Process and apparatus for separating polymer solids, hydrocarbon fluids, and purge gas

An apparatus for slurry polymerization in a hydrocarbon fluid and for separating hydrocarbon fluid from solid polymer particles and purge gas, the apparatus comprising:

• (a) a polymerization reactor in which one or more olefins are polymerized to form solid polymer particles in a hydrocarbon fluid;
• (b) an intermediate pressure chamber adapted for the separation of hydrocarbon fluid from the solid polymer particles, the chamber having an inlet for receiving hydrocarbon fluid and solid polymer particles from the polymerization reactor, a polymer outlet for discharging solid polymer particles, and a gas outlet for discharging vaporized hydrocarbon fluid;
• (c) a condenser fluidically connected to the gas outlet of the intermediate pressure chamber and adapted to condense the vaporized hydrocarbon fluid by heat exchange and without compression;
• (d) a purge column fluidically connected to the polymer outlet of the intermediate pressure chamber, the purge column adapted to receive the solid polymer particles from the intermediate pressure chamber without passing through an additional pressure chamber;
• (e) a hydrocarbon/purge gas recovery unit adapted to separate hydrocarbon fluid from purge gas, the recovery unit fluidically connected to a top portion of the purge column and adapted to receive a fluid stream comprising purge gas and hydrocarbon fluid from the purge column;
• (f) a recycle tank adapted to receive condensed hydrocarbon vapor from the condenser and to receive a second hydrocarbon fluid stream from the hydrocarbon/purge gas recovery unit;
• (g) a pump and at least one conduit fluidically connected to a bottom portion of the recycle tank, wherein the pump and the at least one conduit are adapted to transport the condensed hydrocarbon fluid from the recycle tank to the reactor without transporting the condensed hydrocarbon fluid through a fractionation system;
• (h) a vapor delivery conduit coupled to a top portion of the recycle tank and fluidically connected to a first fractionation column;
• and
• (i) an extruder feed tank adapted to receive the solid polymer particles from the purge column.

A process for slurry polymerization and for separating hydrocarbon fluid from solid polymer particles and purge gas, said process comprising:

• polymerizing in a reaction zone at least one olefin monomer to produce a slurry, comprising solid polymer particles and hydrocarbon fluid;
• withdrawing a portion of the slurry from the reaction zone;
• separating at least a majority of the hydrocarbon fluid from the solid polymer particles in an intermediate pressure zone as a vaporized hydrocarbon fluid stream;
• condensing the vaporized hydrocarbon fluid stream in a condensing zone, whereby a condensed hydrocarbon fluid stream is formed;
• transferring the condensed hydrocarbon fluid stream from the condensing zone to a recycle zone;
• transferring the solid polymer particles from the intermediate pressure zone to a purge zone in which a purge gas is passed through the solid polymer particles to remove entrained hydrocarbon fluid, thereby forming a mixed stream containing hydrocarbon vapor and purge gas;
• transferring the mixed stream to a recovery zone where the purge gas and hydrocarbon fluid are separated to form a recovered purge gas stream and a recovered hydrocarbon fluid stream;
• passing at least a portion of the recovered purge gas stream from the recovery zone to the purge zone;
• passing a first portion of the recovered hydrocarbon fluid stream from the recovery zone to the recycle zone;
• transferring vapor from the recycle zone to a fractionation zone;
• passing a second portion of the recovered hydrocarbon fluid stream from the recovery zone to the fractionation zone;
• and
• transferring hydrocarbon liquid from the recycle zone to the reaction zone without fractionating the hydrocarbon liquid.

An apparatus for slurry polymerization in a hydrocarbon fluid and for separating hydrocarbon fluid from solid polymer particles and purge gas, the apparatus comprising:

• (a) a loop polymerization reactor in which one or more olefins are polymerized to form solid polymer particles in a hydrocarbon fluid;
• (b) an intermediate pressure chamber adapted to separate hydrocarbon fluid from the solid polymer particles, the chamber having an inlet for receiving hydrocarbon fluid and solid polymer particles from the polymerization reactor, a polymer outlet for discharging solid polymer particles, and a gas outlet for discharging vaporized hydrocarbon fluid;
• (c) a condenser fluidically connected to the gas outlet of the intermediate pressure chamber, the condenser adapted to condense the flashed hydrocarbon fluid by heat exchange and without compression;
• (d) a purge column fluidically connected to the polymer outlet of the intermediate pressure chamber and adapted to receive the solid polymer particles from the intermediate pressure chamber without passing through an additional pressure chamber;
• (e) a hydrocarbon/purge gas recovery unit adapted to separate hydrocarbon fluid from purge gas, wherein the recovery unit is fluidically connected to a top portion of the purge column and adapted to receive a fluid stream comprising purge gas and hydrocarbon fluid from the purge column;
• (f) a recycle tank adapted to receive hydrocarbon liquid from the condenser and to receive hydrocarbon fluid from the hydrocarbon/purge gas recovery unit;
• (g) a liquid delivery conduit fluidically connecting a bottom portion of the recycle tank with the polymerization reactor, wherein the fluidic connection between the recycle tank and the reactor does not include a fractionation column;
• (h) a vapor delivery conduit fluidically connecting a top portion of the recycle tank with a first fractionation column;
• and
• (i) a conduit fluidically connecting the first fractionation column with the hydrocarbon/purge gas recovery unit, wherein the first fractionation column is configured to process hydrocarbon fluid from the hydrocarbon/purge gas recovery unit and vapor from the recycle tank.