Research paperCountercurrent enzymatic saccharification of pretreated corn stover. Part 2: Lime + shock pretreated corn stover and commercial approach

- Shock treatment was investigated as a novel mechanical pretreatment.
- Shock treatment determined to be effective on multiple feedstocks.
- Shock treatment greatly increases the digestibility of biomass when combined with oxidative lime pretreatment.
- Determined recommended shock treatment conditions for corn stover.

Corn stover was pretreated with submerged lime plus shock, a mechanical treatment that subjects biomass to a detonation wave. In a series of bottles, pretreated corn stover was countercurrently saccharified with enzyme loadings of CTec3 (1 mg protein/g dry biomass), CTec3 (1 mg protein/g dry biomass) + HTec3 (1 mg protein/g dry biomass), and CTec3 (2 mg protein/g dry biomass) + HTec3 (2 mg protein/g dry biomass). To reach a given glucan conversion at low enzyme loadings, countercurrent saccharification reduced enzyme loadings by 1.9 times compared with batch saccharification but was not helpful at high enzyme loadings. To preserve the sugars during saccharification, volatile anti-microbials (chloroform and essential oils from thyme and oregano) prevent the growth of contaminating microorganisms. A simple packed column is proposed to perform commercial-scale countercurrent saccharification.