Role and Effect of Catalyst

The catalyst plays a vital role in a pyrolysis process. Pyrolysis in the presence of catalyst requires less energy than a noncatalytic process and results in formation of more branched 

A typical catalyst comprises 20-25% zeolite, 30-35% clay and matrix bound by about 20-30% silica or alumina binder. 

Among all varieties of zeolites, the zeolites with 10-membered oxygen rings in their structure and medium pore size, ZSM-5 and ZSM-11 are remarkably stable as acidic catalysts. 

In the presence of the silica formation of a carbanion ion takes place easily, thus enhancing the fragmentation reaction at lower temperature. 

---