Patent Description:
Several types of regenerative thermal oxidizers (RTOs) are known in the art. RTOs are typically used for oxidation (combustion) of volatile organic compounds (VOCs) in waste gas streams. RTOs often include two separated beds that are in fluid communication with a common reaction room. Waste gas is introduced into the RTO to flow through one of the beds to preheat the waste gas. In the reaction room, VOCs are oxidized and the produced flue gas flows through the other one of the beds and transfers thermal energy to the bed. After a certain time period, the gas flow is switched such that waste is introduced into the RTO to flow through the bed that was previously heated by the flue gas and flue gas produced in the reaction room is directed through the bed that was previously used to preheat the waste gas. Due to the design of RTOs, a substantial amount of (thermal) energy can be recovered.

For a typical RTO, the entire waste gas stream to be oxidized will be mixed and diluted with air prior to entering the RTO. The waste gas often contains burnable compounds, such as VOCs, hydrocarbons (e.g., methane), hydrogen sulfide and carbon monoxide. In some countries, a minimum dilution of the waste gas is to maintain less than <NUM> % of the lower explosion limit of the mixture (waste gas and air). For example, this is required by BS-EN <NUM>. The required amount of air for the dilution of the waste gas is substantial. In some countries, the dilution is set by regulation, in other countries the decision is made in accordance with good engineering practice.

As a result, known RTOs are physically large, expensive to operate and require complex measurement equipment for measuring or determining the lower explosion limit. <CIT> relates to a volatile organic compound (VOC) abatement system employing a bypass valve for introducing a portion of the VOCs directly into a combustion chamber without regenerative preheating. The resulting lowering of thermal efficiency of the regenerative thermal oxidizer allows the exhaust from the regenerative thermal oxidizer to carry more thermal energy. The thermal energy from the exhaust is then transferred to a heat exchanger to heat gasses flowing into the adsorption device. <CIT> relates to a regenerative thermal oxidization system provided with a differential pressure transmitter whereby a duct open to the atmosphere, which is installed in an intake duct that connects the blower of the regenerative thermal oxidizer (RTO) and the exhaust blower of production equipment that generates exhaust gas, is connected to the control damper or the air blower operation inverter of the RTO, said damper or inverter being disposed between the differential pressure transmitter and the blower of the RTO. <CIT> relates to a thermal storage type gas treatment furnace in which a raw gas is supplied to the combustion chamber from an introduction flow channel through a thermal storage chamber, the combustion gas is exhausted from the combustion chamber through another thermal storage chamber, and the thermal storage chamber to which the raw gas is supplied and the thermal storage chamber to which the combustion gas flows out are switched, further provided with a bypass flow channel for directly supplying a part of the raw gas from the introduction flow channel to the combustion chamber, and a flow rate of the raw gas supplied to the combustion chamber through the bypass flow channel is feedback controlled so that a temperature of the combustion chamber is kept at a prescribed set temperature, while keeping the sum of the flow rate of the raw gas supplied to the combustion chamber through the bypass flow channel and the flow rate of the raw gas supplied to the combustion chamber through the thermal storage chamber, to be constant.

It is an object of the present invention to provide an RTO that is physically small. Another object of the present invention is to provide an RTO that is inexpensive to manufacture. Yet another object of the present invention is to provide an RTO that is inexpensive to operate. Yet another object of the present invention is to provide an RTO which reduces energy consumption. Yet another object of the present invention is to provide an RTO that reduces carbon dioxide and/or nitrogen oxide emission.

One or more of the above objects are solved by the combination of features of the independent claims. Advantageous embodiments are provided in the respective dependent claims. Features of an independent claim may be combined with features of one or more claims dependent on the independent claim, and features of one or more dependent claims can be combined with each other.

According to an aspect of the present invention, a regenerative thermal oxidizer is presented as defined in claim <NUM>.

According to an aspect of the present invention, a system is presented as defined in claim <NUM>.

The system includes any herein disclosed regenerative thermal oxidizer.

According to an aspect of the present invention, a method of operating a regenerative thermal oxidizer is presented as defined in claim <NUM>.

Any herein disclosed regenerative thermal oxidizer may be operated by the method. Any herein disclosed system may be operated by the method.

According to the present invention, at least a portion of waste gas including a compound to be oxidized, for example a pollutant, may be directed towards the reaction chamber of the regenerative thermal oxidizer without dilution of the waste gas with air prior to entering the regenerative thermal oxidizer. For example, all of the waste gas or the entire waste gas may be introduced into the regenerative thermal oxidizer without dilution. The waste gas may not flow through a bed of the regenerative thermal oxidizer to be preheated. Also, a portion of the waste gas may be introduced into the regenerative thermal oxidizer without dilution (undiluted) and another portion of the waste gas may introduced into the regenerative thermal oxidizer diluted, for example diluted by air. The diluted portion of the waste gas may flow through a bed to be preheated and the undiluted portion of the waste gas may not flow through a bed to be preheated. Oxygen required for the oxidation of the compound to be oxidized may be separately introduced into the regenerative thermal oxidizer. For example, the required oxygen may be directed to the regenerative thermal oxidizer together with the diluted portion of the waste gas or (fully) separately from the waste gas. By separately introducing at least a portion of waste gas and oxygen into the regenerative thermal oxidizer, a significantly smaller gas volume flows through the beds of the regenerative thermal oxidizer and, hence, an efficiency of preheating of the waste gas is increased.

A regenerative thermal oxidizer may comprise a bed which is preheated from a previous oxidation cycle to preheat the input gases, e.g., waste gas. Thereby, (thermal) energy can be regenerated. Compounds of the input gases may be oxidized at an elevated temperature, for example at least <NUM>.

The regenerative thermal oxidizer includes a first transfer chamber and a second transfer chamber. Each of the transfer chambers may be a half-chamber, i.e., at least one side of the chamber may be open. The first and second transfer chambers may be (partially) separated by a wall. The wall may extend in the regenerative thermal oxidizer, preferably towards the reaction chamber.

The first transfer chamber comprises a first bed. The second transfer chamber comprises a second bed. Each of the herein disclosed beds may comprise a packing. For example, the packing may be a structured packing or a random packing. Each of the herein disclosed beds may comprise a ceramic material. The oxygen-containing gas and/or a portion of the waste gas may flow through the bed to exchange (thermal) energy with the bed. For example, when the temperature of the oxygen-containing gas and/or the portion of the waste gas is lower than the temperature of a bed, the oxygen-containing gas and/or the portion of the waste gas is heated or preheated when it flows through the bed.

The first transfer chamber is in fluid communication with the reaction chamber of the regenerative thermal oxidizer. The second transfer chamber is in fluid communication with the reaction chamber of the regenerative thermal oxidizer. The reaction chamber may be a reaction room. For example, the transfer chambers may be (physically) separated from each other. One side of each of the transfer chambers may be open towards the reaction chamber. Preferably, the first transfer chamber, the second transfer chamber and the reaction chamber may be designed such that a fluid (e.g., a gas or a liquid) may flow from the first transfer chamber to the reaction chamber. From the reaction chamber, the fluid may flow to the second transfer chamber. Preferably, inside the regenerative thermal oxidizer a fluid is not able to flow from the first transfer chamber to the second transfer chamber without passing through the reaction chamber.

A transfer chamber may be designed such that a fluid (e.g., a gas or a liquid) is guided from outside of the regenerative thermal oxidizer through the bed of the transfer chamber to the reaction chamber and/or a transfer chamber may be designed such that a fluid (e.g., a gas or a liquid) is guided from the reaction chamber through the bed of the transfer chamber to outside of the regenerative thermal oxidizer.

The oxidizable compound of the waste gas may be oxidized in the reaction chamber. The oxidation of the oxidizable compound may occur by a chemical reaction of the oxidizable compound and oxygen of the oxygen-containing gas.

A temperature in the reaction chamber may be at least <NUM>, preferably at least <NUM>, more preferably at least <NUM>, more preferably at least <NUM>. Alternatively or additionally, the temperature in the reaction chamber may be at most <NUM>, preferably at most <NUM>, more preferably at most <NUM>. Specifically, the temperature in the reaction chamber may be between <NUM> and <NUM>.

As mentioned above, the waste gas may comprise one or more oxidizable compound. Preferably, the waste gas comprises at least two different oxidizable compounds, more preferably at least three different oxidizable compounds, more preferably at least five different oxidizable compounds, more preferably at least ten different oxidizable compounds, more preferably at least twenty different oxidizable compounds. Different oxidizable compounds may be different by at least one chemical or physical characteristic. For example, different oxidizable compounds may have a different chemical composition and/or different oxidizable compounds may have a different boiling point.

Specific examples of an oxidizable compound include at least one hydrocarbon (e.g., methane), at least one volatile organic compound (VOCs), hydrogen sulfide (H<NUM>S), hydrogen (H<NUM>) and/or carbon monoxide (CO). Preferably, the waste gas includes at least one sulfur-containing compound or elementary sulfur. The sulfur-containing compound or elementary sulfur may be the oxidizable compound in the waste gas. Also, the at least one hydrocarbon may be the oxidizable compound in the waste gas.

The waste gas may be gas which was treated or pretreated in a previous gas treatment unit. For example, the waste gas may be tail gas of a sulfur recovery unit. The sulfur recovery unit may employ or comprise a Claus process. In general, the waste gas may be any gas that comprises an oxidizable compound, preferably the oxidizable compound is a pollutant. The waste gas may include vent gas and/or sweep gas from a sulfur pit. Also, vent gas and/or sweep gas from a sulfur pit may be introduced into the regenerative thermal oxidizer separately from the waste gas.

The waste gas source may be gas treatment unit, for example a sulfur recovery unit. The waste gas source may be an outlet or exit of the gas treatment unit.

Preferably, the oxygen-containing gas includes at least <NUM> vol. -% oxygen (O<NUM>), more preferably at least <NUM> vol. -% oxygen, more preferably at least <NUM> vol. -% oxygen, more preferably at least <NUM> vol. -% oxygen, more preferably at least <NUM> vol. -% oxygen, more preferably at least <NUM> vol. -% oxygen, more preferably at least <NUM> vol. -% oxygen, more preferably at least <NUM> vol. -% oxygen, more preferably at least <NUM> vol. -% oxygen, more preferably at least <NUM> vol. -% oxygen, more preferably at least <NUM> vol. -% oxygen, more preferably at least <NUM> vol. -% oxygen, more preferably at least <NUM> vol.

For example, the oxygen-containing gas may be air. The air may be air surrounding the regenerative thermal oxidizer and/or the system. The oxygen-containing gas source may be the surrounding or the environment of the regenerative thermal oxidizer and/or the system.

