Method for recovering titanium tetrachloride from a waste liquid
| Title: | Method for recovering titanium tetrachloride from a waste liquid |
|---|---|
| Patent Number: | 7,976,818 |
| Publication Date: | July 12, 2011 |
| Appl. No: | 11/791564 |
| Application Filed: | November 21, 2005 |
| Abstract: | A method for continuously recovering titanium tetrachloride TiCl4 from a waste liquid comprising TiCl4 and by-products, wherein said waste liquid is subjected, as a flowing liquid film, to an evaporation step for a residence time of less than 15 minutes at a temperature higher than 90° C. |
| Inventors: | Vincenzi, Paolo (Ficarolo-Rovigo, IT); Spoto, Rosa (Ferrara, IT); Badalocchi, Matteo (Padua, IT) |
| Assignees: | Basell Poliolefine Italia s.r.l. (Milan, IT) |
| Claim: | 1. A method for continuously recovering titanium tetrachloride TiCl 4 from a waste liquid comprising TiCl 4 and by-products, the method comprising subjecting a flowing waste liquid film to an evaporation step comprising a residence time of less than 15 minutes at a temperature from higher than 90° C. to 150° C., without cracking and decomposition of the by-products. |
| Claim: | 2. The method according to claim 1 , wherein said by-products comprise: at least one titanium (halo) alkoxide of formula TiX p (OR) q , wherein X is halogen, R is a C 1 -C 10 alkyl group, p=0-3, q=1-4, and 2 |
| Claim: | 3. The method according to claim 1 , wherein said liquid film has a thickness lower than 3 cm. |
| Claim: | 4. The method according to claim 1 , wherein said residence time is less than 5 minutes. |
| Claim: | 5. The method according to claim 1 , wherein the temperature in said evaporation step is comprised between 100 and 150° C. |
| Claim: | 6. The method according to claim 1 , wherein during said evaporation step TiCl 4 flashes away as a vapour stream. |
| Claim: | 7. The method according to claim 1 , wherein said evaporation step is carried out by means of a thin film evaporator. |
| Claim: | 8. The method according to claim 7 , wherein said thin film evaporator comprises internal walls, a stator comprising heating jackets, and a rotor distributing the liquid as a film onto the internal walls of the evaporator. |
| Claim: | 9. The method according to claim 1 , further comprising subjecting said waste liquid comprising TiCl 4 and by-products to a preliminary distillation in a column operated under vacuum at a bottom temperature comprised between 90° C. and 115° C. |
| Claim: | 10. The method according to claim 9 , wherein said preliminary distillation is carried out at pressures ranging from 0.1 bar to 0.8 bar. |
| Current U.S. Class: | 423/492 |
| Patent References Cited: | 2245358 June 1941 Pechukas 2460602 February 1949 Semon 3156630 November 1964 Fahnoe et al. 3395203 July 1968 Morita 3819663 June 1974 Levine et al. 5242549 September 1993 Potter et al. 5948212 September 1999 Kilty et al. 2005/0084433 April 2005 Te Nijenhuis et al. 49 095896 September 1974 03/074425 September 2003 WO03/074425 December 2003 |
| Assistant Examiner: | Nguyen, Colette |
| Primary Examiner: | Mayes, Melvin C |
| Attorney, Agent or Firm: | Dilworth IP, LLC |
| Accession Number: | edspgr.07976818 |
| Database: | USPTO Patent Grants |
| Language: | English |
|---|