EVOLUTION OF INDIVIDUAL HYDROCARBONS (C1-C4) BY NONISOTHERMAL PYROLYSIS OF PETROLEUM SOURCE ROCKS

Nonisothermal pyrolysis of Toarcian oil shales from the Hils Syncline area, conducted at a low heating rate of 0.1-degrees-C/min, resulted in evolution profiles of individual alkanes (C1-C4) and alkenes (C2-C4) from which kinetic parameters and amounts of hydrocarbons were derived. The immature (R(m) = 0.48%) shale sample displayed at least four methane-generation reactions. The activation energies assessed by simple nonisothermal kinetics for the generation of alkanes (C1-C4) and alkenes (C2-C4) increased with increasing maturity of the shales, with the position of the maximum dependent on the individual hydrocarbon. Increasing shale maturity appeared to promote alkane and alkene formation.