Methods of making intermediate oxidation products by controlling pre-coalescing temperature and transient temperature difference in an atomized liquid

• US 5,801,282 A
• Filed: 06/07/1995
• Issued: 09/01/1998
• Est. Priority Date: 06/07/1995
• Status: Expired due to Fees

• Current Assignee: RPC Incorporated (Estate of R Randall Rollins)
• Original Assignee: Twenty-First Century Research Corporation
• Inventors: Vassiliou, Eustathios, Dassel, Mark William
• Primary Examiner(s): BARTS, SAMUEL A
• Application Number:
  US08/477,195
• Time in Patent Office: 1,182 Days
• Field of Search: 562/413, 562/512.4, 562/528, 562/538, 562/543, 562/529, 568/357, 568/358, 568/570, 568/836
• US Class Current: 562/413
• CPC Class Codes: B01J 10/002 carried out in foam, aerosol or bubbles
• CPC Class Codes: B01J 19/24 Stationary reactors without moving elements inside B01J19/08, B01J19/26 take precedence; with stationary particles B01J8/02
• CPC Class Codes: B01J 2219/00058 Temperature measurement
• CPC Class Codes: Y02P 20/582 Recycling of unreacted starting or intermediate materials

Abstract

Methods of making intermediate oxidation products by atomizing a first liquid (in the form of droplets) containing a reactant into a gas containing an oxidant in a manner to form an intermediate oxidation product different than carbon monoxide and/or carbon dioxide. The oxidation is controlled by monitoring the pre-coalescing temperature (temperature of the droplets just before they coalesce into a mass of liquid), or transient temperature difference (difference between the pre-coalescing temperature and the temperature of the droplets just before atomized), or transient conversion (conversion taking place in the time interval between the formation of the droplets and their coalescence into a mass of liquid) or a combination thereof.

Claims

1. A method of preparing an intermediate oxidation product from a first liquid containing a first reactant and a gas containing an oxidant, the method comprising the steps of:

atomizing the first liquid to form a plurality of droplets in the gas at an atomization temperature and at an atomization distance from a mass of a second liquid;

causing a substantially non-destructive oxidation at an oxidation pressure between the first reactant and the oxidant to form the intermediate oxidation product;

coalescing the droplets into the mass of the second liquid;

controlling a parameter or determinant selected from a group consisting of pre-coalescing temperature of the droplets, transient temperature difference of the droplets, and a combination thereof, to be within respective predetermined ranges, substantially immediately before said droplets coalesce into the second liquid; and

separating the intermediate oxidation product from the second liquid.

2. A method as defined in claim 1, wherein the droplets have an average droplet diameter and are produced at a desired first flow rate, the gas flows at a second flow rate, the droplets contain volatile ingredients volatilizing at a volatilization rate, the first liquid contains first reactant at a first content, the gas contains oxidant at a second content, and controlling of said parameter is performed by a step selected from a group consisting of

changing the atomization temperature,

changing the reaction pressure,

changing the atomization distance,

changing the average droplet diameter,

changing the first flow rate,

changing the second flow rate,

changing the volatilization rate,

changing the first content,

changing the second content, and

a combination thereof.

3. A method as defined in claim 1, further comprising a step of controlling transient conversion of the first reactant to intermediate oxidation product in the droplets to be within a predetermined pre-coalescing transient conversion range before the droplets are coalesced into the second liquid.

4. A method as defined in claim 3, wherein the transient conversion is monitored by a chromatographic method.

5. A method as defined in claim 1, wherein a major portion of the oxidation product is an organic compound.

6. A method as defined in claim 5, wherein the first reactant is an organic compound.

7. A method as defined in claim 6, wherein the oxidant is oxygen.

8. A method as defined in claim 7, wherein the major portion of the oxidation product is an intermediate oxidation product different than CO, CO₂ or a mixture thereof.

9. A method as defined in claim 8, wherein the major portion of the intermediate oxidation product is an organic acid.

10. A method as defined in claim 9, wherein the organic acid is adipic acid.

11. A method as defined in claim 10, wherein the predetermined pre-coalescing temperature range is 50°

to 150°

C.

