Hydrocracking units

Hydrocracking is a process unit that combines catalytic reaction technology, refining technology and high-pressure technology. The selection of the process flow is related to catalyst performance, feedstock properties, product variety, product quality, unit size, equipment supply conditions and unit production flexibility.

There are various types of industrial units for hydrocracking, which can be divided into fixed-bed, boiling-bed and suspended-bed forms depending on the state of the catalyst in the reactor. Depending on the raw material and the purpose of the product, it can also be subdivided into many forms, such as: distillate hydrocracking, residue hydrocracking, as well as single-stage process, one-stage tandem process and two-stage process hydrocracking, etc.

(i) Fixed-bed hydrocracking

Fixed bed refers to the placement of a granular catalyst in the reactor to form a static catalyst bed. Depending on the nature of the feedstock, the intended product, the size of the process and the performance of the catalyst, fixed-bed hydrocracking can be divided into one-stage, two-stage and tandem processes.

(ii) Boiling bed hydrocracking

Boiling bed (also known as expanded bed, the process is driven by the fluid flow rate with a certain degree of particle size of the catalyst movement, the formation of gas, liquid, solid three-phase bed, so that the hydrogen, raw oil and catalyst in full contact to complete the hydrogenation reaction process.

(iii) Suspended bed hydrogenation process

Suspended bed (slurry bed) process is a hydrogenation process that has regained importance in order to accommodate very poor quality feedstock. The principle is similar to that of a boiling bed. The basic process is to pre-mix a fine powdered catalyst with the feedstock and feed it into the reactor with the hydrogen gas flowing from the bottom up, with the catalyst suspended in the liquid phase for the hydrocracking reaction and the catalyst flowing out of the top of the reactor with the reaction products.