An apparatus and a method for processing a feedstock material using microwave radiation

Abstract

An apparatus adapted to and a method for processing a feedstock material. The apparatus comprising at least one microwave source unit and at least one process unit. The process unit comprises a first elongated rod element, and a second elongated electrical conductor surrounding the first elongated rod element at a distance from each other, thereby forming an elongated feedstock process chamber. The process unit at least has a first waveguide port, wherein the first waveguide port is operatively connected to the at least one microwave source unit and adapted to guide microwave radiation generated by the microwave unit via the first waveguide port into the feedstock process chamber. The process unit further comprises at least one feedstock material port provided in the first elongated rod element or the second electrical conductor for feeding the feedstock material into the feedstock process chamber.

Description

[0001] Title

[0002] An apparatus and a method for processing a feedstock material using microwave radiation

[0003] Background

[0004] In a few decades many of earth’s natural deposits are expected to be depleted, therefore the recycling of materials will become increasingly important in order to keep the availability of raw materials in the market. Despite this, many materials are still combusted or buried after their primary use. Incineration destroys valuable raw materials, while burial lead to uncontrolled decomposition processes that result in the formation of gases and liquids that must be treated separately, often at great expense. Methane gas, for example, is often produced from landfill sites and a large percentage of it is simply flared off.

[0005] A catalytic chemistry process, driven by microwaves, can be used to process solids such as plastics, gases such as methane, and liquids such as oils, into high- quality raw materials. Unfortunately, microwave systems that provide good conversions and yields in the laboratory setting, are often found to be difficult for scaling up to industrial viability. Hitherto, researchers have only been successful in breaking down a few grams of plastic in laboratory settings.

[0006] It is therefore the goal of the disclosure to circumvent the problems of existing heat-based recycling apparatuses, to be as efficient as small lab scale microwave reactors and also provide high throughput of the feedstock material and high-quality product yield at an industrial scale.

[0007] Summary of the invention

[0008] The disclosure pertains to an apparatus adapted to process a feedstock material. The apparatus comprises at least one microwave source unit and at least one process unit, wherein the process unit comprises a first elongated rod element and a second elongated electrical conductor surrounding the first elongated rod element at a distance from each other, thereby forming an elongated feedstock process chamber, in the form of a waveguide. The process unit has at least an initial waveguide port, wherein this first waveguide port is physically connected to at least one microwave source unit and adapted to guide microwave radiation generated by the microwave unit via the first waveguide port into the feedstock process chamber. The process unit further comprises at least one feedstock material port provided in the first elongated rod element or the second electrical conductor for feeding the feedstock material into the feedstock process chamber, in the form of a waveguide.

[0009] By providing some distance between the first elongated rod element and the second electrical conductor a hollow space is generated, which is labelled the feedstock process chamber, in the form of a waveguide. It may be understood that the first elongated rod element in the elongated length direction is never touching the second electrical conductor. This hollow space is used to be filled with the feedstock material, such that microwave radiation that is contained between the first elongated rod element and the second electrical conductor is absorbed by the feedstock material.

[0010] During operation, a feedstock material is fed into the apparatus through the at least one feedstock material port and processed with microwave radiation by means of electromagnetic absorption, such that the feedstock material heats up and disintegrates. Thereafter, the products of the microwave treated feedstock material are collected in the feedstock process chamber and / or exits through the at least one feedstock material port. In a preferable configuration this process occurs continuously, such that high throughput of the feedstock material can be achieved.

[0011] The feedstock material can be fed into the apparatus with ease through the at least feedstock material port because the feedstock material may act as a fluid. Namely, the feedstock material may be a bulk solid comminuted into particulates, for example plastic, or it may be a liquid, for example methanol or formic acid, or it may be a gas, for example methane or ethane. The feedstock material and / or a potentially used catalyst, may thus be understood to be liquid, gaseous, or solid.

[0012] Furthermore, the configuration of an apparatus having a first elongated rod element being surrounded by a second elongated conductor allows for better power acceptance of the microwave radiation by the feedstock material, a higher efficiency, a higher power level and a high-volume continuous process. This allows the apparatus to be as efficient as small lab-scale reactors, while still allowing feedstock material throughput at an industrial scale, such that high-quality raw materials can be efficiently produced at a continuous rate.

[0013] As an example, the first elongated rod element can either be made of an electrically conductive material, or can be made of a dielectric material, such as but not limited to alumina, quartz, sapphire, carbon, PTFE, PEEK, or polyethylene (PE).

[0014] When the first elongated rod element is made of an electrically conductive material the microwave radiation in the feedstock process chamber can be controlled more effectively.

[0015] In an example of the disclosure, the feedstock process chamber further comprises a second or multiple waveguide port(s) at some distance of the first waveguide port seen along the elongated guide orientation of the feedstock process chamber, operatively connected to the at least one microwave source unit and adapted to guide the microwave radiation via the second or multiple waveguide port(s) into the feedstock process chamber.

[0016] In this configuration microwave radiation is guided into the feedstock process chamber from two directions. This way, more microwave radiation power can be subjected to the feedstock material, such that the microwave process obtains a higher efficiency and / or such that more feedstock material can be processed in a shorter amount of time, leading to higher throughput.

[0017] In another example, the at least one microwave source unit comprises a first and a second microwave source unit, wherein the first microwave source unit is operatively connected to the first waveguide port and the second microwave source unit is operatively connected to the second waveguide port.

[0018] In yet another example, the at least one microwave source unit may further comprise a further microwave source unit operatively connected to the feedstock process chamber through the second electrical conductor.

[0019] One single microwave source unit might not output enough power for a given feedstock microwave process, might be too costly to manufacture, or might have a too large form-factor, therefore multiple sources may be connected to reach the desired adequate power, reduce overall costs of the apparatus, or reduce the overall size of the apparatus, respectively.

[0020] According to the disclosure, in yet another example, the at least one feedstock material port is provided at a location between the first waveguide port and the second waveguide port seen along the elongated guide orientation of the feedstock process chamber.

[0021] Alternatively, in an example, the at least one feedstock material port is provided upstream of the first waveguide port seen along the elongated guide direction of the feedstock process chamber.

[0022] For feeding feedstock material into the feedstock process chamber the feedstock material port feeds the material directly into the feedstock process chamber. Then processing can occur immediately, since the feedstock material is subjected immediately to high-intensity microwave radiation upon entering of the feedstock process chamber.

[0023] In another example the first elongated rod element comprises at least one tapered section seen along the elongated guide direction of the feedstock process chamber.

[0024] Alternatively, according to another example of the disclosure the second electrical conductor comprises at least one tapered section seen along the elongated guide direction of the feedstock process chamber.

[0025] Providing a taper in either the first elongated rod element and / or the second electrical conductor allows to shape the microwave radiation throughout the feedstock process chamber. For example, the microwave radiation density could be shaped such that it reflects the absorption changes of the feedstock material, as is it being processed while traveling through the feedstock process. In this regard, it can be understood that the feedstock material has not been processed when it is supplied into the feedstock process chamber, but the further it travels from the feedstock material port, the more it has been processed. In other words, the pure feedstock material goes from pure to a mixture with the product material, thereby changing its dielectric properties.

[0026] In yet another example, the first elongated rod element and the second electrical conductor are oriented parallel to each other, such that the distance of a surface normal of the first elongated rod element towards the second electrical conductor are equidistant along the entire guide direction of the waveguide.

