(498c) High Titer Ethanol Production From SPORL Pretreated Lodgepole Pine by Simultaneous Enzymatic Saccharification and Combined Fermentation (SSCombF) of Enzymatic and Pretreatment Hydrolysates

We will present high titer ethanol production of 47 g/L from softwood lodgepole pine by SPORL pretreatment using S. cerevisiae YRH400.  SPORL pretreatment was conducted at 180C for 20 min with solids loading of 25%.  Sulfuric acid and sodium bisulfite charge on oven dry wood were 2.2 and 8 (wt/wt)%, respectively.  Simultaneous enzymatic saccharification of SPORL pretretaed solids and combined fermentation with pretretament liquor were conducted at total soldis of 20% to achieve ethanol yield of 285 L/ton.  The SPORL pretreated solids were not washed and combined with pretretament liquor directly in enzymatic saccharification. The CTec2 loading was only 10 FPU/g solids.  The liquor was conditioned using lime to adjust pH and evaporated to achieve total solids of 20% in processing.  This liquor conditioning process reduced acetic acid and furfural concentration, but did not significantly affect HMF, the major inhibitor derived from sofwood.  No sugar loss was observed through evaporation. This study demonstrated the fisrt step process integration by eliminating substrate washing, very important to reduce water usage, without using high enzyme loadings.