The role of coal pitch in the preparation of activated carbon mainly includes:
1.As a binder: Coal pitch binds activated carbon feedstock together to form a porous carbon embryo body. During the high-temperature treatment process, the organic molecules of coal pitch gradually decompose and volatilize, while the carbon elements left behind form a porous structure, which helps to increase the mechanical strength of the activated carbon and reduce the breakage rate.
2.Increase porosity: Addition to raw materials by solvent or dry process can increase the ductility and plasticity of raw materials, thereby promoting the porosity formation of raw materials. In addition, coal pitch can slow down the pyrolysis rate of the raw material, allowing for more adequate pore formation.
3.Improve the specific surface area: the macromolecular content in coal pitch is high, has strong adsorption performance, and can adsorb impurities in raw materials, thereby improving the purity and specific surface area of activated carbon. In addition, coal pitch also contains some oxygen functional groups and heterocyclic compounds, which are easy to decompose at high temperatures, which can form more active sites and pore structures, and improve the adsorption capacity of activated carbon.
4.Improved thermal stability and mechanical strength: Coal pitch contains high binders and gums, which can form a strong structure, thereby improving the mechanical strength of activated carbon. In addition, the natural gas compounds and aromatic hydrocarbons in coal pitch have high thermal stability, which can prevent the decarburization, dehydrogenation and thermal cracking of activated carbon in a high-temperature environment.
Through these effects, coal pitch can improve the adsorption performance, catalytic performance, mechanical strength and thermal stability of activated carbon. For more information, it is advisable to consult the relevant literature or consult a chemist.