12. A method as defined in claim 9, wherein the organic acid is terephthalic acid.

13. A method as defined in claim 12, wherein the predetermined pre-coalescing temperature range is 50°

to 250°

C.

14. A method as defined in claim 8, wherein the first reactant comprises a compound selected from a group consisting of cyclohexane, cyclohexanone, cyclohexanol, o-xylene, p-xylene, m-xylene, a mixture of at least two of cyclohexane, cyclohexanone, and cyclohexanol, and a mixture of at least two of o-xylene, p-xylene, and m-xylene.

15. A method as defined in claim 14, wherein the first reactant comprises a compound selected from a group consisting of cyclohexane, cyclohexanone, cyclohexanol, and a mixture thereof.

16. A method as defined in claim 8, wherein the first reactant comprises cyclohexane.

17. A method as defined in claim 8, wherein the first reactant comprises cyclohexanone.

18. A method as defined in claim 14, wherein the first reactant comprises a compound selected from a group consisting of o-xylene, p-xylene, m-xylene and a mixture thereof.

19. A method as defined in claim 8, wherein the first reactant comprises p-xylene.

20. A method as defined in claim 3, wherein

the first reactant comprises a compound selected from the group consisting of cyclohexane, cyclohexanone, cyclohexanol, o-xylene, m-xylene, p-xylene, and a mixture thereof;

the oxidant comprises oxygen; and

a major portion of the intermediate oxidation product comprises a compound selected from a group consisting of adipic acid, cyclohexanol, cyclohexanone, cyclohexylhydroperoxide, phthalic acid, isophthalic acid, terephthalic acid, a mixture of at least two of cyclohexane, cyclohexanone, cyclohexanol, and cyclohexylhydroperoxide, and a mixture of at least two of phthalic acid, isophthalic acid, and terephthalic acid.

21. A method as defined in claim 1, wherein the step of atomizing is performed by spraying the first liquid from a point over the second liquid at the atomization distance.

22. A method as defined in claim 21, wherein spraying is performed by an airless technique.

23. A method as defined in claim 1, wherein at least part of the second liquid is recirculated.

24. A method as defined in claim 23, wherein a third liquid containing first reactant is also added to the first liquid to replenish first reactant consumed during the substantially non-destructive oxidation.

25. A method as defined in claim 24, wherein the intermediate oxidation product is a solid, and the step of separating said intermediate oxidation product from the second liquid includes a step of filtering the intermediate oxidation product out of the second liquid.

26. A method as defined in claim 1, wherein an adequate amount of antistatic compound is added to a component selected from a group consisting of the first liquid, the gas, and a combination thereof, in order to prevent development of electrostatic charges and sparking.

27. A method as defined in claim 26, wherein the antistatic compound comprises water.

28. A method as defined in claim 1, further comprising a step of internally condensing condensible substantially under reaction pressure.

29. A method as defined in claim 1, wherein the non-destructive oxidation is conducted in a reaction zone surrounded by a thick film or curtain of liquid.

30. A method as defined in claim 14, wherein the non-destructive oxidation is conducted in a reaction zone surrounded by a thick film or curtain of liquid.

31. A method as defined in claim 1, further comprising a step of adding a catalyst to the first liquid, the catalyst comprising metal ions, the ions being able to exist at a state selected from a group consisting of a lower valance state, a higher valance state, and a mixture thereof, the catalyst having been formed by steps of

atomizing a solution comprising metal ions of the lower valance state to form a plurality of droplets in a gas containing an oxidant;

causing at least partial oxidation of the lower valance state ions to ions of higher valance state in the solution.

32. A method as defined in claim 14, further comprising a step of adding a catalyst to the first liquid, the catalyst having been formed by steps of

atomizing a solution comprising bivalent cobalt ions to form a plurality of droplets in a gas containing an oxidant;

causing at least partial oxidation of the bivalent cobalt ion to trivalent cobalt ion.

33. A method as defined in claim 1, wherein at least one of pre-coalescing temperature, transient temperature difference, and transient conversion is controlled by changing the level of catalyst in the first liquid.