Method for preparing nitrogen-doped carbon material from biomass

Abstract

The invention relates to a method for preparing a nitrogen-doped carbon material from biomass. The method comprises the following steps: crushing biomass into fine particles; uniformly mixing the crushed biomass particles with an acidic ammonium salt solution according to a certain ratio to form a mixture; putting the mixture into a hydrothermal reaction kettle, and carrying out a hydrothermal reaction under a certain temperature condition; dehydrating and drying hydrothermal carbon obtained after the hydrothermal reaction; and putting the dried hydrothermal carbon into a pyrolyzing furnace, and carrying out rapid pyrolysis under the protection of an inert atmosphere under a certain temperature condition to obtain a nitrogen-doped carbon material subjected to rapid pyrolysis. According tothe invention, the raw material adopted by the method is renewable energy, covers all biomass raw materials, and has the advantages of rich reserves, low cost and environmental protection compared with coal as a raw material for preparing the activated carbon.

Description

technical field [0001] The invention belongs to the field of nitrogen-doped carbon material preparation, especially the field of biomass preparation of nitrogen-doped carbon material. Background technique [0002] Due to its developed pore structure, large specific surface area and abundant functional groups on the surface, activated carbon has been widely used in various fields of production and life; at present, the commonly used raw materials for the preparation of activated carbon are mainly coal and wood, but As a raw material for preparation, coal will cause a series of problems such as tight resource utilization, high cost, and environmental pollution; my country is a large agricultural and forestry country, and there are very rich biomass resources such as agricultural and forestry waste, and resourceful use of agricultural and forestry waste to prepare high-performance activated carbon It has important research significance and has broad prospects in industrial produc...

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Problems solved by technology

[0004] The physical activation method is to use gas (air, flue gas, CO2, etc.), water vapor or a mixture thereof to activate the raw material. The activation temperature is generally 700-1200 ° C. The advantage is that the operation is simple, but the energy consumption is high. General activation effect;

[0005] The chemical activation method is a method of preparing activated carbon under the protection of inert gas or spontaneous atmosphere after mixing and impregnating raw materials and activators in a certain proportion. It has the advantages of low energy consumption, high yield and good effect, but the required activator requires High, high reagent cost, low nitrogen doping rate;

[0006] The hydrothermal carbonization method refers to the process of using biomass as a raw material and water as a reaction medium, mixing them into a sealed pressure vessel, heating to 100-375°C, and generating a thermochemical reaction between biomass and water in a subcritical state. Water can not only promote the hydrolysis reaction of biomass, but also transmit pressure to modify the biomass physically and chemically, but the disadvantage is that the yield of activated carbon is average and the pore structure is not developed.

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