What is hydrocracking in chemistry?
Hydrocracking is a process by which the hydrocarbon molecules of petroleum are broken into simpler molecules, as of gasoline or kerosene, by the addition of hydrogen under high pressure and in the presence of a catalyst.
What is meant by hydrocracking?
Definition of hydrocracking : the cracking of hydrocarbons in the presence of hydrogen.
What’s the difference between hydrotreating and hydrocracking?
The key difference between hydrocracking and hydrotreating is that hydrocracking includes the conversion of high boiling constituents into low boiling constituents, whereas hydrotreating includes the removal of oxygen and other heteroatoms. Hydrocracking and hydrotreating are useful processes in petroleum oil refining.
Is hydrocracking exothermic?
Hydrocracking reactions are the main sources of hydrocarbons (C1, C2, C3 and C4). The reactions are highly exothermic and consume high amounts of hydrogen. Cracking results in the loss of the reformate yield.
How is hydrocracking done?
A hydrocracking unit, or hydrocracker, takes gas oil, which is heavier and has a higher boiling range than distillate fuel oil, and cracks the heavy molecules into distillate and gasoline in the presence of hydrogen and a catalyst.
Is hydrocracking endothermic or exothermic?
What catalyst is used in hydrocracking?
The catalysts used for residue hydroprocessing are sulfides of Co-, Ni-, W- and Mo-supported catalysts, which have a variety of pore structure and active metal dispersion (active sites). Typical composition of the catalyst is 3–15 wt% Group VIB metal oxide and 2–8 wt% Group VIII metal oxide.
What is mild hydrocracking?
Mild hydrocracking (MHC) is catalytic cracking in the presence of hydrogen and operating at ‘mild’ hydrogen partial pressures (in comparison to conventional hydrocracking). Unlike hydrotreating, where hydrogen is used to break C-S and C-N bonds, mild hydrocracking uses hydrogen to break C-C bonds.
Is hydrocracking endothermic?
Another difference between hydrocracking and catalytic cracking includes the change in enthalpy; while catalytic cracking is an endothermic process, hydrocracking is an exothermic process. The heat for catalytic cracking is supplied by the regeneration of catalysts.
What are the products of the hydrocracking reaction?
The products of this process are saturated hydrocarbons; depending on the reaction conditions (temperature, pressure, and catalyst activity), these products range from ethane and LPG to heavier hydrocarbons mostly composed of isoparaffins.
How is hydrocracking related to the isomerization reaction?
Isomerization is a mildly exothermic reaction and leads to the increase of an octane number. Hydrocracking reactions are the main sources of C 4 − hydrocarbons (C 1, C 2, C 3 and C 4 ). The reactions are highly exothermic and consume high amounts of hydrogen. Cracking results in the loss of the reformate yield.
What happens to the reformate yield in hydrocracking?
The reactions are highly exothermic and consume high amounts of hydrogen. Cracking results in the loss of the reformate yield. Paraffin hydrocracking: Other paraffins can crack to give C 1 –C 4 products. Coke can also deposit during hydrocracking resulting in the deactivation of the catalyst.
Which is an exothermic reaction in the hydrocracking reaction?
Isomerization is a mildly exothermic reaction and leads to the increase of an octane number. 5.2.4.5 Hydrocracking Reactions Hydrocracking reactions are the main sources of C − 4 hydrocarbons (C 1, C 2, C 3 and C 4). The reactions are highly exothermic and consume high amounts of hydrogen.