CN-121991713-A - Method for preparing biomass charcoal with high specific surface area from waste biomass and biomass charcoal

CN121991713ACN 121991713 ACN121991713 ACN 121991713ACN-121991713-A

Abstract

The invention provides a method for preparing biomass charcoal with high specific surface area from waste biomass and biomass charcoal, wherein the method comprises the steps of crushing waste biomass raw materials, drying, and carrying out double-layer screening treatment after drying so as to ensure that raw material particles are uniform; introducing inert gas into the carbonization reaction area for purging, adopting a dual heating mode of combining inner-layer electric heating and outer-layer gas heating, uniformly and continuously feeding the pretreated raw materials into the carbonization reaction area for carbonization reaction to generate biochar and smoke, recovering waste heat of the smoke generated in the carbonization process, directly using the recovered waste heat of the smoke for drying the raw materials, and rapidly cooling the generated biochar. The method for preparing the biomass charcoal with high specific surface area by efficiently carbonizing the waste biomass is efficient, energy-saving, environment-friendly and convenient to operate, realizes the efficient recycling of the waste biomass, and prepares the biomass charcoal with high specific surface area which meets the requirements of high-end application.

Inventors

ZENG DUO
LI QIUNAN
LONG HAIBO
CUI YI
YANG YUHANG
GUO CHEN
DING YUXIAO
HE CHUAN
YU CHANGCHUN
LI CHAO
CHEN FENG

Assignees

华能重庆珞璜发电有限责任公司
西安热工研究院有限公司

Dates

Publication Date: 20260508
Application Date: 20260402

Claims (10)

1. A method for preparing biomass charcoal with high specific surface area from waste biomass, which is characterized by comprising the following steps: Crushing and drying the waste biomass raw materials, and performing double-layer screening treatment after drying to ensure that the raw material particles are uniform; Introducing inert gas into the carbonization reaction area for purging; the pretreated raw materials are uniformly and continuously fed into a carbonization reaction area to carry out carbonization reaction by adopting a dual heating mode of combining inner-layer electric heating and outer-layer gas heating, so as to generate biochar and flue gas; Waste heat recovery is carried out on the flue gas generated in the carbonization process, wherein the recovered flue gas waste heat is directly used for drying raw materials; and (5) rapidly cooling the generated biochar.
2. The method according to claim 1, wherein the pre-treated raw materials are uniformly and continuously fed into the carbonization reaction area for carbonization reaction by adopting a dual heating mode of combining inner layer electric heating and outer layer gas heating, and the method comprises the following steps: The carbonization temperature is controlled to be 550-750 ℃, the carbonization pressure is controlled to be 0.1-MPa-0.2 MPa, and the carbonization time is controlled to be 1-1.5 h.
3. The method according to claim 2, wherein the pretreated raw material is uniformly and continuously fed into the carbonization reaction zone for carbonization reaction by adopting a dual heating mode of combining inner layer electric heating and outer layer gas heating, and the method further comprises the following steps of Simultaneously stirring the raw materials at a constant speed, wherein the stirring speed is 30-40 r/min.
4. The method of claim 1, wherein the comminuting the waste biomass feedstock comprises: The waste biomass raw material is crushed to the grain diameter less than or equal to 3mm.
5. The method of claim 1, wherein torrefying the waste biomass feedstock comprises: The drying temperature of the flue gas waste heat is controlled to be 80-100 ℃.
6. The method of claim 1, wherein purging the carbonization reaction zone with an inert gas comprises: and controlling the inert gas to purge at a flow rate of 0.5-1 m/s.
7. The method of claim 1, wherein after recovering waste heat from flue gas generated during carbonization, the method further comprises: and (3) purifying the flue gas after waste heat recovery to remove pollutants in the flue gas.
8. The method of claim 1, wherein the rapid cooling of the generated biochar comprises: And (3) rapidly cooling the biomass charcoal to room temperature in a circulating water cooling mode, wherein the cooling time is controlled to be less than or equal to 30min.
9. The method of claim 1, wherein the waste biomass feedstock comprises straw, wood chips, or fruit shells.
10. A biomass char, characterized in that it is produced by the method for producing biomass char of high specific surface area from waste biomass according to any one of claims 1 to 9.

