Effect of harvest age on acid-catalyzed steam explosion pretreatment of Populus euramericana

Populus euramericana has been touted as an important bioenergy crop owing to its potential utility as a short-rotation woody crop with genetic improvements.

Here, we report the effects of harvest age on acid-catalyzed steam explosion pretreatment of P. euramericana (1, 4, and 9 years). Furthermore, we optimized acid-catalyzed steam explosion for the pretreatment of P. euramericana (1, 4, and 9 years) using a response surface methodology. The reaction parameters studied were sulfuric acid concentration (0.1% – 1%), reaction temperature (200 – 225 °C) and residence time (1 – 10 min). The process was optimized for cellulose recovery and glucose conversion obtained by enzymatic hydrolysis on pretreated P. euramericana (1, 4, and 9 years).

Glucose conversion was affected by sulfuric acid concentration and residence time more than the effect of reaction temperature on P. euramericana harvest age (1, 4, and 9 years). The proposed quadratic model to predict cellulose recovery and glucose conversion from P. euramericana (1, 4, and 9 years) had high F and R² values, indicating its the ability to represent the relationship among the independent variables studied.

Optimum conditions that maximized the glucose conversion from P. euramericana (1, 4, and 9 years) were: sulfuric acid at a concentration between 0.6% and 0.85%, reaction temperature between 200.5 and 201.4 °C, and residence time between 6.2 and 13.7 min. Furthermore, our model validation showed a good agreement between experimental results and the predicted responses.