High-temperature synthesis of pitch

Resumo

The heat treatment of the anthracene fraction of coal tar under pressure is considered. In the production of synthetic pitch, the duration of the process is varied from 10 to 80 min, at a temperature of 500°C and a pressure of 3 MPa. Kinetic data for the formation of γ and α₁ fractions show that the polycondensation of the γ fraction is of second order, while the formation of the α₁ fraction is of zero order. Pitch obtained with holding for 10–40 min does not contain the α₁ fraction. Extending the process beyond 30 min does not affect the removal of heteroatoms. IR spectroscopic data indicate that dealkylation predominates for the first 40 min. Then the process slows, and compaction develops.