Bringing Crude Oil Further: the Fluid Catalytic Cracking

In a previous article, we talked about the fractioning process of distillation, which separates crude oil into different types of fuel.

At this initial stage of the refining process, crude oil is divided into 'cuts', depending on the boiling point of its components. For example, at the lowest boiling point, about 35°C, naphtha can be obtained. The next cut, at about 150°C, is for kerosene (used as jet fuel), while the highest boiling point (300°C and over) produces diesel fuel.

All the fuels so far are indeed semi-finished products, as they will later be further refined to obtain better-quality and more efficient fuels.

The problem with this type of refining is that it leaves a part of the crude oil intact, namely the one composed of long-chain hydrocarbons, with an even higher boiling point.

For this reason, with the growing demand of fuels a new refining technique was invented in the 1930s, called fluid catalytic cracking, to break hydrocarbons with a higher boiling point. Since then, it has become one of the most important refining methods, especially for the production of gasoline.

How fluid catalytic cracking works

Fluid catalytic cracking can process crude oil at a boiling point of 340°C and over, using a mineral-based catalyst (called zeolite) to induce the reaction.

The most important components of a fluid catalytic cracking plant are the reactor and the regenerator. The undistilled crude oil is mixed with the catalyst in the reactor and separated into hydrocarbons with shorter chain. The catalyst is then collected in the regenerator and purified, ready to start the cycle again. 

Cividac's involvement in fluid catalytic cracking projects

For the Malaysian engineering company UOP (Universal Oil Products), for their refinery in Cilacap, Indonesia, Cividac built a PSA adsorption equipment and an off-gas drum, which is used to collect the residual gas from the absorption process.