Ionic liquid pretreatment to increase succinic acid production from lignocellulosic biomass

• AmimCl pretreated biomass were explored for succinic acid production.
• Bacterial growth and succinic acid production was inhibited by AmimCl.
• Cellulose content and enzymatic hydrolysis rate increased after AmimCl pretreatment.
• 20.7 g/L succinic acid was produced from IL pretreated pine wood.

In this study, pinewood and corn stover pretreated with the ionic liquid (IL) 1-allyl-3-methylimidazolium chloride (AmimCl) were used as a feedstock for succinic acid production. Results reveal that 5% (v/v) AmimCl inhibited bacterial growth, whereas 0.01% (v/v) AmimCl inhibited succinic acid production. AmimCl was effective in extracting cellulose from pinewood and in degrading pinewood into a uniform pulp, as revealed by scanning electron microscopy (SEM). The rate of enzymatic hydrolysis of pinewood extract reached 72.16%. The combinations of AmimCl pretreatment with steam explosion or with hot compressed water were effective in treating corn stover, whereas AmimCl treatment alone did not result in a significant improvement. Pinewood extract produced 20.7 g/L succinic acid with an average yield of 0.37 g per gram of biomass. Workflow calculations indicated pine wood pretreated with IL has a theoretical yield of succinic acid of 57.1%. IL pretreatment led to increase in succinic acid yields.