Preparation method of lignin-based carbon material rich in meso-pores or meso-pores and macro-pores

Abstract

The invention discloses a preparation method of a lignin-based carbon material rich in meso-pores or meso-pores and macro-pores. The preparation method of the lignin-based carbon material rich in meso-pores, which takes lignin as a carbon-forming raw material, calcium chloride as a meso-porous template and silicon spheres as a macro-porous template, comprises the following process steps: (1) dissolving lignin in water to prepare a lignin solution, then adding calcium chloride or calcium chloride and silicon spheres to form a mixed slurry of lignin and calcium chloride, and drying the mixed slurry to form a solid blank; (2) calcining the solid blank in a nitrogen atmosphere to obtain a carbon material containing calcium chloride or a carbon material containing calcium chloride and silicon spheres; and (3) performing cleaning to remove calcium chloride in order to obtain the lignin-based carbon material rich in meso-pores or remove the calcium chloride and silicon spheres to obtain the lignin-based carbon material rich in meso-pores and macro-pores.

Description

technical field [0001] The invention belongs to the technical field of biomass resource utilization, and relates to a method for preparing a renewable carbon material rich in mesopores or mesopores and macropores by using lignin as a raw material and adopting a template method. Background technique [0002] The utilization of biomass resources has received more and more attention, and the preparation of carbon materials from biomass resources has a good prospect. Compared with other biomass, lignin widely exists in renewable resources such as papermaking black liquor and fermentation residues. It has high carbon content and large production volume, and is very suitable as a raw material for the preparation of carbon materials. [0003] For lignin raw materials, the template method is generally used to prepare lignin-based carbon materials, and the templates used include molecular sieves, polyethers, silicon spheres, etc.; 2 etc. as activators to treat carbon materials to in...

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Problems solved by technology

However, there are many problems in the above method: 1) The molecular sieve itself has a pore structure and can be used as a mesoporous and macroporous template, but the synthesis process of the molecular sieve is relatively complicated and the cost is high, and it is eroded in the step of removing the template for the preparation of carbon materials , cannot be recycled; at the same time, the regulation of mesoporous channel size depends on the re-synthesis of new molecular sieves, and it is difficult to achieve timely and effective channel regulation

2) Polyether is a mesoporous templating agent, which can obtain relatively regular mesoporous pores, but its price is high, and it is decomposed in the process of preparing carbon materials, so it cannot be recycled; like molecular sieves, the regulation of mesoporous channel size depends on the selection Different types of polyethers make it difficult to achieve timely and effective channel regulation

3) Silicon spheres are mainly macroporous templates. Although the carbon material itself will obtain some mesopores during the pyrolysis process, the mesopore content is small, and it is difficult to control the size of the mesopores.

4) The activator treatment of carbon materials mainly uses etching carbon to create pores, which will lose a large amount of carbon materials, resulting in low mass yield; at the same time, the mesopore size of carbon materials is difficult to be effectively controlled

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