FIELD OF THE INVENTION The present invention relates to apparatus and a method for processing a raw material in order to extract required constituents of the material. In particular but not exclusively the invention relates to apparatus and a method for extracted required organic and inorganic chemical constituents. BACKGROUND

It is known to process raw material containing organic compounds such as plastics, rubber and the like in order to extract condensable and non-condensable hydrocarbon compounds such as methane, ethane, propane, butane and oils including light oils and heavy oils.

In one known process the raw material is extracted by pyrolysis. Pyrolysis involves heating of the raw material in a low oxygen environment in order to extract the hydrocarbon compounds without burning the compounds.

FIG.1 shows a know processing plant 1 for extracting organic compounds from a raw material by pyrolysis. The plant 1 has a substantially cylindrical reactor vessel 10 oriented with its cylinder axis substantially horizontal. The reactor vessel 10 is in the form of a chamber 12 surrounded by a jacket 13. Raw material may be placed in the chamber 12 and the chamber heated by a gas burner 16. The chamber 12 is arranged to be sealed in a substantially air tight manner in order to prevent oxygen ingress to the raw material during the heating process. Combustion products from burning of gas by the gas burner 16 flow around the chamber 12 within the jacket 13. The jacket 13 has an exhaust pipe 21 coupled thereto which conveys the combustion products to an exhaust gas purification portion 20 arranged to remove environmental toxins from the exhaust gas before exhausting it to atmosphere through a flue 29. An extraction conduit 41 is coupled to the chamber 12 at one end of the vessel 10 in order to allow extraction of gases evolved from the raw material during pyrolysis of the raw material. The extraction conduit 41 conveys the evolved gas to a water-cooled condenser portion 40 of the plant. Here the evolved gas is cooled. Hydrocarbons condensing in the condenser are fed to a storage tank 45 for storage.

Some hydrocarbons that evolve such as methane, ethane, propane and butane have boiling points below the temperature of the condenser. These gases therefore pass through the condenser without condensing. A portion of these gases are fed back to the gas burner 16 of the reactor 10 whilst excess gas is burned in an auxiliary burner 49.

Once the hydrocarbons of interest have been removed from the raw material the raw material is removed from the chamber 12. If pyrolysis is allowed to progress until substantially all hydrocarbons have been removed, the pyrolysed material will typically contain carbon black and any non-pyrolysable matter present in the raw material. In the case of pyrolysed rubber tyres the material may contain grit and steel.

The pyrolysed material is transferred from the reactor vessel 10 to a storage vessel 30. In use the raw material in the chamber 12 is heated by the gas burner 16 to a temperature of around 400 'Ό. As the vessel 10 is heated hydrocarbons begin to evolve from the raw material. Lighter hydrocarbons such as methane, ethane, propane and butane typically evolve first, followed by light oils such as petroleum and subsequently heavier oils such as kerosene and diesel.

It is desirable to provide improved apparatus and an improved method of extracting hydrocarbons from waste materials such as plastics materials and rubber.

STATEMENT OF THE INVENTION

Embodiments of the invention may be understood by reference to the appended claims.

Aspects of the invention provide a material processing unit and a method. In a further aspect of the invention for which protection is sought there is provided a substantially self contained processing unit for performing pyrolysis of hydrocarbon- containing material, the unit comprising:

a reactor vessel arranged to receive material to be pyrolysed;

a source of microwave radiation; and

control means for controlling the unit,

the unit being operable by means of the control means to irradiate material contained within the reactor vessel with microwave radiation thereby to heat the material to evolve hydrocarbon compounds therefrom, the unit being operable to provide a flow of evolved hydrocarbons from pyrolysed material to a storage means.

It is to be understood that by the term unit is meant a substantially self-contained apparatus provided with a reactor vessel, a source of microwave radiation and control mean. The unit is suitable for substantially autonomous operation by means of the control means. Some units according to embodiments of the invention are suitable for installation in a domestic environment such as a home, a commercial environment such as a hospital, a restaurant, a hotel, a school or the like or an industrial environment such as a factory, a food processing centre or any other suitable environment in which hydrocarbon-containing waste is generated that is suitable for pyrolysis to recover useful hydrocarbons.

