Processes and apparatus for refining sugarcane to produce sugars, biofuels, and/or biochemicals

Abstract

Conventionally, sugarcane processing avoids leaving residual sucrose in the bagasse, since the bagasse will be burned and the value of the sucrose would be lost. However, when coupled with a Green Power+® process to extract hemicelluloses, sucrose may also be extracted and recovered from the bagasse. In some variations, a process includes mechanically treating a feedstock to generate a sucrose-rich stream and lignocellulosic material that intentionally retains a significant amount of the initial sucrose in the feedstock; extracting the lignocellulosic material with steam and/or hot water to produce cellulose-rich solids and an extract liquor containing hemicellulosic oligomers and sucrose; and then hydrolyzing the hemicellulosic oligomers into a hemicellulose sugar stream. Each of the sucrose-rich stream and the hemicellulose sugar stream (containing the starting residual sucrose) may be recovered or further processed (e.g., fermented to ethanol). Similar processes are possible with energy cane, sugar beets, and energy beets.