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US 2018/0002255 A1Published application
Method for improving propylene recovery from fluid catalytic cracker unit
AssigneeTechnip France
InventorsTanmay TARAPHDAR, Babu N. SHARATH
Life of this patent
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Abstract
The present invention relates to a method for treating a cracked stream stemming from a fluid catalytic cracker unit (FCCU) in order to improve propylene recovery. The present invention also relates to the corresponding installation to implement the method.
Claims18
Method for treating a cracked stream stemming from a fluid catalytic cracker unit (FCCU) comprising the following steps:
- compressing and partly condensing the gas stream from the main fractionator column overhead receiver of the FCCU;
- separating the partly condensed gas stream in order to recover an upstream liquid and an upstream gas;
- heating the upstream liquid;
- introducing this heated liquid into an upstream stripper for recovering at the top of the stripper a stream rich in C2 compounds and at the bottom a first liquid stream rich in C3+ hydrocarbons;
- introducing the first liquid stream rich in C3+ into a first heat exchanger and then into a second heat exchanger;
- introducing the liquid recovered from the second heat exchanger into a stabilizer column for recovering at the top of the stabilizer column a stream rich in C3 and C4 hydrocarbons and from the side of the stabilizer column a liquid stream rich in C5 and C6 hydrocarbons and from the bottom of the stabilizer column a liquid stream rich in C5, C6 and C7+ hydrocarbons;
- introducing the liquid stream rich in C5 and C6 hydrocarbons into the first heat exchanger;
- introducing a liquid stream from stabilizer column bottom into a primary absorber and introducing the upstream gas into a primary absorber for recovering at the top of the primary absorber a first gas stream;
- and at the bottom of the primary absorber a second liquid stream;
- introducing lean oil from FCCU main fractionator into a sponge absorber;
- cooling the first gas stream from primary absorber and introducing it into a propylene absorber;
- cooling the liquid stream rich in C5 and C6 hydrocarbons from the first heat exchanger;
- introducing the liquid stream rich in C5 and C6 hydrocarbons recovered from the first heat exchanger into the propylene absorber;
- recovering a bottom liquid rich in C3 hydrocarbons at the bottom of the propylene absorber and a top gas poor in C3 hydrocarbons at the top of the propylene absorber;
- introducing the top gas recovered at the top of the propylene absorber into the sponge absorber, preferably to recover a fuel gas and a rich oil.
12 more elements
An installation for treating a cracked stream stemming from a fluid catalytic cracker unit (FCCU) comprising:
- means for compressing and partly condensing a gas stream from the main fractionator column receiver of the FCCU (1);
- means for separating the partly condensed gas stream to recover an upstream liquid and an upstream gas;
- for heating the upstream liquid;
- a stripper column and means for introducing the heated upstream liquid into the stripper in order to recover at the top of the stripper a stream rich in C2 compounds and at the bottom of the stripper a first liquid stream rich in C3+ hydrocarbons;
- a first heat exchanger and means for introducing into this first heat exchanger the first liquid stream rich in C3+ hydrocarbon;
- a stabilizer column and means for introducing the liquid stream rich in C3+ hydrocarbons from the first heat exchanger into the stabilizer column to recover from the side of the stabilizer column a first liquid stream rich in C5 and C6 hydrocarbons and at the top of the stabilizer column a gas stream rich in C3 and C4 hydrocarbons;
- means for introducing the first liquid stream rich in C5 and C6 hydrocarbons into the first heat exchanger;
- means for cooling the liquid stream rich in C5 and C6 hydrocarbons from the first heat exchanger;
- a primary absorber and means for introducing to said primary absorber a liquid stream rich in C5, C6 and C7+ hydrocarbons from stabilizer column and the upstream gas from the separator for recovering at the top of the primary absorber a first gas stream and at the bottom of the primary absorber a liquid stream;
- a propylene absorber and means for introducing to this propylene absorber the cooled liquid stream rich in C5 and C6 hydrocarbons;
- a sponge absorber and means for introducing to this sponge absorber a lean oil;
- means for cooling the first gas stream from the primary absorber;
- means for introducing into the propylene absorber the first gas stream from the primary absorber for recovering at the top of the propylene absorber a gas stream poor in C3 hydrocarbons and at the bottom of the propylene absorber a liquid stream rich in C3 hydrocarbons;
- means tier introducing into the sponge absorber the gas stream poor in C3 hydrocarbons recovered at the top of the propylene absorber.
11 more elements
Dependencies are inferred from the claim text.