It is both physically and catalytically that abundant addition of CaO influence on oil sand pyrolysis.

Addition of abundant CaO inhibited the devolatilizing during oil-producing stage.

Addition of abundant CaO do little influence on the tar yields at 480 ºC, but water and gas yields decreased obviously.

Compared with alone pyrolysis, the composition of tar had changed as the asphaltene and aromatic were reduced.

More alkanes with long carbon chain and less olefins were generated when pyrolyzed with abundant CaO additives.