Halohydrocarbon recovery process

• US 5,837,106 A
• Filed: 12/12/1994
• Issued: 11/17/1998
• Est. Priority Date: 08/20/1993
• Status: Expired due to Fees

• Current Assignee: Technichem Engineering, Ltd.
• Original Assignee: Technichem Engineering, Ltd.
• Inventors: Ng, Mark J., Maeda, Bruce T.
• Primary Examiner(s): MANOHARAN, VIRGINIA
• Application Number:
  US08/353,789
• Time in Patent Office: 1,436 Days
• Field of Search: 203/41, 203/DIG. 11, 203/DIG. 16, 203/14, 34/469, 34/472, 34/73.8, 210/689, 210/664, 210/690, 210/691, 210/669
• US Class Current: 203/41
• CPC Class Codes: B01D 3/143 by two or more of a fractionation, separation or rectification step
• CPC Class Codes: B01D 3/38 Steam distillation
• CPC Class Codes: D06F 43/081 Reclaiming or recovering the solvent from a mixture of solvent and contaminants, e.g. by distilling
• CPC Class Codes: Y10S 203/13 Spirits
• CPC Class Codes: Y10S 203/17 Saline water conversion

Abstract

A halohydrocarbon solvent recovery process. The process in one embodiment included heating a gross mixture including solvent, fatty-acid impurities and water in a bath to vaporize at least a portion of the solvent and the impurities. A portion of the vapor is then condensed in a reflux condenser to form a condensate mixture. After drying and impurity adsorption, a solvent product of at least 99% purity may be recovered. In one embodiment, the gross mixture is obtained from steam stripping dry-cleaner filter cartridges.

Claims

1. A solvent recovery process for purification of a solvent comprising halohydrocarbons, said method comprising the steps of:

heating a gross mixture comprising halohydrocarbons, fatty-acid impurities and water in a bath to vaporize at least a portion of said halohydrocarbons and said impurities;

condensing at least a portion of said vapor in a reflux condenser to form a condensate mixture;

collecting the condensate mixture;

drying at least a portion of said condensate mixture in a dryer to remove said water, said dryer containing a quantity of calcium silicate, magnesium silicate or a combination thereof;

adsorbing the dried condensate mixture to remove a majority of said fatty acid impurities in an adsorber, said adsorber containing a quantity of adsorbent, wherein said adsorbent is silica gel; and

recovering halohydrocarbon solvent product of at least 99% purity.

2. The solvent recovery process of claim 1, wherein said process is a batch process.

3. The solvent recovery process of claim 1, wherein said quantity of silica gel is from about 0.05 to about 1.5 grams silica gel per 100 grams solvent.