Formation Kinetics of Potential Fermentation Inhibitors in a Steam Explosion Process of Corn Straw

The weak acids, furan derivatives, and phenolic compounds formed during lignocellulose pretreatment are potential inhibitors of subsequent enzymatic and microbial processes. In this work, the effects of the steam explosion process on the formation of weak acids, furan derivatives, and phenolic compounds were explored. The correlations of different steam explosion conditions and formation kinetics of degradation products showed that the formation of weak acids and furan derivatives was in the first-order reactions, which are expressed as \( A\times {e^{{{{{-{E_a}}} \left/ {RT } \right.}}}}\cdot t \). The formation of weak acids and furan derivatives increases with pretreatment temperature and time. On the other hand, the formation of phenolic compounds showed typical characteristics of continuous reaction, expressed as \( {{{{A_1}\times {e^{{{{{-{E_{a1 }}}} \left/ {RT } \right.}}}}}} \left/ {{{A_2}\times {e^{{{{{-{E_{a2 }}}} \left/ {RT } \right.}}}}\cdot t}} \right.} \). The formation was affected by the active energies in two stages, temperature and time, and thus existed at extreme value. This work revealed the formation rules of weak acids, furan derivatives, and phenolic compounds in a steam explosion process and provided theoretical guidelines for improving the process and limiting the production of certain inhibitors.