The regenerative thermal oxidizer comprises one or more first waste gas inlet for introducing at least a portion of waste gas into the regenerative thermal oxidizer. The one or more first waste gas inlet is positioned between at least a portion of the first bed and at least a portion of the reaction chamber. For example, the one or more first waste gas inlet may be a bore or a nozzle in a wall of the first transfer chamber. Alternatively, the one or more first waste gas inlet may be a bore or a nozzle in a wall of the reaction chamber.

The first waste gas inlet may be positioned or disposed such that the portion of the waste gas enters into the first transfer chamber and/or into the reaction chamber.

When oxygen-containing gas flows through the first bed of the first transfer chamber to the reaction chamber, the one or more first waste gas inlet may be positioned or disposed downstream (in the direction in which the fluid flows) of at least a portion of the first bed. In other words, the one or more first waste gas inlet may be positioned such that the portion of waste gas enters the regenerative thermal oxidizer downstream or after at least a portion of the first bed.

A distance between the one or more first waste gas inlet and the portion of the first bed may be less than <NUM>, preferably less than <NUM>, more preferably less than <NUM>, more preferably less than <NUM>, more preferably less than <NUM>, more preferably less than <NUM>, more preferably less than <NUM>. Alternatively or additionally, a distance between the one or more first waste gas inlet and the first bed may be at least <NUM>, preferably at least <NUM>, more preferably at least <NUM>.

Alternatively, the one or more first waste gas inlet may be positioned between at least a portion of the second bed and at least a portion of the reaction chamber. For example, the one or more first waste gas inlet may be a bore or a nozzle in a wall of the second transfer chamber. Alternatively, the one or more first oxygen-containing gas inlet may be a bore or a nozzle in a wall of the reaction chamber. The one or more first waste gas inlet between at least a portion of the second bed and the portion of the reaction chamber may be designed and/or positioned and/or disposed similar or equally than the one or more first waste gas inlet between at least a portion of the first bed and the portion of the reaction chamber.

For example, a distance between the one or more first waste gas inlet and at least a portion of the second bed may be less than <NUM>, preferably less than <NUM>, more preferably less than <NUM>, more preferably less than <NUM>, more preferably less than <NUM>, more preferably less than <NUM>, more preferably less than <NUM>. Alternatively or additionally, a distance between the one or more first waste gas inlet and at least a portion of the second bed may be at least <NUM>, preferably at least <NUM>, more preferably at least <NUM>.

It is preferred that the one or more first waste gas inlet is positioned closer to the reaction chamber than to an inlet of the oxygen-containing gas into the regenerative thermal oxidizer. More preferably, the one or more first waste gas inlet is positioned closer to the reaction chamber than to an inlet of the oxygen-containing gas into the first transfer chamber or into the second transfer chamber.

In general, the portion of the reaction chamber may be any portion of the reaction chamber. Preferably, a distance between the portion of the reaction chamber and a bed, for example the first bed and/or the second bed, may be at least <NUM>, preferably at least <NUM>, more preferably at least <NUM>, more preferably at least <NUM>, more preferably at least <NUM>, more preferably at least <NUM>, more preferably at least <NUM>, more preferably at least <NUM>. Alternatively or additionally, a distance between the portion of the reaction chamber and a bed, for example the first bed and/or the second bed, may be at most <NUM>, preferably at most <NUM>, more preferably at most <NUM>, more preferably at most <NUM>, more preferably at most <NUM>, more preferably at most <NUM>, more preferably at most <NUM>, more preferably at most <NUM>. A distance between the portion of the reaction chamber and a bed, for example the first bed and/or the second bed, may be about <NUM>, about <NUM>, about <NUM> or about <NUM>.

In general, a distance may be a shortest distance between two objects or elements or points (e.g. the length of the space between two objects or elements or points).

In general, the first portion of waste gas may be introduced into the regenerative thermal oxidizer such that the first portion of waste gas is introduced into a bed, for example the first bed or the second bed. Alternatively or additionally, the first portion of waste gas may be introduced into the regenerative thermal oxidizer such that the first portion of waste gas introduced outside a bed, for example the first bed or the second bed.

In general, the portion of a bed, for example the portion of the first bed or a portion of the second bed, may be any portion of the bed. The portion of the bed may be an upper portion or a lower portion of the bed. The portion of the bed may be located between an upper portion and a lower portion of the bed. For example, the portion of the bed may be a portion that is an outermost portion of the bed in downstream direction. For example, the portion of the bed may be a portion that is an outermost, upper or lower half portion of the bed in downstream direction. Also, the portion of the bed may be a portion that is an outermost portion of the bed in upstream direction. Also, the portion of the bed may be a portion that is an outermost, upper or lower half portion of the bed in upstream direction.

When oxygen-containing gas flows through a bed, for example the first bed and/or the second bed, to the reaction chamber, the oxygen-containing gas may be preheated. At the same time, the bed may be cooled. When gas, for example flue gas produced by oxidizing the oxidizable compound of the waste gas in the reaction chamber, flows from the reaction chamber through a bed, for example the first bed and/or the second bed, the gas may be cooled. At the same time, the bed may be heated.

Oxygen of the oxygen-containing gas may be used to oxidize the oxidizable compound of the waste gas. Preferably, oxygen of the oxygen-containing gas may not be used to fire a burner.

The oxygen-containing gas may be introduced into the regenerative thermal oxidizer to provide oxygen in the reaction chamber. In the reaction chamber, the oxygen may oxidize the oxidizable compound of the waste gas.

The regenerative thermal oxidizer comprises the one or more first waste gas inlet for introducing the first portion of waste gas into the regenerative thermal oxidizer positioned between at least a portion of the first bed and at least a portion of the reaction chamber. Further, the thermal oxidizer comprises one or more second waste gas inlet for introducing the first portion of waste gas into the regenerative thermal oxidizer positioned between at least a portion of the second bed and at least a portion of the reaction chamber. The portion of the reaction chamber may be one portion or the same portion of the reaction chamber.

The one or more first waste gas inlet may correspond to the first transfer chamber, preferably correspond to the first bed. The one or more second waste gas inlet may correspond to the second transfer chamber, preferably correspond to the second bed.

When the one or more first waste gas inlet is open to introduce the first portion of waste gas into the regenerative thermal oxidizer, the one or more second waste gas inlet may be closed such that no waste gas is introduced into the regenerative thermal oxidizer via the one or more second waste gas inlet. When the one or more second waste gas inlet is open to introduce the first portion of waste gas into the regenerative thermal oxidizer, the one or more first waste gas inlet may be closed such that no waste gas is introduced into the regenerative thermal oxidizer via the one or more first waste gas inlet.

Preferably, only the one or more first waste gas inlet is open at a point in time. Only the one or more second waste gas inlet may be open at a point in time.

The regenerative thermal oxidizer may comprise a heater. The one or more first waste gas inlet may be positioned or disposed closer to the first bed than to the heater. Preferably, a distance between the one or more first waste gas inlet and the first bed may be smaller than a distance between the one or more first waste gas inlet and the heater. The distance between the one or more first waste gas inlet and the first bed may be smaller by at least <NUM>, preferably by at least <NUM>, more preferably by at least <NUM>, more preferably by at least <NUM>, than a distance between the one or more first waste gas inlet and the heater.

A distance between the one or more first waste gas inlet and the heater may be at least <NUM>, preferably at least <NUM>, more preferably at least <NUM>, more preferably at least <NUM>, more preferably at least <NUM>, more preferably at least <NUM>, more preferably at least <NUM>, more preferably at least <NUM>, more preferably at least <NUM>.

The one or more second waste gas inlet may be positioned similarly or equally relative to the heater and/or relative to the second bed as the one or more first waste gas inlet.

At least a second portion of waste gas may be introduced into the regenerative thermal oxidizer to flow through the first bed to the reaction chamber. Alternatively or additionally, at least a second portion of waste gas may be introduced into the regenerative thermal oxidizer to flow through the second bed to the reaction chamber.

For example, the first portion of waste gas may be introduced into the regenerative thermal oxidizer without flowing through a bed. At the same time, the second portion of waste gas may be introduced into the regenerative thermal oxidizer to flow through a bed. The second portion of waste gas may be preheated by flowing through the bed.

The first portion and the second portion of waste gas may originate from the waste gas source. The flow of waste gas may be split into the first portion of waste gas and into the second portion of waste gas. The first portion of waste gas may be introduced into the regenerative thermal oxidizer without dilution, for example without dilution by oxygen-containing gas. The second portion of waste gas may be introduced into the regenerative thermal oxidizer with dilution, for example with dilution by oxygen-containing gas.

Oxygen-containing gas and the second portion of waste may be introduced into the regenerative thermal oxidizer together, for example as a mixture. Oxygen in the mixture of the oxygen-containing gas and the second portion of waste gas may be sufficient to oxidize oxidizable compounds of the first portion of waste and the second portion of waste gas in the regenerative thermal oxidizer.

The first portion of waste may be at least <NUM> %, preferably at least <NUM> %, more preferably at least <NUM> %, more preferably at least <NUM> %, more preferably at least <NUM> %, more preferably at least <NUM> %, more preferably at least <NUM> %, more preferably at least <NUM> %, more preferably at least <NUM> %, of the total amount of waste gas introduced into the regenerative thermal oxidizer. Additionally or alternatively, the first portion of waste may be at most <NUM> %, preferably at most <NUM> %, more preferably at most <NUM> %, more preferably at most <NUM> %, more preferably at most <NUM> %, more preferably at most <NUM> %, more preferably at most <NUM> %, more preferably at most <NUM> %, more preferably at most <NUM> %, of the total amount of waste gas introduced into the regenerative thermal oxidizer. The first portion of waste gas may be between <NUM> % and <NUM> %, preferably between <NUM> % and <NUM> %, more preferably between <NUM> % and <NUM> %, more preferably between <NUM> % and <NUM> %, more preferably between <NUM> % and <NUM> %, more preferably about <NUM> %, of the total amount of waste gas introduced into the regenerative thermal oxidizer.

