Method For Directly Reducing A Material By Means Of Microwave Radiation

Patent metadata

Field	Value
Publication number	US-2022016595-A1
Application number	US-202117458213-A
Country	US
Kind code	A1
Filing date	Aug 26, 2021
Priority date	Feb 28, 2019
Publication date	Jan 20, 2022
Grant date	—

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; and separating 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

1 . A process for the 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, and wherein 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 50-200° 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 at least a cation of an element selected from among Ti, Fe, Co, Zr, Cr, Nb, Ta, W, Mo, rare earths and U.

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 MW 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 the reduced state, wherein an oxidized molecule, after its reduction, generates said chemical product.

14 . The process of claim 13 , wherein:
the oxidized molecule is CO 2 and the desired product is CO or the desired product is selected between H 2 O and H 2 S and the desired product is H 2 , or
the oxidized molecule is a mixture of gases containing H 2 O y CO 2 and the desired product are hydrocarbons.

15 . 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, to form products with new functional groups.

16 . 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, to form products with new functionalities.

17 . The process of claim 1 further comprising the step of storing energy in the reduced material.

18 . The process of claim 1 further comprising the step of simultaneously evacuating the oxidation product and selectively reducing the material comprised in the negative electrode.

19 . A reduced material obtained through the process defined in claim 1 .

20 . An apparatus for reduction of a material, wherein the reduction of material includes 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, and wherein the process is carried out without using reducing chemical agents, the material is an inorganic material, 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; the apparatus comprising:
at least one microwave radiation source,
a microwave applicator cavity,
a container in which the material to be reduced is deposited, and
a second source of microwave radiation for in-situ conductivity measurements and without interference with the first radiation source.

21 . The apparatus of claim 20 further comprising:
at least one temperature sensor to measure the temperature of the material during microwave application, and
at least one means for evacuation of fluids originated during the reduction process.

22 . The apparatus of claim 20 , wherein the microwave radiation source for irradiation is selected from a magnetron-based microwave generator and a microwave generator based on a solid state amplifier.

23 . The apparatus of claim 20 wherein the microwave radiation source has means to operate at frequencies between 300 MHz and 300 GHz.

24 . The apparatus of claim 20 , wherein the applicator cavity is a microwave resonator.

25 . The apparatus of claim 20 , wherein the microwave radiation is introduced into the applicator cavity through a waveguide, or through a coupling or opening based on an electrical probe or a magnetic probe.

26 . The apparatus of claim 20 , wherein the applicator cavity has at least one non-radiating orifice located on the upper wall and a second non-radiating orifice located on the bottom wall, which allow the passage of substances.

27 . The apparatus of claim 20 , wherein the non-radiating orifices located on the upper wall and bottom wall allow the introduction and evacuation of gases.

28 . The apparatus of claim 20 , further comprising means of evacuating fluids originated during the reduction process.

Assignees

• Univ Valencia Politecnica
• Consejo Superior Investigacion

Inventors

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

Classifications

• Y02P20/133

  Renewable energy sources, e.g. sunlight · CPC title

• Y02E60/36

  Hydrogen production from non-carbon containing sources, e.g. by water electrolysis · CPC title

• C02F1/70

  by reduction {(C02F1/4676 takes precedence)} · CPC title

• B01J19/126 Primary

  Microwaves · CPC title

• H05B6/806

  for laboratory use · CPC title