Abstract: Methods for removing polymer skins or build-up from reactor walls in polymerization reactor systems containing a loop slurry reactor are disclosed. Such methods can employ removing some or all of the comonomer from the reactor system in combination with increasing the polymerization temperature of the loop slurry reactor.

Abstract: A polyethylene production process, comprising contacting ethylene and a polymerization catalyst under suitable reaction conditions to yield a polymerization product stream, separating a light gas stream from the polymerization product stream, wherein the light gas stream comprises ethane and unreacted ethylene, contacting the light gas stream with an absorption solvent system, wherein at least a portion of the ethylene from the light gas stream is absorbed by the absorption solvent system, removing unabsorbed gases of the light gas stream from contact with the absorption solvent system to form a waste gas stream, and recovering ethylene from the absorption solvent system.

Abstract: An olefin polymerization process and apparatus wherein a fluid slurry comprising monomer, diluent and catalyst is circulated in a continuous loop reactor by two or more pumps. The process and apparatus allow operating the reaction at significantly higher solids content in the circulating fluid slurry. In a preferred embodiment, the fluid slurry is circulated by two impellers arranged so that the downstream impeller benefits from the rotational energy imparted by the upstream impeller. An olefin polymerization process operating at higher reactor solids by virtue of more aggressive circulation has improved efficiencies, particularly in larger-volume reactors.

Abstract: The present embodiments provide a system and method for separation within a polymer production process. Specifically, a flashline heater configured according to present embodiments may provide more time than is required for complete vaporization of liquid hydrocarbons that are not entrained within a polymer fluff produced within a polymerization reactor. Such extra time may allow for liquid hydrocarbons that are entrained within the polymer fluff to be vaporized.

Abstract: Techniques and systems for producing a polyolefin using reactors in series are described. Described embodiments include techniques and systems for polymerizing a monomer in a first polymerization reactor to form a first polyolefin, discharging a first slurry continuously from the first polymerization reactor to a second polymerization reactor, and discharging a second slurry continuously from the second polymerization reactor. Using continuous take-off devices disposed on either or both reactors, pressure control may be attained such that the rate of transfer between and withdrawal from both reactors are within a desired range.

Abstract: A manufacturing system for producing polyolefin includes a polymerization reactor, a flash chamber, and a purge column. In certain embodiments, the purge column may receive a solids stream directly from the flash chamber. Further, the purge column may function as a feed tank for an extruder within an extrusion/loadout system. According to certain embodiments, the manufacturing system may be configured to consume less than 445 kilowatt-hours of energy per metric ton of polyolefin produced based on consumption of electricity, steam, and fuel gas.

Abstract: A process for recovery of ethylene from a polymerization product stream of a polyethylene production system, comprising separating a light gas stream from the polymerization product stream, wherein the light gas stream comprises ethane and unreacted ethylene, contacting the light gas stream with an absorption solvent system, wherein the contacting the light gas stream with the absorption solvent system occurs at a temperature in a range of from about 40° F. to about 110° F., wherein at least a portion of the unreacted ethylene from the light gas stream is absorbed by the absorption solvent system, and recovering unreacted ethylene from the absorption solvent system to yield recovered ethylene.

Abstract: A process for component separation in a polymer production system, comprising separating a polymerization product stream into a gas stream and a polymer stream, wherein the gas stream comprises ethane and unreacted ethylene, distilling the gas stream into a light hydrocarbon stream, wherein the light hydrocarbon stream comprises ethane and unreacted ethylene, contacting the light hydrocarbon stream with an absorption solvent system, wherein at least a portion of the unreacted ethylene from the light hydrocarbon stream is absorbed by the absorption solvent system, and recovering a waste gas stream from the absorption solvent system, wherein the waste gas stream comprises ethane, hydrogen, or combinations thereof.

Abstract: A system and method for measuring pressure and flow rate of polymer slurry circulating in a loop reactor. For flow rate measurement, the loop reactor has a pressure tap on an outside radius of an elbow of the loop and a pressure tap on an inside radius of the elbow. The pressure taps incorporate diaphragms. Sensing legs couple the pressure taps with a differential pressure meter configured to provide a signal indicative of the flow rate of the polymer slurry. For pressure measurement, pressure taps without diaphragms at the loop reactor wall may be disposed at various points along the loop reactor, the pressure taps coupled to pressure sensing lines. A diluent flush line having a screen disposed therein may provide diluent to the pressure taps. The screen may reduce fouling of the pressure tap and sensing line with solids from the reactor.

