Gas production system and gas production method

Patent metadata

Field	Value
Publication number	US-11987498-B2
Application number	US-201917432532-A
Country	US
Kind code	B2
Filing date	Apr 23, 2019
Priority date	Apr 23, 2019
Publication date	May 21, 2024
Grant date	May 21, 2024

Abstract

This gas production system includes: a gas production device having a reactor forming a flow path for a treatment target gas, a first electrode and a second electrode to which voltage is applied, and a catalyst layer provided in the flow path and containing a catalyst; voltage generation means for generating voltage to be applied to the first electrode and the second electrode; and gas supply means for supplying the treatment target gas to the gas production device. The voltage generation means has frequency setting means for setting the frequency of the voltage in accordance with the treatment target gas, plasma generated between the first electrode and the second electrode is applied to the catalyst layer, and the treatment target gas is reformed to obtain a product gas.

First claim

The invention claimed is:

1. A gas production system which applies plasma to a catalyst and reforms a selected treatment target gas from among a plurality of treatment target gases to produce a product gas, the gas production system comprising:
voltage generation circuitry for generating voltage;
plasma generation circuitry for generating the plasma to be applied to the catalyst, using the voltage generated by the voltage generation circuitry;
frequency setting circuitry for changing and setting a frequency of the voltage used to generate the plasma, based on the selected treatment target gas, to vibrationally excite molecules of gas reactive material constituting the selected treatment target gas to produce the product gas;
a depressurizer to reduce a pressure in a reactor; and
a heat source to heat the catalyst, the heat source being different from the plasma generation circuitry and the plasma, wherein
the selected treatment target gas is a hydrocarbon-based gas and an oxidant gas, and the product gas is a hydrogen containing gas,
the frequency setting circuitry is configured to change and set the frequency of the voltage that is generated by an external power supply, based on the selected treatment target gas, in a range not less than 10 kHz and not greater than 1 MHz, and
the depressurizer sets the pressure in the reactor in accordance with the frequency of the voltage that is generated by the external power supply based on the treatment target gas.

2. The gas production system according to claim 1 , further comprising:
a gas producer having a reactor forming a flow path for the selected treatment target gas, a first electrode and a second electrode to which the voltage generated by the voltage generation circuitry is applied, and the catalyst layer in the flow path between the first electrode and the second electrode and containing the catalyst; and
a gas supply to supply the selected treatment target gas to the gas producer, wherein
the voltage generation circuitry is the external power supply connected to the first electrode and the second electrode, and
the frequency setting circuitry sets the frequency of the voltage that is generated by the external power supply, based on the selected treatment target gas, and the plasma is generated between the first electrode and the second electrode based on the voltage changed and set based on the selected treatment target gas.

3. The gas production system according to claim 2 , wherein the second electrode and the reactor have cylindrical shapes, an outer circumference of the reactor is coated with the second electrode, and the first electrode is on a center axis of the reactor.

4. The gas production system according to claim 2 , wherein the reactor is made from a dielectric material.

5. The gas production system according to claim 1 , wherein the depressurizer sets a pressure in a catalyst layer in a range not less than 1 Pa and not greater than 100 kPa.

6. The gas production system according to claim 2 , further comprising boosting circuitry for further boosting the voltage that is generated by the external power supply.

7. The gas production system according to claim 1 , wherein the oxidant gas is one gas or a mixed gas of two or more gases, selected from water vapor, carbon dioxide gas, and oxygen gas.

8. The gas production system according to claim 1 , wherein the catalyst includes one element or two or more elements, selected from a transition metal group.

9. The gas production system according to claim 1 , wherein the heat source is low-temperature exhaust heat, and heats the catalyst through heat exchange with the low-temperature exhaust heat.

10. A gas production method in which plasma is applied to a catalyst layer containing a catalyst and a treatment target gas is reformed to produce a product gas, the gas production method comprising:
heating, using a heater, the catalyst layer,
supplying the treatment target gas to the catalyst layer;
generating voltage to generate the plasma;
generating, using plasma generation circuitry, the plasma using the generated voltage, and applying the plasma to the catalyst layer;
setting, using frequency setting circuitry, a frequency of the voltage used to generate the plasma, based on the treatment target gas, to vibrationally excite molecules of gas reactive material constituting the treatment target gas;
reforming the treatment target gas and producing the product gas; and
setting pressure associated with the catalyst layer using a depressurizer, said setting the pressure including the depressurizer reducing a pressure in the catalyst layer, wherein
the selected treatment target gas is a hydrocarbon-based gas and an oxidant gas, and the product gas is a hydrogen containing gas, and
the frequency setting circuitry is configured to change and set the frequency of the voltage that is generated by an external power supply, based on the selected treatment target gas, in a range not less than 10 kHz and not greater than 1 MHz,
the heater is different from the plasma generation circuitry and the plasma, and
said setting the pressure associated with the catalyst layer is in accordance with the frequency of the voltage that is generated by the external power supply based on the treatment target gas.

11. The gas production method according to claim 10 , wherein said reducing the pressure in the catalyst layer is performed before said supplying the treatment target gas to the catalyst.

12. A gas production system which applies plasma to a catalyst and reforms a selected treatment target gas from among a plurality of treatment target gases to produce a product gas, the gas production system comprising:
voltage generation circuitry for generating voltage;
plasma generation circuitry for generating the plasma to be applied to the catalyst, using the voltage generated by the voltage generation circuitry;
frequency setting circuitry for changing and setting a frequency of the voltage used to generate the plasma, based on the selected target treatment gas, to vibrationally excite molecules of gas reactive material constituting the selected treatment target gas to produce the product gas;
a depressurizer to reduce a pressure in the reactor; and
a heat source to heat the catalyst, the heat source being different from the plasma generation circuitry and the plasma, wherein
the catalyst includes one element or two or more elements, selected from a transition metal group,
the frequency setting circuitry is configured to change and set the frequency of the voltage that is generated by an external power supply, based on the selected treatment target gas, in a range not less than 10 kHz and not greater than 1 MHz, and
the depressurizer sets the pressure in the reactor in accordance with the frequency of the voltage that is generated by the external power supply based on the treatment target gas.

13. A gas production system which applies plasma to a catalyst and reforms a selected treatment target gas from among a plurality of treatment target gases to produce a product gas, the gas production system comprising:
voltage generation circuitry for generating voltage;
plasma generation circuitry for generating the plasma to be applied to the catalyst, using the voltage generated by the voltage generation circuitry;
frequency setting circuitry for changing and setting a frequency of the voltage used to generate the plasma, based on the selected treatment target gas, to vibrationally excite molecules of gas reactive material constituting the selected treatment target gas to produce the product gas;
a heat source to heat the catalyst, the heat source being

Assignees

• Mitsubishi Electric Corp
• Tokyo Inst Tech

Inventors

• Aketagawa Kyohei
• Hirashiki Isamu
• Nozaki Tomohiro
• SAKATA Kenta

Classifications

• C01B3/26 Primary

  using catalysts · CPC title

• C01B3/342

  with the aid of electrical means, electromagnetic or mechanical vibrations, or particle radiations · CPC title

• C01B2203/0861

  by plasma · CPC title

• C01B2203/16

  Controlling the process · CPC title

• C01B3/38 Primary

  using catalysts · CPC title