Publication Date:
2016-01-01
Description:
The process sulfite pretreatment to overcome recalcitrance of lignocelluloses (SPORL) has been the focus of this study. Pilot-scale (50 kg) pretreatment of wood chips of lodgepole pine (Pinus contortaDouglasexLoudon) killed by mountain pine beetle (Dendroctonus ponderosaeHopkins) were conducted at 165°C with a dilute sulfite solution of pH 2 for bioconversion to ethanol and lignosulfonate (LS). The pretreatment duration was optimized in laboratory bench scale experiments with a certain severity based on a combined hydrolysis factor (CHF). The sodium bisulfite loading was 8% and the liquor to wood ratio 3. The pretreated solids were disk milled together with the spent liquid and the resultant slurry with a 25% solids content was directly (without detoxification) submitted to a simultaneous enzymatic saccharification and fermentation (SSF) withSaccharomycescerevisiaeYRH400 at cellulase loading of 35 ml kg-1of untreated wood. At solids loading of 20%, the alcohol yield was 288 l t-1wood (with a final concentration of 52.2 g l-1), which corresponds to a 72.0% theoretical yield based on total glucan, mannan, and xylan. The LS from SPORL was highly sulfonated and its molecular weight was lower than that of a purified commercial softwood LS, and therefore it has a high potential as a directly marketable co-product.
Print ISSN:
0018-3830
Electronic ISSN:
1437-434X
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
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