Method and reactor for processing a gas
A plasma processing method for a gas includes: supplying a gas inside a cavity for plasma processing, supplying microwaves having a predetermined frequency and power in order to generate a plasma of the gas, and propagating the microwaves in the gas by a waveguide which communicates directly with the cavity so as to provide a plasma cracking processing operation for the gas inside the cavity.
1 . A plasma processing method for a gas, the method comprising:
supplying a gas inside a cavity for plasma processing,
supplying microwaves having a predetermined frequency and power in order to generate a plasma of the gas,
propagating the microwaves in the gas by means of a waveguide which communicates directly with the cavity so as to provide a plasma cracking processing operation for the gas inside the cavity, the internal volume with respect to the cavity and the waveguide not having any discontinuities,
receiving the gas and the microwaves from the waveguide in a processing pipe of the cavity,
conveying the gas and the microwaves inside an electromagnetic resonator which is arranged along the processing pipe, the electromagnetic resonator being in the form of a widening of the processing pipe and concentrating the microwaves so as to generate a plasma of the gas inside the electromagnetic resonator, wherein the electromagnetic resonator is arranged along the processing pipe downstream of the waveguide in relation to a direction of flow of the gas and propagation of the microwaves by the waveguide towards the processing pipe.
2 . The method according to claim 1 , further comprising receiving the gas and the microwaves in the electromagnetic resonator only after the gas and the microwaves have been discharged from the waveguide.
3 . The method according to claim 1 , wherein the microwaves propagate from the waveguide to the cavity through the gas without encountering any obstacle.
4 . The method according to claim 1 , wherein the generation of the plasma inside the cavity is fed by the gas without adding any additional gas being introduced into the cavity intended to sustain the generation of the plasma inside the cavity, and wherein the gas comprises a pyrolysis gas.
5 . The method according to claim 1 , wherein the plasma cracking is carried out at atmospheric pressure.
6 . A plasma-chemical reactor for carrying out the plasma processing method for a gas according to claim 1 , the plasma-chemical reactor comprising
a plasma processing cavity which is configured to receive the gas inside the cavity,
an electromagnetic wave source which is configured to supply microwaves having a predetermined frequency and power in order to generate a plasma of the gas inside the cavity,
a waveguide which communicates directly with the cavity, the internal volume with respect to the cavity and the waveguide not having discontinuities, the waveguide being configured to receive the microwaves from the electromagnetic wave source and to propagate the microwaves in a guided manner in the cavity through the gas so as to provide a plasma cracking processing operation for the gas inside the cavity, the cavity comprising an inlet pipe which is configured to convey the gas towards the waveguide and a processing pipe which is configured to receive the gas and the microwaves from the waveguide so as to provide the plasma cracking processing operation for the gas inside the processing pipe and
an electromagnetic resonator which is arranged along the processing pipe, the electromagnetic resonator being configured to receive the gas and the microwaves along the processing pipe and to concentrate the microwaves inside the electromagnetic resonator so as to generate a plasma of the gas passing through the electromagnetic resonator, the electromagnetic resonator being in the form of a widening of the processing pipe, wherein the electromagnetic resonator is arranged along the processing pipe downstream of the waveguide in relation to a direction of flow of the gas and propagation of the microwaves by the waveguide towards the processing pipe.
7 . The plasma-chemical reactor according to claim 6 , wherein the electromagnetic resonator along the processing pipe is spaced apart from the waveguide by a first distance and the processing pipe has a first diameter, the first distance being greater than the first diameter, and being between two and ten times the first diameter.
8 . The plasma-chemical reactor according to claim 7 , wherein the electromagnetic resonator extends along the longitudinal extent of the processing pipe over a second distance which is less than the first distance, the first distance being between two and ten times the second distance.
9 . The plasma-chemical reactor according to claim 6 , wherein the waveguide has a hollow linear structure which extends along a first axis, the hollow linear structure of the waveguide having a rectangular cross-section.
10 . The plasma-chemical reactor according to claim 6 , wherein the waveguide has a hollow linear structure which extends along a first axis and the cavity and/or the inlet pipe and/or the processing pipe have a hollow linear structure which extends along a second axis, the second axis being perpendicular to the first axis.
11 . The plasma-chemical reactor according to claim 10 , wherein the hollow linear structure of the cavity and/or the inlet pipe and/or the processing pipe having has a circular cross-section.
12 . The plasma-chemical reactor according to claim 10 , wherein the linear structure of the waveguide extends along the first axis over a first length and along the second axis over a second length, the first length being from three to ten times the second length.
13 . The plasma-chemical reactor according to claim 12 , wherein the first length is from six to seven times the second length.
14 . The plasma-chemical reactor according to claim 12 , wherein the cross-section of the waveguide extends in a direction perpendicular to the plane defined by the first axis and the second axis over a third length, the second length being from one to two thirds of the third length.
15 . The plasma-chemical reactor according to claim 6 , wherein the electromagnetic resonator has a hollow cylindrical structure which extends along the second axis of the processing pipe, the hollow cylindrical structure having a cross-section greater than a cross-section of the processing pipe, and wherein the processing pipe has a first diameter, and the electromagnetic resonator has a second diameter greater than the first diameter.
16 . The plasma-chemical reactor according to claim 6 , wherein the electromagnetic resonator has a second diameter and extends along the longitudinal extent of the processing pipe over a second distance less than or approximately equal to the second diameter.
17 . The plasma-chemical reactor according to claim 6 , wherein the electromagnetic resonator does not have moving parts.
18 . An installation for pyrolysis and/or gasification of biomass, comprising a pyrolyzer and/or gasifier which is configured to supply a pyrolysis gas which is generated by the pyrolysis and/or gasification of the biomass and furthermore the reactor according to claim 6 , wherein the reactor is configured to receive the pyrolysis gas and to provide a plasma cracking processing operation for the pyrolysis gas.