(523e) Pretreatment for Bioconversion

Catchlight Energy is the Chevron | Weyerhaeuser joint venture whose mission is to commercialize the production of liquid transportation fuels from sustainable forest-based resources.  Catchlight Energy has developed a sulfite-based pretreatment process to achieve excellent enzymatic hydrolysis with a wide variety of potential forest-based feedstocks, including softwood, hardwood, and switchgrass.  The combination of mature technology components and feedstock flexibility offers a practical alternative for achieving biofuel facilities at significant scale and increases the possibility that pulp mill retrofits may prove feasible.

Sugar conversion yields on Southern Pine forest residual, a highly recalcitrant feedstock, exceed 90% with levels of inhibitors like HMF and furans that are below the levels that require conditioning such as overliming.  The results to date have achieved sugar titers over 10% and hydrolysis times less than 96 hours at reasonable enzyme loading levels.  Keys to these results are less intensive pretreatment conditions and more effective chemical reactions occurring.  The base metal used (calcium, magnesium, or ammonium) may have a moderating effect on the degradation of monomer sugars that are released during the pretreatment.