Method and apparatus of hydrolytic saccharification of cellulosic biomass

Abstract

The hydrolytic saccharification method and hydrolytic saccharification apparatus according to the present invention use a hydraulic cylinder-type pressurized reactor as a reactor for causing cellulosic biomass to be in a supercritical or subcritical state, and use a hydraulic cylinder-type steam compressor as a source of superheated steam, such that the reactor and the compressor are operated in conjunction with each other. Surplus hydraulic pressure that is generated when hydrolysis of the cellulosic biomass is completed is recovered as compression power of the hydraulic cylinder-type steam compressor. Moreover, flash steam generated from slurry containing a hydrolysate is supplied to the hydraulic cylinder-type steam compressor for cyclic use of the flash steam.

1 . A method of hydrolytic saccharification of cellulosic biomass, in which cellulosic biomass is hydrolytically saccharified by pressurizing slurry of the cellulosic biomass together with superheated steam into a supercritical or subcritical state in at least one hydraulic cylinder-type pressurized reactor, the method comprising:
 supplying, by at least one hydraulic cylinder-type steam compressor, the superheated steam to the hydraulic cylinder-type pressurized reactor;   recovering hydraulic pressure of a hydraulic pressure chamber of the hydraulic cylinder-type pressurized reactor into a hydraulic pressure chamber of the hydraulic cylinder-type steam compressor at a time of reducing pressure in the hydraulic cylinder-type pressurized reactor to a pressure of the supercritical or subcritical state or lower after the cellulosic biomass has been hydrolytically saccharified, wherein a hydraulic pressure return passage of the hydraulic cylinder-type pressurized reactor and the hydraulic pressure chamber of the hydraulic cylinder-type steam compressor are in a state of connection via a hydraulic pressure recovery passage; and   after supplying the slurry, the cellulosic biomass of which has been hydrolytically saccharified, into a flash tank, flash-evaporating the slurry and recovering flash steam into the hydraulic cylinder-type steam compressor.   
     
     
         2 . The method of hydrolytic saccharification of cellulosic biomass according to  claim 1 , wherein
 the at least one hydraulic cylinder-type pressurized reactor comprises a plurality of hydraulic cylinder-type pressurized reactors, and the at least one hydraulic cylinder-type steam compressor comprises a plurality of hydraulic cylinder-type steam compressors, and   the number of hydraulic cylinder-type steam compressors, which perform the supplying of the superheated steam to the hydraulic cylinder-type pressurized reactors, is the same as the number of hydraulic cylinder-type pressurized reactors,   the method comprising cyclically recovering the hydraulic pressure of the hydraulic pressure chamber of each hydraulic cylinder-type pressurized reactor into the hydraulic pressure chamber of a corresponding one of the hydraulic cylinder-type steam compressors at the time of reducing the pressure in the hydraulic cylinder-type pressurized reactor to the pressure of the supercritical or subcritical state or lower after the cellulosic biomass has been hydrolytically saccharified, wherein the hydraulic pressure return passage of each hydraulic cylinder-type pressurized reactor and the hydraulic pressure chamber of the corresponding hydraulic cylinder-type steam compressor are in the state of connection via the hydraulic pressure recovery passage.   
     
     
         3 . The method of hydrolytic saccharification of cellulosic biomass according to  claim 1 , wherein
 the hydraulic pressure recovery passage is formed as a single passage at a portion connecting to the hydraulic pressure return passage and at a portion connecting to the hydraulic pressure chamber of the hydraulic cylinder-type steam compressor, and a remaining portion of the hydraulic pressure recovery passage is divided into a plurality of sub-passages, and   each sub-passage is provided with a corresponding one of air chambers which are assigned different pressure storage setting values, respectively,   the method comprising:
 storing the hydraulic pressure of the hydraulic pressure chamber of the hydraulic cylinder-type pressurized reactor sequentially in the air chambers in descending order of the pressure storage setting value; and then 
   releasing the hydraulic pressure sequentially from the air chambers in ascending order of the pressure storage setting value to supply the hydraulic pressure to the hydraulic pressure chamber of the hydraulic cylinder-type steam compressor.   
     
     
         4 . The method of hydrolytic saccharification of cellulosic biomass according to  claim 1 , wherein a steam generator is connected to the flash tank,
 the method comprising:
 mixing steam supplied from the steam generator and the flash steam; and 
 supplying resultant steam to the hydraulic cylinder-type steam compressor. 
   
