Acid pretreatment and fractionation of source-separated organic waste for lignocellulosic saccharification

This study compared two acidic pretreatments on Source-Separated Organic (SSO) waste preprocessed by Aufbereitungs Technology and System thermal-screw, on the basis of fermentable sugars for bioethanol production. The result showed that the SSO contained on average 27% glucan, 5.4% xylan, 1.2% arabinan, 5.7% mannan and 1.2% galactan. Dilute sulfuric acid pretreatment (at 121°C and 16.2 psi) was insufficient to solubilize cellulose and hemicellulose and did not remove much of the lignin. Cellulose-solvent and Organic Solvent-based Lignocellulose Fractionation (COSLIF) (at 50°C and atmospheric pressure) generated high glucose yield (70%). Substituting ethanol for acetone as organic solvent increased the yield to 89.5%. Fermentation using Zymomonas mobilis 8b with this hydrolysate confirmed the pretreatment is promising for the SSO conversion. Amenability of the SSO for biofuel production is validated. Enzymatic hydrolysis of both pretreatments using Accellerase 1500 is preferred over Celluclast 1.5L due to higher activity. Future work includes design of an appropriate batch and/or continuous bioreactor, and further understanding of Zymomonas mobilis 8b.