Carbonization device and technology for preparing biochar at low temperature

Abstract

The invention belongs to the technical field of biochar preparation, and particularly relates to a carbonization device and technology for preparing biochar at low temperature. The carbonization device comprises a drying device, a low-temperature carbonization device and a high-temperature pyrolysis device which are separately arranged; a discharge outlet of the drying device is connected with a feed inlet of the low-temperature carbonization device and a feed inlet of the high-temperature pyrolysis device through a feeding mechanism, an exhaust port of the high-temperature pyrolysis device is connected with a fuel inlet of the low-temperature carbonization device, and an exhaust port of the low-temperature carbonization device is connected with a fuel inlet of the drying device. According to the device and technology, by conducting two-stage carbonization operation on biomass, the biomass carbonization temperature and time can be effectively controlled, the biomass liquidity can be improved, the biochar yield can be increased, and the biochar quality can be improved.

Description

technical field [0001] The invention belongs to the technical field of biochar preparation, in particular to a carbonization equipment and process for preparing biochar at low temperature. Background technique [0002] Biochar is the carbonization of biomass. Biochar has a wide range of uses. It can be used as high-quality energy, soil improver, reducing agent, fertilizer slow-release carrier, and carbon dioxide sequestering agent. At present, biochar has been widely used in the fields of carbon sequestration and emission reduction, water purification, heavy metal adsorption and soil improvement. [0003] The preparation method of biochar in the prior art is to pyrolyze and carbonize biomass under high-temperature anaerobic conditions, but the reaction of biomass in the process of high-temperature pyrolysis is relatively complicated, and there are phenomena of heat absorption and heat release at the same time, and external supply is used. Heat, resulting in pyrolysis temper...

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Problems solved by technology

[0003] The preparation method of biochar in the prior art is to pyrolyze and carbonize biomass under high-temperature anaerobic conditions, but the reaction of biomass in the process of high-temperature pyrolysis is relatively complicated, and there are phenomena of heat absorption and heat release at the same time, and external supply is used. heat, the pyrolysis temperature is easy to rise but hard to fall, and it is difficult to achieve stable control

This not only reduces the carbon production rate of biomass, but also the biochar produced by biomass is affected by the high temperature environment, the carbon structure is changed, the bonding force between carbon atoms is very stable and it is difficult to combine with functional groups, which leads to biological Charcoal only retains a strong adsorption effect, but its surface activity and biological activity basically disappear, becoming commonly known as "dead charcoal".

When this kind of biochar is used as a soil improver, it can absorb more nutrients from the soil, but due to the stable structure between carbon atoms, it is difficult to be decomposed and utilized as a carbon source for microorganisms

Moreover, most of the biochar processing equipment in the prior art is designed in one piece, the fluidity of the biomass is poor and the drying and pyrolysis processes affect each other, which not only causes waste of energy, but also affects the stage of the biomass carbonization process Temperature control, and more importantly, a certain standard for the selection of biomass types, such as peanut shells and other small-volume biomass is difficult to flow smoothly according to the process design direction

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