SIMULATED THERMAL MATURATION OF TYPE-I AND TYPE-III KEROGENS IN THE PRESENCE, AND ABSENCE, OF CALCITE AND MONTMORILLONITE

The effects of a mineral matrix on hydrocarbon generation from differe nt types of kerogen were examined. Simulated thermal maturation of typ e I, III/a and III/b kerogens, alone and mixed with minerals, was inv estigated using anhydrous pyrolysis. Both calcite and montmorillonite modified the products of simulated thermal maturation of the kerogens. Montmorillonite slightly reduced, and calcite slightly enhanced the f ormation of oil-like products from the coals (type III/a and III/b ker ogens). At higher levels of maturation, however, the catalytic effect of calcite resulted in cracking of the pyrolysates. For retention of t he pyrolysis products of type I kerogen, montmorillonite proved to be a very active matrix whereas the products were less affected by calcit e. The amount of soluble bitumen extracted from heated type I kerogen was higher in the presence of minerals than in their absence. On the c ontrary, the amount of soluble bitumen obtained from heated type III/a kerogen was smaller in the presence of minerals. In the case of type III/b kerogens this effect of minerals changed as a function of the te mperature of simulated thermal maturation.