Description

Method for preparing biomass charcoal with high specific surface area from waste biomass and biomass charcoal Technical Field The invention belongs to the technical field of biomass charcoal, and particularly relates to a method for preparing biomass charcoal with high specific surface area from waste biomass and biomass charcoal. Background The biomass charcoal is a carbon-rich solid material prepared by carbonizing waste biomass (such as straw, wood dust, fruit shells, livestock and poultry manure and the like) at high temperature under anoxic or anaerobic conditions, has the characteristics of large specific surface area, developed pore structure, excellent adsorption performance, good environmental compatibility and the like, and is widely applied to the fields of soil improvement, water pollution control, carbon fixation, emission reduction, energy storage and the like. At present, the utilization rate of waste biomass resources is low, a large amount of straws, wood chips and the like are burnt or discarded, so that not only is the resource wasted, but also the problem of environmental pollution is caused. The biomass charcoal is converted into biomass charcoal with high added value through carbonization technology, and is an important way for realizing the resource utilization of waste biomass. However, the existing biomass carbonization technology generally has the problems of low carbonization efficiency, high energy consumption, small specific surface area of the prepared biomass charcoal, imperfect pore structure and the like, and the biomass raw material is heated unevenly in the carbonization process, so that coking and carbon deposition phenomena are easy to occur, the quality of the biomass charcoal is unstable, and the high-end application of the biomass charcoal is limited. The Chinese patent document CN 114196425A discloses a process method and a device for preparing charcoal by biomass pyrolysis, which comprise drying, pre-carbonization, calcination and cooling discharging stages of biomass, wherein natural gas is combusted or fuel gas self-produced by a system provides heat for the drying, pre-carbonization and carbonization stages, dry flue gas is discharged from the drying stage to form dry flue gas circulation, pyrolysis reaction occurs in the pre-carbonization and carbonization stages, reaction heat is released to provide heat for the calcination stage, discharged pyrolysis gas is cooled by a pyrolysis gas condensation system and byproducts of biological oil, cooled fuel gas is circulated back to a pyrolysis furnace to form pyrolysis gas circulation, part of fuel gas is preheated to high-temperature fuel gas, part of high-temperature fuel gas is fed into a gas boiler to be combusted and supplied with energy, part of fuel gas is fed into the pyrolysis furnace to replace natural gas to provide heat for other batches, and the biomass bed is cooled step by using the self-produced fuel gas after the reaction is finished and then discharged. The technical scheme disclosed in the Chinese patent document CN 114196425A has the advantages of simple structure and convenient operation, can realize batch preparation of biomass charcoal, but has the defects that firstly, a carbonization furnace adopts a single heating mode, biomass raw materials are heated unevenly, local overheating coking or insufficient carbonization easily occurs, the specific surface area of the biomass charcoal is low (generally less than or equal to 800m < 2 >/g), the pore structure is imperfect, secondly, smoke generated in the carbonization process is directly discharged, heat waste is caused, the environment is polluted, thirdly, the carbonization time is long, the carbonization efficiency is low, the energy consumption of unit products is high, the large-scale industrial application is not facilitated, and fourthly, the accurate regulation and control of raw material pretreatment are lacked, and the quality stability of the biomass charcoal can be further influenced by uneven raw material moisture content and particle size. In summary, in the currently disclosed biomass charcoal preparation technical scheme, there is still a large improvement space in carbonization efficiency, energy consumption control, product quality (specific surface area, pore structure) and environmental protection, so that a method for preparing biomass charcoal with high specific surface area with high efficiency, energy saving and environmental protection is needed. Disclosure of Invention The invention aims to at least solve one of the technical problems in the prior art, and provides a method for preparing biomass charcoal with high specific surface area from waste biomass and biomass charcoal. One aspect of the present invention provides a method for preparing biomass charcoal with high specific surface area from waste biomass, the method comprising: Crushing and drying the waste biomass raw materials, and performing double-layer screening t