     
     
         5 . The method of hydrolytic saccharification of cellulosic biomass according to  claim 1 , wherein an air and/or nitrogen supply device is connected to at least one of the flash tank and steam piping connecting the flash tank and the hydraulic cylinder-type steam compressor,
 the method comprising mixing air and/or nitrogen into steam to be supplied to a steam compression chamber of the hydraulic cylinder-type steam compressor, such that the air and/or nitrogen mixed into the steam is in an amount that is not less than 1/7 and not more than ⅓ of an amount of the steam.   
     
     
         6 . An apparatus for hydrolytic saccharification of cellulosic biomass comprising:
 at least one hydraulic cylinder-type pressurized reactor configured to pressurize slurry of cellulosic biomass together with superheated steam into a supercritical or subcritical state;   at least one hydraulic cylinder-type steam compressor configured to supply the superheated steam to the hydraulic cylinder-type pressurized reactor; and   a flash tank configured to be supplied with the slurry that is removed from the hydraulic cylinder-type pressurized reactor, the slurry being in a high-temperature and high-pressure state, and to flash-evaporate the slurry, wherein   a hydraulic pressure return passage of the hydraulic cylinder-type pressurized reactor and a hydraulic pressure chamber of the hydraulic cylinder-type steam compressor are connected via a hydraulic pressure recovery passage,   hydraulic pressure of a hydraulic pressure chamber of the hydraulic cylinder-type pressurized reactor is recovered into the hydraulic pressure chamber of the hydraulic cylinder-type steam compressor through the hydraulic pressure recovery passage,   the flash tank is connected to the hydraulic cylinder-type steam compressor, and   flash steam generated from the slurry in the high-temperature and high-pressure state is recovered into the hydraulic cylinder-type steam compressor.   
     
     
         7 . The apparatus for hydrolytic saccharification of cellulosic biomass according to  claim 6 , wherein
 the at least one hydraulic cylinder-type pressurized reactor comprises a plurality of hydraulic cylinder-type pressurized reactors, and the at least one hydraulic cylinder-type steam compressor comprises a plurality of hydraulic cylinder-type steam compressors,   the number of hydraulic cylinder-type steam compressors, which supply the superheated steam to the hydraulic cylinder-type pressurized reactors, is the same as the number of hydraulic cylinder-type pressurized reactors,   the hydraulic pressure return passage of each hydraulic cylinder-type pressurized reactor is connected to the hydraulic pressure chamber of a corresponding one of the hydraulic cylinder-type steam compressors via the hydraulic pressure recovery passage,   the hydraulic pressure of the hydraulic pressure chamber of each hydraulic cylinder-type pressurized reactor is recovered into the hydraulic pressure chamber of the corresponding hydraulic cylinder-type steam compressor via the hydraulic pressure recovery passage,   the flash tank is connected to the plurality of hydraulic cylinder-type steam compressors, and   the flash steam generated from the slurry in the high-temperature and high-pressure state is cyclically recovered into the plurality of hydraulic cylinder-type steam compressors.   
     
     
         8 . The apparatus for hydrolytic saccharification of cellulosic biomass according to  claim 6 , wherein
 the hydraulic pressure recovery passage is formed as a single passage at a portion connecting to the hydraulic pressure return passage and at a portion connecting to the hydraulic pressure chamber of the hydraulic cylinder-type steam compressor, and a remaining portion of the hydraulic pressure recovery passage is divided into a plurality of sub-passages,   each sub-passage is provided with a corresponding one of air chambers which are assigned different pressure storage setting values, respectively, and   the hydraulic pressure of the hydraulic pressure chamber of the hydraulic cylinder-type pressurized reactor is sequentially stored in the air chambers in descending order of the pressure storage setting value, and then the hydraulic pressure is released sequentially from the air chambers in ascending order of the pressure storage setting value and supplied to the hydraulic pressure chamber of the hydraulic cylinder-type steam compressor.   
     
     
         9 . The apparatus for hydrolytic saccharification of cellulosic biomass according to  claim 6 , wherein
 a steam generator is connected to the flash tank, and   steam supplied from the steam generator and the flash steam are mixed, and then resultant steam is supplied to the hydraulic cylinder-type steam compressor.   
     
     
         10 . The apparatus for hydrolytic saccharification of cellulosic biomass according to  claim 6 , wherein
 an air and/or nitrogen supply device is connected to at least one of the flash tank and steam piping connecting the flash tank and the hydraulic cylinder-type steam compressor, and   air and/or nitrogen is mixed into steam to be supplied to a steam compression chamber of the hydraulic cylinder-type steam compressor, such that the air and/or nitrogen mixed into the steam is in an amount that is not less than 1/7 and not more than ⅓ of an amount of the steam.