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EP-4247535-B1 - THERMAL REACTOR COMPRISING A GAS PERMEABLE CAGE ARRANGED TO INFLUENCE A FLOW PATH OF GAS

EP4247535B1EP 4247535 B1EP4247535 B1EP 4247535B1EP-4247535-B1

Inventors

  • FORSBERG, Gustaf
  • BAELING, PETER
  • ANDERSSON, RONNIE

Dates

Publication Date
20260513
Application Date
20211122

Claims (13)

  1. A plasma reactor (100) comprising: a vessel (101), said vessel comprising: a gas inlet (102), a gas permeable cage (104) arranged in the vessel (101), and in fluid connection to the gas inlet (102), wherein the vessel (101) and the cage (104) are provided with a mutual gas outlet (103), and plasma generating means (105;105') arranged to create a plasma zone (106) within the cage (104), wherein the cage (104) is provided with holes (107), and wherein a first subset of the holes (107') is arranged along at least a portion of a first circumferential surface (110) of the cage (104) and a second subset of the holes (107") is arranged along at least a portion of a second circumferential surface (111) of the cage (104), wherein the first (110) and second (111) circumferential surfaces are offset and non-parallel, and the first subset of holes (107') and the second subset of holes (107") are mutually distinct, and wherein the cage (104) is spaced from the walls of the vessel (101).
  2. The plasma reactor according to claim 1, wherein the vessel (101) is a pressurized vessel arranged to operate at different pressure than atmospheric pressure, preferably a pressure being higher than atmospheric pressure.
  3. The plasama reactor according to any one of claims 1-2, wherein the vessel (101) further comprises cooling means (108).
  4. The plasma reactor according to claim 3, wherein the cooling means (108) are arranged in the outlet (103) or in direct connection to the outlet (103).
  5. The plasma reactor according to any one of claims 1-4, wherein the cage (104) is a metal cage.
  6. The plasma reactor according to any one of claims 1-4, wherein the cage (104) is a ceramic cage.
  7. The plasma reactor according to any one of claims 1-4, wherein the cage (104) is made of a non-metallic conductive material, such as graphene or reduced graphene oxide or graphene-metal composites.
  8. The plasma reactor according to any one of claims 1-7, wherein the temperature generating means (105; 105') are electrodes.
  9. The plasma reactor according to any one of claims 1-7, wherein the temperature generating means (105; 105') are antennas.
  10. The plasma reactor according to any one of the preceding claims, wherein the plasma reaction zone (106) is produced using electromagnetic waves of radio frequency or microwaves.
  11. The plasma reactor according to any one of the preceding claims, wherein the cage (104) has a central longitudinal axis around which the cage (104) is symmetrical.
  12. The plasma reactor according to any of the preceding claims, wherein the gas permeable cage (104) is a first gas permeable cage (104-1) and the plasma reactor further comprises: a second gas permeable cage (104-2), wherein the holes (107) of the first gas permeable cage (104-1) are first holes (107-1), and the second gas permeable cage (104-2) is provided second holes (107-2), wherein the second gas permeable cage (104-2) is smaller than the first gas permeable cage (104-1), so that the second gas permeable cage (104-2) is arranged inside the first gas permeable cage (104-1).
  13. The plasma reactor according to claim 12, wherein the first and second holes (107-1, 107-2) of the first and second gas permeable cages (104-1, 104-2) are arranged offset so that the first and second holes (107-1, 107-2) are not aligned.

Description

TECHNICAL FIELD The present disclosure relates to the field of reaction chambers and in particular to thermal reaction chambers for gaseous thermal reactions. BACKGROUND Thermal reactors, such as plasma reactors, are used to react gases into forming different compounds in various fields, such as fuel conversion and removal of pollutants from gas streams. A discharge or excitation by electromagnetic waves, such as radiofrequency or microwaves, of high intensity is applied to a fluid containing the substances to be treated causing decomposition, and possibly recombination, of substances. There are different demands on the thermal reactor depending on the type of thermal reactions or plasma that can vary in both temperature and intensity. Consequently, different reactor chamber designs for these reactions exist today, such as tubular reactors allowing the fluid to pass through the plasma arranged in the middle of the tube. One plasma reactor is presented in US2003/0024806 A1 wherein a plasma is combined with comminution means to provide for enhanced angular momentum within the chemical reactor. Another plasma reactor is known from WO 00/71866 A1. US 2018/243713 A1 describes a thermal reactor with a vessel and a cage arranged inside the vessel. High temperature thermal reactions such as plasmas are energy demanding and in order to ensure satisfactory reaction yield in combination with energy efficiency there are improvements to be made over prior art. SUMMARY The present disclosure aims to provide a thermal reactor with satisfactory reaction yield in combination with energy efficiency. The inventors have realized that such a reactor should overcome the majority, preferably all, of the following problems: a) that the reacting gas is diluted when cold gas is mixed into the hot gas causing a non-uniformity and inefficiency of the reactionb) convection of hot gas from the reaction area and heat irradiation from the reaction area giving rise to high temperatures on the surface of the reaction chamber wall, that i) can be detrimental to the solid materials of the reactor wall, particularly for applications made at other pressures than the atmospheric pressure which is challenging for the mechanic stability of the reactor vessel, and that ii) can lead to undesirable heat leakage.c) sub-optimal residence time distribution. As a consequence, there is a risk that there will not be enough time for the aimed reaction to take place throughout the fluid, or reversely that the reaction chamber needs excessive dimensions in order to avoid such insufficient residence time.d) by-pass of unreacted gas beside the reaction zone, leading to undesired dilution of the reaction products and a waste of heat to unreacted gas. Accordingly, the present disclosure provides the following aspects and embodiments: The invention is defined in claim 1 as a thermal reactor (100) comprising: a vessel (101), said vessel comprising: a gas inlet (102),an outlet (103),a gas permeable cage (104) arranged in the vessel (101), and in fluid connection to the gas inlet (102), wherein the vessel (101) and the cage (104) are provided with a mutual gas outlet (103), andtemperature generating means (105;105') arranged to create a thermal reaction zone (106) within the cage (104),wherein the cage (104) is provided with holes (107), andwherein a first subset of the holes (107') is arranged along at least a portion of a first circumferential surface (110) of the cage (104) and a second subset of the holes (107") is arranged along at least a portion of a second circumferential surface (111) of the cage (104),wherein the first (110) and second (111) circumferential surfaces are offset and non-parallel,and the first subset of holes (107') and the second subset of holes (107") are mutually distinct, andwherein the cage (104) is spaced from the walls of the vessel (101),wherein the thermal reactor is a plasma reactor (100), the thermal reaction zone is a plasma zone (106) and the temperature generating means (105;105') are plasma generating means (105;105'). In one embodiment, the vessel (101) is a pressurized vessel arranged to operate at different pressure than atmospheric pressure, preferably a pressure being higher than atmospheric pressure. In one embodiment, the vessel (101) further comprises cooling means (108). In one embodiment, the cooling means (108) are arranged in the outlet (103) or in direct connection to the outlet (103). In one embodiment, the cage (104) is porous. In one embodiment, the cage (104) is a metal cage. In one embodiment, the cage (104) is a ceramic cage. In one embodiment, the cage (104) is made of a non-metallic conductive material, such as graphene or reduced graphene oxide or graphene-metal composites. In one embodiment, the temperature generating means (105; 105') are electrodes. In one embodiment, the temperature generating means (105; 105') are antennas. In one embodiment,the thermal reaction zone (106) is produced using electromagn