Integrated process for production of ozone and oxygen

• US 9,371,228 B2
• Filed: 09/12/2013
• Issued: 06/21/2016
• Est. Priority Date: 09/12/2013
• Status: Active Grant

• Current Assignee: Air Products and Chemicals Incorporated (Linde Plc)
• Original Assignee: Air Products and Chemicals Incorporated (Linde Plc)
• Inventors: Sisodia, Sunita S., Golden, Timothy Christopher, Dholakia, Vipul P.
• Primary Examiner(s): Slifka, Colin W
• Application Number:
  US14/024,686
• Publication Number:
  US 20150068365A1
• Time in Patent Office: 1,013 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: C01B 13/0203 from inorganic compounds
• CPC Class Codes: C01B 13/0229 Purification or separation processes
• CPC Class Codes: C01B 13/10 Preparation of ozone
• CPC Class Codes: C22B 1/02 Roasting processes C22B1/16 takes precedence
• CPC Class Codes: Y02P 10/20 Recycling
• CPC Class Codes: Y02P 20/10 Process efficiency

Abstract

Embodiments of the present invention provide systems and methods for efficiently producing both a low-pressure ozone stream and high-pressure oxygen stream using a single air separation unit. The low-pressure ozone stream and high-pressure oxygen stream can be produced with significant energy savings and can be used in variety of applications, including the extraction of precious metals from ore with aqueous oxidation reactors and high-pressure oxidation reactors.

Claims

1. A process for producing oxygen and ozone, comprising:

(a) compressing an air feed stream;

(b) introducing the compressed air stream into an air separation unit to produce a purified oxygen stream;

(c) introducing the purified oxygen stream into an ozone generator to produce a resultant stream comprising oxygen and ozone;

(d) compressing the resultant stream;

(e) introducing the compressed resultant stream into a first reactor;

(f) performing an oxidation reaction of inorganic materials in an aqueous solution in the first reactor to produce an oxygen-rich effluent stream;

(g) compressing the oxygen-rich effluent stream from the first reactor;

(h) introducing the compressed oxygen-rich stream into a second reactor; and

(i) performing an oxidation reaction of inorganic materials in a non-aqueous solution in the second reactor, wherein the oxidation reaction in the second reactor is performed at a temperature that is greater than or equal to 140 degrees Celsius and less than or equal to 350 degrees Celsius.

2. The process of claim 1, wherein step (i) comprises performing an oxidation reaction comprising a combustion, roasting, high pressure oxidation or autoclaving reaction.

3. The process of claim 1, further comprising:

(j) prior to performing step (g), pretreating the oxygen-rich effluent stream from the first reactor in an ozone destruct unit to decompose any unreacted ozone and produce an oxygen-rich stream.

4. The process of claim 3, wherein step (j) comprises pretreating the oxygen-rich effluent stream from the first reactor in an ozone destruct unit to decompose any unreacted ozone and produce an oxygen-rich stream having an oxygen concentration that is greater than or equal to 90 wt %.

5. The process of claim 1, wherein step (b) comprises introducing the compressed air feed stream into the air separation unit at a pressure greater than or equal to 2 bara (200 kPa) and less than or equal to 6 bara (600 kPa) to produce a purified oxygen stream.

6. The process of claim 1, wherein the purified oxygen stream introduced into the ozone generator has an oxygen concentration that is greater than or equal to 95 vol %.

7. The process of claim 1, wherein step (h) comprises introducing the compressed oxygen-rich stream into the second reactor at a pressure greater than or equal to 5 bara (500 kPa) and less than or equal to 40 bara (4,000 kPa).

8. The process of claim 1, wherein step (b) comprises introducing the compressed air stream into a cryogenic air separation unit to produce a purified oxygen stream.

9. The process of claim 1, wherein step (b) further comprises producing a nitrogen rich stream for use as a flotation or regeneration agent.

10. The process of claim 1, wherein step (c) comprises introducing the purified oxygen stream into an ozone generator to produce a resultant stream comprising oxygen and ozone at a rate that is greater than or equal to 300 tons/day.