Petroleum refining industry  

Petroleum refining industry extensively involves heterogeneous solid catalytic processes. The major catalytic processes are shown in Fig 1.

Fig. 1. Various solid catalytic processes in petroleum refining industries

Catalytic cracking

Catalytic cracking of gas oil is among the most important catalytic processes and major source of fuels. This process involves simultaneous occurrence of various reactions. Some typical reactions in catalytic cracking process are shown in Fig. 2.

Fig. 2. Some typical reactions in catalytic cracking process

 

Process

Usually catalytic cracking of gas oil is carried out at 500-550⁰C at 2 -3 atm pressure, in a fluidized bed reactor . In the fluidized bed reactor, most of the cracking occurs in the transport-line (riser). Catalyst to oil weight ratio is usually maintained at 4-6 with residence time of 2-6 seconds in the riser reactor. The gasoil feed stock is usually consist of C₂₀-C₄₀ in the boiling range of 350 -550⁰C. Catalyst circulation rate of about 6 ton/m³ of total feed is maintained for smooth operation. The schematic diagram of a typical fluidized catalytic cracking reactor is shown in Fig. 3.