Pyrolysis characteristics of cellulosic biomass in the presence of alkali and alkaline-earth-metal (AAEM) oxalates

The pyrolysis characteristics including reaction kinetics and products distribution of cellulose pyrolysis in the presence of AAEM oxalates were preliminarily studied by using the TG and PY-GC/MS analysis. In general, the main mass loss region took place at 300–400 °C and the maximum mass loss temperature was about 380 °C. The activation energy E a of cellulose pyrolysis (159 kJ/mol) was decreased in the presence of AAEM oxalates (K 2 C 2 O 4 —123 kJ/mol, MgC 2 O 4 —151 kJ/mol and CaC 2 O 4 —138 kJ/mol). The major pyrolytic components were classified into furans, anhydrosugars, acids, esters, alcohols, aldehydes, pyrans, ketones, hydrocarbons and phenols, etc. The presence of AAEM oxalates promoted the generation of ketones. In particular, K 2 C 2 O 4 and MgC 2 O 4 showed a high selectivity (relative content: > 30%) on the production of ketones. As a good candidate of MgO, MgC 2 O 4 or MgCO 3 has a high potential for both gas upgrading and porous carbon production in biomass pyrolysis. Graphic abstract