Energy, fuels, and chemicals 

 WOOD 



3223 



WATER 



ACID 



FURFURAL LIME 



r 



r6 



T, 



DIGESTER 



FLASH 

 2 



FURFURAL 



LIME 



SLUDGE 



TOWER NEUTRALIZATION CLARIFIER 

 3 4 5 



WATER" 



^ 



YEAST ALCOHOL EXTRACTIVE 



FERMENTERS SEPARATION STRIPPER TOWER 



6 7 8 9 



ETHANOL 



6~^~^ 



RECTIFYING 



TOWER 



10 



J" 



EVAPORATORS 



11 



PENTOSE 

 ■^ CONCENTRATE 



Figure 26-38. — Ethanol from wood by the Madison process. (1) Cellulose converted to 

 sugar by acid hydrolysis under high pressure and temperature. (2) Sugar solution 

 flashed. (3) Furfural in flash condensate recovered. (4) Sugar solution neutralized. (5) 

 Calcium sulfate separated. (6) Sugars (6 carbon type) fermented to ethanol and 

 carbon dioxide. (7) Yeast separated for re-use. (8) Ethanol stripped from dilute liquor. 

 (9) Contaminants extracted from ethanol. (1 0) Ethanol concentrated to 1 90 proof. (1 1 ) 

 Sugars (5 carbon type) concentrated. (Drawing after Baker 1980.) 



com cobs, grain hulls, sugar cane bagasse, and oak sawdust. Furfural is used as 

 a solvent and as an intermediate for the production of furan derivatives. 



The largest use of phenol is in producing plywood adhesives. Thus, the 

 phenol market fluctuates with demand for new housing. Phenol is also used in 



