Method for cooling in distillation and polymerisation process by absorption refrigeration
Processes for the separation of a hydrocarbon-containing feed streams are described herein. The processes generally include cooling the hydrocarbon-containing feed stream using a first absorption refrigeration cycle to form a cooled feed stream, introducing the cooled feed stream into a first distillation zone for subjecting the cooled feed stream to distillation conditions adapted to remove a first bottom stream including co-monomer and a first overhead stream including hydrocarbon diluents, olefin monomer and further components selected from H 2 , N 2 , O 2 , CO, CO 2 , formaldehyde and combinations thereof, passing the overhead stream from the first distillation zone to a second distillation zone for subjecting the overhead stream to distillation conditions adapted to remove a second bottom stream including substantially olefin-free hydrocarbon diluents, a side stream including hydrocarbon diluent and a second overhead vapor stream including olefin monomer, diluents and further components selected from H 2 , N 2 , O 2 , CO, CO 2 , formaldehyde and combinations thereof, cooling the second overhead vapor stream using a second absorption refrigeration cycle to form a cooled overhead vapor stream and separating olefin monomer from diluents in the cooled overhead vapor stream.
1. A process for the separation of a hydrocarbon-containing feed stream comprising:
cooling the hydrocarbon-containing feed stream using a first absorption refrigeration cycle to form a cooled feed stream;
introducing the cooled feed stream into a first distillation zone for subjecting the cooled feed stream to distillation conditions adapted to remove a first bottom stream comprising co-monomer and a first overhead stream comprising hydrocarbon diluents, olefin monomer and further components selected from H 2 , N 2 , O 2 , CO, CO 2 , formaldehyde and combinations thereof;
passing the first overhead stream from the first distillation zone to a second distillation zone for subjecting the first overhead stream to distillation conditions adapted to remove a second bottom stream comprising substantially olefin-free hydrocarbon diluents, a side stream comprising hydrocarbon diluent and a second overhead vapor stream comprising olefin monomer, diluents and further components selected from H 2 , N 2 , O 2 , CO, CO 2 , formaldehyde and combinations thereof;
cooling the second overhead vapor stream using a second absorption refrigeration cycle to form a cooled overhead vapor stream; and
separating olefin monomer from diluents in the cooled overhead vapor stream.
2. The process of claim 1 , wherein the cooled overhead vapor stream has a temperature of between 0° C. and −40° C.
3. The process of claim 1 , wherein the second absorption refrigeration cycle utilizes water and ammonia as working fluids.
4. The process of claim 1 , wherein the second absorption refrigeration cycle is driven from heat recycled from a reboiler of the first distillation zoned.
5. The process of claim 1 further comprising cooling the side stream using a third absorption refrigeration cycle.
6. The process of claim 5 , wherein the third absorption refrigeration cycle utilizes water and lithium bromide as working fluids.
7. The process of claim 5 , wherein the third absorption refrigeration cycle utilizes water and ammonia as working fluids.
8. The process of claim 1 , wherein the first absorption refrigeration cycle utilizes water and lithium bromide as working fluids.
9. The process of claim 1 further comprising passing the first bottom stream from the first distillation zone to a third distillation zone for subjecting the first bottom stream to distillation conditions adapted to remove a third bottom stream comprising co-monomer and a third overhead stream comprising hydrocarbon diluents.
10. The process of claim 1 , wherein the hydrocarbon-containing feed stream is a product of a polyolefin production process.