Coal utilization can be improved by coupling a fluidized bed pyrolyzer to a CFB boiler

which enables a co-production of pyrolysis oil and electricity. In this process

the pyrolyzer uses generally the self-generated pyrolysis gas as the fluidizing gas. The present study deals with the pyrolysis oil production in a fluidized bed reactor through using a simulated pyrolysis gas as the reaction atmosphere

and both the yield and composition were analyzed with TG-FTIR. For a bituminous coal used in steam boilers

the oil yield reaches its possible peak value of 13%(mass

daf). The presence of H2 and CO2 in the reaction atmosphere decreases the tar yield

whereas the addition of CO and CH4 into the atmosphere increases the tar production. TG-FTIR analysis demonstrated that adding H2 into the pyrolysis atmosphere increases the contents of phenolic and carboxylic compounds in the produced pyrolysis oil

while it promotes as well the cracking of aliphatic hydrocarbons during pyrolysis. Adding CH4 causes more aliphatic hydrocarbons

single aromatic ring chemicals and phenolic compounds in the pyrolysis oil.