Recycling of lignocellulose based board materials

Abstract

A method of recovering a constituent of a board material comprised of a matrix of adhesively bonded lignocellulosic elements, the method comprising subjecting the material to a combination of (i) electromagnetic radiation and (ii) soaking or immersion in a liquid medium, and recovering the constituent.

1 - 22 . (canceled)  
   
   
       23 . A method of recovering a constituent of a board material comprised of a matrix of adhesively bonded lignocellulosic elements, the method comprising 
 (a) swelling the material by subjecting the material to a combination of (i) electromagnetic radiation and (ii) soaking or immersion in a liquid medium, wherein the electromagnetic radiation has a frequency in the range of from 896±20 MHz to 2450±25 MHz or a frequency in the range of from 100 kHz to 100 MHz, and    (b) recovering the constituent.    
   
   
       24 . A method as claimed in claim  1 , wherein the electromagnetic radiation has a frequency of 896±20 MHz.  
   
   
       25 . A method as claimed in claim  1 , wherein the electromagnetic radiation has a frequency of 2450±25 MHz.  
   
   
       26 . A method as claimed in claim  1 , wherein the electromagnetic radiation has a frequency in the range of from 10 MHz to 50 MHz.  
   
   
       27 . A method as claimed in claim  1 , wherein the power of the electromagnetic radiation is in the range of from 500 W to 30 kW.  
   
   
       28 . A method as claimed in claim  1 , wherein the liquid medium comprises water.  
   
   
       29 . A method as claimed in claim  1 , wherein the liquid medium comprises an organic or inorganic solvent.  
   
   
       30 . A method as claimed in claim  1 , wherein the board material is initially subjected to the electromagnetic radiation (step (i)) and then immersed in the liquid medium (step (ii)).  
   
   
       31 . A method as claimed in claim  1 , wherein the liquid medium is at elevated temperature.  
   
   
       32 . A method as claimed in  claim 31 , wherein the liquid medium is at a temperature of from 60° to 90° C.  
   
   
       33 . A method as claimed in claim  1 , wherein the board material is immersed in the liquid medium and subjected to the electromagnetic radiation while immersed.  
   
   
       34 . A method as claimed in claim  1 , wherein the treated board material is subjected to mechanical agitation in the liquid medium to produce a fibrous suspension.  
   
   
       35 . A method as claimed in  claim 34 , wherein lignocellulose is recovered from the fibrous suspension.  
   
   
       36 . A method as claimed in  claim 35 , wherein the lignocellulose is recovered by drying of the suspension.  
   
   
       37 . A method as claimed in claim  1 , wherein the board material is lignocellulose based board material and is or comprises a particle board or fibre board.  
   
   
       38 . A method as claimed in  claim 37 , wherein the lignocellulose based board material is or comprises Medium Density Fibreboard.  
   
   
       39 . A method as claimed in claim  1 , wherein the electromagnetic radiation comprises microwaves.  
   
   
       40 . A method as claimed in claim  1 , wherein the electromagnetic radiation comprises radio frequency (RF) waves.  
   
   
       41 . A method of recovering a lignocellulose constituent of a board material comprised of a matrix of adhesively bonded lignocellulosic elements, the method comprising 
 (a) swelling the board material by subjecting the board material to a combination of (i) electromagnetic radiation having a frequency in the range of from 10 MHz to 2500 MHz and a power level in the range of from 500 W to 30 kW, and (ii) soaking or immersion in a liquid medium at a temperature in the range of 60 C to 90 C,    (b) mechanically agitating the board material in the liquid medium to produce a fibrous suspension, and    (c) recovering the lignocellulose constituent from the fibrous suspension.    
   
   
       42 . A method of recovering a lignocellulose constituent of a board material comprised of a matrix of adhesively bonded lignocellulosic elements, the method comprising 
 (a) swelling the board material by (i) subjecting the board material to electromagnetic radiation having a frequency in the range of from 10 MHz to 2500 MHz and a power level in the range of from 500 W to 30 kW for between 30 and 90 seconds, followed within 5 to 15 seconds by (ii) soaking or immersion in a liquid medium at a temperature in the range of 60 C to 90 C for between 10 and 25 minutes,    (b) mechanically agitating the board material in the liquid medium to produce a fibrous suspension, and    (c) recovering the lignocellulose constituent from the fibrous suspension.