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.