Process for drying HCFO-1233zd
Disclosed is a process to dry 1-chloro-3,3,3-trifluoropropene (HCFO-1233zd) or its mixtures by washing with water and or alkaline solution. The resulting liquid mixture, containing HCFO-1233zd, other organic, and water, is allowed to settle, and thereafter, the lighter water layer is decanted off from the top of the mixture. The heavier HCFO-1233zd layer is then withdrawn from the bottom of the decanter to a desiccant dryer (e.g., molecular sieve, activated alumina, silica gel, and the like) to further remove the residual soluble moisture from the HCFO-1233zd to about 80 ppm or less.
1. In the process of purifying crude 1-chloro-3,3,3-trifluoropropene (HCFO-1233zd), wherein the crude HCFO-1233zd product requires aqueous washing to remove HF, HC1, and other acidic components,
the improvement comprising conducting each of the following steps in order:
(a) washing the crude HCFO-1233zd with water to form a washed mixture;
(b) condensing the washed mixture; and
(c) separating the washed mixture into a lighter water layer and heavier HCFO-1233zd layer, followed by drying the HCFO-1233zd layer with a desiccant, thereby producing an HCFO-1233zd product with a moisture level of 80 ppm or less.
2. The process of claim 1 , wherein the moisture level is about 50 ppm or less.
3. The process of claim 1 , wherein the moisture level is about 20 ppm or less.
4. The process of claim 1 , wherein the moisture level is about 10 ppm or less.
5. The process of claim 1 , wherein the crude HFC-1233zd is washed with an alkaline solution.
6. The process of claim 1 , wherein the desiccant is selected from the group consisting of molecular sieve 3A, 4A, activated alumina, silica gel, CaSO 4 , and mixtures thereof.
7. The process of claim 6 , wherein the desiccant comprises molecular sieve 3A.
8. The process of claim 6 , wherein the desiccant is comprises molecular sieve 4A.
9. The process of claim 6 , wherein the desiccant comprises activated alumina.
10. The process of claim 6 , wherein the desiccant comprises silica gel.
11. The process of claim 6 , wherein the desiccant comprises CaSO 4 .