Abstract: A manufacturing system for producing polyolefin includes a polymerization reactor, a flash chamber, and a purge column. In certain embodiments, the purge column may receive a solids stream directly from the flash chamber. Further, the purge column may function as a feed tank for an extruder within an extrusion/loadout system. According to certain embodiments, the manufacturing system may be configured to consume less than 445 kilowatt-hours of energy per metric ton of polyolefin produced based on consumption of electricity, steam, and fuel gas.

Abstract: Techniques are provided for producing polymer particles of a size just slightly larger than the size of polymer fines. The technique may prevent or limit the occurrence of reactor fouls associated with large polymer particles. The technique also may provide a greater weight percentage of solids in the reactor. The desired polymer particle size may be achieved by employing a catalyst having particles of a size determined based on the expected catalyst productivity. In certain embodiments, the catalyst particle size may be determined based on the expected catalyst productivity, the polymer particle density, the catalyst particle density, and/or the polymer particle size.

Abstract: A polyethylene production process, comprising contacting ethylene and a polymerization catalyst under suitable reaction conditions to yield a polymerization product stream, separating a light gas stream from the polymerization product stream, wherein the light gas stream comprises ethane and unreacted ethylene, contacting the light gas stream with an absorption solvent system, wherein at least a portion of the ethylene from the light gas stream is absorbed by the absorption solvent system, removing unabsorbed gases of the light gas stream from contact with the absorption solvent system to form a waste gas stream, and recovering ethylene from the absorption solvent system.

Abstract: Techniques are provided for producing polymer particles of a size just slightly larger than the size of polymer fines. The technique may prevent or limit the occurrence of reactor fouls associated with large polymer particles. The technique also may provide a greater weight percentage of solids in the reactor. The desired polymer particle size may be achieved by employing a catalyst having particles of a size determined based on the expected catalyst productivity. In certain embodiments, the catalyst particle size may be determined based on the expected catalyst productivity, the polymer particle density, the catalyst particle density, and/or the polymer particle size.

Abstract: A manufacturing process for producing polyolefin, having a feed system, a reactor system including at least one polymerization reactor, a diluent/monomer recovery system, a fractionation system, and an extrusion/loadout system having an extruder. The manufacturing process is configured to consume less than 325 kilowatt-hours of electricity per metric ton of polyolefin produced.

Abstract: The present techniques provide systems and methods for recovering energy from flare gases in chemical plants and refineries. The systems use an engine to burn a portion of gas diverted from the flare system. The engine may be a reciprocating engine, or a burner in a boiler system, among others. The power generated by burning the flare gas is then used to power an energy recovery device. The energy recovery device may be an electrical generator, a compressor, or a steam boiler, among others.

Abstract: A reactor system including an enclosed pressure relief system and/or a control system. The enclosed pressure relief system including a slurry separation system communicatively coupled with a pressure relief valve coupled to a loop reactor such that activation of the pressure relief valve results in discharge of a slurry from the loop reactor to the slurry separation system, wherein the slurry separation system is capable of separating solid and liquid components from gas components of the slurry and transmitting the gas components to a flare via a flare header.

Abstract: A manufacturing process for producing polyolefin, having a feed system, a reactor system including at least one polymerization reactor, a diluent/monomer recovery system, a fractionation system, and an extrusion/loadout system having an extruder. The manufacturing process is configured to consume less than 325 kilowatt-hours of electricity per metric ton of polyolefin produced.

Abstract: Techniques and systems for producing a polyolefin using reactors in series are described. Described embodiments include techniques and systems for polymerizing a monomer in a first polymerization reactor to form a first polyolefin, discharging a first slurry continuously from the first polymerization reactor to a second polymerization reactor, and discharging a second slurry continuously from the second polymerization reactor. Using continuous take-off devices disposed on either or both reactors, pressure control may be attained such that the rate of transfer between and withdrawal from both reactors are within a desired range.

Abstract: Techniques are provided for producing polymer particles of a size just slightly larger than the size of polymer fines. The technique may prevent or limit the occurrence of reactor fouls associated with large polymer particles. The technique also may provide a greater weight percentage of solids in the reactor. The desired polymer particle size may be achieved by employing a catalyst having particles of a size determined based on the expected catalyst productivity. In certain embodiments, the catalyst particle size may be determined based on the expected catalyst productivity, the polymer particle density, the catalyst particle density, and/or the polymer particle size.

Abstract: A manufacturing process for producing polyolefin, having a feed system, a reactor system including at least one polymerization reactor, a diluent/monomer recovery system, a fractionation system, and an extrusion/loadout system having an extruder. The manufacturing process is configured to consume less than 325 kilowatt-hours of electricity per metric ton of polyolefin produced.