[0027] It should be noted that the surfaces of the first and second electrical conductor do not necessarily need to be straight or linear. Namely, they can also be tapered or even be wavy. In this example of the disclosure, wherein the first elongated rod element and second electrical conductor are parallel to each other, the same distance is maintained throughout the feedstock process chamber, in the form of a waveguide, such that the electromagnetic field shape is conserved throughout the feedstock process chamber.

[0028] A cross-section of the first elongated rod element, in yet another example according to the disclosure, taken perpendicular to the elongated guide direction of the feedstock process chamber has a cross-sectional shape, which is selected from but not limited to circular, elliptical, rectangular, starred, or square.

[0029] Alternatively, in another example, a cross-section of the second electrical conductor taken perpendicular to the elongated guide direction of the feedstock process chamber has a cross-sectional shape, which is selected from but not limited to circular, elliptical, rectangular, starred, or square.

[0030] It should be understood that the different cross-sectional shapes distribute the microwave radiation differently. Additionally, they offer a different volume for the feedstock material in the feedstock process chamber. Dependent on the exact feedstock material and or the desired throughput, the first and the second electrical conductor may have a similar cross-sectional shape or might have different cross- sectional shapes. It should also be noted that the cross-sectional shape is not per se conserved. For instance, close to the first waveguide port the cross-sectional shape of either rod element or electrical conductor might be spherical, whereas close to the second waveguide port the cross-sectional shape may be rectangular.

[0031] It should be understood that the diameters of the cross-sections of either the rod element and / or electrical conductor may vary within the same basis cross-sectional shape. I.e., the electrical conductor may be a straight tube, with the rod element having different diameters seen along the length direction. These diameters may be ad hock or step-like, or smooth transitions in transition section. In another example, the rod element is a straight rod, and the outer electrical conductor has a varying diameter. The localized varying volume of the feedstock process chamber, or in other words the effective cross-sectional area of the feedstock process chamber at a given position along its length, is important for the impedance matching and the resulting frequency bandwidth. This ensures, high efficiency of transferring the microwave radiation energy into the feedstock material. According to another example, the first elongated rod element and the second electrical conductor may be oriented coaxially with respect to each other.

[0032] Throughout the disclosure, coaxial is defined as having a common central axis. However, due to engineering tolerances, it may be understood that coaxial rod element and conductor have the same central axis within a range of 5% of their respective cross-sectional dimensions.

[0033] In an example, the first elongated rod element comprises temperature regulating means and / or wherein the second elongated electrical conductor comprises temperature regulating means.

[0034] Temperature regulating means may be understood as a cooling liquid which is being flowed through or passed by the surfaces of the first elongated rod and / or second elongated electrical conductor, as well as a temperature sensor which contact the cooling liquid, such that the process chamber and the material therein obtain the same temperature as the cooling liquid. Alternatively, the temperature regulating means may be understood as electrical temperature regulating means, which are in direct contact with the surfaces of the first elongated rod element comprises temperature regulating means and / or wherein the second elongated electrical conductor. Furthermore, a controller and a temperature sensor would be comprised by the temperature regulating means, such that a feedback system is obtained to control the temperature regulating means. The temperature sensor may be placed inside the process chamber, but preferably is placed outside the process chamber, i.e. contacting the surface of the first elongated rod element and / or the surface of the second elongated electrical conductor and / or the cooling liquid.

[0035] In a particular example thereof, the first elongated rod is hollow, such that a coolant can be flowed through the first elongated rod. That way, it is possible to precisely and finely monitor and control the temperature of the feedstock material being subjected to microwave radiation. The coolant can be gas or a liquid, such as oil, water, or water / glycol mixture, connected to a bath with a pump. In a preferred example, the first elongated rod comprises two concentric tubes, wherein coolant can be fed into the core tube. The two concentric tubes are of a different length, such that the coolant can travel upwards through the space between the two tubes. The two tubes may be separated for connecting for a respective inlet and outlet of a cooling system, wherein the system may comprise a pump and a cooling liquid bath. Note that the separation may only occur after the combined concentric tubes extend past the process chamber and / or central waveguide. Namely, otherwise the electromagnetic field from the microwave radiation coming from the microwave source may be disturbed, reducing power transfer to the feedstock material or changing the microwave radiation distribution in the process chamber.

[0036] In a further example, the second elongated conductor can be temperature controlled from the outside of the process chamber as well by means of a coolant.

[0037] In the previous two examples, the precise temperature control of the feedstock material allows for putting in higher microwave radiation power to either speed-up the process or to perform chemical processes requiring higher energy levels.

[0038] In other words, an example of the apparatus may comprise a first elongated rod element that is temperature controlled and / or a second elongated electrical conductor that is temperature controlled.

[0039] The feedstock process chamber, in yet another example, is oriented at least substantially vertically with respect to a horizontal.

[0040] In this configuration, the apparatus is oriented upright such that gravity may assist the flow of feedstock material, especially for the cases, wherein the feedstock material is solid or liquid. This way, the feedstock material can be pulled into the apparatus, such that no additionally feeding machines or pumps are needed, thereby reducing the costs, and reducing the energy usage of the apparatus.

[0041] In a further example, the at least one feedstock material port is formed as a plurality of openings.

[0042] Thus far, no specifications have been given to the at least one feedstock material port, however a person skilled in the art may understand that an over large, even by being of a few millimetres, opening of the at least one feedstock material port may leak out microwave radiation, thereby reducing the efficiency of the apparatus and risks to the environment. Therefore, to obtain higher throughput of feedstock material and not leak microwave radiation, a plurality of openings may be used, such that microwave radiation cannot leak out, but feedstock material may still enter the apparatus. These openings may be provided around the periphery of the second electrical conductor.

[0043] Furthermore, it may be understood that these openings may have shapes, being circular, square, rectangular, oval, star, etc., or they might be formed as slits. The process unit, in another example, may comprise at least one feedstock supply member adapted to contain and supply the feedstock material to the at least one feedstock material port.

[0044] In order to guide feedstock material properly and continuously into the apparatus, the apparatus may be equipped with a supply member, for instance a funnel or a chute. This way feedstock material can be contained and supplied in an efficient manner, otherwise individual particulates, or drops of liquid etc. have to be supplied into the system through other means, which would lead to reduced throughput.

[0045] As a first example of this, the feedstock supply member may be formed as a supply pipe communicating with the at least one feedstock material port. Alternatively, as a second example, the feedstock supply member is formed as a tapered member mounted to and surrounding the at least one feedstock material port.

[0046] A pipe would be beneficial for instance for liquid or gaseous feedstock material, since that has better flow properties to be transferred through a pipe into the feedstock process chamber. The second example of a tapered member surrounding the at least one feedstock material port may be used for liquid and / or solid feedstock material, such as high viscosity liquids or particulates, which has worse flow properties when needing to be supplied through a pipe. The tapered member may even be shaped like a cone, or a hopper attached to the feedstock process chamber, such that a small form factor container is formed in which the feedstock material can be stored and supplied from into the feedstock process chamber.

[0047] In another example, the at least one feedstock material port comprises a first and at least one further feedstock material port.