The second portion of waste may be at least <NUM> %, preferably at least <NUM> %, more preferably at least <NUM> %, more preferably at least <NUM> %, more preferably at least <NUM> %, more preferably at least <NUM> %, more preferably at least <NUM> %, more preferably at least <NUM> %, more preferably at least <NUM> %, of the total amount of waste gas introduced into the regenerative thermal oxidizer. Additionally or alternatively, the second portion of waste may be at most <NUM> %, preferably at most <NUM> %, more preferably at most <NUM> %, more preferably at most <NUM> %, more preferably at most <NUM> %, more preferably at most <NUM> %, more preferably at most <NUM> %, more preferably at most <NUM> %, more preferably at most <NUM> %, of the total amount of waste gas introduced into the regenerative thermal oxidizer. The second portion of waste gas may be between <NUM> % and <NUM> %, preferably between <NUM> % and <NUM> %, more preferably between <NUM> % and <NUM> %, more preferably between <NUM> % and <NUM> %, more preferably between <NUM> % and <NUM> %, more preferably about <NUM> %, of the total amount of waste gas introduced into the regenerative thermal oxidizer.

The total amount of waste gas introduced into the regenerative thermal oxidizer may be the sum of the first portion of waste gas and the second portion of waste gas introduced into the regenerative thermal oxidizer.

The regenerative thermal oxidizer may comprise at least a third transfer chamber. The third transfer chamber may comprise a third bed. The reaction chamber may be in fluid flow communication with the third transfer chamber. The regenerative thermal oxidizer may comprise one or more third waste gas inlet for introducing the first portion of waste gas into the regenerative thermal oxidizer positioned between at least a portion of the third bed and at least a portion of the reaction chamber.

For example, the third transfer chamber may be a half-chamber. The first, second and third transfer chambers may be (partially) separated by a wall, at least two walls or at least three walls.

The one or more third waste gas inlet may be positioned between at least a portion of the third bed and at least a portion of the reaction chamber. The one or more third waste gas inlet may be a bore or a nozzle in a wall of the third transfer chamber.

A distance between the one or more third waste gas inlet and at least a portion of the third bed may be less than <NUM>, preferably less than <NUM>, more preferably less than <NUM>, more preferably less than <NUM>, more preferably less than <NUM>, more preferably less than <NUM>, more preferably less than <NUM>. Alternatively or additionally, a distance between the one or more third waste gas inlet and at least a portion of the third bed may be at least <NUM>, preferably at least <NUM>, more preferably at least <NUM>.

The one or more third waste gas inlet may be positioned closer to the reaction chamber than to an inlet of the waste gas into the regenerative thermal oxidizer.

A distance between the one or more third waste gas inlet and at least a portion of the third bed may be smaller than a distance between the third waste gas inlet and the heater. A distance between the one or more third waste gas inlet and at least a portion of the third bed may be smaller by at least <NUM>, preferably by at least <NUM>, more preferably by at least <NUM>, more preferably by at least <NUM>, than a distance between the one or more third waste gas inlet and the heater.

A distance between the one or more third waste gas inlet and the heater may be at least <NUM>, preferably at least <NUM>, more preferably at least <NUM>, more preferably at least <NUM>, more preferably at least <NUM>, more preferably at least <NUM>, more preferably at least <NUM>, more preferably at least <NUM>, more preferably at least <NUM>.

The one or more third waste gas inlet may correspond to the third transfer chamber. When the one or more third waste gas inlet is open to introduce (the first portion of the) waste gas into the regenerative thermal oxidizer, the one or more first waste gas inlets and the one or more second waste gas inlet may be closed.

The regenerative thermal oxidizer may comprise at least two waste gas inlets per transfer chamber. Preferably, the regenerative thermal oxidizer comprises at least three waste gas inlets per transfer chamber. More preferably, the regenerative thermal oxidizer comprises at least four waste gas inlets per transfer chamber.

For example, the one or more first waste gas inlet may comprise at least two first waste gas inlets. The one or more first waste gas inlet may introduce (the first portion of the) waste gas into the regenerative thermal oxidizer. Each of the first waste gas inlets may correspond to the first transfer chamber. The first waste gas inlet may comprise at least three first waste gas inlets or at least four first waste gas inlets.

Similarly, the one or more second waste gas inlet may comprise at least two second waste gas inlets, at least three second waste gas inlets or at least four second waste gas inlets. Similarly, the one or more third waste gas inlet may comprise at least two third waste gas inlets, at least three third waste gas inlets or at least four third waste gas inlets.

Each of the transfer chambers may have a circular or polygonal (e.g., rectangular or square) cross section. The one or more first waste gas inlet, second waste gas inlet and/or third waste gas inlet may be evenly or non-evenly distributed along a circumference of the respective transfer chamber. For example, when the one or more first waste gas inlet comprises two, three or four first waste gas inlets, the two, three or four first waste gas inlets may be evenly or non-evenly distributed along the circumference of the first transfer chamber. Waste gas inlets of the one or more second waste gas inlet and/or the one or more third waste gas inlet may be similarly or equally positioned at the respective transfer chamber.

Each of the transfer chambers may comprise more than one transfer chamber. For example, the first, second and/or third transfer chamber may comprise at least two, at least three, at least four, at least five or at least ten transfer chambers.

As mentioned above, a system comprises a regenerative thermal oxidizer. A first waste gas tube connects a waste gas source with at least a second waste gas tube. The second waste gas tube connects the first waste gas tube with the regenerative thermal oxidizer.

The first waste gas tube may be any suitable tube for connecting the waste gas source with the second waste gas tube. The second waste gas tube may connect the first waste gas tube with the regenerative thermal oxidizer, preferably with the first, second and/or third transfer chamber.

The first waste gas tube may comprise one or more valves. The second waste gas tube may comprise one or more valves. Different sections of the first waste gas tube and/or the second waste gas tube may be open or closed, depending on the valve position of the one or more valves.

The oxygen-containing gas tube may be any suitable tube for connecting the oxygen-containing gas source with the regenerative thermal oxidizer such that the oxygen-containing gas source and the regenerative thermal oxidizer are in fluid flow communication. The oxygen-containing gas tube may comprise one or more valves. Different sections of the oxygen-containing gas tube may be open or closed, depending on the valve position of the one or more valves.

When oxygen-containing gas flows through a bed (e.g. the first bed or the second bed or the third bed) of a transfer chamber (e.g. the first transfer chamber or the second transfer chamber or the third transfer chamber) towards the reaction chamber, the oxygen-containing gas may be introduced into the regenerative thermal oxidizer upstream of the bed. The first portion of the waste gas may be introduced into the regenerative thermal oxidizer downstream of at least a portion of the bed. The second portion of the waste gas may be introduced into the regenerative thermal oxidizer upstream of the bed.

The system comprises a controller. The controller may be a hardware component configured to control the overall operations of the regenerative thermal oxidizer and/or the system. The controller may include at least one processor. A processor may be implemented as an array of a plurality of logic gates or can be implemented as combination of a microprocessor and a memory. A program executable by the microprocessor may be stored in the memory. The skilled person readily understands that the controller may be implemented in various hardware forms. Functions of the regenerative thermal oxidizer and/or of the system may be controlled by the controller.

The controller is configured to direct at least a first portion of waste gas via the first waste gas tube and via the second waste gas tube to the regenerative thermal oxidizer, such that the first portion of the waste gas enters the regenerative thermal oxidizer downstream of at least a portion of the first bed and/or downstream of at least a portion of the second bed.

The pressure in the waste gas source may be higher than the pressure in the regenerative thermal oxidizer. A pressure unit, for example a blower, may be arranged along the first and/or second waste gas tube for increasing the pressure of the waste gas. Similarly, a pressure unit, for example a blower, may be arranged along the oxygen-containing gas tube for increasing the pressure of the oxygen-containing gas.

The controller is configured to direct oxygen-containing gas via the oxygen-containing gas tube to the regenerative thermal oxidizer, such that the at least one oxidizable compound is oxidized in the reaction chamber. The oxygen-containing gas may be introduced into the regenerative thermal oxidizer upstream of a bed.

The system may comprise a third waste gas tube. The third waste gas tube may connect the waste gas source with the first transfer chamber. Alternatively or additionally, the third waste gas tube may connect the waste gas source with the second transfer chamber. The controller may be configured to direct the first portion of waste gas via the second waste gas tube to the regenerative thermal oxidizer. The controller may be configured to direct at least a second portion of waste gas via the third waste gas tube through the first bed to the reaction chamber, such that the second portion of the waste gas is preheated by the first bed. Alternatively or additionally, the controller may be configured to direct at least a second portion of waste gas via the third waste gas tube through the second bed to the reaction chamber, such that the second portion of the waste gas is preheated by the second bed.

The oxygen-containing gas and the second portion of waste gas may be introduced together, for example as a mixture, into the regenerative thermal oxidizer.

The controller may be configured to direct the oxygen-containing gas via the oxygen-containing gas tube through the first bed to the reaction chamber, such that the oxygen-containing gas is preheated by the first bed. Alternatively or additionally, the controller may be configured to direct the oxygen-containing gas via the oxygen-containing gas tube through the second bed to the reaction chamber, such that the oxygen-containing gas is preheated by the second bed.

During a first cycle, the controller may be configured to direct the first portion of waste gas via the second waste gas tube to the regenerative thermal oxidizer, such that the first portion of waste gas enters the regenerative thermal oxidizer downstream of at least a portion of the first bed. During a first cycle, the controller may be configured to direct the second portion of waste gas via the third waste gas tube through the first bed to the reaction chamber, such that the second portion of the waste gas is preheated by the first bed. During a second cycle, the controller may be configured to direct the first portion of waste gas via the second waste gas tube to the regenerative thermal oxidizer, such that the first portion of the waste gas enters the regenerative thermal oxidizer downstream of at least a portion of the second bed. During a second cycle, the controller may be configured to direct the second portion of waste gas via the third waste gas tube through the second bed to the reaction chamber, such that the second portion of the waste gas is preheated by the second bed.

In general, the regenerative thermal oxidizer or the system may perform predefined functions, preferably for a predetermined time period, in a cycle. In different cycles the functions performed by the regenerative thermal oxidizer or the system may be different. Also, different cycles may be performed for different time periods. The regenerative thermal oxidizer or the system may be configured to perform cycles repeatedly. For example, a first cycle may be performed. Then, a second cycle may be performed. Afterwards, a first cycle may be performed again followed by another second cycle, etc..

Preferably, the first cycle and the second cycle may be performed during different time periods. In other words, only one of the cycles may be performed in a point in time or during a time period. The first cycle and the second cycle may be consecutively performed, i.e., the second cycle follows the first cycle, the second cycle is followed by the first cycle, etc. Additional cycles may be performed before, between or after first and second cycles.

The first cycle may be performed for at least <NUM>, preferably for at least <NUM>, more preferably for at least <NUM>, more preferably for at least <NUM>, more preferably for at least <NUM>, more preferably for at least <NUM>. The second cycle may be performed for at least <NUM>, preferably for at least <NUM>, more preferably for at least <NUM>, more preferably for at least <NUM>, more preferably for at least <NUM>, more preferably for at least <NUM>, more preferably for at least <NUM>.

