Recovery of fermentation salts from dilute aqueous solutions

• US 6,478,965 B1
• Filed: 11/16/1999
• Issued: 11/12/2002
• Est. Priority Date: 06/30/1997
• Status: Expired due to Fees

• Current Assignee: Texas A&M University System
• Original Assignee: Texas A&M University System
• Inventors: Luettich, Torsten, Davison, Richard R., Holtzapple, Mark T.
• Primary Examiner(s): Popovics, Robert J.
• Application Number:
  US09/441,211
• Time in Patent Office: 1,092 Days
• Field of Search: 210/634, 210/195.1, 210/255, 210/511, 210/522, 210/521, 210/802, 210/805, 366/15, 366/290, 366/291
• US Class Current: 210/634
• CPC Class Codes: B01D 11/0457 comprising rotating mechanisms, e.g. mixers, mixing pumps
• CPC Class Codes: B01D 17/00 Separation of liquids, not provided for elsewhere, e.g. by thermal diffusion devices for separating or removing fatty or oily substances or similar floating material from water, waste water, or sewage C02F1/40; cleaning or keeping clear the surface of open water from oil or like materials E02B15/04; arrangements for separating lubricants from refrigerants F25B43/02
• CPC Class Codes: B01D 17/0211 with baffles
• CPC Class Codes: B01D 17/0214 with removal of one of the phases
• CPC Class Codes: B01D 17/041 with moving devices
• CPC Class Codes: B01D 17/042 by changing the temperature
• CPC Class Codes: B01D 17/044 by changing the pressure
• CPC Class Codes: B01D 17/045 with coalescers
• CPC Class Codes: B01D 17/047 with separation aids
• CPC Class Codes: B01D 17/048 by changing the state of aggregation
• CPC Class Codes: C07C 51/48 by liquid-liquid treatment
• CPC Class Codes: C07C 53/08 Acetic acid pyroligneous acid C10C; preparation of vinegar C12J

Abstract

Dilute solutions of fermentation sales may be concentrated by extracting water using low-miscibility, low-molecular-weight secondary and tertiary amines, e.g. triethylamine (TEA), diisopropyl amine (DIA), N,N-diethylmethylamine (DEMA), and mixtures thereof. At 30° C.-55° C., which corresponds to typical fermentation temperatures, these low-molecular-weight amines or their mixtures, can extract large amounts of water from dilute aqueous solutions containing fermentation salts. Thus, dilute fermentation salt solutions can be concentrated by selectively removing water. At these low temperatures, the amine phase contains 20-35% water and a much reduced quantity of fermentation salt. When the temperature is raised, water phases out of the amine, allowing the amine to be recycled and reused to extract additional water. Using this approach, about 82.5% of water can be removed from a 3% dilute solution using conventional multistage, countercurrent extraction, thus providing a 15% concentrated fermentation salt solution.

Claims

1. An extraction tank comprising

a mixing section adapted for mixing a first fluid input stream and a second fluid input stream;

a separating section comprising a plurality of plates parallel to each other and in substantially horizontal orientation; and

a gathering section adapted for collecting an upper fluid layer and a lower aqueous fluid layer, having two weirs, a first weir being in fluid communication with the upper fluid layer and a second weir in fluid communication with the lower layer, the two weirs being in fluid communication with a first collection structure and a second collection structure, respectively;

wherein one end of the parallel plates of the separating section is in fluid communication with the mixing section and an other end of the parallel plates is in fluid communication with the gathering section.

2. The extraction tank of claim 1, wherein the parallel plates are rippled sheets.

3. The extraction tank of claim 1, wherein the end of the plurality of plates in fluid communication with the gathering section slopes such that a lower plate extends further into the gathering section than the immediately higher plate.

4. The extraction tank of claim 1, wherein the gathering section further includes a well to collect settled solids and facilitate their removal.

5. The extraction tank of claim 1, where a pump removes material from the interface of the two fluids in the gathering section, whereby accumulated solids are removed.

6. The extraction tank of claim 1, wherein the n mixing section contains a plurality of rotating shafts having projections, projections of respective shafts being interspersed such that even, gentle mixing is obtained.

7. The extraction tank of claim 1, further comprising means for introducing a large flowrate of aqueous layer to the plurality of parallel plates whereby settled solids are flushed therefrom, and means for collecting the aqueous layer, wherein the solids settle for removal.

8. The extraction tank of claim 1, in which sections of the plurality of parallel plates can cleaned of settled solids by isolating said sections and introducing a large flowrate of aqueous layer, collecting the aqueous flow in the gathering section, and recovering settled solids from the gathering section.

9. A method of extracting a solute component from a first fluid containing said solute component into a second fluid, wherein said first fluid and said second fluid are immiscible and have different densities, said method comprising

i) feeding said first and second fluids into an extraction tank, wherein the extraction tank comprises:

a mixing section adapted for mixing a first fluid input stream and a second fluid input stream;

a separating section comprising a plurality of plates parallel to each other and in substantially horizontal orientation; and

a gathering section adapted for collecting an upper fluid layer and a lower aqueous fluid layer, having two weirs, a first weir being in fluid communication with the upper fluid layer and a second weir in fluid communication with the lower layer, the two weirs being in fluid communication with a first collection structure and a second collection structure, respectively;

wherein one end of the parallel plates of the separating section is in fluid communication with the mixing section and an other end of the parallel plates is in fluid communication with the gathering section, and

ii) collecting the respective fluid from the first and second collection structures.