Solar potable water recovery and power generation from salinous water

• US 4,078,975 A
• Filed: 01/31/1977
• Issued: 03/14/1978
• Est. Priority Date: 01/31/1977
• Status: Expired due to Term

• Current Assignee: UOP Des Plaines IL A NY General Partnership
• Original Assignee: UOP Llc (Honeywell International Inc.)
• Inventors: Spears, John F. Jr.
• Primary Examiner(s): Hart, Charles N.
• Assistant Examiner(s): Therkorn, Ernest G.
• Application Number:
  US05/764,256
• Time in Patent Office: 407 Days
• Field of Search: 60/641, 60/648, 60/655, 60/677, 126/270, 126/271, 202/234, 202/185 R, 203/10, 203/49, 203/100, 203/DIG. 1, 203/DIG. 20
• US Class Current: 203/10
• CPC Class Codes: C02F 1/10 by direct contact with a particulate solid or with a fluid, as a heat transfer medium
• CPC Class Codes: C02F 1/14 using solar energy
• CPC Class Codes: F24S 10/13 Salt-gradient ponds
• CPC Class Codes: Y02A 20/211 Solar-powered water purification
• CPC Class Codes: Y02A 20/212 Solar-powered wastewater sewage treatment, e.g. spray evaporation
• CPC Class Codes: Y02E 10/44 Heat exchange systems
• CPC Class Codes: Y02W 10/37 using solar energy
• CPC Class Codes: Y10S 203/01 Solar still
• CPC Class Codes: Y10S 203/21 Acrylic acid or ester

Abstract

A process for recovering potable water from a source of salinous water -- e.g. sea and/or ocean water. Certain modifications afford the simultaneous generation of power. A portion of salinous water and an air stream are introduced into a solar radiation heat sink, with the air stream flowing over the salinous water. Heated, water-containing air is withdrawn from the heat sink and reduced in temperature to recover potable water. The heated salinous water, from the heat sink, may be recycled thereto, or at least in part introduced into a flash separation zone, maintained at a subatmospheric pressure to provide a non-salinous vaporous phase which is passed through a turbine, from the resulting motion of which power is generated. The exiting turbine vapors are cooled and/or condensed via indirect contact with a second portion of salinous water to recover additional potable water. Alternatively, the heated, water-containing air stream may be cooled by vaporizing a hydrocarbon which then passes through a turbine for the purpose of producing energy. Salinous water which is returned to the original source thereof is at a temperature not more than 15 ° F. greater than the coldest salinous water obtained from the source.

Claims

1. A process for recovering potable water from a source of salinous water which comprises the sequential steps of:

(a) introducing a portion of salinous water from said source into a solar radiation heat sink;

(b) introducing an air stream into said solar radiation heat sink and flowing said air stream over said salinous water to produce a water containing air stream;

(c) exposing said salinous water and said air stream, within said solar radiation heat sink, to absorbed solar energy for a time sufficient to increase (i) the temperature of said salinous water and, (ii) the temperature and water content of said flowing air stream;

(d) withdrawing the thus-heated (i) water-containing air stream and, (ii) salinous water from said solar radiation heat sink;

(e) reducing the temperature of said water-containing air stream via indirect contact with a vaporizable hydrocarbon or halohydrocarbon, wherein the resultant vaporizable hydrocarbon or halohydrocarbon is introduced into and through a turbine from which motion energy is produced, said reduction in temperature of said water-containing air stream resulting in separating and recovering a potable, non-salinous water from said water-containing air stream; and

(f) recycling the resulting cooled air stream to said solar radiation heat sink.

2. The process of claim 1 further characterized in that at least a portion of the heated salinous water withdrawn from said heat sink is recycled thereto.

3. The process of claim 1 further characterized in that said air stream is introduced into said solar radiation heat sink at a temperature above about 120°

F.

4. The process of claim 1 further characterized in that (i) said air stream and, (ii) said salinous water are withdrawn from said solar radiation heat sink at a temperature in the range of about 130°

F. to about 210°

F.

5. The process of claim 4 further characterized in that said air stream and said salinous water portion are withdrawn from said solar radiation heat sink at a temperature above about 150°

F.

6. The process of claim 1 further characterized in that said salinous water is withdrawn from said solar radiation heat sink at a temperature higher than that of said air stream.

7. The process of claim 1 further characterized in that (i) at least a portion of said heated salinous water is introduced into a flash separation zone, maintained at subatmospheric pressure, to provide a non-salinous vaporous phase and a salinous liquid phase, and, (ii) said vaporous phase is introduced into and through a turbine, from the resulting motion of which power is generated.

8. The process of claim 7 further characterized in that the exit vapors from said turbine are indirectly contacted with a second salinous water portion from said source to recover additional potable water.

9. The process of claim 8 further characterized in that said second salinous water portion and the salinous water portion introduced into said solar radiation heat sink are obtained from said source at substantially the same temperature.

10. The process of claim 8 further characterized in that the temperature of said second salinous water portion is at least 5°

F. to about 15°

F. lower than that of the salinous water portion introduced into said solar radiation heat sink.