SYSTEMS AND METHODS FOR RECOVERING HYDROCARBONS FROM A POLYOLEFIN PURGE GAS PRODUCT

• Main Authors: RANDALL L. FORCE, GEORGE W. SCHWARZ JR, DANIEL W. MOSSER, CLOID RUSSELL SMITH, DONALD A. FISCHER, JAMES L. SWECKER, ROBERT D. OLSON, MARK W. BLOOD, THEODORE D. DUNCAN
• Format: Patent
• Language: English; Spanish
• Published: 16.03.2016
• Subjects: ACYCLIC OR CARBOCYCLIC COMPOUNDS; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F,C08G; CHEMISTRY; COMPOSITIONS BASED THEREON; GENERAL PROCESSES OF COMPOUNDING; MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVINGCARBON-TO-CARBON UNSATURATED BONDS; METALLURGY; ORGANIC CHEMISTRY; ORGANIC MACROMOLECULAR COMPOUNDS; PERFORMING OPERATIONS; PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL; SEPARATION; THEIR PREPARATION OR CHEMICAL WORKING-UP; TRANSPORTING; WORKING-UP

Provided are systems and methods for separating a purge gas recovered from a polyethylene product. The method includes recovering a polyethylene product containing one or more volatile hydrocarbons from a polymerization reactor and contacting the polyethylene product with a purge gas to remove at least a portion of the volatile hydrocarbons to produce a polymer product having a reduced concentration of volatile hydrocarbons and a purge gas product enriched in volatile hydrocarbons. The purge gas product is compressed to a pressure of 2,500 kPaa to 10,000 kPaa, and is then cooled and separated into at least a first product, a second product, and a third product. A portion of one or more of the first, second, or third products is then recycled as a purge gas, to the polymerization reactor, or to the purge gas product enriched in volatile hydrocarbons prior to compression, respectively. Provistos son sistemas y métodos para separar un gas de purga recuperado a partir de un producto de polietileno. El método incluye recuperar un producto de polietileno conteniendo uno o más hidrocarburos volátiles a partir de un reactor de polimerización y poniendo contacto con el producto de polietileno con un gas de purga para remover por lo menos una porción de los hidrocarburos volátiles para producir un producto de polímero teniendo una concentración reducida de hidrocarburos volátiles y un producto de gas de purga enriquecido con hidrocarburos volátiles. El producto de gas de purga se comprime a una presión de 2,500 kPaa a 10,000 kPaa, y luego se enfría y se separa en por lo menos un primer producto, un segundo producto, y un tercer producto. Una porción de uno o más de los primer, segundo, o tercer productos entonces se recicla como un gas de purga, al reactor de polimerización, o el producto de gas de purga enriquecido en hidrocarburos volátiles previo a compresión, respectivamente.