Biomass gasification gas tar catalytic cracking purification process and its device

Abstract

The invention discloses a biomass gasification fuel gas tar catalytic cracking and purifying process and a device thereof. The process comprises a tar catalytic cracking process and a catalyst oxidation regenerating process, wherein the tar catalytic cracking process comprises the following steps: enabling coarsely gasified gas to enter a first bubbling fluidized bed or a second bubbling fluidizedbed through a regenerator flue gas heat exchanger to carry out tar catalytic cracking, carrying out purification, gasification, dust removal and cooling on the tar obtained after catalytic cracking,and sending the gasified gas into a spray tower to carry out chilling; the catalyst oxidation regenerating process comprises the following steps: importing air into the second bubbling fluidized bed or the first bubbling fluidized bed to remove carbon deposit on the catalyst, and heating and coarsely gasifying the generated high-temperature catalyst through the regenerator flue gas heat exchanger.According to the purifying process and the device thereof, a scheme of using two bubbling fluidized beds to alternately carry out tar catalytic cracking and catalyst oxidation regeneration is adopted, so that the continuous operation of tar catalytic cracking is realized, and the heat efficiency of a system is improved by utilizing internal steps of heat.

Description

technical field [0001] The invention relates to the technical field of biomass energy, in particular to a biomass gasification gas tar catalytic cracking purification process and a device thereof. Background technique [0002] Biomass gasification power generation technology has the advantages of flexible scale and can realize distributed and in-situ consumption of biomass raw materials. And due to the use of gas internal combustion engines (both reciprocating and turbine types), biomass gasification power generation can achieve high power generation efficiency even on a small scale. Therefore, it is especially suitable for the problem that the planting of biomass raw materials in my country is scattered, and the transportation cost added to the price of raw materials is too high. Therefore, biomass gasification power generation is expected to become a large-scale application of biomass power generation technology. [0003] However, since biomass itself has a relatively hi...

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Problems solved by technology

[0005] However, the following defects still exist in the above-mentioned prior art: 1. The water spray gas purification scheme has many disadvantages, such as the formation of saponification reaction, the precipitation of fatty acid salts, accumulation and precipitation in the system pipeline; water solvents are common in tar oil The solubility of weak polar components such as hydrocarbons is low; the purification treatment of wastewater is more expensive, which may increase additional sewage discharge; tar is difficult to recycle and reuse, resulting in a decrease in gasification efficiency; However, organic solvents are usually expensive and difficult to regenerate; 3. The temperature required for pyrolysis of tar is relatively high, above 1000°C, and the outlet gas temperature of the biomass gasification system is usually at Below 850°C; 4. In the traditional tar catalytic cracking process, there are two major problems. One is that tar catalysis usually requires a higher temperature, above about 800°C, and additional heating is required; the other is that the catalyst is prone to carbon deposition and deactivation. Regeneration, so most processes are difficult to achieve continuous stable operation, and the thermal efficiency is usually low

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