Thermodynamic stability of petroleum C15 polyalkylated bicyclo[4.4.0]decanes at 500 and 600 K

Abstract

The thermodynamic equilibrium concentrations of petroleum C 15 polymethylated bicy clo[4.4.0]decanes (sesquiterpanes) at 500 and 600 K have been experimentally obtained for the first time via the aluminosilicate mediated equilibrium isomerization of the saturated 200-300°C fraction of crude oils of different genotypes. It has been found that sesquiterpane isomers with an angular carbon atom and methyl and ethyl substituents in the molecule are the least thermodynamically stable in the equilibrium mixture and their relative concentration increases with increasing temperature from 500 to 600 K; the most stable isomer is 2,3,3,7,7 pentamethylbicyclo[4.4.0]decane.