Method of performing a chemical reaction

• US 6,747,178 B1
• Filed: 10/02/2000
• Issued: 06/08/2004
• Est. Priority Date: 11/05/1997
• Status: Expired due to Fees

• Current Assignee: Nuclear Decommissioning Authority
• Original Assignee: British Nuclear Technology
• Inventors: Atherton, Malcolm John, Harston, Paul, Holmes, Robert G., Spink, Robert, Chambers, Richard Dickinson
• Primary Examiner(s): Carr, Deborah D.
• Application Number:
  US09/530,231
• Time in Patent Office: 1,345 Days
• Field of Search: 570/175
• US Class Current: 570/175
• CPC Class Codes: B01J 19/0093 Microreactors, e.g. miniaturised or microfabricated reactors laboratory containers with capillary fluid transport in microfabricated channels or chambers B01L3/5027
• CPC Class Codes: B01J 2219/00822 Metal
• CPC Class Codes: B01J 2219/00833 Plastic
• CPC Class Codes: B01J 2219/00835 Comprising catalytically active material
• CPC Class Codes: B01J 2219/00873 Heat exchange
• CPC Class Codes: B01J 2219/00889 Mixing
• CPC Class Codes: B01J 2219/0093 Electric or magnetic energy
• CPC Class Codes: C07B 39/00 Halogenation
• CPC Class Codes: C07C 17/04 to unsaturated halogenated hydrocarbons
• CPC Class Codes: C07C 22/00 Cyclic compounds containing halogen atoms bound to an acyclic carbon atom
• CPC Class Codes: C07C 381/00 Compounds containing carbon and sulfur and having functional groups not covered by groups C07C301/00 - C07C337/00
• CPC Class Codes: C07C 45/46 Friedel-Crafts reactions
• CPC Class Codes: C07C 51/62 by reactions not involving the carboxylic acid halide group
• CPC Class Codes: C07C 55/40 containing halogen outside the carboxyl halide group
• CPC Class Codes: C07C 67/307 by introduction of halogen; by substitution of halogen atoms by other halogen atoms
• CPC Class Codes: C07C 69/716 Esters of keto-carboxylic acids or aldehydo-carboxylic acids

Abstract

According to the present invention there is provided a method of carrying out a chemical reaction between at least two fluids, the method comprising providing respective flow paths for the at least two fluids, said flow paths communicating with each other in a region in which the at least two fluids may contact each other, and flowing the at least two fluids along said flow paths such that in said region the at least two fluids contact each other and a chemical reaction occurs between them, said region having a width perpendicular to the direction of flow in the range 10-10,000 micrometers. It has been found that using a so-called “microreactor”, that is a reactor having dimensions perpendicular to the flow direction of less than 10,000 micrometers, according to the present method, improved control over a fluid chemical reaction can be achieved, which can result in significant improvements in reaction product yield and/or purity, as well as other benefits. The present method has been found to be particularly beneficial for fluorination reactions.

Claims

1. A method of carrying out a reaction between at least two miscible fluids, one of the at least two miscible fluids comprising a compound to be fluorinated and another of the at least two fluids comprising a fluorinating agent, the method comprising providing respective flow paths for the at least two miscible fluids, said flow paths communicating with each other, and flowing the at least two miscible fluids along said flow paths such that in said region the at least two miscible fluids contact each other and a chemical reaction between said at least two miscible fluids occurs, said region having a width perpendicular to the direction of flow in the range of 10-10,000 micrometers.

2. A method according to claim 1 and wherein the width is in the range 10-500 micrometers.

3. A method according to claim 2 and wherein the width is in the range 10-200 micrometers.

4. A method of carrying out a fluorination reaction, as in claim 1 and wherein the at least two miscible fluids are each independently a liquid, a gas, or a supercritical fluid.

5. A method according to claim 1 and wherein energy is supplied to said region from an external source.

6. A method according to claim 5 and wherein the energy is at least one of heat, light and electrical energy.

7. A method according to claim 5 and wherein the energy is supplied to initiate the reaction.

8. A method according to claim 1 and wherein cooling is applied to said region.

9. A method according to claim 1 and wherein the reaction is quenched before it reaches completion and an intermediate product is isolated.

10. A method according to claim 1 and wherein a solid catalyst is located at or near said region.

11. A method according to claim 1 and wherein at least one of the least two miscible fluids is hazardous or explosive.

12. A method according to claim 1 and wherein the fluorinating agent is fluorine gas.

13. A method according to claim 1 wherein said region includes essentially the whole or the flow paths of one of the fluids.

14. A method according to claim 13 wherein the arrangement is such that in said region one of said fluids substantially surrounds the or another of said fluids transversely to the direction of fluid flow.

15. A method according to claim 1 wherein said region has a width between 0.75 mm and 0.1 mm.

16. A method according to claim 15 wherein said width is between 0.5 mm and 0.2 mm.

17. A method according to claim 1 wherein said region has a length between 150 mm and 20 mm.

18. A method according to claim 17 wherein said length is between 100 mm and 40 mm.

19. A method according to claim 18 wherein the ratio of length to width of said region is between 200 and 80.

20. A method according to claim 1 wherein the temperature in said region is from 25°

C. to −

10°

C.

21. A method according to claim 1 wherein the fluids are fed from said region into tubing having a length between 0.05 m and 120 m.

22. A method according to claim 21 when said tubing has a length between 0.1 m and 0.5 m.

23. A method according to claim 21 wherein the temperature within said tubing is maintained between 100°

C. and 200°

C.

24. A method of carrying out a fluorination reaction between at least two fluids that are miscible, and wherein a multiplicity of flow paths as in claim 1 are employed thereby forming a multiplicity of regions in which the chemical reaction occurs.