ACRYLIC ACID, AND METHODS OF PRODUCING THEREOF
Provided herein are methods of producing acrylic acid from beta-propiolactone. Such methods may involve the use of a heterogeneous catalyst, such as a zeolite.
1 . A method of producing acrylic acid from beta-propiolactone, comprising:
combining beta-propiolactone, a zeolite, and a polymerization inhibitor; and
producing acrylic acid from at least a portion of the beta-propiolactone.
2 . The method of claim 1 , the zeolite is an acidic zeolite.
3 . The method of claim 1 , wherein the zeolite is Zeolite Y or Zeolite ZSM-5, or a combination thereof.
4 . The method of claim 1 , wherein the polymerization inhibitor is phenothiazine.
5 . The method of claim 1 , wherein the beta-propiolactone is provided at a rate of less than 1.5 g/min.
6 . The method of claim 5 , wherein the beta-propiolactone is provided at a rate of between 0.75 g/min and 1.25 g/min.
7 . The method of claim 1 , wherein the acrylic acid produced is continuously isolated.
8 . The method of claim 1 , wherein the acrylic acid is produced at a yield of at least 50%.
9 . The method of claim 1 , wherein the acrylic acid is produced at a temperature of between 170° C. and 200° C.
10 . The method of claim 1 , wherein the beta-propiolactone, the polymerization inhibitor, and the zeolite are further combined with a solvent.
11 . The method of claim 10 , wherein the solvent comprises a polar aprotic solvent.
12 . The method of claim 10 , wherein the solvent comprises sulfolane.
13 . The method of claim 1 , wherein the acrylic acid produced has a purity of greater than 95%.
14 . The method of claim 1 , further comprising isolating acrylic acid.
15 . The method of claim 14 , wherein the acrylic acid is isolated by distillation.
16 . The method of claim 1 , wherein the beta-propiolactone is produced from ethylene oxide and carbon monoxide.
17 . A method of producing a superabsorbent polymer,
comprising:
polymerizing acrylic acid produced according to the method of claim 1 in the presence of a cross-linker to produce the superabsorbent polymer.
18 . A system, comprising:
a reactor, wherein the reactor comprises one or more inlets and a vapor port; and
a collection vessel,
wherein the one or more inlets of the reactor are configured to receive beta-propiolactone, a zeolite, and a polymerization inhibitor,
wherein the reactor is configured to produce acrylic acid vapors from at least a portion of the beta-propiolactone received, and to continuously strip off at least a portion of the acrylic acid vapors produced, and
wherein the vapor port is configured to pass at least a portion of the acrylic acid vapors to the collection vessel.
19 . The system of claim 18 , further comprising an acid/base scrubber.