Method for preparing hierarchical-pore phosphorus-doped carbon material from biomass

Abstract

The invention relates to a method for preparing a hierarchical-pore phosphorus-doped carbon material from biomass. The method comprises the following steps: firstly, crushing the biomass into tiny particles; then uniformly mixing the crushed biomass particles with a phosphoric acid-containing solution according to a certain ratio to form a mixture; putting the mixture into a hydrothermal reactionkettle, and carrying out a hydrothermal reaction at a certain temperature to generate hydrothermal carbon; dehydrating and drying the hydrothermal carbon obtained after the hydrothermal reaction; andputting the dried hydrothermal carbon into a pyrolyzing furnace, and carrying out rapid pyrolysis under the protection of an inert atmosphere to obtain a hierarchical-pore phosphorus-doped carbon material after rapid pyrolysis. According to the method disclosed by the invention, a rapid pyrolysis scheme is combined with phosphoric acid hydrothermal pre-carbonization, so a very ideal effect can beachieved only by performing rapid pyrolysis in a very short time, carbon preparation efficiency is greatly improved, and energy consumption is remarkably reduced; and meanwhile, due to the existence of phosphorus, a good carbon sequestration effect can be achieved, and carbon yield is increased.

Description

technical field [0001] The invention belongs to the field of preparation of phosphorus-doped carbon materials, in particular to the field of preparing hierarchical porous phosphorus-doped carbon materials from biomass. Background technique [0002] Biomass is the world's fourth largest energy after coal, oil and natural gas, accounting for about 14% of the world's primary energy consumption. China produces about 2.4 billion tons of waste biomass (crop rice straw, sawdust, weeds, etc.) every year. The energy contained in these waste biomass is equivalent to 1 billion tons of standard coal, which is a huge treasure house of resources. However, due to high labor costs, low economic benefits and increasingly stringent environmental regulations, the recycling of biomass has not been widely promoted at present, and most of the biomass is directly discarded; carbon materials are characterized by their good surface chemical properties, excellent It has the characteristics of mecha...

AI Technical Summary

Problems solved by technology

The process is simple, but the use of organic carbon precursors and phosphorus-containing ligands is usually costly

[0005] (2) Post-treatment doping method: This method usually refers to the introduction of functional groups containing phosphorus atoms on the activated carbon material through surface modification such as dry or wet methods. This method may cause the collapse of the activated carbon structure and cause its specific surface area decrease, due to the stable chemical properties of activated carbon materials, it is difficult to uniformly incorporate phosphorus atoms

[0010] c) CN201810591723.1 A phosphorus-doped microporous / mesoporous carbon material and its preparation method, the patent relates to a preparation method of phosphorus-doped microporous / mesoporous carbon material, said microporous / mesoporous carbon material The preparation method comprises the following steps: washing the okra with clear water, drying it, and freeze-drying it at -45°C to -80°C for 48 hours to 96 hours to obtain the freeze-dried okra; Heat treatment for 2 hours to 4 hours to obtain phosphorus-doped microporous / mesoporous carbon materials; the pretreatment method involved in this patent is low-temperature freeze-dried okra, which is different from the acid hydrothermal pretreatment method in this patent and cannot be realized Simultaneous deashing, acid loading and pre-carbonization cannot promote the carbonization process and reduce the processing time; the raw material used is usable okra, not biomass waste, and the cost is high; heat treatment at high temperature for 2 to 4 hours, It takes a long time, consumes a lot of energy, and the prepared carbon material has a small specific surface area

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