Co-pyrolysis of an aromatic petroleum residue with triphenylsilane

The effect of silicon on the pyrolysis of a petroleum residue has been stud ied. In this work, controlled co-pyrolysis of an aromatic petroleum residue and triphenylsilane, TPS, as a silicon source, under 1 MPa nitrogen atmosp here and at 440 degreesC is performed. Soaking time was varied between 1.5 and 6 h, and the silicon concentration added to the petroleum residue range d from 0 to 2 wt%. Silicon content in the final solid product increases wit h soaking time. The effect of silicon upon the solid yield, insoluble conte nt and mesophase development is appreciable only when the concentration of silicon in the residue is above 0.4 wt%. Initially TPS acts as a diluting a gent and a mild proton donor, inhibiting reactivity of the radicals formed in the system and molecular growth. As reaction progresses TPS reacts, crea ting tetrahedral bonds within macromolecules and, as a consequence, after a period, molecular growth is enhanced. However, the planar stacking leading to mesophase formation and growth is inhibited by silicon and consequently the development of mesophase structures is limited to small spheres and fi ne mosaics. Optically isotropic material is obtained when silicon concentra tion is above 1 wt%. (C) 2001 Elsevier Science Ltd. All rights reserved.