Catalytic cracking, general products

Ethylene as a By-Product. The contribution to world ethylene production is small, but not zero. In petroleum refining fluid catalytic cracking (FCC) units, small amounts of ethylene are produced but generally not recovered, except in a few locations where large FCC units are adjacent to petrochemical faciUties. 

Cracking is effected by one of three general methods thermal cracking, catalytic cracking, or hydrocracking. Each process has its own characteristics concerning operating conditions and product compositions. 

Hydrocracking Distillates heavier than diesel are catalytically cracked at high pressure in the presence of hydrogen to produce either gasoline or diesel and lighter products. Generally, the objective is to produce diesel and lighter products such as two-carbon... 

Temperature is likely the most important variable affecting the catalytic cracking of plastics. Reaction temperatures are usually in the range 300-450°C. In general, a temperature increase leads towards a parallel activity enhancement of the catalysts. Nevertheless, it must be taken into account that at high temperatures the simultaneous occurrence of thermal cracking reactions is favoured, which may modify the product selectivity. 

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