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Machine translation
1. (WO1980002387) IMPROVED PROCESS FOR REMOVAL AND RECOVERY OF VINYL CHLORIDE MONOMER FROM VENT GAS STREAM IN POLYVINYL CHLORIDE PLANT
Latest bibliographic data on file with the International Bureau   

Pub. No.:    WO/1980/002387    International Application No.:    PCT/US1980/000254
Publication Date: 13.11.1980 International Filing Date: 10.03.1980
IPC:
B01D 53/70 (2006.01)
Applicants:
Inventors:
Priority Data:
35140 02.05.1979 US
Title (EN) IMPROVED PROCESS FOR REMOVAL AND RECOVERY OF VINYL CHLORIDE MONOMER FROM VENT GAS STREAM IN POLYVINYL CHLORIDE PLANT
(FR) PROCEDE AMELIORE DE PRELEVEMENT ET DE RECUPERATION DE MONOMERE DE CHLORURE DE VINYLE A PARTIR D"UN COURANT DE GAZ D"EVENT DANS DES INSTALLATIONS DE PRODUCTION DE CHLORURE DE POLYVINYLE
Abstract: front page image
(EN)In polyvinyl chloride production plants air enters the process during production operations and must be vented to the atmosphere. The air becomes mixed with gaseous vinyl chloride monomer during the process and not all of the vinyl chloride monomer can be condensed therefrom as liquid in the normal monomer recovery operation. Consequently the vent gas stream contains appreciable proportions of vinyl chloride monomer along with air, and in many cases is saturated with watervapor. In order to remove and recover the vinyl chloride monomer from the vent gas before it is released to the atmosphere, the vent gas stream is treated counter-currently with a stream of liquid solvent which absorbs the vinyl chloride monomer and the vinyl chloride monomer is then stripped from the solvent by application of heat and condensed as liquid vinyl chloride while recycling the lean solvent to the absorption step. The solvent used as the absorbent is a branched chain saturated aliphatic hydrocarbon containing 8 carbon atoms and composed predominantely of 2,2,4-trimethyl pentane. This solvent enables the vinyl chloride content of the gases vented to the atmosphere to be reduced to less than 5 and even less than 1 part per million by volume. Its use assures that any solvent vapors emitted with the vent gas are controllable so as to be not harmful to the environment. Its use also assures that the normal steam supply at the plant will provide the heat necessary to strip the absorbed vinyl chloride monomer from the solvent.
(FR)Dans des usines de production de chlorure de polyvinyle de l"air entre au cours du procede pendant les operations de production et doit etre evacue vers l"atmosphere. L"air se melange au monomere de chlorure de vinyle gazeux pendant le procede et tout le monomere de chlorure de vinyle ne peut se condenser sous forme liquide dans la recuperation normale du monomere. En consequence, le courant gazeux d"event contient des proportions appreciables de monomere de chlorure de vinyle melangees a de l"air, et dans de nombreux cas il est sature avec de la vapeur d"eau. De maniere a prelever et recuperer le monomere de chlorure de vinyle des gaz d"event avant qu"ils ne se degagent dans l"atmosphere, le courant gazeux d"event est traite en contre-courant avec un courant de solvant liquide qui absorbe le monomere de chlorure de vinyle et ce dernier est separe du solvant par application de chaleur et il est condense sous forme de chlorure de vinyle liquide, le solvant simple etant recycle vers la phase d"absorption. Le solvant utilise comme absorbant est une chaine ramifiee d"hydrocarbure aliphatique sature contenant huit atomes de carbone et compose essentiellement de 2,2,4-trimethyle pentane. Ce solvant permet de reduire la teneur de chlorure de vinyle des gaz evacues vers l"atmosphere jusqu"a moins de cinq et meme moins de une partie par millions en volume. Son utilisation permet de controler les emissions de vapeur du solvant avec les gaz d"event de maniere telle qu"ils ne soient pas nocifs pour l"environnement. Son utilisation assure egalement que l"alimentation normale de vapeur dans l"usine fournit la chaleur necessaire pour separer du solvant le monomere de chlorure de vinyle absorbe.
Designated States:
Publication Language: English (EN)
Filing Language: English (EN)