ETHANOL PRODUCTION FACILITY AND METHOD FOR REDUCING RESIDUE QUANTITY

PROBLEM TO BE SOLVED: To provide an ethanol production facility and a residue quantity reducing method, to reduce the quantity of discharged residue without using a particular enzyme and improve yield of ethanol and oil.SOLUTION: An ethanol production facility 10 includes a saccharifying apparatus 14 to saccharify a biomass material and produce a mixture containing a saccharified liquid and residue, first separation apparatuses 16, 18 to separate the saccharified liquid and the residue from the mixture, a fermentation apparatus 20 to ferment the saccharified liquid and obtain a fermented liquid, and a distillation apparatus 22 to distill the fermented liquid. The ethanol production facility is further provided with an enzymatic reaction treatment apparatus 30 to perform enzymatic reaction treatment process by adding a polymer decomposing enzyme to the residue separated by the first separation apparatuses 16, 18 and performing the enzymatic reaction treatment to produce an enzymatic reaction product containing an enzymatic reaction liquid, and a second separation apparatus 32 to separate the enzymatic reaction liquid from the enzymatic reaction product produced by the enzymatic reaction treatment apparatus 30. The enzymatic reaction liquid separated by the second separation apparatus 32 is supplied to the saccharifying apparatus 14.