During the charring process of wood, lignin undergoes structural condensation through pyrolysis, transforming into a polycyclic aromatic hydrocarbon (PAH) structure. Some carbonaceous precursors, when preheated at 600°C, can be categorized into easy-graphitization types and non-graphitizable types, depending on the original material and the temperature applied during heat treatment. Charcoal is a dark brown or black porous solid fuel that remains after wood or woody materials undergo incomplete combustion or pyrolysis in an air-insulated environment. When activated using gas activation methods, the aliphatic and post-aromatic carbon lattices are gradually burned away as the mass loss increases. This loss occurs more rapidly along the crystallite orientation than in the diameter direction, leading to an increase in the average thickness of the crystallites. As the crystallites refine into active microcrystals, micropores and mesopores develop, enhancing the adsorption capacity of the material.
The primary components of wood include cellulose, hemicellulose, and lignin. Kuriyama Asahi from Japan conducted research on the pyrolysis of cellulose, lignin, and wood. His findings suggest that cellulose (and similarly hemicellulose) first undergoes dehydration to form a ketol-type intergranular glycosylated structure, which then further oxidizes and decomposes into an aromatic structure.
Activation plays a crucial role in creating a highly porous structure in activated carbon. The carbonized material serves as a semi-finished product that is then activated to produce various forms of activated carbon used in filtration, purification, and other applications.
Understanding the transformation of wood components during pyrolysis and activation helps optimize the production of high-performance carbon-based materials for industrial and environmental uses.
Http://news.chinawj.com.cn Submission:
Universal Valve,Universal Butterfly Valve,Universal Angle Valve,Universal Valve Adapter
Chongqing Xingjida Import and Export Trade Co., Ltd. , https://www.xjdvalve.com