Purged polymer, process and apparatus for production thereof

A process for producing a polymer, in particular a purged polymer, comprising the steps of:

• i) manufacturing a polymer in a polymerization reactor in the presence of a catalyst at a first temperature (T1), wherein the catalyst has a maximum catalyst capability dependent on temperature, and wherein the polymer has a tackiness limit dependent on temperature;
• ii) discharging the polymer from the polymerization reactor into a first process vessel;
• iii) at least partially removing undesirable compounds including volatile organic compounds and/or residual polymerization reactants from the polymer and/or odorous compounds, and optionally contacting the polymer with a flow of a first purge gas in the first process vessel;
• iv) transferring the polymer from the first process vessel to a second process vessel;
• v) contacting the polymer in the second process vessel with a flow of a second purge gas;
• and
• vi) recovering a polymer product comprising the polymer from which undesirable compounds have been purged;
• wherein the first temperature is allowed to rise to the maximum of the catalyst capability and/or the tackiness limit of the polymer to prevent plugging and fouling;
• and
• wherein the steps ii) to v) are operated while maintaining the polymer at a second temperature (T2) such that T1−20° C.≤T2≤T1 and/or 70° C.≤T2≤T1, wherein the T2 for the step ii) may be different than the T2 for the step v).

A system for producing a purged polymer comprising:

• a polymerization reactor suitable for being operated at a first temperature (T1) and for producing a polymer;
• a first process vessel configured for at least partially removing undesirable compounds including volatile organic compounds and/or residual polymerization reactants and/or odorous compounds from the polymer, the first process vessel comprising a first polymer inlet fluidically connected to the polymerization reactor for receiving the polymer, a first polymer outlet for discharging the polymer with a reduced content of undesirable compounds, a first exhaust gas outlet for evacuating at least some of the undesirable compounds, and optionally a first purge gas inlet for introducing a first purge gas;
• a second process vessel configured for purging the polymer with a reduced content of undesirable compounds, comprising a second polymer inlet fluidically connected to the first process vessel for receiving the polymer with a reduced content of undesirable compounds, a second polymer outlet for discharging a polymer product comprising the polymer from which undesirable compounds have been purged, a second purge gas inlet for introducing a second purge gas and a second exhaust gas outlet for discharging the second purge gas charged with undesirable compounds purged from the polymer;
• a purge gas system configured to introduce the second purge gas in the second process vessel;
• a purged polymer recovery section fluidically connected to the second process vessel;
• wherein the system is configured for maintaining the polymer at a second temperature (T2) while the polymer is flowing from the polymerization reactor to the second process vessel, such that T1−20° C.≤T2≤T1 and/or 70° C.≤T2≤T1.

A process for producing a polymer, in particular a purged polymer, comprising the steps of:

• i) manufacturing a polymer in a polymerization reactor in the presence of a catalyst;
• ii) discharging the polymer from the polymerization reactor into a first process vessel;
• iii) at least partially removing undesirable compounds including volatile organic compounds and/or residual polymerization reactants from the polymer and/or odorous compounds, and optionally contacting the polymer with a flow of a first purge gas in the first process vessel;
• iv) transferring the polymer from the first process vessel to a second process vessel;
• v) contacting the polymer in the second process vessel with a flow of a second purge gas;
• and
• vi) recovering a polymer product comprising the polymer from which undesirable compounds have been purged;
• wherein the step ill) comprises flowing the polymer in a plug-flow fashion into the first process vessel and feeding superheated steam in a countercurrent fashion to the polymer.