Upgrading - Catalytic Conversion

Catalytic Conversion is another way to crack oil molecules into smaller, refineable hydrocarbons. Because it too requires high temperatures, catalytic conversion is really an enhanced form of thermal conversion. Catalysts have a very interesting effect on chemical reactions. They help those reactions to take place, but the catalyst itself is not chemically altered by the reaction. There can be different types of catalysts used (shaped like beads or pellets). The surface area of the catalyst is quite important; the cracking occurs when heated bitumen contacts active sites on the catalyst. Catalysts encourage “cracking” of hydrocarbons in two ways. When large hydrocarbons contact active sites on a catalyst, they react by breaking down into smaller molecules. Catalysts also act as sieves letting some molecules with specific sizes and shapes through while holding others back to continue reacting. Sometimes high-pressure hydrogen is added in the process of catalytic cracking. This is called hydroprocessing. Adding hydrogen helps to produce lighter, hydrogen rich molecules. This is necessary in upgrading bitumen, which is rich in carbon but proportionally less hydrogen than conventional oils.

Catalytic conversion is more expensive than thermal conversion but it does produce more upgraded product for later refining.