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US 12,604,388 B2Granted
Systems and methods for nonequilibrium plasmas
AssigneeWashington University
InventorsElijah Thimsen, Colin Page, Xinhua Liang
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Abstract
Described herein are systems and methods for nonequilibrium plasmas. In particular, described herein are methods to achieve sustained operation of plasma reactors contained in electrically insulating tubes, high power radiofrequency plasma devices using capacitively coupled electrodes, and methods to produce a carbonaceous compound and hydrogen using a nonequilibrium plasma device.
Claims14
A method of operating a plasma reactor, comprising:
- providing the plasma reactor, the plasma reactor comprising:
- at least one dielectric tube defining at least one lumen;
- at least one electrode positioned adjacent to the dielectric tube, the at least one electrode configured to produce a high voltage and high energy signal alternating at a frequency ranging from about 0.1 MHz to about 10,000 MHZ, wherein the high voltage and high energy signal is delivered to at least one plasma region within at least one lumen of the at least one dielectric tube;
- a hydrogen gas source operatively coupled to the at least one dielectric tube, the hydrogen gas source configured to introduce gaseous hydrogen at a predetermined constant rate to the at least one plasma region;
- and
- a carbon gas source operatively coupled to the at least one dielectric tube, the carbon gas source configured to introduce a carbon-containing gas to the at least one plasma region at a controllable flow rate ranging between essentially zero rate and a predetermined setpoint rate;
- and
- introducing the gaseous hydrogen to the at least one plasma region at the predetermined constant rate and introducing the carbon-containing gas to the at least one plasma region in an alternating pattern of essentially zero flow rate for a plasma region cleaning interval and the predetermined setpoint rate for a product synthesis interval, wherein a molar ratio of H2:C of a gas mixture within the at least one plasma region is less than about 10:1 during the product synthesis interval.
5 more elements
A plasma reactor, comprising:
- at least one dielectric tube defining at least one lumen;
- at least one electrode positioned adjacent to the at least one dielectric tube, the at least one electrode configured to produce a high voltage and high energy signal alternating at a frequency ranging from about 0.1 MHz to about 10,000 MHZ, wherein the high voltage and high energy signal is delivered to at least one plasma region within at least one lumen of the at least one dielectric tube;
- a hydrogen gas source operatively coupled to the at least one dielectric tube, the hydrogen gas source configured to introduce gaseous hydrogen at a predetermined constant rate to the at least one plasma region;
- and
- a carbon gas source operatively coupled to the at least one dielectric tube, the carbon gas source configured to introduce a carbon-containing gas to the at least one plasma region in an alternating pattern of essentially zero flow rate for a plasma region cleaning interval and at a predetermined setpoint rate for a product synthesis interval, wherein a molar ratio of H2:C of a gas mixture within the at least one plasma region is less than about 10:1 during the product synthesis interval.
2 more elements
A method of producing hydrogen (H2) and a product compound by nonequilibrium plasma synthesis, the method comprising:
- introducing methane (CH4) and nitrogen (N2) into a nonequilibrium plasma reactor at a CH4:N2 molar ratio of about 3:0.75 to produce a mixture of acetylene (C2H2), hydrogen cyanide (HCN) and hydrogen (H2) at a C2H2:HCN:H2 molar ratio of about 1:1:4.5;
- introducing the mixture of acetylene (C2H2), hydrogen cyanide (HCN), and hydrogen (H2) into a thermocatalytic reactor configured to cause the mixture to react in the presence of a catalyst to produce a second mixture comprising hydrogen (H2) and the product compound;
- introducing the second mixture into a separation device to separate the hydrogen (H2) from the product compound;
- and
- introducing the gaseous hydrogen to the at least one plasma region at the predetermined constant rate and introducing the carbon-containing gas to the at least one plasma region in an alternating pattern of essentially zero flow rate for a plasma region cleaning interval and the predetermined setpoint rate for a product synthesis interval, wherein a molar ratio of H2:C of a gas mixture within the at least one plasma region is less than about 10:1 during the product synthesis interval.
2 more elements
Dependencies are inferred from the claim text.