Method for directly reducing a material by means of microwave radiation

Patent metadata

Field	Value
Publication number	US-12397277-B2
Application number	US-202117458213-A
Country	US
Kind code	B2
Filing date	Aug 26, 2021
Priority date	Feb 28, 2019
Publication date	Aug 26, 2025
Grant date	Aug 26, 2025

Abstract

The present invention relates to the reduction of materials at low temperatures (<600° C.) by means of microwave radiation without needing to use chemical reducing agents or electrical contacts. It relates more specifically to a method for reducing a material, which comprises the following steps:applying microwave radiation to a material disposed in a microwave application cavity; andseparating simultaneously the fluid oxidation products generated from the reduced material,such that the method is carried out without chemical reducing agents or electrical contacts.

First claim

The invention claimed is:

1. A process for the direct chemical reduction of a material, comprising the following steps:
applying microwave radiation to a material placed in a microwave applicator cavity,
heating to at least exceeding a shot temperature in the material, and
separating fluid oxidation products generated from the reduced material,
such that the process is carried out without using reducing chemical agents,
wherein:
the material is an inorganic material,
application of microwave radiation produces a temperature increase between 50-200° C. over the shot temperature, and
the shot temperature is a temperature at which electrical conductivity of the material is increased at least 4% within a 4° C. temperature increase with respect to the electrical conductivity of the material without reduction.

2. The process according to claim 1 , wherein the process is carried out without use of electrical contacts.

3. The process according to claim 1 wherein the steps are carried out in a container that has the ability to evacuate fluids.

4. The process according to claim 1 wherein the step of applying microwave radiation produces a temperature increase between 50-100° C.

5. The process according to claim 1 , wherein the material that is reduced is in one of a solid state, a melted state, a suspension in a liquid, or a solution in a liquid.

6. The process according to claim 5 , wherein the liquid is water or a hydrocarbon able to be in a liquid state at the conditions at which the process takes place.

7. The process according to claim 1 , wherein the separation of the fluid oxidation products generated from the reduced material is carried out by means of one of:
the application of vacuum,
the use of an entrainment fluid,
use of a reactive fluid that consumes the reduced material,
use of a selective separator of the generated oxidation product, or
a combination thereof.

8. The process according to claim 1 , further comprising a step of in-situ measurement of the conductivity of the material to be reduced by applying microwave radiation from a second source and an associated receiver without mutual inference.

9. The process according to claim 1 , wherein the material is a solid material, the composition of which comprises cerium oxide doped with gadolinium (CGO).

10. The process according to claim 1 , that further comprises the following steps:
placing the material in a container capable of evacuating fluids and inert to microwave radiation,
inserting the container through an orifice located in a wall of the applicator cavity in an area of uniform and an electric field as intense as possible for uniform and efficient heating,
identifying the “shot temperature” for that material,
carrying out, while the microwave radiation is applied, a continuous adjustment of the power applied for the radiation, and
separating the fluid oxidation products generated from the reduced material, wherein the process is carried out without the use of reducing chemical agents.

11. The process of claim 1 further comprising the steps of:
contacting the reduced material with a gaseous stream, and
selectively absorbing one or more components of the gaseous stream.

12. The process of claim 1 further comprising the steps of:
contacting the reduced material with a gaseous stream, and
selectively removing at least one of O 2 , F 2 , Cl 2 , Br 2 , HCl, HBr, HF, H 2 S or mixtures thereof from the gaseous stream.

13. The process of claim 1 further comprising the step of:
carrying out a reaction of the material in a reduced state and a second organic molecule which can be reduced.

14. The process of claim 1 further comprising:
generating a chemical product through the reaction of the material in a reduced state and a molecule selected from alkanes, alkenes, naphthenes and aromatic hydrocarbons.

15. The process of claim 1 further comprising the step of recharging batteries with the reduced material.

Assignees

• Univ Valencia Politecnica
• Consejo Superior Investigacion
• Consejo Superior Investigacion

Inventors

• Serra Alfaro José Manuel
• Catala Civera José Manuel
• García Baños Beatriz
• Borrás Morell Juan Francisco
• Navarrete Algaba Laura

Classifications

• H05B6/806

  for laboratory use · CPC title

• C01B3/061

  by reaction of water with metal oxides · CPC title

• B01J2219/1206

  Microwaves · CPC title

• C01B32/40

  Carbon monoxide · CPC title

• B01J2204/005

  the outlet side being of particular interest · CPC title