KINETIC EVALUATIONS OF INDIVIDUAL HYDROCARBON (C1-C4) GENERATION BY NONISOTHERMAL SOURCE-ROCK PYROLYSIS

Nonisothermal pyrolysis experiments on an immature Toarcian oil shale sample provided evolution profiles of individual alkanes (C1-C4) and a lkenes (C2-C4). Using the activation energies and pre-exponential Arrh enius factors assessed by application of the single-reaction model (si mple nonisothermal kinetics), the extrapolation to geological heating rates resulted in hydrocarbon formation temperatures that appeared to be too low according to organic geochemical concepts. Evaluation of th e experimental evolution profiles with a kinetic model, implying a dis crete activation energy distribution, yielded more probable kinetic pa rameters and geological hydrocarbon formation temperatures commonly ac cepted for natural gas generation.