Use of low pressure distillate as absorber oil in a FCC recovery section
AssigneeShell Oil Company
InventorPim Ghijsen
Life of this patent
Estimating the term…
Abstract
A process for the recovery of gaseous products from the product mixture obtained by contacting a hydrocarbon feed with a catalyst in a fluid catalytic cracking process, wherein the liquid, obtained by separating the top product of main fractionators into gaseous and liquid fraction, when supplied to the absorber has a temperature of between about 8–25 DEG C. This liquid may be pre-saturated with gaseous top product from absorber; or also a high boiling fraction (cat cracker naphtha/light cycle oil) may be first separated from this liquid by distillation.
Claims11
A process for the recovery of gaseous products from a product mixture obtained by contacting a hydrocarbon feed with a catalyst in a fluid catalytic cracking process, wherein the recovery comprises;
- the following sequence of steps:
- (a) separating the product mixture in a first distillation step in which a gaseous top product is obtained comprising products boiling below about 200° C.;
- (b) cooling the gaseous top product of step (a) to obtain a first liquid and gaseous fractions and separating said first liquid and gaseous fractions to provide a first liquid fraction and a first gaseous fraction;
- (c) pressurizing the first gaseous fraction obtained in step (b) in a compressor step to obtain a pressurized product;
- (d) cooling the pressurized product of step (c) and to obtain a second liquid and gaseous fractions and separating said second liquid and gaseous fractions to provide a second liquid fraction and a second gaseous fraction;
- (e) supplying the second gaseous fraction obtained in step (d) to an absorber section of a stripper-absorber column in which the second gaseous fraction is contacted with the first liquid fraction obtained in step (b) to thereby provide for yielding from said stripper-absorber column a lower boiling fraction rich in gaseous products having a boiling point of ethane or below;
- (f) supplying the second liquid fraction obtained in step (d) to a stripper section of said stripper-absorber column which provides for yielding from said stripper-absorber column a liquid fraction rich in hydrocarbons having a boiling point higher than ethane;
- and,
- (g) supplying the liquid fraction rich in hydrocarbons having a boiling point higher than ethane obtained in step (f) to a debutanizer distillation step whereby a light fraction comprising butane and lower boiling compounds and a higher boiling fraction are obtained,
- wherein the first liquid fraction obtained in step (b) has a temperature of between from about 8° C. to about 25° C. when supplied to the absorber section in step (e).
Dependencies are inferred from the claim text.