Gas-solid joint biomass partition speed control pyrolysis system and use method thereof

Abstract

The invention relates to a gas-solid joint biomass partition speed control pyrolysis system and a use method thereof. The gas-solid joint biomass partition speed control pyrolysis system is mainly characterized in that the process for pyrolyzing by a device includes three stages, wherein the first stage is the drying and deashing stage, and the second stage is the secondary-moderate-temperature pyrolysis stage, and the third stage is the moderate-temperature pyrolysis stage. In the first stage, the low-temperature smoke is taken as the heat carrying medium, and all the waste gas is diffused; in the second stage, the inert solid ball is taken as the heat carrying medium, and the main purpose is to reduce the amount of the smoke entering the pyrolysis gas and avoid the secondary pyrolysis of the tar in the high-temperature region so as to improve the yield of the liquid product; and in the third stage, the high-temperature smoke is taken as the heat carrying medium, and the convection current is adopted to strengthen the medium transfer and the heat transfer in the holes of the biomass. The gas-solid joint biomass partition speed control pyrolysis system in the invention has the comprehensive effects that the quality of the product of pyrolysis is improved greatly, the heat efficiency of the gas-solid joint biomass partition speed control pyrolysis system is improved greatly, the gas treatment equipment is simplified, and the power consumed to treat the gas is reduced greatly.

Description

Technical field [0001] The invention relates to a method for biomass pyrolysis, in particular to a gas-solid combined heat-carrying biomass zone-controlled speed-controlled pyrolysis system using different heat-carrying substances in sections and controlling the pyrolysis speed in sections and a use method thereof. Background technique [0002] Known biomass pyrolysis technologies include indirect heating pyrolysis technology using reactors and direct heating pyrolysis technology carried by gas heat. [0003] The indirect heating process is to shape the biomass, put it into the reactor to isolate the air and heat it up for pyrolysis, the heat source heats the wall of the reactor outside the reactor, and the heat is transmitted to the biomass in the reactor through the wall. The disadvantage of indirect heating is mainly the low heat transfer efficiency. In this process, the temperature rise of the biomass in the middle of the kettle is mainly realized by heat conduction. Sin...

AI Technical Summary

Problems solved by technology

The disadvantage of indirect heating is mainly the low heat transfer efficiency. In this process, the temperature rise of the biomass in the middle of the kettle is mainly realized by heat conduction. Since the thermal conductivity of the biomass itself is low, and the surrounding biomass is filled with gas with high thermal resistance, So heat transfer is slow

Inefficient heat transfer has three adverse effects on production:

[0004] 1. In the indirect heating process, the temperature of biomass rises slowly, resulting in a decrease in the pyrolysis rate of biomass, which ultimately reduces the yield of liquid products in biomass pyrolysis products

[0005] 2. Under the condition that the treatment equipment remains unchanged, the reduction of biomass pyrolysis rate will eventually lead to the decrease of biomass treatment capacity and the increase of treatment cost

[0006] 3. In the indirect heating process, the low heat transfer efficiency leads to low thermal efficiency in the whole heating process, which is also one of the reasons for the high cost of biomass pyrolysis

[0008] 1. After the heat carrier directly enters the pyrolysis product, the inert components in the pyrolysis gas will increase, and the quality of the gas will decrease, resulting in a decrease in the utilization efficiency of the gas. At the same time, the investment in gas purification equipment will increase, and the power consumption will increase.

[0009] 2. The fluidized bed process used in the gas heat-carrying pyrolysis process, the pyrolysis gas contains a large amount of dust, the cost of dust removal is very high, and the liquid product contains a large amount of inorganic dust that is difficult to separate, making the deep processing of bio-oil very difficult

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