[0048] Dependent on the application and the material of the feedstock material, the products of the microwave process may not solely be gaseous. Furthermore, in those cases to not suspend or halt the microwave process, open the feedstock process chamber, and remove the products, the at least one further feedstock material port may be used to create two potential exits for the products of the microwave process: namely, the first feedstock material port and the at least one further feedstock material port.

[0049] It should be noted, that alternatively, even the at least one further feedstock material port may be used to provide feedstock material into the feedstock process chamber, and to collect the products at the first feedstock process chamber. At least, having two feedstock material ports allows for establishing a continuous flow of feedstock material going into and products coming out of the feedstock process chamber.

[0050] In a particular example, the first feedstock material port is positioned near the first waveguide port at a first end of the feedstock process chamber and the at least one further feedstock material port is positioned near the other end of the feedstock process chamber.

[0051] In this configuration the two feedstock material ports are positioned at the ends of the waveguide, such that the material is subjected to the microwave radiation through the entire feedstock process chamber, in the form of a waveguide, thereby improving the power absorption.

[0052] Furthermore, this configuration ensures that there are no dead spots for the flow of the feedstock material, where feedstock material of products might get caught. This way, the flow of the feedstock material in the feedstock process chamber is also improved.

[0053] In the same way more than two feedstock material ports are possible along the process chamber.

[0054] According to yet another example of the disclosure, the process unit comprises at least one discharge unit adapted to discharge the processed feedstock material through the at least one further feedstock material port from the waveguide.

[0055] In this configuration, products from the microwave radiation process can be guided away from the apparatus, thereby improving the flow of the feedstock material, such that clogging is reduced.

[0056] In another example, the apparatus may further comprise a gas collector adapted to collect fluids generated in the feedstock process chamber from processing the feedstock material.

[0057] For instance, said gas collector may have a conical shape surrounding the feedstock process chamber positioned above the at least one feedstock material port, such that (a lighter-than-air) gaseous product material exiting the apparatus by travelling through the at least one feedstock material port can be collected.

[0058] Alternatively, a gas collector may be positioned on the inside of the feedstock process chamber, such that gaseous products from the microwave radiation process may be directed away out of the feedstock process chamber. The at least one process unit of the apparatus, as an example, may further comprise an agitator unit adapted to promote the supply of the feedstock material towards the feedstock process chamber.

[0059] Having an agitator unit may help feeding feedstock material through the feedstock process chamber of the apparatus. Especially, high viscosity liquids or solid feedstock material might flow with difficultly through the feedstock process chamber. By agitating the feedstock material its flow may therefore be improved, such that higher throughput can be achieved.

[0060] In yet another example, a surface side of the first elongated rod element and / or the second electrical conductor facing the feedstock process chamber is / are provided with a coating or cover material.

[0061] In some processes, the products of the microwave radiation process may chemically interact with the first elongated rod element and / or the second electromagnetic conductor. Providing a coating material on them may help to protect the feedstock process chamber against these products of the microwave radiation process. This coating material may be selected from a list not limited to stainless steel, aluminium, brass, copper, alumina, quartz, sapphire, carbon, diamond, platinum, or polymeric material, such as PTFE or PEEK.

[0062] According to the disclosure, the first elongated rod element and / or second electrical conductor, for example, are at least partially made of an electrically conductive material, such as a metal, like stainless steel, aluminium, brass, or copper.

[0063] In another example according to the disclosure, the first elongated rod element and / or second electrical conductor might have openings in the metallic surface, which are covered or coated by dielectric materials, such as alumina, quartz, sapphire, carbon, diamond, platinum, or a polymeric material, such as PTFE or PEEK.

[0064] As described in the previous example, the metallic surface of the first elongated rod element or second electrical conductor can be coated with a dielectric. Equally, however, it can also be advantageous to coat an easy-to-produce geometry with a metallic surface so that the mechanical stability is provided by any material that is metallically coated to produce a two-conductor system.

[0065] In yet another example, the microwave source unit outputs microwave radiation at a frequency between 1 MHz and 6 GHz, preferably between 500 MHz and 3 GHz, more preferably between 700 MHz and 1.5 GHz, most preferably between 800 MHz and 1.1 GHz.

[0066] The exact frequency will depend on the material of the feedstock material that is being processed and on the exact dimensions of the apparatus. Two standard ISM- frequency-bands used for microwave radiation are 900-930 MHz and 2.4-2.5 GHz, these might be particularly useful for the apparatus, since in those cases standardized microwave sources could be implemented. These standard frequency-bands change, accordingly to different countries.

[0067] In a further example, the microwave source unit outputs microwave radiation of a power of at least 500W, preferably at least 1 kW, more preferably at least 10 kW or even 120 kW per single source.

[0068] In yet another example, the microwave source unit outputs with several single microwave sources microwave radiation of a power of less than 500 kW, preferably, less than 200 kW, more preferably less than 120kW.

[0069] The apparatus according to the disclosure is particularly suited for high-power, industrial applications.

[0070] In a further example, the at least one process unit comprises a plurality of process units. By providing more operative feedstock process chambers, more volume is introduced for the feedstock material to be processed in. This may be understood as double the amount of process units, would result in double the amount of feedstock material that can be processed or several different feedstocks can be processed with this one unit.

[0071] In a first example thereof, the first waveguide port of each of the plurality of the process units are operatively connected with the at least one microwave source unit via a central microwave supply guide.

[0072] It may be beneficial in order to reduce the cost of the apparatus to operatively connect the at least one microwave source to multiple process units. This, in the end, depends on the exact material of the feedstock material and on the microwave radiation power that the at least one microwave source can supply, whether multiple process units can be operatively connected to the at least one microwave source.

[0073] The disclosure also pertains to a method of processing a material, comprising of the steps of: i) feeding the feedstock material through an at least one feedstock material port into a feedstock process chamber; ii) irradiating the feedstock material with microwave radiation guided from the microwave source unit into the feedstock process chamber; and iii) collecting at least one product from processing the feedstock material at the at least one feedstock material port.

[0074] In an example of the method, the first step i) of feeding the feedstock material into the feedstock process chamber is promoted by agitating the feedstock material, such that a greater throughput can be achieved.

[0075] The method according to the disclosure offers a way to process feedstock material continuously at a high efficiency having an industrial-scale throughput. This way high-quality raw materials can be produced without the negative environmental effects of heat-based recycling apparatuses, thereby making raw materials available in the market without depleting natural resources.

[0076] The atmosphere of the process chamber can be controlled in a way, which is beneficial for the process. Beside the pressure, the gas composition can be optimized for process and safety reasons.

[0077] Short description of the figures

[0078] Figure 1 describes a first example of an apparatus for microwave radiation processing of a feedstock material according to the disclosure.

[0079] Figure 2 describes a second coaxial example of an apparatus for microwave radiation processing of a feedstock material according to the disclosure with a tapered first electromagnetic electrode.

[0080] Figure 3 describes another example of an apparatus for microwave radiation processing of a feedstock material according to the disclosure having temperature control of the first elongated rod element.

[0081] Figure 4 describes a further example of an apparatus for microwave radiation processing of a feedstock material according to the disclosure having two waveguide ports. Figure 5 describes yet another example of an apparatus for microwave radiation processing of a feedstock material according to the disclosure having a pipe-like feedstock material port.

