

8. The wastewater generated in the crude gas purification process of claim 1 enters a crude gas scrubbing wastewater treatment system.

Technical Field

The invention relates to the technical field of fuel gas purification and quality improvement, in particular to a process for purifying crude fuel gas generated in a household garbage pyrolysis and gasification process.

Background

The waste incineration is to treat organic waste in an oxidation combustion mode, and the reduction and harmless effects are obvious. Under the background of general shortage of urban land, the incineration technology is widely applied in China. However, the waste incineration technology still has some problems which are difficult to solve: 1) secondary pollution is serious, and gas pollutants, dioxin, fly ash, furnace slag and the like generated in the burning process are difficult to treat all the time; 2) the energy conversion efficiency is low, and the average power generation efficiency of the waste incineration plants in China is only 14.6 percent. The pyrolysis gasification technology is considered to be a cleaner and efficient solid waste heat treatment technology, the generation of dioxin is avoided by controlling the content of environmental oxygen in the pyrolysis gasification process, the crude fuel gas of the final product of pyrolysis gasification has a higher heat value, the crude fuel gas can directly enter an internal combustion generator for power generation after being purified, and the energy conversion efficiency can reach 30%. The main components of the crude fuel gas are CO and H ₂And CH ₄The main pollution components are as follows: dust, HCl, H ₂S、NH ₃And a small amount of tar. In order to meet the air intake requirement of the internal combustion generator, the pollutant components in the crude fuel gas need to be removed. The pyrolysis gasification technology is an innovative garbage heat treatment technology, and the purification process of crude fuel gas is only reported recently. Patent CN105525478B provides a device and a method for purifying crude fuel gas by gasifying biomass through cyclone corona, but the method only has a function of removing tar and dust in the crude fuel gas, and the method does not mention the purification of acid-base gas and the like in the crude fuel gas.

The invention aims to solve the problem of purification of crude fuel gas in the process of pyrolysis and gasification of household garbage, and provides an effective treatment process for purification and quality improvement of the crude fuel gas.

Disclosure of Invention

The order of removing the pollutants in the crude fuel gas is as follows: dust, tar, acid-base gas and deep dust removal, and the process flow of crude gas purification mainly comprises the following steps: high-temperature cyclone dust removal, heat exchange, Venturi cyclone dust removal, a spray tower and a bag-type dust remover.

The crude gas is generated in a pyrolyzer and a gasifier, the temperature is as high as 800-850 ℃, more dust is carried, and most of the dust is removed by a high-temperature cyclone dust collector. And (4) the dedusted crude fuel gas enters a heat exchange system to recover heat.

The venturi cyclone processor is combined with the advantages of a venturi and a cyclone dust collector, and mainly removes dust, tar, partial acid and alkali gases and the like in the crude fuel gas. Gas and liquid are mixed at the throat of the venturi, and the gas passing through the venturi is subjected to natural sedimentation and a cyclone dust collector to remove impurities. The inlet temperature of the venturi cyclone was about 100 c and the outlet temperature was about 70 c.

The spray tower is mainly used for removing HCl and H ₂S and NH ₃Waiting for acid and alkaline gases, adopting water and NaOH solution as an absorbent, wherein the inlet temperature of the spray tower is 70 ℃, and the outlet temperature is lower than 40 ℃; the bag-type dust collector is used as a guarantee link, and a filter bag made of polytetrafluoroethylene is adopted, so that the dust concentration in the fuel gas can be effectively controlled. After the crude fuel gas is treated by the process, the quality is greatly improved, and the follow-up internal combustion power generation requirements can be met.

And (4) enabling the wastewater generated in the purification process to enter a crude gas washing wastewater treatment system, and performing landfill treatment on the generated ash.

The process is provided with purification links aiming at dust, tar and acid-base gas in the crude fuel gas respectively, and has the advantages of strong pertinence, good effect, low cost and the like.

Drawings

FIG. 1 is a process flow diagram of crude gas scrubbing wastewater.

Detailed Description

The invention is described in further detail below with reference to fig. 1. In the household garbage pyrolysis gasification process matched with the process, pyrolysis and gasification links are respectively carried out in two reaction devices, tar generated by pyrolysis is greatly decomposed in a high-temperature environment (1000-1200 ℃) of a gasifier and is converted into combustible gas, and therefore, the content of tar in crude gas in the process is extremely low.

The coarse fuel gas is led out from an outlet of the gasifier and firstly enters a high-temperature cyclone dust collector to remove most of dust. The temperature of the dedusted crude gas is about 800 ℃, the heat is high, the crude gas enters a heat exchanger to preheat a gasifying agent, and then enters an inner jacket and an outer jacket of a pyrolyzer to heat the pyrolyzer, so that the heat in the crude gas is fully recovered. The temperature of the heat-exchanged crude fuel gas is reduced to about 100 ℃, the crude fuel gas is introduced into the Venturi cyclone dust collector through the induced draft fan, is fully mixed with water in the Venturi tube, enters the main body part of the Venturi cyclone dust collector, is naturally settled and separated to obtain partial heavy dust and tar, then enters the cyclone dust collector to further remove the dust and the tar, and simultaneously, the temperature is reduced to about 70 ℃. After dust removal and decoking treatment, the crude fuel gas enters a spray tower which is provided with two stages, wherein water is used as an absorbent at one stage; the first stage uses NaOH solution as absorbent for removing HCl and H in crude fuel gas ₂S and NH ₃And the like. After being treated by the spray tower, the temperature of the crude fuel gas is reduced to about 40 ℃ from 70 ℃, and finally the crude fuel gas enters the bag-type dust remover as a guarantee link to further reduce the dust concentration. The waste water generated in the process is collected and then enters a crude gas washing waste water treatment system for treatment, the ash generated by the high-temperature cyclone dust collector enters an ash bin of the gasifier, and the ash generated by the bag-type dust collector is subjected to landfill treatment.