During the first cycle, no oxygen-containing gas may be directed through the second bed to the reaction chamber. Alternatively or additionally, during the second cycle, no oxygen-containing gas may be directed through the first bed to the reaction chamber. During the first cycle, the second portion of waste gas may not be directed through the second bed to the reaction chamber. During the second cycle, the second portion of waste gas may not be directed through the first bed to the reaction chamber.

During the first cycle, the controller may be configured to direct flue gas, produced by oxidation of the oxidizable compound of the waste gas in the reaction chamber, from the reaction chamber through the second bed, such that the flue gas is cooled by the second bed. During the second cycle, the controller may be configured to direct the flue gas from the reaction chamber through the first bed, such that the flue gas is cooled by the first bed.

When the flue gas is cooled by the second bed, the second bed may be heated by the flue gas. When the flue gas is cooled by the first bed, the first bed may be heated by the flue gas.

Flue gas may be produced in the reaction chamber by reaction of the at least one oxidizable compound of the waste gas and oxygen of the oxygen-containing gas. The gas composition resulting from the reaction may be called flue gas. The reaction may be endothermic or exothermic.

The regenerative thermal oxidizer may comprise at least a third transfer chamber. The third transfer chamber may comprise a third bed. The reaction chamber may be in fluid flow communication with the third transfer chamber. During a third cycle, the controller may be configured to direct the first portion of waste gas via the second waste gas tube to the regenerative thermal oxidizer, such that the first portion of waste gas enters the regenerative thermal oxidizer downstream of at least a portion of the third bed. During a third cycle, the controller may be configured to direct the second portion of waste gas via the third waste gas tube through the third bed to the reaction chamber, such that the second portion of waste gas is preheated by the third bed. During a third cycle, the controller may be configured to direct oxygen-containing gas via the oxygen-containing gas tube through the third bed to the reaction chamber, such that the oxygen-containing gas is preheated by the third bed.

The regenerative thermal oxidizer may comprise at least three transfer chambers. The regenerative thermal oxidizer may be operated in at least three cycles or at least six cycles.

The system may comprise a bypass tube for connecting a heat exchanger with the regenerative thermal oxidizer, preferably for connecting the heat exchanger with the reaction chamber of the regenerative thermal oxidizer. The controller may be configured to direct gas from the regenerative thermal oxidizer to the heat exchanger such that the gas is cooled by the heat exchanger.

Preferably, flue gas from the reaction chamber of the regenerative thermal oxidizer may be directed to the heat exchanger. The flue gas may be cooled by the heat exchanger.

The heat exchanger may be configured to allow an exchange of (thermal) energy or heat between gas from the regenerative thermal oxidizer and the (first and/or second portion of the) waste gas prior to entry of the (first and/or second portion of the) waste gas into the regenerative thermal oxidizer. Also, the heat exchanger may be configured to allow an exchange of (thermal) energy or heat between gas from the regenerative thermal oxidizer and the oxygen-containing gas prior to entry of the oxygen-containing gas into the regenerative thermal oxidizer. Also, the heat exchanger may be configured to allow an exchange of (thermal) energy or heat between gas from the regenerative thermal oxidizer and a heat recovery system. Also, the heat exchanger may be configured to allow an exchange of (thermal) energy or heat between gas from the regenerative thermal oxidizer and a superheater, preferably a steam superheater.

Gas from the regenerative thermal oxidizer, preferably from the reaction chamber of the regenerative thermal oxidizer, may be directed to the heat exchanger during any one of the cycles. Preferably, gas from the regenerative thermal oxidizer, preferably from the reaction chamber of the regenerative thermal oxidizer, is directed to the heat exchanger during the first, second and third cycles.

The first portion of waste gas may comprise less than <NUM> vol. -% oxygen (O<NUM>). Preferably, the first portion of waste gas comprises less than <NUM> vol. -% oxygen, more preferably less than <NUM> vol. -% oxygen, more preferably less than <NUM> vol. -% oxygen, more preferably less than <NUM> vol. -% oxygen, more preferably less than <NUM> vol. -% oxygen, more preferably less than <NUM> vol. -% oxygen, more preferably less than <NUM> vol. -% oxygen, more preferably less than <NUM> vol. -% oxygen, more preferably less than <NUM> vol. -% oxygen, more preferably less than <NUM> vol. -% oxygen, more preferably less than <NUM> vol. -% oxygen, more preferably less than <NUM> vol. -% oxygen, more preferably less than <NUM> vol. -% oxygen, more preferably less than <NUM> vol. -% oxygen, more preferably less than <NUM> vol. -% oxygen, in particular when entering the regenerative thermal oxidizer. The first portion of the waste gas may be free of oxygen, i.e., the first portion of the waste gas may comprise no oxygen.

When entering the regenerative thermal oxidizer, the first portion of the waste gas may have substantially the same composition as the waste gas at the waste gas source.

The second portion of waste gas may comprise at least <NUM> vol. -% oxygen (O<NUM>). Preferably, the second portion of waste gas comprises at least <NUM> vol. -% oxygen, more preferably at least <NUM> vol. -% oxygen, more preferably at least <NUM> vol. -% oxygen, more preferably at least <NUM> vol. -% oxygen, more preferably at least <NUM> vol. -% oxygen, more preferably at least <NUM> vol. -% oxygen, more preferably at least <NUM> vol. -% oxygen, more preferably at least <NUM> vol. -% oxygen, more preferably at least <NUM> vol. -% oxygen, more preferably at least <NUM> vol. -% oxygen, more preferably at least <NUM> vol. -% oxygen, more preferably at least <NUM> vol. -% oxygen, more preferably at least <NUM> vol. -% oxygen, more preferably at least <NUM> vol. -% oxygen, more preferably at least <NUM> vol. -% oxygen, more preferably at least <NUM> vol. -% oxygen, more preferably at least <NUM> vol. -% oxygen more preferably at least <NUM> vol.

When entering the regenerative thermal oxidizer, the second portion of waste gas may be a mixture of oxygen-containing gas and waste gas from the waste gas source. Also, when entering the regenerative thermal oxidizer, the second portion of waste gas may have substantially the same composition as the waste gas at the waste gas source.

The regenerative thermal oxidizer may comprise a heater. The heater may be configured to heat at least a portion of the regenerative thermal oxidizer. The heater may comprise a burner and/or an electrical heating element.

The heater may be configured to heat the reaction chamber and/or the beds of the regenerative thermal oxidizer.

The burner may be operated by fuel, for example a fuel gas. The fuel gas may comprise at least one hydrocarbon and/or hydrogen. Preferably, the fuel gas comprises hydrogen. The burner may be supplied with oxygen, for example with air, additionally, separately or independently from the oxygen-containing gas supplied to the regenerative thermal oxidizer used to oxidize the at least one oxidizable compound in the waste gas.

The electrical heating element may be a resistive heating element. The electrical heating element may be supplied with electrical energy from a renewable energy source. The renewable energy source may be wind energy or solar energy.

During a start-up cycle, the heater may heat the regenerative thermal oxidizer to a start temperature. For example, the reaction chamber and/or the beds may be heated to the start temperature. The first, second and/or third cycles may be performed after the start-up cycle.

Preferably, the heater is not operated during the first, second and/or third cycles. Alternatively, the heater may be operated during the first, second and/or third cycles.

During the start-up cycle, the heater may be controlled such that regenerative thermal oxidizer is heated to a predetermined temperature. No waste gas may be directed to the regenerative thermal oxidizer, preferably to the reaction chamber of the regenerative thermal oxidizer, during the start-up cycle.

The herein presented method may comprise: Directing at least a second portion of waste gas through the first bed, such that the second portion of the waste gas is preheated by the first bed.

During a first cycle, the method may comprise: Directing the first portion of waste gas to the reaction chamber of the regenerative thermal oxidizer, such that the first portion of waste gas enters the regenerative thermal oxidizer downstream of at least a portion of the first bed. During a first cycle, the method may comprise: Directing the oxygen-containing gas through the first bed to the reaction chamber of the regenerative thermal oxidizer. During a first cycle, the method may comprise: Directing the second portion of waste gas through the first bed of the regenerative thermal oxidizer. During a second cycle, the method may comprise: Directing the first portion of waste gas to the reaction chamber of the regenerative thermal oxidizer, such that the first portion of waste gas enters the regenerative thermal oxidizer downstream of at least a portion of a second bed of the regenerative thermal oxidizer. During a second cycle, the method may comprise: Directing the oxygen-containing gas through the second bed to the reaction chamber of the regenerative thermal oxidizer, such that the oxygen-containing gas is preheated by the second bed. During a second cycle, the method may comprise: Directing the second portion of waste gas through the second bed of the re-generative thermal oxidizer, such that the second portion of waste gas is preheated by the second bed.

The second portion of waste gas may be mixed with the oxygen-containing gas prior to entering the regenerative thermal oxidizer. The first portion of waste gas may be introduced into the regenerative thermal oxidizer separately from the second portion of waste gas and/or separately from the oxygen-containing gas. The first portion of waste gas, the second portion of waste gas and the oxygen-containing gas may be mixed in the regenerative thermal oxidizer, preferably in the reaction chamber of the regenerative thermal oxidizer.

A flow rate of the oxygen-containing gas into the regenerative thermal oxidizer may be controlled based on at least one of a composition of the waste gas and a flow rate of the waste gas (e.g., the sum of the flow rates of the first portion of waste gas and the second portion of waste gas). Preferably the flow rate of the oxygen-containing gas into the regenerative thermal oxidizer may be controlled based on both the composition of the waste gas and the flow rate of the waste gas (e.g., the sum of the flow rates of the first portion of waste gas and the second portion of waste gas).

The composition of the waste gas may be measured by one or more sensors. The flow rate of the waste gas may be measured by one or more sensors.

Specifically, the flow rate of the oxygen-containing gas into the regenerative thermal oxidizer may be controlled such that the amount of oxygen introduced into the regenerative thermal oxidizer is sufficient to oxidize the at least one oxidizable compound of the waste gas.

The above-mentioned attributes and other features and advantages of the present invention and the manner of attaining them will become more apparent and the present invention itself will be better understood by reference to the following description of embodiments of the present technique taken in conjunction with the accompanying drawings, wherein:.

Hereinafter, above-mentioned and other features of the present invention are described in detail. Various embodiments are described with reference to the drawings, wherein like reference numerals are used to refer to like elements throughout. In the following description, for purpose of explanation, numerous specific details are set forth in order to provide a thorough understanding of one or more embodiments It may benoted that the illustrated embodiments are intended to explain, and not to limit the invention.

