Scale-Up of Biomass Conversion Using 1-Ethyl-3-Methylimidazolium Acetate as the Solvent

The Science

Demonstrate feasibility of ionic liquid (IL) pretreatment, bridge of gap between lab and bench studies to pilot-scale implementation.

At ABPDU, scale up 1-ethyl-3-methylimidazolium acetate ([C₂C1Im][OAc]) pretreatment to a 40-kg batch in a 210-liter customized pressure reactor followed by enzymatic saccharification at a 50-L stirred tank.

The pretreatment was followed by enzymatic hydrolysis through which the process efficiency for biomass conversion to monomeric sugars was determined. The results show that 43 wt% of switchgrass was dissolved in IL after 2 h of pretreatment at 160 °C with 15 wt% solid loading.

The Impact

• [C₂C₁Im][OAc] pretreatment of switchgrass has been successfully scaled up to 40 kg.
• Enzymatic hydrolysis of the pretreated switchgrass resulted in efficient sugar conversions—96% glucan and 98% xylan conversion.
• Mass flow of the overall process was established, and the major scale-up challenges were identified and discussed.
• Identified needs to improve transitional processes such as material transfer, biomass recovery from aqueous IL stream, IL recycling, and improvement of enzyme’s tolerance to ILs.

References

Liang, L., J. Yang, Q. He, T. Luong, T. R. Pray, B. A. Simmons, N. Sun. 2018. “Scale-up of Biomass Conversion Using 1-ethyl-3-methylimidazolium Acetate as the Solvent,” Green Energy & Environment 4(4), 432–438. DOI:10.1016/j.gee.2018.07.002.