[0082] Figure 6 describes another example of an apparatus for microwave radiation processing of a feedstock material according to the disclosure having a feedstock material port provided in the first elongated rod element

[0083] Figure 7 describes examples of cross-sections of the feedstock process chambers.

[0084] Figure 8 describes an example of an apparatus for microwave radiation processing of a feedstock material according to the disclosure having a plurality of openings for the feedstock material port and a feedstock supply member.

[0085] Figure 9 describes another example of an apparatus for microwave radiation processing of a feedstock material according to the disclosure having a pipe-like feedstock material ports.

[0086] Figure 10 describes a further example of an apparatus for microwave radiation processing of a feedstock material according to the disclosure having two feedstock material ports comprises a plurality of openings.

[0087] Figure 11 describes an example of an apparatus for microwave radiation processing of a feedstock material having two process unit operatively connected to one microwave source.

[0088] Figure 12 describes a further example of an apparatus for microwave radiation processing of a feedstock material having two process unit operatively connected to two microwave sources.

[0089] Figure 13 describes a further example of an apparatus for microwave radiation processing of a feedstock material having two process unit operatively connected to four microwave sources with two of them mounted in the middle of the process chambers.

[0090] Detailed description

[0091] The disclosure pertains to a method and an apparatus 1000 adapted to process a feedstock material 1 , which aims at circumventing the problems of existing heatbased processing and recycling apparatuses by being as efficient as small lab-scale microwave reactors and also providing high throughput of the feedstock material 1 and high-quality product yield at an industrial scale.

[0092] To achieve this, Figure 1 depicts a first example of such apparatus 1000. The apparatus 1000 comprises at least one microwave source unit 100 and at least one process unit 200, wherein the process unit comprises a first elongated rod element 210 and a second elongated electrical conductor 220 surrounding the first elongated rod element 210 at an intermediate distance from each other, thereby forming an elongated feedstock process chamber 230. The process unit 200 at least has a first waveguide port 211 , wherein the first waveguide port 211 is operatively connected to the at least one microwave source unit 100 via a connecting waveguide 150i and adapted to guide microwave radiation generated by the microwave unit 100 via the first waveguide port 211 into the feedstock process chamber 230. The process unit 200 further comprises at least one feedstock material port 222 provided in the second electrical conductor 220 for feeding the feedstock material 1 into the feedstock process chamber 230.

[0093] As can be seen in Figure 1 , an example of an apparatus 1000 for microwave radiation processing of a feedstock material 1 is shown, wherein feedstock material 1 is supplied into the feedstock process chamber 230 through the feedstock material port 222. The feedstock material 1 (which may be a mixture of processing goods and catalysts) is turned into product material 2 by absorption of microwave radiation generated by the microwave source unit 100 and guided into the elongated feedstock process chamber 230. The elongated feedstock process chamber 230 functions as a waveguide for the microwave radiation. In the example of Figure 1 the product material 2 is depicted as a gaseous end product. Note, however, that it may also be liquid end product material 2 or even solid end product material 2 or a mixture of some or all of them. The end product can also be a mixture of a valuable product and used catalysts or non-commercialisable side products.

[0094] In an ideal situation all the feedstock material 1 is converted into end product material 2 that either can be collected through the feedstock material port 222 or in the feedstock process chamber 230. Especially when the end product material 2 is a gaseous end product, it can be collected through the feedstock material port 222, and herewith a continuous conversion process can be achieved. This way, high throughput of the feedstock material 1 at an industrial scale can be achieved of several kilos to several tons per day.

[0095] To achieve these processed volumes, the volume of the feedstock process chamber 230 may be between 0.1 m3and 5 m3. In combination with a single microwave sources 100 achieving a power output of 1-100 kW, 10 to 1000 kg of feedstock material 1 could be processed per day per process unit.

[0096] The first elongated rod element 210 being surrounded by a second elongated electrical conductor 220 allows for better power acceptance of the microwave radiation by the feedstock material 1. In particular, the inner distance between the first elongated rod element 210 and the second elongated electrical conductor 220 can be chosen such that only the basic TEM-mode of the electromagnetic microwave radiation as generated by the microwave source unit 100 is excited into the feedstock process chamber 230. This means that the exact dimensions of the apparatus 1000 also heavily depend on the feedstock material 1 that is being processed, since different feedstock material 1 would have different dielectric properties interacting differently with the microwave radiation. Therefore, the inner volume between the first elongated rod element 210 and the second electrical 220 conductor should be adjusted.

[0097] The configuration of a first elongated rod element 210 being surrounded with a second electrical conductor 220 also allows the first elongated rod element 210 to be cooled with cooling liquid from its inside to control the temperature of the process in the feedstock process chamber 230 as well.

[0098] In Figure 4 and 5, another example of an apparatus according to the disclosure is shown, wherein the first waveguide port 211 and a second waveguide port 212 are positioned at both ends 230a-230b of the feedstock process chamber 230. It is to be understood that the first waveguide port 211 and a second waveguide port 212 are made of a material which is impenetrable for the feedstock material 1 and / or product material 2. However, both waveguide ports 211 , 212 should be microwave radiation transparent. This way microwave radiation can enter and exit the feedstock process chamber 230, but the feedstock material 1 and / or the product material 2 cannot exit the process chamber 230 through the waveguide ports 211 , 212. For example, the material of the waveguide ports 211 , 212 may be quartz or alumina, or a perforated material, perhaps even covered by a metallic wall. In some other cases a transparency might be useful if a product needs to be guided through that area. Please note, that such material properties might not even be needed if the product material 2 for instance is microwave transparent, in those cases the microwave ports 211 , 212 may just simply be open connections from the central waveguide 150 to the feedstock process chamber 230.

[0099] The feedstock process chamber 230, in the examples shown in Figures 1-5, is oriented at least substantially vertically with respect to a horizontal. In this way, gravity may be used to assist the flow of feedstock material 1 in the direction of the waveguide port 211 towards the other waveguide port 212 at the other end 230b of the feedstock process chamber 230, such that no further feeding devices or force is needed to make the feedstock material 1 move towards the bottom of the feedstock process chamber 230.

[0100] However, in case the flow of the feedstock material 1 is not sufficient by just using gravity, the at least one process unit 200 of the apparatus 1000 may further comprise an agitator unit 270 adapted to promote the supply of the feedstock material 1 towards the feedstock process chamber 230.

[0101] The first elongated rod element 210 and / or second electrical conductor 220, for example, may be at least partially made of an electrically conductive material, such as a metal, like stainless steel, aluminium, brass, or copper, or alternatively the first elongated rod element and / or second electrical conductor are made are at least partially made of a dielectric, such as alumina, quartz, sapphire, carbon, diamond, platinum, or a polymeric material, such as PTFE or PEEK.

[0102] Electrically conductive materials are known to contain microwave radiation; therefore, they may be an effective choice to be used for the feedstock process chamber 230. However, in some cases the feedstock material 1 and / or the product material 2 may chemically interact with the conductive material, such that a dielectric cover may be needed. Additionally, the latter may be cheaper to manufacture.