It may be noted that terms like "first", "second" and "third" are merely used to distinguishing elements, not to count elements. For example, when a "second" element is addressed, this does not imply that a "first" element must be present.

<FIG> schematically shows a system <NUM>. The system <NUM> may comprise a regenerative thermal oxidizer <NUM>.

The regenerative thermal oxidizer <NUM> may comprise a first transfer chamber <NUM> and a second transfer chamber <NUM>. The first transfer chamber <NUM> may include a first bed <NUM>. The second transfer chamber <NUM> may include a second bed <NUM>. The first transfer chamber <NUM> and the second transfer chamber <NUM> may be in fluid flow communication with a reaction chamber <NUM> of the regenerative thermal oxidizer <NUM>.

The first transfer chamber <NUM> and the second transfer chamber <NUM> may be physically separated such that the first bed <NUM> and the second bed <NUM> are physically separated from each other. The separation can be achieved by a wall which extends in the regenerative thermal oxidizer <NUM>. At one side, the first transfer chamber <NUM> and the second transfer chamber <NUM> may be open, preferably towards the reaction chamber <NUM>.

The extension of the wall separating the first bed <NUM> and the second bed <NUM> may define an upper end of the first transfer chamber <NUM> and the second transfer chamber <NUM>. For example, an end of the wall separating the first bed <NUM> and the second bed <NUM> may define the end of the first transfer chamber <NUM> and the second transfer chamber <NUM>.

The regenerative thermal oxidizer <NUM> may comprise a heater <NUM>. The heater <NUM> may be used to heat at least a portion of the regenerative thermal oxidizer <NUM>. For example, the reaction chamber <NUM> may be heated by the heater <NUM>. Alternatively or additionally, the first bed <NUM> and the second bed <NUM> may be heated by the heater <NUM>. The heater <NUM> may be a burner or an electrical heater.

The system <NUM> may comprise a controller <NUM>. The controller <NUM> may be configured to control the overall operation of the system <NUM>. The controller <NUM> may be configured to control the overall operation of the regenerative thermal oxidizer <NUM>. The controller <NUM> may be located in an overall control station (not shown) of the system <NUM>. The controller <NUM> may be a part of a controlling computer of the system <NUM>.

The system <NUM> may comprise a first waste gas tube <NUM>. The first waste gas tube <NUM> may connect a waste gas source <NUM> and the regenerative thermal oxidizer <NUM>.

Specifically, the first waste gas tube <NUM> may be connected to a second waste gas tube <NUM>. The second waste gas tube <NUM> may be connected to one or more waste gas inlet <NUM>, <NUM>, <NUM>, <NUM> as will be described in more detail with reference to <FIG>.

Preferably, one or more first waste gas inlet <NUM>, <NUM>, <NUM>, <NUM> corresponds to the first transfer chamber <NUM> and/or one or more second waste gas inlet <NUM>, <NUM>, <NUM>, <NUM> corresponds to the second transfer chamber <NUM>.

The one or more first waste gas inlet <NUM>, <NUM>, <NUM>, <NUM> may be positioned such that the (first portion of the) waste gas enters the first bed <NUM> (indicated by a dashed arrow in <FIG>). Also, the one or more first waste gas inlet <NUM>, <NUM>, <NUM>, <NUM> may be positioned such that the (first portion of the) waste gas enters the regenerative thermal oxidizer <NUM> outside the first bed <NUM> (indicated by a solid arrow in <FIG>).

The first waste gas tube <NUM> may be connected to a third waste gas tube <NUM>. The third waste gas tube <NUM> may connect the waste gas source <NUM> and the first transfer chamber <NUM> and the second transfer chamber <NUM>.

A first portion of waste gas may flow from the waste gas source <NUM> via the first waste gas tube <NUM> and the second waste gas tube <NUM> to the regenerative thermal oxidizer <NUM>. A second portion of waste gas may flow from the waste gas source <NUM> via the first waste gas tube <NUM> and the third waste gas tube <NUM> to the regenerative thermal oxidizer <NUM>.

A valve <NUM> may be implemented between the first waste gas tube <NUM>, the second waste gas tube <NUM> and the third waste gas tube <NUM>. At valve <NUM>, waste gas from the waste gas source <NUM> may be split into a first portion of waste gas and a second portion of waste gas. A flow rate of the first portion of waste gas and the second portion of waste may be controlled, for example by valve <NUM>.

The third waste gas tube <NUM> may comprise at least a first valve <NUM>. The third waste gas tube <NUM> may comprise at least a second valve <NUM>. When the first valve <NUM> is open, waste gas may flow from the waste gas source <NUM> to the first transfer chamber <NUM>. When the first valve <NUM> is closed, waste gas may not flow from the waste gas source <NUM> to the first transfer chamber <NUM>. When the second valve <NUM> is open, waste gas may flow from the waste gas source <NUM> to the second transfer chamber <NUM>. When the second valve <NUM> is closed, waste gas may not flow from the waste gas source <NUM> to the second transfer chamber <NUM>.

The pressure at the waste gas source <NUM> may be higher than at the first transfer chamber <NUM> and/or the second transfer chamber <NUM>. Also, a pressure unit (not shown) may be disposed along the first waste gas tube <NUM>, the second waste gas tube <NUM> and/or the third waste gas tube <NUM> to force the waste gas to the first transfer chamber <NUM> and/or to the second transfer chamber <NUM> and/or to the regenerative thermal oxidizer <NUM>. The pressure unit may be a blower. The waste gas source <NUM> may be an exit or an outlet of a gas treatment unit.

A gas-liquid separation unit <NUM>, for example a knock-out drum or demister, may be disposed along the first waste gas tube <NUM>, the second waste gas tube <NUM> and/or the third waste gas tube <NUM>. The gas-liquid separation unit <NUM> may separate and/or remove liquid components in the waste gas. Preferably, the gas-liquid separation unit <NUM> is positioned close to the waste gas source <NUM>.

The system <NUM> may comprise an oxygen-containing gas tube <NUM>. The oxygen-containing gas tube <NUM> may connect an oxygen-containing gas source <NUM> with the regenerative thermal oxidizer <NUM>, preferably with the first transfer chamber <NUM> and/or the second transfer chamber <NUM>. Oxygen-containing gas may flow from the oxygen-containing gas source <NUM> via the oxygen-containing gas tube <NUM> to the regenerative thermal oxidizer <NUM>.

Specifically, the oxygen-containing gas tube <NUM> may be connected to the third waste gas tube <NUM>. Oxygen-containing gas may flow from the oxygen-containing gas source <NUM> to the third waste gas tube <NUM>. The second portion of waste gas may be mixed with the oxygen-containing gas in the third waste gas tube <NUM>.

The oxygen-containing gas tube <NUM> may comprise at least one valve <NUM>. When the valve <NUM> is open, oxygen-containing gas may flow from the oxygen-containing gas source <NUM> to the regenerative thermal oxidizer <NUM>, preferably via the third waste gas tube <NUM>. When the valve <NUM> is closed, oxygen-containing gas may not flow from the oxygen-containing gas source <NUM> to the regenerative thermal oxidizer <NUM>, preferably may not flow via the third waste gas tube <NUM> to the regenerative thermal oxidizer <NUM>.

A pressure unit (not shown) may be disposed along the oxygen-containing gas tube <NUM> to force the oxygen-containing gas to the regenerative thermal oxidizer <NUM>, in particular to the first transfer chamber <NUM> and/or to the second transfer chamber <NUM> via the third waste gas tube <NUM>. The oxygen-containing gas source <NUM> may be surrounding air. The pressure unit may be a blower.

The system <NUM> may comprise a flue gas tube <NUM>. As will be described in more details below, an oxidizable compound of the waste gas may be oxidized in the reaction chamber <NUM> of the regenerative thermal oxidizer <NUM> by oxygen of the oxygen-containing gas. By oxidizing the oxidizable compound, flue gas may be produced in the reaction chamber <NUM>.

The flue gas tube <NUM> may connect the first transfer chamber <NUM> and/or the second transfer chamber <NUM> with a flue gas outlet <NUM>. Flue gas may flow from the regenerative thermal oxidizer <NUM>, in particular from the reaction chamber <NUM> of the regenerative thermal oxidizer <NUM> or from the first transfer chamber <NUM> and/or from the second transfer chamber <NUM>, via the flue gas tube <NUM> to the flue gas outlet <NUM>.

The flue gas tube <NUM> may comprise at least a first valve <NUM>. The flue gas tube <NUM> may comprise at least a second valve <NUM>. When the first valve <NUM> is open, flue gas may flow from the first transfer chamber <NUM> to the flue gas outlet <NUM>. When the first valve <NUM> is closed, flue gas may not flow from the first transfer chamber <NUM> to the flue gas outlet <NUM>. When the second valve <NUM> is open, flue gas may flow from the second transfer chamber <NUM> to the flue gas outlet <NUM>. When the second valve <NUM> is closed, flue gas may not flow from the second transfer chamber <NUM> to the flue gas outlet <NUM>. The flue gas outlet <NUM> may be the environment of the regenerative thermal oxidizer <NUM>. Thus, flue gas may be released to the environment.

The pressure in the first transfer chamber <NUM> and/or the second transfer chamber <NUM> may be higher than the pressure at the flue gas outlet <NUM>. Also, the flue gas tube <NUM> may comprise a pressure unit (not shown) to force the flue gas towards the flue gas outlet <NUM>. The pressure unit may be a blower.

The system <NUM> may comprise a bypass tube <NUM>. The bypass tube <NUM> may connect a heat exchanger <NUM> with the regenerative thermal oxidizer <NUM>, in particular with the reaction chamber <NUM> of the regenerative thermal oxidizer <NUM>. Gas may flow from the regenerative thermal oxidizer <NUM>, in particular from the reaction chamber <NUM> of the regenerative thermal oxidizer <NUM> to the heat exchanger <NUM>. The gas may be flue gas.

The gas may be cooled in the heat exchanger <NUM>. For example, the heat exchanger <NUM> may be configured to transfer (thermal) energy from the gas to the waste gas (e.g., the first portion of waste gas and/or the second portion of waste gas) prior to entry of the waste gas into the regenerative thermal oxidizer, to the oxygen-containing gas prior to entry of the oxygen-containing gas into the regenerative thermal oxidizer, to a heat recovery system and/or to a superheater.

The bypass tube <NUM> may comprise at least one valve <NUM>. When the valve <NUM> is open, gas may flow from the regenerative thermal oxidizer <NUM> to the heat exchanger <NUM>. When the valve <NUM> is closed, gas may not flow from the regenerative thermal oxidizer <NUM> to the heat exchanger <NUM>.

