Anaerobic batch conversion of pine wood torrefaction condensate

Abstract Organic compound rich torrefaction condensate, owing to their high water content and acidic nature, have yet to be exploited for practical application. In this study, microbial conversion of torrefaction condensatefrom pine wood through anaerobic batch digestion (AD) to produce methane was evaluated. Torrefaction condensateexhibited high methane potentials in the range of 430–492 mL/g volatile solids (VS) and 430–460 mL/g VS under mesophilicand thermophilic conditions, respectively. Owing to the changes in the composition, the methane yields differed with the torrefaction condensatesproduced at different temperatures (225, 275 and 300 °C), with a maximum of 492 ± 18 mL/g VS with the condensateproduced at 300 °C under mesophiliccondition. The cyclic batch AD experiments showed that 0.1 VS substrate :VS inoculum is optimum, whereas the higher substrate loading (0.2–0.5) resulted in a reversible inhibition of the methane production. The results suggest that torrefaction condensatecould be practically valorized through AD.