Comprehensive reuse of pyrolysis chars from coals for fabrication of highly insulating building materials.

Abstract A comprehensive concept for coal conversion is proposed in this work, from which a series of products generated including light volatiles, liquid oils, and pyrolysis chars. The result indicates the optimal temperature for the pyrolysis from organic solvent extraction residue is between 700 °C to 900 °C, producing largest amount of liquid oils and giving rise to a chemically stable pyrolysis char sample with considerable BET specific surface area. The pyrolysis chars are then utilized as an alternative material for the fabrication of heat-insulating building material (char clay plaster-CCP, char brick-CB and foam glass-FA). Due to the inherent large specific surface area and ample pore channels, the water could be absorbed and stored in these pores, resulting in the effects of regulating indoor humidity and also low thermal conductivity. The char-based building material makes the exterior walls good breathing properties, able to maintain a proper humidity level. The building energy saving will be benefited from the excellent insulation property of these building products. Graphical abstract Schematic illustration of pyrolysis char derived building materials. Image 1004 Highlights • A clean production technique of coal conversion into building material is investigated. • Optimal pyrolysis temperature when producing chars for better performance is determined. • The enhanced property is attributed to the inherent porosity nature of pyrolysis chars. [ABSTRACT FROM AUTHOR]