Method and apparatus for multi-component fractionation

Claim 2

A fractionation method, comprising passing a feedstream to be fractionated to a first fractionator and (a) withdrawing a first relatively heavy product and a second relatively light product from said first fractionator; (b) introducing said second relatively light product into a light product stripping zone; (c) introducing said first relatively heavy product into a stripping zone of a second fractionator for stripping relatively lighter components from said first relatively heavy product, said second fractionator operating in a predetermined moderate pressure range sufficient to provide integration of said second fractionator with said first fractionator and said light product stripping zone; and (d) introducing a quench stream comprising relatively light stripped product from said light product stripping zone into a rectifying zone of said second fractionator to control an end point of said overhead product exiting said second fractionator.

Claim 3

The method as in claim 1, wherein said overhead product exiting said second fractionator is introduced into said light product stripping zone.

Claim 4

The method as in claim 1, wherein said overhead product exiting said second fractionator is introduced into said first fractionator.

Claim 5

The method as in claim 1, wherein said first relatively heavy product is withdrawn from a bottom draw of said first fractionator.

Claim 6

The method as in claim 1, wherein said first relatively heavy product is withdrawn from a side draw of said first fractionator.

Claim 7

A fractionation method, comprising passing a feedstream to be fractionated to a first fractionator and (a) withdrawing bottoms product from said first fractionator and introducing said withdrawn bottoms product into a second fractionator operating in a predetermined moderate pressure range sufficient to provide integration of said second fractionator with said first fractionator and to allow transfer of overhead product from said second fractionator into a stripper zone and thereafter into said first fractionator; (b) separating said withdrawn bottoms product into relatively light ends and relatively heavy ends by introducing stripping vapor into said second fractionator; (c) introducing a controlled stream of light product quench comprising bottoms product from said stripper zone at a predetermined low temperature and variable flow rate into said second fractionator to adjust an end point of overhead products exiting said second fractionator; (d) passing said overhead products exiting said second fractionator into said stripper and introducing relatively lighter product components from said first fractionator into said stripper zone, said overhead products from said second fractionator stripping light ends from said relatively lighter product components; and (e) separating overhead product from said stripper zone into relatively light ends and relatively heavy ends by introducing overhead product from said stripper zone into said first fractionator, such that said stripper overhead product is further fractionated in said first fractionator.

Claim 8

A fractionation method, comprising passing a feedstream to be fractionated to a first fractionator and (a) withdrawing bottoms product from said first fractionator and introducing said withdrawn bottoms product into a second fractionator operating in a predetermined moderate pressure range sufficient to provide integration of said second fractionator with said first fractionator and to allow transfer of overhead product from said second fractionator into a stripper zone and thereafter into said first fractionator; (b) separating said withdrawn bottoms product into relatively light ends and relatively heavy ends by introducing stripping vapor into said second fractionator; (c) introducing a controlled stream of light product quench comprising bottoms product from said stripper zone at a predetermined low temperature and variable flow rate into said second fractionator to adjust an end point of overhead products exiting said second fractionator; (d) passing said overhead products exiting said second fractionator into said stripper and introducing relatively lighter product components from said first fractionator into said stripper zone, said overhead products from said second fractionator stripping light ends from said relatively lighter product components; and (e) separating overhead product from said stripper zone into relatively light ends and relatively heavy ends by introducing overhead product from said stripper zone into said first fractionator, such that said stripper overhead product is further fractionated in said first fractionator.

Claim 9

The method as in claim 6, wherein said first fractionator is a main column fractionator of a fluid catalytic conversion system.

Claim 10

The method as in claim 7, wherein said stripping zone comprises a light cycle oil stripper.

Claim 11

The method as in claim 8, wherein said second fractionator comprises a main column bottoms/light cycle oil fractionator.

Claim 12

The method as in claim 9, wherein said stripping vapor and said bottoms product from said main column fractionator are mixed prior to being introduced into said main column bottoms/light cycle oil fractionator.

Claim 13

The method as in claim 10, wherein said controlled stream of light cycle oil quench is passed through cooling means prior to being introduced into said main column bottoms/light cycle oil fractionator.

