Kinetic Modeling of Lime Pretreatment of Switchgrass

Kinetic models applied to oxygen bleaching of paper pulp focus on the degradation of polymers, either lignin or carbohydrates. Traditionally, they separately model two or three different moieties: (1) a rapid, easy-to-remove polymer, (2) medium, and (2) a slow more-recalcitrant polymer. These models were successfully applied to lignin and carbohydrate degradation of switchgrass submitted to oxidative pretreatment with lime at a wide range of conditions: temperature, total pressure and pretreatment time. The models properly fitted experimental data and were used to determine selectivity of pretreatment in two fashions: differential and integral. Through assessment of selectivity, the detrimental effect of pretreatment on carbohydrates at high temperatures and at low lignin content, amply discussed in literature, was ratified.