초록 ▼

Carbon dioxide is purified through the use of catalytic oxidation. Carbon dioxide is exposed to at least one catalyst, oxidizing at least a portion of the nonvolatile organic residues to form purified carbon dioxide that is directed to an application. Carbon dioxide that is in a near-critical, criti

Carbon dioxide is purified through the use of catalytic oxidation. Carbon dioxide is exposed to at least one catalyst, oxidizing at least a portion of the nonvolatile organic residues to form purified carbon dioxide that is directed to an application. Carbon dioxide that is in a near-critical, critical, or supercritical phase can be exposed to the catalyst.

대표청구항 ▼

1. A method for delivering purified carbon dioxide to an application, comprising the steps of:a) determining an acceptable level of nonvolatile organic residues in purified carbon dioxide, b) exposing carbon dioxide which is in a condition selected from the group of near-critical, critical and super

1. A method for delivering purified carbon dioxide to an application, comprising the steps of:a) determining an acceptable level of nonvolatile organic residues in purified carbon dioxide, b) exposing carbon dioxide which is in a condition selected from the group of near-critical, critical and supercritical, to at least one catalyst at a temperature controlled to produce the purified carbon dioxide, wherein said purified carbon dioxide has a concentration of less than 10 ppb of nonvolatile organic residues; and c) directing the purified carbon dioxide an application. 2. The method of claim 1, further including the step of mixing an oxidant with the carbon dioxide before exposing the carbon dioxide to the catalyst, wherein the oxidant is at least one of the group selected from oxygen, air, and oxygen enriched air.3. The method of claim 1, wherein the application is a semiconductor process.4. The method of claim 1, further including the step of heating the carbon dioxide before it is exposed to the catalyst.5. The method of claim 1, further including the step of cooling the purified carbon dioxide before it is directed to the application.6. The method of claim 5, wherein the purified carbon dioxide is in a liquid state when it is directed to the application.7. The method of claim 1, further including the step of pressurizing the purified carbon dioxide before it is directed to the application.8. The method of claim 1, further including the step of pressurizing the carbon dioxide before it is exposed to the catalyst.9. The method of claim 1, further including the step of directing the purified carbon dioxide to at least one purification unit before it is directed to the application, where said purification unit is selected from die group consisting of a filter, a coalescing filter, an adsorption bed, an absorption bed, a reactor, and a scrubbing unit.10. The method of claim 9, wherein the temperature of the purified carbon dioxide is selected to optimize the separation capability of the purification unit.11. The method of claim 1, further including the step of directing the carbon dioxide to at least one coalescing filter before it is exposed to at least one catalyst.12. The method of claim 1, further including the step of directing at least a portion of the purified carbon dioxide to at least one analyzer unit selected from the group consisting of a light-scattering analyzer and a single-particle counter.13. The method of claim 1, wherein the purified carbon dioxide contains less than 100,000 particles of nonvolatile organic residues, each with a diameter greater than 0.1 micron, per cubic foot when measured at normal temperature and pressure.14. The method of claim 1, wherein water is added to the carbon dioxide before it is exposed to the catalyst.15. The method of claim 1, further including the step of recycling at least a portion of the purified carbon dioxide used in the application and exposing the recycled portion to the catalyst.16. A method for purifying carbon dioxide, comprising the steps of:a) exposing carbon dioxide to at least one catalyst, wherein the carbon dioxide is in a condition selected from the group consisting of near-critical, critical, and supercritical; and b) oxidizing at least a portion of the contaminants, thereby forming purified carbon dioxide. 17. A The method of claim 16, further including the step of directing the purified carbon dioxide to an application.18. The method of claim 17, wherein the application is a semiconductor process.19. The method of claim 17, further including the step of mixing an oxidant with the carbon dioxide before exposing the carbon dioxide to the catalyst, wherein the oxidant is at least one of the group selected from oxygen, air, and oxygen enriched air.20. The method of claim 16, wherein the conditions of the carbon dioxide are modified to produce supercritical carbon dioxide before the carbon dioxide is exposed to the catalyst.21. The method of claim 16, further including the step of cooling the purified carbon dioxide after it is exposed to the catalyst.22. The method of claim 16, further including the step of directing the purified carbon dioxide to at least one purification unit selected from the group consisting of a filter, a coalescing filter, an adsorption bed, a distillation tower, an absorption/distillation unit, a reactor, a scrubbing unit, and an absorption bed.23. The method of claim 22, wherein the temperature of the purified carbon dioxide is selected to optimize the separation capability of the purification unit.24. The method of claim 16, further including the step of directing at least a portion of the purified carbon dioxide to at least one analyzer unit selected from the group consisting of a light-scattering analyzer and a single-particle particle counter.25. The method of claim 16, wherein the purified carbon dioxide contains less than 100,000 particles of nonvolatile organic residues, each with a diameter greater than 0.1 micron, per square foot when measured at normal temperature and pressure.26. The method of claim 16, further including the step of recycling at least a portion of the purified carbon dioxide and exposing it to the catalyst.27. A method for delivering purified carbon dioxide to an application, comprising the steps of:a) determining a minimum oxidation temperature, wherein exposing carbon dioxide which is in a condition selected from the group of near-critical, critical and supercritical, to a catalyst at that minimum oxidation temperature will result in a purified carbon dioxide having a concentration of less than 10 ppb nonvolatile organic residues b) exposing carbon dioxide in one of the said condition to the catalyst at the said temperature thereby producing purified carbon dioxide; and c) directing at least a portion of the purified carbon dioxide to an application.