The pressure in the regenerative thermal oxidizer <NUM> may be higher than the pressure in the heat exchanger. Also, a pressure unit (not shown) may be disposed along the bypass tube <NUM> to force the gas from the regenerative thermal oxidizer <NUM> to the heat exchanger. The pressure unit may be a blower.

The heat exchanger <NUM> may be connected to the flue gas tube <NUM>. Gas exiting the heat exchanger may be introduced into the flue gas tube <NUM>.

<FIG> schematically shows a system <NUM>. Some of the components of the system <NUM> shown in <FIG> are equal to the same components of the system shown in <FIG>. In the following, differences between <FIG> and <FIG> will be described.

The system <NUM> may comprise a regenerative thermal oxidizer <NUM>. The regenerative thermal oxidizer <NUM> may comprise a first transfer chamber <NUM>, a second transfer chamber <NUM> and a third transfer chamber <NUM>. The first transfer chamber <NUM> may include a first bed <NUM>. The second transfer chamber <NUM> may include a second bed <NUM>. The third transfer chamber <NUM> may include a third bed <NUM>. The first transfer chamber <NUM>, the second transfer chamber <NUM> and the third transfer chamber <NUM> may be in fluid flow communication with a reaction chamber <NUM> of the regenerative thermal oxidizer <NUM>.

The first transfer chamber <NUM>, the second transfer chamber <NUM> and the third transfer chamber <NUM> may be physically separated such that the first bed <NUM>, the second bed <NUM> and the third bed <NUM> are physically separated from each other. The separation can be achieved by one or more walls which extend in the regenerative thermal oxidizer <NUM>. For example, the first transfer chamber <NUM> and the second transfer chamber <NUM> may be separated by a first wall. The second transfer chamber <NUM> and the third transfer chamber <NUM> may be separated by a second wall.

The heater <NUM> may be configured to heat the reaction chamber <NUM>. Alternatively or additionally, the first bed <NUM>, the second bed <NUM> and the third bed may be heated by the heater <NUM>.

The system <NUM> may comprise a first waste gas tube <NUM>. The first waste gas tube <NUM> may connect a waste gas source <NUM> and the regenerative thermal oxidizer <NUM>. Specifically, the third waste gas tube <NUM> may connect the waste gas source <NUM> and the first transfer chamber <NUM>, the second transfer chamber <NUM> and the third transfer chamber <NUM>.

The third waste gas tube <NUM> may comprise at least a first valve <NUM>, at least a second valve <NUM>, and at least a third valve <NUM>. When the first valve <NUM> is open, waste gas may flow from the waste gas source <NUM> to the first transfer chamber <NUM>. When the first valve <NUM> is closed, waste gas may not flow from the waste gas source <NUM> to the first transfer chamber <NUM>. When the second valve <NUM> is open, waste gas may flow from the waste gas source <NUM> to the second transfer chamber <NUM>. When the second valve <NUM> is closed, waste gas may not flow from the waste gas source <NUM> to the second transfer chamber <NUM>. When the third valve <NUM> is open, waste gas may flow from the waste gas source <NUM> to the third transfer chamber <NUM>. When the third valve <NUM> is closed, waste gas may not flow from the waste gas source <NUM> to the third transfer chamber <NUM>.

The system <NUM> may comprise an oxygen-containing gas tube <NUM>. The oxygen-containing gas tube <NUM> may connect an oxygen-containing gas source <NUM> with the regenerative thermal oxidizer <NUM>.

The system <NUM> may comprise a flue gas tube <NUM>. The flue gas tube <NUM> may connect the first transfer chamber <NUM>, the second transfer chamber <NUM> and/or the third transfer chamber <NUM> with a flue gas outlet <NUM>.

The flue gas tube <NUM> may comprise at least a first valve <NUM>, at least a second valve <NUM> and at least a third valve <NUM>. When the first valve <NUM> is open, flue gas may flow from the first transfer chamber <NUM> to the flue gas outlet <NUM>. When the first valve <NUM> is closed, flue gas may not flow from the first transfer chamber <NUM> to the flue gas outlet <NUM>. When the second valve <NUM> is open, flue gas may flow from the second transfer chamber <NUM> to the flue gas outlet <NUM>. When the second valve <NUM> is closed, flue gas may not flow from the second transfer chamber <NUM> to the flue gas outlet <NUM>. When the third valve <NUM> is open, flue gas may flow from the third transfer chamber <NUM> to the flue gas outlet <NUM>. When the third valve <NUM> is closed, flue gas may not flow from the third transfer chamber <NUM> to the flue gas outlet <NUM>.

The system may comprise a purge tube <NUM>. The purge tube <NUM> may connect the third waste gas tube <NUM> with the first transfer chamber <NUM>, the second transfer chamber <NUM> and the third transfer chamber <NUM>. Gas, preferably flue gas, may flow from the first transfer chamber <NUM>, the second transfer chamber <NUM> and/or the third transfer chamber <NUM> to the third waste gas tube <NUM>.

The purge tube <NUM> may comprise a first valve <NUM>, a second valve <NUM> and a third valve <NUM>. When the first valve <NUM> is open, gas may flow from the first transfer chamber <NUM> to the third waste gas tube <NUM>. When the first valve <NUM> is closed, gas may not flow from the first transfer chamber <NUM> to the third waste gas tube <NUM>. When the second valve <NUM> is open, gas may flow from the second transfer chamber <NUM> to the third waste gas tube <NUM>. When the second valve <NUM> is closed, gas may not flow from the second transfer chamber <NUM> to the third waste gas tube <NUM>. When the third valve <NUM> is open, gas may flow from the third transfer chamber <NUM> to the third waste gas tube <NUM>. When the third valve <NUM> is closed, gas may not flow from the third transfer chamber <NUM> to the third waste gas tube <NUM>.

The purge gas tube <NUM> may comprise a pressure unit <NUM> to force the gas towards the third waste gas tube <NUM>.

<FIG> schematically shows a transfer chamber of a regenerative thermal oxidizer <NUM>. The transfer chamber will be described with reference to the first transfer chamber <NUM>. Other transfer chambers of the regenerative thermal oxidizer, for example the second transfer chamber <NUM> and/or the third transfer chamber <NUM> may be designed in a similar or equal or equivalent way.

The first transfer chamber <NUM> comprises a bed <NUM>. In <FIG>, a cut plane is indicated. The corresponding cross section view is shown in <FIG>.

The first transfer chamber <NUM> may have a circular or polygonal cross section. The polygonal cross section may be rectangular or square. The cross section may be oriented in a plane perpendicular to a flow direction of the waste gas through the first transfer chamber <NUM>.

The first transfer chamber <NUM> may comprise a waste gas inlet <NUM>. The waste gas inlet <NUM> may be a bore or a hole in the first transfer chamber <NUM>, preferably in a side wall of the first transfer chamber <NUM>. The waste gas inlet <NUM> may comprise a nozzle.

When oxygen-containing gas flows through the first bed <NUM> of the first transfer chamber <NUM> towards the reaction chamber <NUM> of the regenerative thermal oxidizer <NUM>, the waste gas inlet <NUM> may be formed downstream of at least a portion of the first bed <NUM>.

The waste gas inlet <NUM> may be positioned such that the waste gas, preferably the first portion of waste gas, enters the first bed <NUM> of the first transfer chamber <NUM>. Also, the waste gas inlet <NUM> may be positioned such that the waste gas, preferably the first portion of waste gas, enters the regenerative thermal oxidizer <NUM> outside the first bed <NUM> of the first transfer chamber <NUM>.

The first transfer chamber <NUM> may comprise two waste gas inlets <NUM>, <NUM>. Preferably the first transfer chamber <NUM> comprises three waste gas inlets <NUM>, <NUM>, <NUM>, more preferably the first transfer chamber <NUM> comprises four waste gas inlets <NUM>, <NUM>, <NUM>, <NUM>, more preferably the first transfer chamber <NUM> comprises more than four waste gas inlets (not shown).

The one or more oxygen-containing gas inlets <NUM>, <NUM>, <NUM>, <NUM> may be evenly or non-evenly distributed along a circumference of the first transfer chamber <NUM>.

A distance between a portion of the first bed <NUM> and a first waste gas inlet <NUM> may be the same as a distance between the portion of the first bed <NUM> and a second waste gas inlet <NUM>. Each of the waste gas inlets <NUM>, <NUM>, <NUM>, <NUM> may have the same distance to the portion of the first bed <NUM>. In general, the distance may be a distance in the flow direction of oxygen-containing gas through the first transfer chamber <NUM>.

A distance between one or more of the waste gas inlets <NUM>, <NUM>, <NUM>, <NUM> and the portion of the first bed <NUM> may be different than a distance of at least another one of the waste gas inlets <NUM>, <NUM>, <NUM>, <NUM> and the portion of the first bed <NUM>.

<FIG> schematically shows a regenerative thermal oxidizer <NUM> which functions in a similar way as the regenerative thermal oxidizer <NUM> as shown in <FIG> and as described with reference to <FIG>.

The regenerative thermal oxidizer <NUM> may comprise a first transfer chamber <NUM>, a second transfer chamber <NUM> and a third transfer chamber <NUM>. The first transfer chamber <NUM> may comprise a first bed <NUM>. The second transfer chamber <NUM> may comprise a second bed <NUM>. The third transfer chamber <NUM> may comprise a third bed <NUM>.

The first bed <NUM> may be positioned (directly) adjacent or between the second bed <NUM> and the third bed <NUM>. The second bed <NUM> may be positioned (directly) adjacent or between the third bed <NUM> and the first bed <NUM>. The third bed <NUM> may be positioned (directly) adjacent or between the first bed <NUM> and the second bed <NUM>.

The regenerative thermal oxidizer <NUM> may comprise a housing <NUM>. The housing <NUM> may have a substantially cylindrical shape or a substantially circular cross section. The first bed <NUM>, the second bed <NUM> and the third bed <NUM> may be positioned in the housing <NUM>.

The first transfer chamber <NUM> may comprise one or more first waste gas inlet 145a. The second transfer chamber <NUM> may comprise one or more second waste gas inlet 145b. The third transfer chamber <NUM> may comprise one or more waste gas inlet 145c.

<FIG> schematically shows a system <NUM> during a first cycle. The system <NUM> may be similar or equal to the system as shown in <FIG> and described with reference to <FIG>. Flow paths are indicated in the drawings by bold tubes or bold tube sections.