[0103] In the view of manufacturing the feedstock process chamber 230 inert and microwave confining, the first elongated rod element 210 and / or the second electrical conductor 220 may also be provided with a coating material towards the feedstock process chamber. This coating material may be selected from a list not limited like stainless steel, aluminium, brass, or copper, alumina, quartz, sapphire, carbon, diamond, platinum, or a polymeric material, such as PTFE or PEEK. The microwave source unit 100 outputs microwave radiation at a frequency between 1 MHz and 6 GHz, preferably between 500 MHz and 3 GHz, more preferably between 700 MHz and 1.5 GHz, and most preferably between 800 MHz and 1.1 GHz, wherein the exact frequency will depend on the material of the feedstock material 1 that is being processed. 915 MHz and 2.45 GHz are commonly used microwave frequencies and are thus of particular interest since multiple microwave sources exist that work at these frequencies.

[0104] In case the decomposition process does not reach 100% conversion or in case the end product material 2 may also be solid or liquid, it is preferable that the at least one feedstock material port 222 of the apparatus 1000 comprises a first feedstock material port 222a and an at least one further feedstock material port 222b, such that a continuous flow of feedstock material 1 can be obtained. Here, dependent on the type of feedstock material 1 and end product material 2 either one of the two feedstock material ports 222a, 222b will be used as collection port or even both may be used as such.

[0105] In Figures 2, 3, and 4, an example of an apparatus 1000 according to the disclosure is graphically depicted, having a first feedstock material port 222a at or near a first end 230a of the feedstock process chamber 230 and an at least one further feedstock material port 222b at or near a second end 230b of the feedstock process chamber 230 to ensure that a continuous flow of feedstock material 1 can be achieved. Here, as an example, solid feedstock material 1 is supplied into the feedstock process chamber 230 through the first feedstock material port 222a forming gaseous product material 2 in the feedstock process chamber 230 due to its interaction with the microwave radiation. As shown, the solid feedstock material pellet 1 reduces in size as it travels through the feedstock material waveguide 230 by absorption of microwave radiation and decomposes into product material 2. The remainder of the feedstock material 1 is collected at the at least one further feedstock material port 222b and the gaseous product material 2 is collected at the first feedstock material port 222a.

[0106] As already pointed out the material of the feedstock material 1 may be solid, liquid or even gaseous. Dependent on the nature of the feedstock material 1 either the first feedstock material port 222a may be used to supply and / or collect the feedstock material 1 or its end product material 2, and the same goes for the at least one further feedstock material port 222b, which may be used to supply and / or collect the feedstock material 1 or its end product material 2.

[0107] In the particular depiction of Figure 2, the first feedstock material port 222a is positioned near the first waveguide port 211 and the at least one further feedstock material port 222b is positioned near the second waveguide port 212 at the other end of the feedstock material waveguide 230.

[0108] This way the feedstock material 1 has to travel the longest distance through the feedstock process chamber 230, giving the feedstock material 1 the greatest chance of absorbing microwave radiation, such that the decomposition reaction has the greatest chance of success and takes place with the highest efficiency.

[0109] Additionally, by positioning the first feedstock material port 222a and the at least one further feedstock material port 222b the furthest apart from each other, it is ensured that no dead spots in the flow of the feedstock material 1 through the feedstock material waveguide 230 can be formed. For example, in case that the at least one further feedstock material port 222b would be positioned halfway the feedstock process chamber 230 between both ends 230a and 230b thereof, the entire bottom half of the feedstock process chamber could act as a dead spot for feedstock material 1 to get stuck in, limiting the efficiency of the apparatus 1000.

[0110] Furthermore, it is shown that the first elongated rod element 210 comprises a tapered section 210a along the elongated guide direction of the feedstock process chamber 230. With such taper the electromagnetic microwave radiation can be tuned to the changing properties of the feedstock material 1 and product material 2 dielectric properties.

[0111] As shown in the figure, a feedstock material pellet 1 shrinks as it travels along the feedstock process chamber 230 and as a result product material 2 is being formed. Since this is a continuous process, it can be understood that the top of the feedstock process chamber 230 mostly consists of pure feedstock material 1 , just fed into the apparatus, whereas the bottom of the feedstock process chamber 230 would consist of less feedstock material 1 and more product material 2. The dielectric properties of the pure feedstock material 1 (at the top) and the mixture of feedstock material 1 and product material 2 may be different, such that absorption and the radial electromagnetic field distribution may be different as well. Exactly these effects can be counteracted with such a tapered section 210a in the first elongated rod element

[0112] 210.

[0113] Additionally, it is shown in Figure 2, that the first elongated rod element 210 and the second electrical conductor 220 are oriented coaxially with respect to each other, meaning they have the same central axis 230z seen along the guide direction of the feedstock process chamber 230.

[0114] Because of engineering tolerances, it may be understood to the expert in the field, which being “coaxial” would fall within a tolerance of 5% with respect to the position of the common centre axis as seen in a cross-section of each rod element or conductor 210, 220.

[0115] Being coaxial ensures that the field distribution in the feedstock process chamber 230 is axisymmetric and makes it easier to control the excitation of only the basic TEM-mode of the electromagnetic radiation.

[0116] The apparatus 1000 of Figure 3 is of a similar configuration as the apparatus 1000 of Figure 2. However, the example of Figure 3 shows that, the apparatus 1000 may also comprise temperature regulating means. These temperature regulating means may be electrical, i.e. Peltier elements, or as shown in Fig. 3 fluidic temperature regulating means. The fluidic temperature regulating means comprise a pump, a cooling liquid bath, tubing, a controller and a temperature sensor. The first elongated rod 210 is shown to be hollow, such that a coolant can be flowed through the first elongated rod 210. A temperature-controlled cooling liquid is then in heat-exchange with the surface of the first elongated rod 210, such that heat can be extracted from the process chamber 230. More precisely, the first elongated rod 210 of Figure 3 is shown to comprise two concentric tubes of different length, wherein the furthest end of the outer tube 2102 of the first elongated rod 210 is fluidly sealed, and wherein the furthest end of the centre tube 210i is fluidly open. That way, a continuous flow of a coolant can be established through the centre tube 210i along the space between the two tubes out through the outer tube 2102, indicated with an arrow. Note that the pump, the controller, the temperature sensor and the cooling liquid bath are not shown in the figure.

[0117] Utilizing a coolant, allows for precisely and finely monitoring and controlling the temperature of the feedstock material 1 being subjected to microwave radiation. The coolant may be gas or a liquid, such as oil, water, or water / glycol mixture, connected to a bath with a pump (not shown in the figure). It should be understood that the configuration of the temperature controlled first elongated rod 210 of Figure 3 is a preferred example and that other configurations are possible as well. I.e. the first elongated 210 may also simply be a straight hollow tube through with coolant is flowed.

[0118] It should be noted that although not depicted in the figures, the second elongated conductor 220 can be temperature controlled from the outside of the process chamber 230 as well by means of a coolant.

[0119] It should further be noted that the temperature sensor and or the temperature regulating means should be incorporated into the apparatus 1000, such that the microwave radiation distribution is not being disturbed. Accordingly, in Figure 3, the centre tube 210i and the outer tube 2102 of the first elongated rod 210 are shown to at least extend straight passed the centre conductor 150.

[0120] Another example of an apparatus according to the disclosure is shown in Figure 4, wherein the first elongated rod element 210 and the second electrical conductor 220 are coaxial and the first elongated rod element 210 comprises two tapered sections 210a, 210b narrowing towards the centre of the feedstock process chamber 230, forming an hourglass shape.

