The pore change and the volatile matter release of Shenmu coal and Huadian oil shale during thermal pretreatment at 150-400℃ were investigated.The effect of the pretreatment on the successive slow pyrolysis of the coal and oil shale was studied.The results showed that

after the thermal pretreatment

the pore structure of oil shale significantly increased and the specific surface area increased by more than 4 times and pore volume increased by more than 5 times.In contrast

the pore structure of Shenmu coal significantly reduced

in particular

for the pore larger than 1 nm

its pore volume reduced by nearly 60% and the surface area reduced by nearly 80%.However

the pore below 1 nm is relatively stable

and the pore volume and specific surface area reduced by only about 10%.When the thermal pretreatment temperature is below 400℃

in addition to the removal of adsorbed water

other volatile components

mainly CO2

and a small amount of CO

also were released

but the total mass loss caused by volatile release is not more than 5%.The slow pyrolysis experiments with a fixed bed reactor showed that

after the thermal pretreatment

the oil yield of oil shale increased by 22.7%

the yield of water and gas products reduced

and the content of H2 in the gas decreased while CH4 increased.The thermal pretreatment had no obvious influence on the oil yield of coal pyrolysis

while increased the yield of the gas product and CH4 content in the gas and decreased H2 content.