Response machanisms and prediction models of changes in wood chemical components to steam-heat treatment

Sapwood and heartwood of Chinese fir were thermal treated with steam that was used as a shielding gas and a heating medium at temperatures ranging from 170 to 230°C and time duration from 1 to 5 hours in an airtight chamber with an atmosphere comprising less than 2 per cent of oxygen. The chemical component contents of wood were investigated under different treatment combinations. The results showed that the holocellulose and α-cellulose contents decreased while the relative lignin content increased with the increase of treatment temperature and time. FTIR analysis indicated that the functional groups in wood had been decreased due to pyrolysis reaction. The prediction models between treatment parameters and chemical component contents were established in order to provide theoretical support to wood industry.