[0121] Furthermore, the feedstock process chamber of the apparatus in Figure 4 comprises a second waveguide port 212 at some distance of the first waveguide port 211 seen along the elongated guide orientation of the feedstock process chamber 230, operatively connected to the at least one microwave source unit 100 and adapted to guide the microwave radiation via the second waveguide port 232 into the feedstock process chamber 230. It is shown in Figure 4, that the second waveguide port 212 operatively is connected to the at least one microwave source unit 100 via another connecting waveguide 1502.

[0122] This way microwave radiation is guided into the feedstock process chamber 230 from two sides, such that the absorption of the microwave radiation by the feedstock material 2 can be improved.

[0123] It may be clear to the expert in the field that when microwave radiation is supplied only from one side, microwave radiation power will decrease, while interacting with the feedstock depending on the dielectric properties of the feedstock. This could lead to very low power levels left at the end of the feedstock process chamber 230 to be absorbed by the feedstock material 1 , because it already has been absorbed by the volume of feedstock material in front of it. Therefore, in such configuration with microwave radiation only coming from one side, the microwave process efficiency would be reduced as the feedstock material 1 travels further along the feedstock process chamber 230. However, by supplying microwave radiation from both sides of the feedstock process chamber 230, as shown in Figure 4, the efficiency of the process can be improved.

[0124] In Figure 5 another example of an apparatus according to the disclosure is shown, wherein the second electrical conductor 220 comprises two tapered sections 210a, 210b seen along the elongated guide direction of the feedstock process chamber to counteract for the changing dielectric properties of the feedstock material 1 and product material 2 mixture as is being processed while travelling along the feedstock process chamber 230. The same arguments made for the first elongated rod element 210, wherein a taper can be used to counteract changing dielectric properties, also goes for the second electrical conductor 220, which is shown in Figure 5.

[0125] Furthermore, the apparatus of Figure 5 is shown to process a liquid feedstock material 1 , which is being supplied through the first feedstock material port 222a via a feedstock supply member 240. More in particular, this feedstock supply member 240 is formed as a supply pipe communicating with the at least one feedstock material port 222.

[0126] With the use of a feedstock supply member 240, feedstock material 1 can be contained and supplied in an efficient manner improving the throughput and conversion efficiency of the apparatus 1000. Especially for liquid feedstock material 1 , as is shown in Figure 5, a pipe is beneficial, because of the beneficial flow properties of liquid feedstock material 1.

[0127] In all previous figures except Figure 4, the at least one feedstock material port 222 was provided at a location between the first waveguide port 211 and the second waveguide port 212 seen along the elongated guide orientation of the feedstock process chamber 230. In Figure 4, the at least one feedstock material port 222 is provided upstream of the first waveguide port 211 seen along the elongated guide direction of the feedstock process chamber 230. In a similar fashion, the at least one further feedstock material port 222b is provided downstream of the second waveguide port 212 seen along the elongated guide direction of the feedstock process chamber 230 in Figure 4.

[0128] This way the feedstock material 1 is exposed to microwave radiation throughout the entire feedstock process chamber 230, such that the absorption process is maximized, since the feedstock material 1 is travelling the entire length of the elongated feedstock process chamber 230, while being subjected to microwave radiation.

[0129] To improve the absorption process, the apparatus in Figure 5 is equipped with a first and a second microwave source unit 100i, IOO2, wherein the first microwave source unit 100i is operatively connected to the first waveguide port 211 and the second microwave source unit IOO2 is operatively connected to the second waveguide port 212.

[0130] One single microwave source unit 100 might not output enough power for a given feedstock microwave process, might be too costly to manufacture one which has enough power, or might have a too large form-factor, therefore multiple microwave sources 100i, IOO2 may be connected to reach the desired microwave radiation power, reduce overall costs of the apparatus 1000, or reduce the overall size of the apparatus 1000, respectively.

[0131] In Figure 5 it is further shown that the first elongated rod element 210 is positioned diagonally or in a skewed orientation inside the second electrical conductor 220. This way more space is generated for the feedstock material 1 to enter and exit the feedstock process chamber, while the tapered sections 220a, 220b of the second electrical conductor 220 ensures that the excitation microwave radiation mode does not exceed the first mode.

[0132] In Figure 6, another example of an apparatus 1000 according to the disclosure is shown, wherein the feedstock supply member 240 is formed as a tube with the first feedstock material port 222a provided in at least partially hollow first elongated rod element 210. With this configuration, the apparatus 1000 has a smaller form factor, since the second electrical conductor 220 is defining the outer most dimension. Similarly, the at least one further feedstock material port 222b is provided in the at least partially hollow first elongated rod element 210 at the other end 230b of the feedstock process chamber 230. Figure 7A-B-C show various cross-sections perpendicular to the elongated guide direction of the feedstock process chamber 230. These images give more insight into the position of the first elongated rod element 210 in relation to the second electrical conductor 220, and their respective shapes.

[0133] In Figure 7A for instance, square cross-sectional shapes are shown for both the first 210 and the second electrical conductor 220. Additionally, it is observed that the first 210 and second electrical conductor 220 are not positioned coaxially.

[0134] In Figure 7B as another example, the first elongated rod element 210 is shown to have a pentagonal cross-section, whereas the second electrical conductor 220 is shown to have a triangular cross-section. Note, that in Figure 7B, both electrical conductors are positioned coaxially around the central axis 230z with respect to each other.

[0135] In Figure 7C, a final example of cross-sectional shapes is shown. Here, a circular cross-section is shown for both the first elongated rod element 210 and the second electrical conductor 220. This is an axisymmetric shape, such that the resulting electromagnetic field distribution in such cross-section will also be axisymmetric. Furthermore, it is shown that according to this disclosure both rod element 210 and electrical conductor 220 are still considered to be coaxial with respect to the central axis 230z, since their respective centres are offset less than 5% of the respective cross-sectional dimension.

[0136] The expert in the field will understand that these figures are mere snapshots taken somewhere along the elongated guide direction of the feedstock process chamber 230, and that these cross-sectional shapes may change as one would follow the feedstock process chamber 230 along its guide direction. Changing cross- sectional shapes may be designed and utilized in order to adjust for changing material properties of the feedstock material 1 and product material 2 mixture and / or to allow for flow adjustment by enlarging or narrowing the effective feedstock process chamber’s 230 volume.

[0137] Regarding Figures 6A-B-C, it should be considered in general that the cross- sectional shapes of either elongated rod element 210 or conductor 220 may be selected from the list not limited to circular, elliptical, rectangular, starred, or square.

[0138] These different cross-sectional shapes distribute the microwave radiation differently. Additionally, they offer a different volume to the feedstock process chamber 230. Therefore, the choice of which cross-sectional shape to use dependents on the exact feedstock material 1 that is used and or the desired throughput that is aimed to be achieved.

[0139] In Figure 8 a further example of an apparatus according to the disclosure is shown, wherein the at least one feedstock material port 222 is formed as a plurality of openings.

[0140] In the previous figures, no specifications have been given about the at least one feedstock material port 222, however a person skilled in the art may understand that a too large opening, typically more than a few millimetres, may cause microwave radiation to leak out and thus the efficiency of the apparatus 1000 will be reduced. Therefore, the implementation of Figure 8 achieves an efficient feeding through of feedstock material 1 into the feedstock process chamber 230, without the risk of leaking of microwave radiation. It is shown that both the first 222a and the at least one further feedstock material port 222b comprise a plurality of openings.

