Patent ID: 11920101
Assignee: EUROPEENNE DE BIOMASSE
Field: Basic materials chemistry (Chemistry)
Classification: CPC C  Y | IPC C

Claim 0:
1. A method for manufacturing a combustible material having a lower heating value greater than or equal to 5.29 MWh/t, for an industrial boiler, from wood chips derived from a mixture of hardwood and softwood, at least 10 wt % of the wood chips being derived from hardwood, wherein the method comprises:
obtaining wood fragments with a moisture content of between 5 and 25% from these wood chips;
continuously introducing a predetermined volume per minute of said obtained wood fragments into a pressurised reactor, said reactor being supplied with substantially saturated steam at a pressure of between 15.6 and 23.2 bars and a temperature of between 200 and 220° C. in the reactor;
exposing the wood fragments introduced into said reactor to said steam for a time between 5 and 9 minutes and sufficient to obtain a steam cracking, a value of said exposure time and a value of the temperature of said substantially saturated steam being selected so that a severity factor is between 4.05 and 4.15, said severity factor being defined as:, FS
  =
  
    log
    ⁡
    
      (
      
        
          ∫
          0
          
            Δ
            ⁢
            t
          
        
        ⁢
        
          
            e
            
              (
              
                
                  T
                  -
                  100
                
                
                  14
                  ,
                  75
                
              
              )
            
          
          ⁢
          dt
        
      
      )
    
  

where T is the temperature of steam in the reactor (expressed in degrees Celsius) and Δt is the exposure time in the reactor (expressed in minutes);
continuously extracting from said reactor a same predetermined volume of wood fragments per minute, through at least one orifice opening into a conduit at substantially atmospheric pressure, so as to cause explosive decompression of said wood fragments extracted from said reactor in said conduit; and
separating said decompressed wood fragments and the residual steam extracted from said reactor, said wood fragments obtained after separation forming said combustible material.