Method for producing synthesis gas by microwave gasification of biochar

Abstract

The invention discloses a method for producing synthesis gas by microwave gasification of biochar. The method comprises the following steps of: 1) fully pyrolyzing a biomass raw material to obtain the biochar, mechanically mixing with a catalyst, crushing, and then filling into a gasification reactor; 2) taking microwaves as a heat source, heating a mixture in the step 1) to the required gasification temperature in an inert gas atmosphere, and fully removing volatile matters in the biochar; and 3) switching inert gas to a gasification agent, performing gasification reaction, generating gas, and cooling to obtain a synthesis gas product. According to the method disclosed by the invention, the biochar with extensive sources and low price is taken as the raw material, the microwaves are taken as the heat source, and then the synthesis gas is prepared by gasification reaction, so that the production efficiency and quality of the synthesis gas are improved, the emission of CO2 is reduced, and the energy consumption and the production cost are reduced.

Description

technical field

[0001] The invention relates to the field of biology, in particular to a method for preparing synthesis gas by microwave gasification of biochar. Background technique

[0002] Biochar generally refers to the products formed by the pyrolysis of biomass such as wood, crop waste and other plant tissues under the conditions of anoxic and relatively low temperature. Common biochars include charcoal, bamboo charcoal, straw charcoal and rice husk charcoal. They are mainly composed of aromatic hydrocarbons and simple carbon or carbon with graphite structure, containing more than 60% carbon elements, and also include H, O, N, S and a small amount of trace elements.

[0003] Syngas mainly contains CO and H 2 , is the basic raw material of C1 chemical industry, mainly using coal, coke and petroleum residues as raw materials, and gasification agent CO 2 、H 2 O is produced by chemical reaction with air etc. at high temperature. The reaction process is strongly endoth...

Examples

Embodiment 1

[0026] The rice straw was completely pyrolyzed at about 500 °C, and the biochar was collected after cooling, and mixed with 5% K 2 O was mechanically mixed, crushed to 0.5 mm particles, and filled into a quartz gasification reactor. With microwave as heat source, at 10ml / min N 2 The biochar solid mixture was heated to 900°C and kept for 30 min, then the carrier gas N 2 Switch to water vapor with a space velocity of 4000h -1 , the gasification reaction is carried out at 900 ° C, and the generated gas is cooled to be the synthesis gas product. The gas composition is detected by gas chromatography (Shimadzu 2014C, TCD detector, Ar is the carrier gas, TDX-1 packed column, and the column oven temperature is 100°C), the test results are shown in Table 1.

Embodiment 2

[0028] The wheat straw is completely pyrolyzed at about 500°C, and the biochar is collected after cooling, and the mass fractions of CaO and SiO are 5% respectively. 2 Mechanically mixed, crushed to 1.5 mm particles, and filled into a quartz gasification reactor. Using microwave as the heat source, the biochar solid mixture was heated to 500 °C under 40 ml / min Ar, and after keeping for 50 min, the carrier gas Ar was switched to CO 2 , the airspeed is 100h -1 , the gasification reaction is carried out at 500°C, and the generated gas is cooled to be the synthesis gas product. The gas composition is detected by gas chromatography (Shimadzu 2014C, TCD detector, Ar is the carrier gas, TDX-1 packed column, and the oven temperature is 100°C), the test results are shown in Table 1.

Embodiment 3

[0030] The cotton stalks are completely pyrolyzed at about 500 °C, and the biochar is collected after cooling, and the mass fractions are 1% MgO and 9% Fe 2 o 3 Mechanically mixed, crushed to 1.0 mm particles, and filled into a quartz gasification reactor. With microwave as heat source, at 30ml / min N 2 The biochar solid mixture was heated to 700°C and kept for 30 min, then the carrier gas N 2 Switch to water vapor, the space velocity is 2000h -1 , the gasification reaction is carried out at 700°C, and the generated gas is cooled to be the synthesis gas product. The gas composition is detected by gas chromatography (Shimadzu 2014C, TCD detector, Ar is the carrier gas, TDX-1 packed column, and the oven temperature is 100°C), the test results are shown in Table 1.

technical field

[0001] The invention relates to the field of biology, in particular to a method for preparing synthesis gas by microwave gasification of biochar. Background technique

[0002] Biochar generally refers to the products formed by the pyrolysis of biomass such as wood, crop waste and other plant tissues under the conditions of anoxic and relatively low temperature. Common biochars include charcoal, bamboo charcoal, straw charcoal and rice husk charcoal. They are mainly composed of aromatic hydrocarbons and simple carbon or carbon with graphite structure, containing more than 60% carbon elements, and also include H, O, N, S and a small amount of trace elements.

[0003] Syngas mainly contains CO and H 2 , is the basic raw material of C1 chemical industry, mainly using coal, coke and petroleum residues as raw materials, and gasification agent CO 2 、H 2 O is produced by chemical reaction with air etc. at high temperature. The reaction process is strongly endoth...

Examples

Embodiment 1

[0026] The rice straw was completely pyrolyzed at about 500 °C, and the biochar was collected after cooling, and mixed with 5% K 2 O was mechanically mixed, crushed to 0.5 mm particles, and filled into a quartz gasification reactor. With microwave as heat source, at 10ml / min N 2 The biochar solid mixture was heated to 900°C and kept for 30 min, then the carrier gas N 2 Switch to water vapor with a space velocity of 4000h -1 , the gasification reaction is carried out at 900 ° C, and the generated gas is cooled to be the synthesis gas product. The gas composition is detected by gas chromatography (Shimadzu 2014C, TCD detector, Ar is the carrier gas, TDX-1 packed column, and the column oven temperature is 100°C), the test results are shown in Table 1.

Embodiment 2

[0028] The wheat straw is completely pyrolyzed at about 500°C, and the biochar is collected after cooling, and the mass fractions of CaO and SiO are 5% respectively. 2 Mechanically mixed, crushed to 1.5 mm particles, and filled into a quartz gasification reactor. Using microwave as the heat source, the biochar solid mixture was heated to 500 °C under 40 ml / min Ar, and after keeping for 50 min, the carrier gas Ar was switched to CO 2 , the airspeed is 100h -1 , the gasification reaction is carried out at 500°C, and the generated gas is cooled to be the synthesis gas product. The gas composition is detected by gas chromatography (Shimadzu 2014C, TCD detector, Ar is the carrier gas, TDX-1 packed column, and the oven temperature is 100°C), the test results are shown in Table 1.

Embodiment 3

[0030] The cotton stalks are completely pyrolyzed at about 500 °C, and the biochar is collected after cooling, and the mass fractions are 1% MgO and 9% Fe 2 o 3 Mechanically mixed, crushed to 1.0 mm particles, and filled into a quartz gasification reactor. With microwave as heat source, at 30ml / min N 2 The biochar solid mixture was heated to 700°C and kept for 30 min, then the carrier gas N 2 Switch to water vapor, the space velocity is 2000h -1 , the gasification reaction is carried out at 700°C, and the generated gas is cooled to be the synthesis gas product. The gas composition is detected by gas chromatography (Shimadzu 2014C, TCD detector, Ar is the carrier gas, TDX-1 packed column, and the oven temperature is 100°C), the test results are shown in Table 1.

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