[0141] These openings may have various shapes and are not limited to the circular shape that is shown in Figure 8, for example, they may be square, rectangular, oval, star, or slit-like as well. The exact shape may be chosen dependent on the feedstock material 1 that is being processed. Also, their arrangement on the second electrical conductor 220 can be different. They may be provided surrounding the entire feedstock process chamber 230 as shown in the figure, or in other words they may be radially distributed around the feedstock process chamber 230, or alternatively they could be condensed on one side of it. Furthermore, they may be arranged in an array, which could be rectangular, triangular, hexagonal, cubic, or random. It is essential that the dimensions of the through opening of each individual opening are such that entrance of the feedstock material 1 into the feedstock process chamber 230 is facilitated, whereas any leaking of microwave radiation is prevented. A beneficial range of diameters of the openings is a millimetre to several centimetres, dependent on the frequency of the microwave radiation.

[0142] In Figure 8 and Figure 9, two different examples of the feedstock supply member 240 are shown, which contains and supplies the feedstock material 1 to the first feedstock material port 222a. In these figures, the feedstock supply members 240 are shown as a funnel or a hopper adapted to be conformal the feedstock process chamber 240. In Figure 8, the feedstock supply member 240 is shown as a hopper on one side of the feedstock process chamber 230, whereas in Figure 9 the feedstock supply member 240 is formed as a tapered member mounted to and surrounding the at least one feedstock material port 222, and more in particular the feedstock process chamber 230.

[0143] Furthermore, in Figure 8 the apparatus 1000 is shown comprising only one single microwave source 100 providing microwave radiation to the feedstock process chamber 230 through two connecting waveguides 150i and 1502. To improve the power transfer the apparatus in Figure 9 is equipped with two microwave sources 100.

[0144] Lastly, it is shown in Figure 8 and Figure 9 that the first elongated rod element 210 and the second electrical conductor 220 are oriented parallel to each other, such that the distance of a surface normal of the first elongated rod element 210 towards the second electrical conductor 220 has an equal distance along the entire guide direction of the waveguide.

[0145] Additionally, the apparatus 1000 in Figure 9 depicts an agitator unit 270 positioned touching the feedstock supply member 240. The agitator unit comprises an agitator arm 271 , which in this particular example hits the side of the feedstock supply member 240, thereby generating small shocks, such that particulate feedstock material 1 rearranges and reorients itself. This way the flow of the solid feedstock material 1 can be improved to flow through the first feedstock material port 222a. It should be noted that the agitator unit in this particular case is not touching the feedstock material 1. In other examples, the agitator unit -270 may actually touch the feedstock material 1 or the agitator unit 270 may agitate the complete process unit 200.

[0146] This last argument is also true for the elongated rod element 210 and the electrical conductor 220 of the apparatus in Figure 10, even though their surfaces may be wavy, the inter-distance between the elongated rod element 210 and the electrical conductor 220 is maintained and both 210, 220 are oriented parallel.

[0147] In Figure 10 the supply member 240 is further depicted as a supply pipe, such that feedstock material can be contained and supplied to the apparatus through the first feedstock material port 222a. In such case, the supply pipe might even contain the microwave radiation a little, such that is cannot be leaked out. Figure 11 , Figure 12, and Figure 13 two more examples of apparatuses 1000 according to the disclosure are shown, wherein the at least one process unit 200 comprises a plurality of process units 200, such that the throughput of the apparatus 1000 can be doubled. In particular, in Figure 11 , all operatively active waveguide ports 211 , 212 are connected to one single microwave source 100, whereas in Figure 12, the first waveguide ports 211 of each of the plurality of the process units 200 are operatively connected with one microwave source 100 via a central microwave supply guide 150i and the second waveguide ports 212 of each of the plurality of process units 200 are operatively connected with another microwave source 100 via another central microwave supply guide 1502, such that (theoretically) more power can be supplied to the apparatus in Figure 12 than in Figure 11 .

[0148] Both figures further show that each process unit 200 may comprise at least one discharge unit 250 adapted to discharge the unprocessed feedstock material 1 and / or product material 2 through the at least one further feedstock material port 222b.

[0149] Furthermore, both figures depict gas collectors 260 adapted to collect product material 2 generated in the feedstock process chamber 230 from processing the feedstock material 1. The particular gas collectors in both Figure 11 and Figure 12 have a conical shape surrounding the feedstock process chamber 230 and are positioned above the first feedstock material port 222a, such that gaseous products that travel through the first feedstock material port 222a can be collected. After collection they are further displaced in a gas collection pipe 261.

[0150] Additionally, Figure 12 and Figure 13 depict another agitator unit 270 positioned in the feedstock supply member 240, which comprises an agitator arm 271 having a paddle-like end, which can rotate and thereby agitates the feedstock material 1. This way, the feedstock material is kept moving and the flow through the entire process unit 200 is improved.

[0151] Figure 13 wherein the apparatus 1000 is shown with two process units 200, further shows four microwave sources 100i , IOO2, and 101 of which the first and the second are connected at both ends 230a, 230b of the feedstock process chambers 230, respectively. The further two microwave sources 101 are positioned to provide microwave radiation into the feedstock process chamber 230 through the second electrical conductor 220 by means of a further microwave supply guides 151. These may be positioned at the centre of the feedstock process chamber 230, or anywhere in between the first waveguide port 211 and the second waveguide port 212. In this configuration, more microwave power can be added to the apparatus 1000, such that the throughput of feedstock material 1 can be increased, or such that feedstock material 1 requiring more microwave absorption, can be processed.

[0152] It should be clear to the person skilled in the art that the examples made in the figures have characteristic features that have been discussed and that the combinations described above are not limited, but that these features can be exchanged between the different apparatuses 1000 of the figures mostly dependent on the feedstock material 1 that will be processed.

[0153] It should also be clear to the person skilled in the art that an apparatus 1000 as presented in this disclosure would still function without having a first elongated rod element 210. However, it should be noted that is that case the microwave process cannot be controlled as effectively.

[0154] All in all, these apparatuses offer a way to process feedstock material 1 efficiently as small lab scale microwave reactors, while providing high throughput of feedstock material 1 and high-quality product material 2 yield at an industrial scale, thereby circumventing the problems of existing heat-based recycling apparatuses.

