Location: Bioenergy ResearchTitle: Bioconversion of beetle-killed lodgepole pine using SPORL: Process scale-up design, lignin co-product, and high solids fermentation without detoxification Author
|Hector, Ronald - Ron|
Submitted to: Industrial and Engineering Chemistry Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/15/2013
Publication Date: 10/31/2013
Publication URL: http://handle.nal.usda.gov/10113/62065
Citation: Zhou, H., Zhu, J.Y., Luo, X., Leu, S.-Y., Wu, X., Gleisner, R., Dien, B.S., Hector, R.E., Yang, D., Qiu, X., Horn, E., Negron, J. 2013. Bioconversion of beetle-killed lodgepole pine using SPORL: Process scale-up design, lignin co-product, and high solids fermentation without detoxification. Industrial and Engineering Chemistry Research. 52:16057-16065. Interpretive Summary: Mountain pine beetle has killed wide swaths of Lodgepole pine trees in the Western United States. There is considerable interest in finding utility for the dead trees so as to commercially justify their removal. In this study, a USDA developed pretreatment process was applied to the wood and the resulting hydrolyzate converted to ethanol using a yeast strain developed by ARS scientists. This report details the successful conversion of the wood to ethanol at a yield of 306 L of ethanol per ton of wood. The study will be of value to companies in the forestry industry, especially those with interest in biorefining.
Technical Abstract: Mountain pine beetle killed Lodgepole pine (Pinus contorta Douglas ex Loudon) wood chips were pretreated using an acidic sulfite solution of approximately pH = 2.0 at a liquor to wood ratio of 3 and sodium bisulfite loading of 8 wt % on wood. The combined hydrolysis factor (CHF), formulated from reaction kinetics, was used to design a scale-up pretreatment on 2000 g wood chips at a relatively low temperature of 165 °C that reduced furan formation and facilitated high solids saccharification and fermentation. The pretreated solids and liquor were disk milled together to result in a biomass whole slurry of 25% total solids. The whole biomass slurry was directly used to conduct simultaneous enzymatic saccharification and combined fermentation (SSCombF) using a commercial cellulase and Saccharomyces cerevisiae YRH400 without detoxification. A terminal ethanol titer of 47.1 g L-1 with a yield of 306 L (tonne wood)-1, or 72.0% theoretical, was achieved when SSCombF was conducted at an unwashed solids loading of 18%. The lignosulfonate (LS) from SPORL was highly sulfonated and showed better dispersibility than a high purity commercial softwood LS, and therefore has potential as a directly marketable coproduct.