Claim 14

The method as in claim 9, wherein said stripping vapor comprises steam.

Claim 15

The method as in claim 9, wherein said overhead product from said main column bottoms/light cycle oil fractionator introduced into said light cycle oil stripper comprises stripping vapor for said cycle oil introduced into said light cycle oil stripper.

Claim 16

The method as in claim 9, wherein said light cycle oil stripper and said main column fractionator fractionate light ends overhead product introduced from said main column bottoms/light cycle oil fractionator into said light cycle oil stripper.

Claim 17

The method as in claim 9, wherein said controlled stream of light cycle oil quench is introduced into a top tray in said main column bottoms/light cycle oil fractionator to control an ASTM End Point of light ends separated from said main column bottoms product introduced into said main column bottoms/light cycle oil fractionator.

Claim 18

The method as in claim 15, wherein said light cycle oil quench is taken directly from said light cycle oil stripper bottoms.

Claim 19

The method as in claim 15, further comprising cooling said light cycle oil stripper bottoms product and taking said light cycle oil quench from said cooled light cycle oil stripper bottoms product.

Claim 20

The method as in claim 9, wherein said main column bottoms/light cycle oil fractionator operates in a pressure range of approximately 40-50 psi.

Claim 21

The method as in claim 9, wherein step (b) comprises a flash separation process.

Claim 22

The method as in claim 9, further comprising introducing overhead product from said first fractionator into a gas-liquid separator and recovering unstabilized gasoline from said separator.

Claim 23

A fractionation apparatus, comprising: (a) a first fractionator having a first relatively heavy product draw and a second relatively light product draw; (b) a light product stripper receiving relatively light product from said second relatively light product draw; and (c) a second fractionator operating in a predetermined moderate pressure range sufficient to provide integration of said second fractionator with said first fractionator and said light product stripping zone, said second fractionator receiving said relatively heavy product draw and having a stripping zone for stripping lighter components from relatively heavier components introduced therein from said first relatively heavy product draw and a rectifying zone receiving a quench stream comprising relatively light stripped product from said light product stripper to control an end point of an overhead vapor stream exiting said second fractionator.

Claim 24

A fractionation apparatus, comprising: (a) a first fractionator having a first relatively heavy product draw and a second relatively light product draw; (b) a light product stripper receiving relatively light product from said second relatively light product draw; and (c) a second fractionator operating in a predetermined moderate pressure range sufficient to provide integration of said second fractionator with said first fractionator and said light product stripping zone, said second fractionator receiving said relatively heavy product draw and having a stripping zone for stripping lighter components from relatively heavier components introduced therein from said first relatively heavy product draw and a rectifying zone receiving a quench stream comprising relatively light stripped product from said light product stripper to control an end point of an overhead vapor stream exiting said second fractionator.

Claim 25

The apparatus as in claim 21, wherein the overhead vapor stream exiting the second fractionator is introduced into said light product stripper.

Claim 26

The apparatus as in claim 21, wherein the overhead vapor stream exiting said second fractionator is introduced into said first fractionator.

Claim 27

The apparatus as in claim 21, wherein said relatively heavy product draw is a bottoms product draw.

Claim 28

The apparatus as in claim 21, wherein said relatively heavy product draw is a side product draw.

Claim 29

A fractionation apparatus, comprising: (a) a first fractionator including a bottoms outlet at a bottom section thereof for removal of bottoms product, an intermediate inlet at an intermediate section thereof and a light product outlet below said intermediate inlet; (b) a stripper including a bottoms outlet, an inlet at a lower section thereof, an inlet at an upper section thereof connected to said light product outlet of said first fractionator, and an overhead outlet connected to said intermediate inlet of said first fractionator; (c) a second fractionator operating in a predetermined moderate pressure range sufficient to provide integration of said second fractionator with said first fractionator and to allow transfer of overhead product from said second fractionator into said stripper and thereafter into said first fractionator, said second fractionator having a bottoms product inlet connected to said bottoms outlet of said first fractionator, means for admitting stripping vapor into said second fractionator below said bottoms product inlet and an overhead products outlet connected to said inlet at said lower section of said stripper; and (d) means for introducing a controlled stream of bottoms product from said bottoms outlet of said stripper into said second fractionator, said stream having a predetermined low temperature and variable flow rate to control an end point of overhead products exiting said overhead products outlet of said second fractionator, whereby bottoms product from said first fractionator flashes in said second fractionator from contact with stripping vapor introduced therein, light ends from said second fractionator pass into said stripper to strip light ends introduced into said stripper from said first fractionator and light ends from said stripper pass into said first fractionator for further fractionation.