[0155] Reference numbers

[0156] 1 feedstock material (can be a mixture)

[0157] 2 product material (can be a mixture)

[0158] 1000 apparatus

[0159] 100 at least one microwave source unit

[0160] 1001 first microwave source unit

[0161] 1002 second microwave source unit

[0162] 101 further microwave source unit

[0163] 150I-1502 central microwave supply guide

[0164] 151 further microwave supply guide

[0165] 200 at least one process unit

[0166] 2001 first process unit

[0167] 2002 second process unit

[0168] 211 first waveguide port

[0169] 212 second waveguide port

[0170] 213 further waveguide port

[0171] 210 first elongated rod element

[0172] 210a first tapered section of first elongated rod element

[0173] 210b second tapered section of first elongated rod element

[0174] 2101 centre tube of first elongated rod element

[0175] 2102 outer tube of first elongated rod element

[0176] 220 second electrical conductor

[0177] 220a first tapered section of second electrical conductor

[0178] 220b second tapered section of second electrical conductor

[0179] 222 at least one feedstock material port

[0180] 222a first feedstock material port

[0181] 222b at least one further feedstock material port

[0182] 230 feedstock process chamber

[0183] 230a first end of feedstock process chamber

[0184] 230b second end of feedstock process chamber

[0185] 230z central axis

[0186] 240 feedstock supply member 250 discharge unit

[0187] 260 gas collector

[0188] 261 conical shaped collecting member

[0189] 262 gas collector tube 270 agitator unit

[0190] 271 agitator arm

Claims

CLAIMS1. An apparatus adapted to process a feedstock material, the apparatus comprising at least one microwave source unit and at least one process unit constructed as a coaxial waveguide, the process unit comprising: a first elongated rod element; a second elongated electrical conductor surrounding the first elongated rod element at a distance from each other oriented coaxially with respect to each other, thereby forming an elongated feedstock process chamber configured to carry only the basic TEM-mode of the electromagnetic radiation, the process unit at least having a first waveguide port, wherein the first waveguide port is operatively connected to the at least one microwave source unit and adapted to guide microwave radiation generated by the microwave unit via the first waveguide port into the feedstock process chamber; at least one feedstock material port provided in the first elongated rod element or the second electrical conductor for feeding the feedstock material into the feedstock process chamber.

2. The apparatus according to claim 1 , wherein the first elongated rod element is made of an electrically conductive material.

3. The apparatus according to claim 1 , wherein the first elongated rod element is made of a dielectric material, such as but not limited to alumina, quartz, sapphire, carbon, PTFE, PEEK, or polyethylene (PE).

4. The apparatus according to any of the preceding claims, wherein the feedstock process chamber comprises a second waveguide port at some distance of the first waveguide port seen along the elongated guide orientation of the feedstock process chamber, operatively connected to the at least one microwave source unit and adapted to guide the microwave radiation via the second waveguide port into the feedstock process chamber.

5. The apparatus according to claim 4, wherein the at least one microwave source unit comprises a first and a second microwave source unit, wherein the first microwave source unit is operatively connected to the first waveguide port and the second microwave source unit is operatively connected to the second waveguide port.

6. The apparatus according to claim 5, wherein the at least one microwave source unit comprises at least one further microwave source unit operatively connected to the feedstock process chamber through the second electrical conductor.

7. The apparatus according to claim 4 or 5, wherein the at least one feedstock material port is provided at a location between the first waveguide port and the second waveguide port seen along the elongated guide orientation of the feedstock process chamber.

8. The apparatus according to claim 4 or 5, wherein the at least one feedstock material port is provided upstream of the first waveguide port seen along the elongated guide direction of the feedstock process chamber.

9. The apparatus according to any of the preceding claims, wherein the first elongated rod element comprises at least one tapered section seen along the elongated guide direction of the feedstock process chamber.

10. The apparatus according to any of the preceding claims, wherein the second electrical conductor comprises at least one tapered section seen along the elongated guide direction of the feedstock process chamber.

11. The apparatus according to any of the preceding claims, wherein the first elongated rod element and the second electrical conductor are oriented parallel to each other.

12. The apparatus according to any of the preceding claims, wherein a crosssection of the first elongated rod element taken perpendicular to the elongated guidedirection of the feedstock process chamber has a cross-sectional shape, which is selected from but not limited to circular, elliptical, rectangular, starred, or square.

13. The apparatus according to any of the preceding claims, wherein a crosssection of the second electrical conductor taken perpendicular to the elongated guide direction of the feedstock process chamber has a cross-sectional shape, which is selected from but not limited to circular, elliptical, rectangular, starred, or square.

14. The apparatus according to any of the preceding claims, wherein the first elongated rod element comprises temperature regulating means and / or wherein the second elongated electrical conductor comprises temperature regulating means.

15. The apparatus according to any of the preceding claims, wherein the feedstock process chamber is oriented at least substantially vertically with respect to a horizontal.

16. The apparatus according to any of the preceding claims, wherein the at least one feedstock material port is formed as a plurality of openings.

17. The apparatus according to any of the preceding claims, wherein the process unit comprises at least one feedstock supply member adapted to contain and supply the feedstock material to the at least one feedstock material port.

18. The apparatus according to claim 17, wherein the feedstock supply member is formed as a supply pipe communicating with the at least one feedstock material port.

19. The apparatus according to claim 17, wherein the feedstock supply member is formed as a tapered member mounted to and surrounding the at least one feedstock material port.

20. The apparatus according to any of the preceding claims, wherein the at least one feedstock material port comprises a first and at least one further feedstock material ports.

21. The apparatus according to claim 20, wherein the first feedstock material port is positioned near the first waveguide port at a first end of the feedstock process chamber and the at least one further feedstock material port is positioned near the other end of the feedstock process chamber.

22. The apparatus according to claim 20 or 21 , wherein the process unit comprises at least one discharge unit adapted to discharge the processed feedstock material through the at least one further feedstock material port from the waveguide.

23. The apparatus according to any of the previous claims, further comprising a fluid collector adapted to collect fluids generated in the waveguide from processing the feedstock material.

24. The apparatus according to any of the previous claims, wherein the at least one process unit further comprises an agitator unit adapted to promote the supply of the feedstock material towards the feedstock process chamber.

25. The apparatus according to any of the preceding claims, wherein a surface side of the first elongated rod element and / or the second electrical conductor facing the feedstock process chamber is provided with a coating or cover material.

26. The apparatus according to any of the preceding claims, wherein the first elongated rod element and / or second electrical conductor are at least partially made of an electrically conductive material, such as a metal, like stainless steel, aluminium, brass, or copper.

27. The apparatus according to any of the preceding claims, wherein the first elongated rod element and / or second electrical conductor are coated or covered with a dielectric, such as but not limited to alumina, quartz, sapphire, carbon, PTFE, PEEK, or polyethylene (PE).

28. The apparatus according to any of the previous claims, wherein the microwave source unit outputs microwave radiation at a frequency between 1 MHz and 6 GHz,preferably between 500 MHz and 3 GHz, more preferably between 700 MHz and 1.5 GHz, most preferably between 800 MHz and 1.1 GHz.

29. The apparatus according to any of the previous claims, wherein the at least one process unit comprises a plurality of process units.

30. The apparatus according to claim 29, wherein the first waveguide port of each of the plurality of the process units are operatively connected with the at least one microwave source unit via a central microwave supply guide.

31. The apparatus according to claim 1 , 2, 4, 5, 7, 9, 12, 13, 14, 15, 16, 17, 19, 20, 21 , 22, 23, 24, 26, 28, 29, and 30, wherein the cross-section taken perpendicular to the elongated guide direction of the feedstock process chamber has a circular cross- sectional shape.

32. A method of processing a feedstock material using an apparatus according to any of the preceding claims, comprising of the steps of: i) feeding the feedstock material through an at least one feedstock material port into a feedstock process chamber; ii) irradiating the feedstock material with microwave radiation guided from the microwave source unit into the feedstock process chamber; and iii) collecting at least one product from processing the feedstock material at least one feedstock material port.

33. The method according to claim 32, wherein the first step i) of feeding the feedstock material into the feedstock process waveguide is promoted by agitating the feedstock material.

Images