Method for preparing porous biochar through ionic liquid modified waste biomass low-temperature pyrolysis, porous biochar and application of porous biochar

Abstract

The invention relates to the technical field of waste biomass resource utilization, in particular to a method for preparing porous biochar through ionic liquid modified waste biomass low-temperature pyrolysis, the porous biochar and application of the porous biochar, and the porous biochar is prepared through the steps of mixing, co-pyrolysis, extraction, filtration, freeze drying, rotary evaporation recycling and the like with waste biochar and ionic liquid as reactants. And the charcoal product with large surface area, high porosity and multiple surface functional groups is prepared at a lowpyrolysis temperature. Compared with the prior art, the method has the advantages that the waste biomass is used as the raw material, so that waste resource utilization is realized; the pyrolysis temperature is low, the residence time is short, and the energy consumption loss is reduced; the specific surface area and the porosity are improved while functional groups on the surface of the biocharare reserved; the ionic liquid can be recycled after the reaction is finished, so that the preparation cost is further reduced; activation treatment is not needed, operation is convenient, and meanwhile secondary pollution to the environment is avoided; the product can be used for adsorbing CO2 in the atmosphere.

Description

technical field [0001] The invention relates to the technical field of resource utilization of waste biomass, in particular to a method for preparing porous biochar by low-temperature pyrolysis of ionic liquid modified waste biomass, porous biochar and its application, and the porous biochar prepared by the method to CO 2 It has a good adsorption effect. Background technique [0002] In recent years, the excessive production of waste biomass in my country and the excessive stacking area have become one of the main reasons for environmental pollution. The preparation of biomass waste into carbon materials with multiple environmental functions under oxygen-limited pyrolysis conditions is an important way for the resource utilization of waste biomass. However, the traditional pyrolysis technology for preparing biochar has problems such as high pyrolysis temperature (generally >500 °C), high energy consumption, serious loss of surface functional groups, and low specific sur...

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Problems solved by technology

[0009] The applicant of the present invention has found that the existing porous carbon preparation technology mainly has the following problems: (1) in the traditional pyrolysis technology, although increasing the pyrolysis temperature can increase the specific surface area and porosity of the porous biochar, it will lead to The loss of functional groups on the surface of porous carbon, in addition to high temperature will also lead to higher energy consumption and increase production costs; (2) the existing technology of using ionic liquids to prepare porous carbons generally does not recycle ionic liquids, and The recovery of ionic liquids cannot be realized, which will cause the loss of ionic liquids. In addition, acid-base activation or microwave activation not only increases the preparation cost, but also causes secondary pollution to the environment. The raw materials used in some technologies are pure chemical substances instead of Waste biomass, did not realize the purpose of resource utilization of waste biomass

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