During the first cycle, the first portion of waste gas may be directed from the waste gas source <NUM> to the first transfer chamber <NUM>. The first portion of waste gas may not be directed to the second transfer chamber <NUM>. The first portion of waste gas may be introduced into the first bed <NUM> or outside the first bed <NUM>. The first portion of waste gas may be introduced into the regenerative thermal oxidizer downstream of at least a portion of the first bed <NUM>.

The second portion of waste gas may be directed from the waste gas source <NUM> through the first bed <NUM> towards the reaction chamber <NUM>. The second portion of waste gas may not be directed to the second transfer chamber <NUM>. For example, valve <NUM> may be in open state. Valve <NUM> may be in closed state.

The second portion of waste gas may flow through the first bed <NUM> (indicated by an arrow in <FIG>). The first bed <NUM> may have a higher temperature than the second portion of waste gas such that the second portion of waste gas is preheated. The second portion of waste gas may then be directed to the reaction chamber <NUM> of the regenerative thermal oxidizer <NUM>.

Oxygen-containing gas may be directed from the oxygen-containing gas source <NUM> to the regenerative thermal oxidizer <NUM>. Specifically, oxygen-containing gas may be directed to the third waste gas tube <NUM>. The oxygen-containing gas may be mixed with the second portion of waste gas. The mixture may be introduced into the regenerative thermal oxidizer <NUM>. The oxygen-containing gas may flow through the first bed <NUM> and may be preheated by the first bed <NUM>. For example, valve <NUM> may be in open state.

The at least one oxidizable compound in the waste gas (e.g., first portion of waste gas and second portion of waste gas) may be oxidized in the reaction chamber <NUM>. The oxidization may be a reaction of the at least one oxidizable compound of the waste gas with oxygen of the oxygen-containing gas. Flue gas may be produced by the oxidation in the reaction chamber <NUM>. The flue gas may have a higher temperature than the waste gas. For example, the oxidation may be an exothermic reaction. Thereby, heat may be produced in the reaction chamber <NUM>. Alternatively or additionally, the reaction chamber <NUM> may be heated by the heater <NUM>. However, preferably, the reaction chamber <NUM> is not heated by the heater during the first cycle.

The flue gas may be directed from the reaction chamber <NUM> to the second transfer chamber <NUM>. Specifically, the flue gas may flow through the second bed <NUM> (indicated by an arrow in <FIG>) of the second transfer chamber <NUM>. The flue gas may have a higher temperature than the second bed <NUM>. Thus, the second bed <NUM> may be heated by the flue gas. At the same time, the flue gas may be cooled by the second bed <NUM>.

Flue gas may flow from the second transfer chamber <NUM> to the flue gas outlet <NUM>. For example, valve <NUM> may be in open state. Valve <NUM> may be in closed state. Flue gas may not flow from the first transfer chamber <NUM> to the flue gas outlet.

<FIG> schematically shows the system <NUM> during a second cycle. The system <NUM> may be similar or equal to the system as shown in <FIG> and described with reference to <FIG>.

During the second cycle, the first portion of waste gas may be directed from the waste gas source <NUM> to the second transfer chamber <NUM>. The first portion of waste gas may not be directed to the first transfer chamber <NUM>. The first portion of waste gas may be introduced into the second bed <NUM> or outside the second bed <NUM>. The first portion of waste gas may be introduced into the regenerative thermal oxidizer <NUM> downstream of at least a portion of the second bed <NUM>.

The second portion of waste gas may be directed from the waste gas source <NUM> through the second bed <NUM> towards the reaction chamber <NUM>. The second portion of waste gas may not be directed to the first transfer chamber <NUM>. For example, valve <NUM> may be in open state. Valve <NUM> may be in closed state.

The second portion of waste gas may flow through the second bed <NUM> (indicated by an arrow in <FIG>). The second bed <NUM> may have a higher temperature than the second portion of waste gas such that the second portion of waste gas is preheated. The second portion of waste gas may then be directed to the reaction chamber <NUM> of the regenerative thermal oxidizer <NUM>.

Oxygen-containing gas may be directed from the oxygen-containing gas source <NUM> to the regenerative thermal oxidizer <NUM>. Specifically, oxygen-containing gas may be directed to the third waste gas tube <NUM>. The oxygen-containing gas may be mixed with the second portion of waste gas. The mixture may be introduced into the regenerative thermal oxidizer <NUM>. The oxygen-containing gas may flow through the second bed <NUM> and may be preheated by the second bed <NUM>. Valve <NUM> may be in open state.

The at least one oxidizable compound in the waste gas (e.g., first portion of waste gas and second portion of waste gas) may be oxidized in the reaction chamber <NUM> and flue gas may be produced. The reaction chamber <NUM> may be heated by the heater <NUM>. However, preferably, the reaction chamber <NUM> is not heated by the heater <NUM> during the second cycle.

The flue gas may be directed from the reaction chamber <NUM> to the first transfer chamber <NUM>. Specifically, the flue gas may flow through the first bed <NUM> (indicated by an arrow in <FIG>) of the first transfer chamber <NUM>. The flue gas may have a higher temperature than the first bed <NUM>. Thus, the first bed <NUM> may be heated by the flue gas and the flue gas may be cooled by the first bed <NUM>.

Flue gas may flow from the first transfer chamber <NUM> to the flue gas outlet <NUM>. For example, valve <NUM> may be in open state. Valve <NUM> may be in closed state. Flue gas may not flow from the second transfer chamber <NUM> to the flue gas outlet.

During the first cycle, the first portion of waste gas may be directed from the waste gas source <NUM> to the first transfer chamber <NUM>. The first portion of waste gas may not be directed to the second transfer chamber <NUM> and/or the third transfer chamber <NUM>. The first portion of waste gas may be introduced into the first bed <NUM> or outside the first bed <NUM>. The first portion of waste gas may be introduced into the regenerative thermal oxidizer downstream of at least a portion of the first bed <NUM>.

The second portion of waste gas may be directed from the waste gas source <NUM> through the first bed <NUM> towards the reaction chamber <NUM>. The second portion of waste gas may not be directed to the second transfer chamber <NUM> and/or to the third transfer chamber <NUM>. For example, valve <NUM> may be in open state. Valves <NUM> and <NUM> may be in closed state.

The second portion of waste gas may flow through the first bed <NUM> (indicated by an arrow in <FIG>). The second portion of waste gas may be preheated. The second portion of waste gas may then be directed to the reaction chamber <NUM> of the regenerative thermal oxidizer <NUM>.

A portion of the flue gas may be directed from the reaction chamber <NUM> to the third transfer chamber <NUM>. Specifically, the portion of the flue gas may flow through the third bed <NUM> (indicated by an arrow in <FIG>) of the third transfer chamber <NUM>. The portion of the flue gas may have a higher temperature than the third bed <NUM>. Thus, the third bed <NUM> may be heated by the portion of the flue gas. At the same time, the portion of the flue gas may be cooled by the third bed <NUM>.

The portion of the flue gas may flow from the third transfer chamber <NUM> to the flue gas outlet <NUM>. For example, valve <NUM> may be in open state. Valves <NUM> and <NUM> may be in closed state. Flue gas may not flow from the first transfer chamber <NUM> and/or the second transfer chamber <NUM> to the flue gas outlet <NUM>.

Another portion of the flue gas may be directed from the reaction chamber <NUM> to the second transfer chamber <NUM>. Preferably, the portion of the flue gas may flow through the second bed <NUM> (indicated by an arrow in <FIG>). The portion of the flue gas may flow from the second transfer chamber <NUM> to the purge tube <NUM>. Preferably, the purge tube <NUM> is not in fluid flow communication with the first transfer chamber <NUM> and/or with the third transfer chamber <NUM> during the first cycle. For example, valve <NUM> may be in open state. Valve <NUM> may be in closed state. Valve <NUM> may be in closed state.

The portion of the flue gas may flow from the purge tube <NUM> to the third waste gas tube <NUM>. From the third waste gas tube <NUM>, the portion of the flue gas may enter the first transfer chamber <NUM>, preferably together with waste gas. By directing a portion of the flue gas through the second transfer chamber <NUM>, the second transfer chamber <NUM> may be purged or flushed.

Alternatively, oxygen-containing gas or another gas may be used to purge or flush the second transfer chamber <NUM>. In this case, oxygen-containing gas or another gas may be directed to the second transfer chamber <NUM> and through the second bed <NUM> to the reaction chamber <NUM>.

The portion of the flue gas that is directed through the second bed <NUM> may be smaller than the portion of the flue gas that is directed through the third bed <NUM>. For example, less than <NUM> % of the flue gas, preferably less than <NUM> % of the flue gas, more preferably less than <NUM> % of the flue gas, more preferably less than <NUM> % of the flue gas, more preferably less than <NUM> % of the flue gas, may be directed through the second bed <NUM>. The relative values (percentage values) are based on the total amount of flue gas that flows through the second bed <NUM> and the third bed <NUM>.

During the second cycle, the first portion of waste gas may be directed from the waste gas source <NUM> to the third transfer chamber <NUM>. The first portion of waste gas may not be directed to the first transfer chamber <NUM> and/or the second transfer chamber <NUM>. The first portion of waste gas may be introduced into the third bed <NUM> or outside the third bed <NUM>. The first portion of waste gas may be introduced into the regenerative thermal oxidizer <NUM> downstream of at least a portion of the third bed <NUM>.

The second portion of waste gas may be directed from the waste gas source <NUM> through the third bed <NUM> towards the reaction chamber <NUM>. The second portion of waste gas may not be directed to the first transfer chamber <NUM> and/or to the second transfer chamber <NUM>. For example, valve <NUM> may be in open state. Valves <NUM> and <NUM> may be in closed state.

The second portion of waste gas may flow through the third bed <NUM> (indicated by an arrow in <FIG>). The second portion of waste gas may be preheated. The second portion of waste gas may then be directed to the reaction chamber <NUM> of the regenerative thermal oxidizer <NUM>.

Oxygen-containing gas may be directed from the oxygen-containing gas source <NUM> to the regenerative thermal oxidizer <NUM>. The oxygen-containing gas may be mixed with the second portion of waste gas in the third waste gas tube <NUM>. The mixture may be introduced into the regenerative thermal oxidizer <NUM>. The oxygen-containing gas may flow through the third bed <NUM> and may be preheated by the third bed <NUM>. For example, valve <NUM> may be in open state.

The at least one oxidizable compound in the waste gas (e.g., first portion of waste gas and second portion of waste gas) may be oxidized in the reaction chamber <NUM>. Flue gas may be produced by the oxidation in the reaction chamber <NUM>. The flue gas may have a higher temperature than the waste gas. The reaction chamber <NUM> may be heated by the heater <NUM>. However, preferably, the reaction chamber <NUM> is not heated by the heater during the second cycle.