Claim 30

A fractionation apparatus, comprising: (a) a first fractionator including a bottoms outlet at a bottom section thereof for removal of bottoms product, an intermediate inlet at an intermediate section thereof and a light product outlet below said intermediate inlet; (b) a stripper including a bottoms outlet, an inlet at a lower section thereof, an inlet at an upper section thereof connected to said light product outlet of said first fractionator, and an overhead outlet connected to said intermediate inlet of said first fractionator; (c) a second fractionator operating in a predetermined moderate pressure range sufficient to provide integration of said second fractionator with said first fractionator and to allow transfer of overhead product from said second fractionator into said stripper and thereafter into said first fractionator, said second fractionator having a bottoms product inlet connected to said bottoms outlet of said first fractionator, means for admitting stripping vapor into said second fractionator below said bottoms product inlet and an overhead products outlet connected to said inlet at said lower section of said stripper; and (d) means for introducing a controlled stream of bottoms product from said bottoms outlet of said stripper into said second fractionator, said stream having a predetermined low temperature and variable flow rate to control an end point of overhead products exiting said overhead products outlet of said second fractionator, whereby bottoms product from said first fractionator flashes in said second fractionator from contact with stripping vapor introduced therein, light ends from said second fractionator pass into said stripper to strip light ends introduced into said stripper from said first fractionator and light ends from said stripper pass into said first fractionator for further fractionation.

Claim 31

The apparatus as in claim 26, wherein said first fractionator comprises a main column fractionator of a fluid catalytic conversion system.

Claim 32

The apparatus as in claim 27, wherein said stripper comprises a light cycle oil stripper.

Claim 33

The apparatus as in claim 28, wherein said second fractionator comprises a main column bottoms/light cycle oil fractionator.

Claim 34

The apparatus as in claim 29, further comprising means for mixing said stripping vapor with said bottoms product and subsequently introducing said mixture into said main column bottoms/light cycle oil fractionator.

Claim 35

The apparatus as in claim 30, further comprising a condenser interconnecting said bottoms outlet of said light cycle oil stripper and said main column bottoms/light cycle oil fractionator.

Claim 36

The apparatus as in claim 29, wherein said stripping vapor comprises steam.

Claim 37

The apparatus as in claim 29, wherein said overhead product from said main column bottoms/light cycle oil fractionator introduced into said lower section of said light cycle oil stripper comprises stripping vapor for said cycle oil introduced into said upper section of said light cycle oil stripper.

Claim 38

The apparatus as in claim 29, wherein said light cycle oil stripper and said main column fractionator fractionate light ends overhead product introduced from said main column bottoms/light cycle oil fractionator into said lower section of said light cycle oil stripper.

Claim 39

The apparatus as in claim 29, wherein said controlled stream of light cycle oil quench is introduced into a top tray in said main column bottoms/light cycle oil fractionator to control an ASTM End Point of light ends separated from said main column bottoms product introduced into said main column bottoms/light cycle oil fractionator.

Claim 40

The apparatus as in claim 35, wherein said light cycle oil quench is taken directly from said light cycle oil stripper.

Claim 41

The apparatus as in claim 35, further comprising means for cooling said light cycle oil stripper bottoms product and wherein said light cycle oil quench comprises light cycle oil stripper bottoms product.

Claim 42

The apparatus as in claim 29, wherein said main column bottoms/light cycle oil fractionator operates in a pressure range of approximately 40-50 psi.

Claim 43

The apparatus as in claim 29, further comprising a gas-liquid separator receiving overhead product from said first fractionator and means for recovering unstabilized gasoline from said separator.