Process and system for production of polypropiolactone
Provided are integrated processes for the conversion of ethylene oxide to polypropiolactone. Systems for the production of polypropiolactone are also provided.
1 . A system for converting ethylene oxide to polypropiolactone (PPL), comprising:
an ethylene oxide source;
a carbon monoxide source;
a carbonylation catalyst source;
a carbonylation solvent source;
a polymerization catalyst source;
a first reaction zone configured to receive ethylene oxide from the ethylene oxide source, carbon monoxide from the carbon monoxide source, carbonylation catalyst from the carbonylation catalyst source, and carbonylation solvent from the carbonylation solvent source, and to output a beta propiolactone (BPL) product stream from contacting the ethylene oxide and the carbon monoxide with the carbonylation catalyst in the presence of the carbonylation solvent in the first reaction zone, wherein the BPL product stream comprises carbonylation solvent and BPL;
a solvent removal unit configured to remove at least a portion of the carbonylation solvent from the BPL product stream; and
a second reaction zone configured to receive the BPL product stream from the solvent removal unit, and polymerization catalyst from the polymerization catalyst source, and to output a PPL product stream from contacting the BPL product stream with the polymerization catalyst in the second reaction zone, wherein the PPL product stream comprises PPL, wherein the polymerization catalyst is comprised of recycled polymerization catalyst.
2 . The system of claim 1 , further comprising a second solvent source, wherein the second solvent source is configured to output a polymerization solvent for combining with the BPL product stream, wherein the second solvent is different from the carbonylation solvent.
3 . The system of claim 2 , wherein the polymerization solvent is less polar than the carbonylation solvent as measured by dielectric constant.
4 . The system of claim 2 , wherein the polymerization solvent comprises a Lewis base and is less polar than 1,3-dioxane, ortho-difluorobenzene, or metadifluorobenzene.
5 . The system of claim 2 , wherein the polymerization solvent has a dielectric constant at 20° C. of less than about 13.6.
6 . The system of claim 1 , wherein the carbonylation solvent comprises a polar donating solvent.
7 . The system of claim 1 , wherein the polymerization catalyst is a salt of a compound of formula:
wherein p is from 0 to 9, and R a is a non-volatile moiety.
8 . The system of claim 1 , wherein the polymerization catalyst is a salt of a compound of formula:
wherein p is 0 to 9.
9 . The system of claim 1 , wherein the BPL product stream is neat when introduced into the second reaction zone.
10 . The system of claim 2 , wherein the polymerization catalyst along with the polymerization solvent is introduced to the BPL product stream.
11 . The system of claim 1 , further comprising a nanofiltration membrane configured to separate at least a portion of carbonylation catalyst from the BPL product stream.
12 . The system of claim 1 , wherein the second reaction zone is a reactive extruder.
13 . The system of claim 1 , wherein the carbonylation solvent has a boiling point below 160° C. at 1 atm.