A portion of the flue gas may be directed from the reaction chamber <NUM> to the second transfer chamber <NUM>. Specifically, the portion of the flue gas may flow through the second bed <NUM> (indicated by an arrow in <FIG>) of the second transfer chamber <NUM>. The portion of the flue gas may have a higher temperature than the second bed <NUM> and the second bed <NUM> may be heated by the portion of the flue gas.

The portion of the flue gas may flow from the second transfer chamber <NUM> to the flue gas outlet <NUM>. For example, valve <NUM> may be in open state. Valves <NUM> and <NUM> may be in closed state. Flue gas may not flow from the first transfer chamber <NUM> and/or the third transfer chamber <NUM> to the flue gas outlet <NUM>.

Another portion of the flue gas may be directed from the reaction chamber <NUM> to the first transfer chamber <NUM>. Preferably, the portion of the flue gas may flow through the first bed <NUM> (indicated by an arrow in <FIG>). The portion of the flue gas may flow from the first transfer chamber <NUM> to the purge tube <NUM>. Preferably, the purge tube <NUM> is not in fluid flow communication with the second transfer chamber <NUM> and/or with the third transfer chamber <NUM> during the second cycle. For example, valve <NUM> may be in open state. Valve <NUM> may be in closed state. Valve <NUM> may be in closed state.

The portion of the flue gas may flow from the purge tube <NUM> to the third waste gas tube <NUM>. From the third waste gas tube <NUM>, the portion of the flue gas may enter the third transfer chamber <NUM>, preferably together with waste gas. By directing a portion of the flue gas through the first transfer chamber <NUM>, the first transfer chamber <NUM> may be purged or flushed.

Alternatively, oxygen-containing gas or another gas may be used to purge or flush the first transfer chamber <NUM>. In this case, oxygen-containing gas or another gas may be directed to the first transfer chamber <NUM> and through the first bed <NUM> to the reaction chamber <NUM>.

<FIG> schematically shows the system <NUM> during a third cycle. The system <NUM> may be similar or equal to the system as shown in <FIG> and described with reference to <FIG>.

During the third cycle, the first portion of waste gas may be directed from the waste gas source <NUM> to the second transfer chamber <NUM>. The first portion of waste gas may not be directed to the first transfer chamber <NUM> and/or the third transfer chamber <NUM>. The first portion of waste gas may be introduced into the second bed <NUM> or outside the second bed <NUM>. The first portion of waste gas may be introduced into the regenerative thermal oxidizer <NUM> downstream of at least a portion of the second bed <NUM>.

The second portion of waste gas may be directed from the waste gas source <NUM> through the second bed <NUM> towards the reaction chamber <NUM>. The second portion of waste gas may not be directed to the first transfer chamber <NUM> and/or to the third transfer chamber <NUM>. For example, valve <NUM> may be in open state. Valves <NUM> and <NUM> may be in closed state.

The second portion of waste gas may flow through the second bed <NUM> (indicated by an arrow in <FIG>). The second portion of waste gas may be preheated. The second portion of waste gas may then be directed to the reaction chamber <NUM> of the regenerative thermal oxidizer <NUM>.

Oxygen-containing gas may be directed from the oxygen-containing gas source <NUM> to the regenerative thermal oxidizer <NUM>. The oxygen-containing gas may be mixed with the second portion of waste gas in the third waste gas tube <NUM>. The mixture may be introduced into the regenerative thermal oxidizer <NUM>. The oxygen-containing gas may flow through the second bed <NUM> and may be preheated by the second bed <NUM>. For example, valve <NUM> may be in open state.

A portion of the flue gas may be directed from the reaction chamber <NUM> to the first transfer chamber <NUM>. Specifically, the portion of the flue gas may flow through the first bed <NUM> (indicated by an arrow in <FIG>) of the first transfer chamber <NUM>. The portion of the flue gas may have a higher temperature than the first bed <NUM> and the first bed <NUM> may be heated by the portion of the flue gas.

The portion of the flue gas may flow from the first transfer chamber <NUM> to the flue gas outlet <NUM>. For example, valve <NUM> may be in open state. Valves <NUM> and <NUM> may be in closed state. Flue gas may not flow from the second transfer chamber <NUM> and/or the third transfer chamber <NUM> to the flue gas outlet <NUM>.

Another portion of the flue gas may be directed from the reaction chamber <NUM> to the third transfer chamber <NUM>. Preferably, the portion of the flue gas may flow through the third bed <NUM> (indicated by an arrow in <FIG>). The portion of the flue gas may flow from the third transfer chamber <NUM> to the purge tube <NUM>. Preferably, the purge tube <NUM> is not in fluid flow communication with the first transfer chamber <NUM> and/or with the second transfer chamber <NUM> during the third cycle. For example, valve <NUM> may be in open state. Valve <NUM> may be in closed state. Valve <NUM> may be in closed state.

The portion of the flue gas may flow from the purge tube <NUM> to the third waste gas tube <NUM>. From the third waste gas tube <NUM>, the portion of the flue gas may enter the second transfer chamber <NUM>, preferably together with waste gas. By directing a portion of the flue gas through the third transfer chamber <NUM>, the third transfer chamber <NUM> may be purged or flushed.

Alternatively, oxygen-containing gas or another gas may be used to purge or flush the third transfer chamber <NUM>. In this case, oxygen-containing gas or another gas may be directed to the third transfer chamber <NUM> and through the third bed <NUM> to the reaction chamber <NUM>.

The regenerative thermal oxidizer may be operated in six cycles.

For example, the first cycle may include a first subcycle and a second subcycle. During the first subcycle, the oxygen-containing gas and/or the second portion of waste gas may flow through the first bed <NUM> to the reaction chamber <NUM>, the second bed <NUM> may be purged or flushed, and flue gas may be directed through the third bed <NUM> towards the flue gas outlet <NUM>. During the second subcycle, the oxygen-containing gas and/or the second portion of waste gas may flow through the first bed <NUM> to the reaction chamber <NUM>, the third bed <NUM> may be purged or flushed, and flue gas may be directed through the second bed <NUM> towards the flue gas outlet <NUM>.

The second cycle may include a first subcycle and a second subcycle. During the first subcycle, the oxygen-containing gas and/or the second portion of waste gas may flow through the third bed <NUM> to the reaction chamber <NUM>, the first bed <NUM> may be purged or flushed, and flue gas may be directed through the second bed <NUM> towards the flue gas outlet <NUM>. During the second subcycle, the oxygen-containing gas and/or the second portion of waste gas may flow through the third bed <NUM> to the reaction chamber <NUM>, the second bed <NUM> may be purged or flushed, and flue gas may be directed through the first bed <NUM> towards the flue gas outlet <NUM>.

The third cycle may include a first subcycle and a second subcycle. During the first subcycle, the oxygen-containing gas and/or the second portion of waste gas may flow through the second bed <NUM> to the reaction chamber <NUM>, the third bed <NUM> may be purged or flushed, and flue gas may be directed through the first bed <NUM> towards the flue gas outlet <NUM>. During the second subcycle, the oxygen-containing gas and/or the second portion of waste gas may flow through the second bed <NUM> to the reaction chamber <NUM>, the first bed <NUM> may be purged or flushed, and flue gas may be directed through the third bed <NUM> towards the flue gas outlet <NUM>.

<FIG> schematically shows a system <NUM> during a start-up cycle. The system <NUM> may be similar or equal to the system as shown in <FIG> and described with reference to <FIG>. Flow paths are indicated in the drawings by bold tubes or bold tube sections.

During the start-up cycle, the heater <NUM> may be operated to heat the regenerative thermal oxidizer <NUM>. Preferably, at least the reaction chamber <NUM> and/or at least one of the first, second and third beds <NUM>, <NUM>, <NUM> are heated. The heater <NUM> may be a burner or an electrical heater.

The heater <NUM> may heat the reaction chamber <NUM> to a predetermined temperature, e.g., at least <NUM> or at least <NUM>. When the predetermined temperature in the reaction chamber <NUM> is reached, a first cycle, a second cycle or a third cycle as described above may be performed.

During the start-up cycle, a gas may flow through at least one of the first transfer chamber <NUM>, the second transfer chamber <NUM> and the third transfer chamber <NUM>. The gas may be oxygen-containing gas.

For example, the first transfer chamber <NUM>, the second transfer chamber <NUM> and/or the third transfer chamber <NUM> may be in fluid flow communication with the oxygen-containing gas source <NUM>. Valve <NUM> may be in open state. Valve <NUM> may be in closed state. Thereby, oxygen-containing gas may flow from the oxygen-containing gas source <NUM> to the first transfer chamber <NUM>, the second transfer chamber <NUM> and/or the third transfer chamber <NUM>.

The gas may flow through at least one of the first transfer chamber <NUM>, the second transfer chamber <NUM> and/or the third transfer chamber <NUM> to the reaction room <NUM>. From the reaction room <NUM>, the gas may exit the regenerative thermal oxidizer <NUM> by flowing through at least one of the first transfer chamber <NUM>, the second transfer chamber <NUM> and/or the third transfer chamber <NUM> to the flue gas tube <NUM>. Valve <NUM>, valve <NUM> and/or valve <NUM> may be in open state.

Claim 1:
A regenerative thermal oxidizer (<NUM>) comprising:
at least a first transfer chamber (<NUM>, <NUM>, <NUM>) and at least a second transfer chamber (<NUM>, <NUM>, <NUM>), wherein the first transfer chamber (<NUM>, <NUM>, <NUM>) comprises a first bed (<NUM>, <NUM>, <NUM>) and the second transfer chamber (<NUM>, <NUM>, <NUM>) comprises a second bed (<NUM>, <NUM>, <NUM>);
at least one reaction chamber (<NUM>) in fluid flow communication with the first transfer chamber (<NUM>, <NUM>, <NUM>) and with the second transfer chamber (<NUM>, <NUM>, <NUM>); and
one or more first waste gas inlet (<NUM>, <NUM>, <NUM>, <NUM>) for introducing at least a first portion of waste gas into the regenerative thermal oxidizer (<NUM>) positioned between at least a portion of the first bed (<NUM>, <NUM>, <NUM>) and at least a portion of the reaction chamber (<NUM>);
characterised in that the regenerative thermal oxidizer (<NUM>) further comprises:
one or more second waste gas inlet (<NUM>, <NUM>, <NUM>, <NUM>) for introducing the first portion of waste gas into the regenerative thermal oxidizer (<NUM>) positioned between at least a portion of the second bed (<NUM>, <NUM>, <NUM>) and at least a portion of the reaction chamber (<NUM>).