160 



GEHRS 



STEAM 

 AND AIR- 



GASIFICATION -^ 



LOW-Btu 



CO, Hj, CH^, -^CLEANUP 



Nj, CO2, HjS 



STEAM AND G 



GASIFICATGN 



MEOIUM-Btu 

 CG, Hj, CH^, U. 

 CGj, HjS 



CLEANUP 



CLEAN GASEOUS FUEL 

 [LOW (100-250) Btu] 



CLEAN GASEOUS FUEL 

 [MEDIUM (250-550) Btu] 



SUBSTITUE 



METHANATION|-^ NATURAL GAS 



[HIGH (950-1000) Btu| 



COAL 



CHEMICAL 

 SYNTHESIS 



.CLEAN LIQUID 

 FUELS AND CHEMICALS 



GAS 



_JL_ 



H^S 



CARBOWIZATION/ 

 HYDROCARBONIZATIOIM 



CHAR 



OILS 



HYDROTREATING 



CLEAN LIQUID FUEL 



HjS 



SOLVATION 



FILTRATION AND 

 SOLVENT REMOVAL 



ASH 



PYRITIC SULFUR 



H^S 



± 



HYDROTREATING 



SYNCRUDE 



SOLIDIFICATION -^ CLEAN SOLID FUEL 



CATALYTIC 

 HYDROGENATION 



SEPARATION 



CLEAN LIQUID 



FUEL 



RESIDUUM 



H YD ROTREATINGH" SYNCRUDE 



I 



Fig. 2 Schematic of five basic approaches for converting coal to 

 gaseous or liquid fuels. (Data from Richmond, Reichle, and Gehrs, 

 1976.) 



fuel are currently being used in several countries. In the United 

 States attempts are being made to demonstrate the use of caking 

 coals (the major type in the eastern United States) and high 

 temperature. In contrast, high-Btu gas can be produced from 

 gasification with oxygen and upgrading of the product. This allows 

 transport of the gas to diverse sources and ultimate substitution for 

 natural gas as a home-heating source. 



Coal liquefaction processes are in the early exploratory stages. 

 Three general approaches are being pursued, pyrolysis or carboniza- 

 tion, dissolution, and hydrogenation. All rely on high temperature, 

 often high pressure, and a reducing atmosphere to produce liquid 



