Abstract: A biomass treatment device and a biomass treatment method, in which contamination is prevented and a final product can be highly concentrated. The biomass treatment device includes a pretreatment device for pretreating a biomass, a slurrying device for slurrying the pretreated biomass, and a saccharification device for saccharifying the slurried biomass with a saccharifying enzyme. A return line for returning a part of an internal fluid in the saccharification device to the slurrying device is provided, and the pretreated biomass from the pretreatment device and the internal fluid returned through the return line are mixed in the slurrying device so as to generate biomass slurry.

Abstract: A system and a method by which the high yield of a final product produced through a pretreatment and a saccharification and fermentation step can be stably obtained, even if a property of the biomass fed to a pretreatment device or the amount of a contained acid component in the biomass may be variable. The biomass is pretreated by a pretreatment device. At least one of pH, acidity, alkalinity, and ultraviolet absorbance of the pretreated biomass is measured by a measurement unit. The amount of a generated decomposition product or a generated undecomposed substance in the pretreatment is obtained on the basis of a measurement result, and an operation condition of the pretreatment device or a property of the biomass before the pretreatment are controlled on the basis of the calculated result.

Abstract: A method of producing ethanol from cellulosic raw materials, including steps of: saccharification of the cellulosic raw materials after adding a fermentation broth derived from a sugar-containing liquid, and ethanol-fermenting a sugar solution obtained in the above saccharifying step, in which the fermentation broth derived from the sugar-containing liquid is obtained by ethanol fermentation of one or more types of sugar-containing liquid selected from the group consisting of extracted juice of crops, molasses, and an enzyme-treated product of cereals containing a water-soluble saccharide.

Abstract: A method of producing ethanol by adding a cellulosic raw material treatment liquid to a sugar-containing liquid and then performing ethanol fermentation, in which the sugar-containing liquid is one or more types selected from the group consisting of extracted juice of crops, molasses, and enzyme-treated products of cereals containing a water-soluble saccharide, and the cellulosic raw material treatment liquid is either a sugar solution derived from cellulosic raw materials obtained by saccharification of the cellulosic raw materials or a fermentation broth derived from the cellulosic raw materials obtained by ethanol fermentation of the sugar solution derived from the cellulosic raw materials.