The unit may be arranged to be powered by an external power source such as a mains electricity supply. Alternatively or in addition the unit may be arranged to be substantially self powered, for example by means of a battery of charge storage cells for powering one or more electric heating elements, by means of hydrocarbons recovered from material by pyrolysis, and/or any other suitable power or fuel source.

It is to be understood that the present inventor has conceived a pyrolysis apparatus on a smaller scale than known industrial pyrolysis systems that is suitable for domestic use. Embodiments of the invention may be employed to generate fuel for a household to augment or replace existing energy supplies. The use of a microwave generator has the advantage that material to be pyrolysed may be heated in a relatively efficient manner,. Furthermore, as described below, a frequency spectrum of microwave radiation used to heat the material may be optimised for different stages of processing, such as initial drying stage of the material, and then a subsequent pyrolysis stage in which material to be pyrolysed is heated to drive off hydrocarbons. For example some embodiments of the invention may be employed to generate fuel to feed appliances such as gas-fired appliances, for example a gas-fired water boiler, a gas-fired cooker and the like. As noted above fuel produced by a unit according to an embodiment of the invention may be used to power the unit.

The unit may also be arranged to generate diesel fuel for use in domestic or industrial vehicles, for example as the sole fuel or as a proportion of the total diesel fuel used. Embodiments of the invention may generate by-products in the form of solid carbon that may be used in agriculture, for example in domestic gardens or other similar applications, for example in the manufacture of terra preta or like materials. Such materials are useful for aiding plant and crop growth organically by adsorbing and absorbing minerals, moisture and salts required by plants and trees, retaining them for the plants to use rather than being washed away by rain. Alternatively the residual carbon can be sold in small or large quantities to industry as carbon black or as activated carbon

Advantageously the unit may further comprise the storage means.

Alternatively or in addition the unit may be operable to provide a flow of evolved hydrocarbons to storage means remote from the unit.

The unit may comprise means for condensing evolved hydrocarbon gas into liquid fractions and storing respective fractions in respective different storage tanks of the storage means.

Advantageously the unit may be operable to control a temperature of material in the reactor vessel responsive to a rate of loss of weight of material in the reactor vessel.

It is to be understood that in some embodiments the control means may be arranged to increase a temperature of the reactor vessel in stages thereby to evolve respective fractions of hydrocarbon materials at different respective times. Once a weight of the reactor vessel has stabilised at a given temperature, it may be determined that substantially all of a given fraction of hydrocarbons that evolve at that temperature have evolved. The temperature can therefore be increased to a higher temperature to evolve higher hydrocarbon fractions.

This feature has the advantage that different fractions can be evolved into different storage tanks one after the other, removing a requirement for post-pyrolysis fractionation. In addition, a risk that lower fractions become overheated is also reduced.

The unit may comprise means for determining the weight of material in the reactor vessel.

The means for determining the weight of material may comprise one or more load cells arranged to measure a weight of the reactor vessel.

Advantageously the control means may be operable automatically to terminate heating of waste material in the reactor vessel when a rate of change of weight of the reactor vessel falls below a prescribed value at a prescribed temperature.

The prescribed temperature may for example be a maximum temperature or range of temperatures to which the unit is arranged to heat waste material in the course of a given processing cycle.

Optionally an upper internal surface of the reactor vessel is sloped thereby to promote rising of evolved hydrocarbon gas to a gas outlet of the reactor vessel. Further optionally the reactor vessel comprises a substantially cylindrical vessel.

A longitudinal axis of the reactor vessel may be tilted thereby to promote flow of evolved gases towards the gas outlet. Advantageously the reactor vessel may be operable to heat the material by mechanically working the material.

Optionally the source of microwave radiation is operable to generate microwave radiation of a first type for exciting water molecules contained in the reactor vessel and microwave radiation of a second type for exciting hydrocarbon molecules contained in the reactor vessel. It is to be understood that by 'type' of radiation is meant radiation having a particular one or more characteristics, such as an intensity distribution across a given range of frequencies. For example the first and second types of radiation may comprise radiation of different respective frequencies.

The first type of microwave radiation may be different from the second type of microwave radiation. Optionally the first type of radiation comprises radiation of a first frequency and not a second frequency different from the first frequency and the second type of radiation comprises radiation of the second frequency.

The second type of radiation may also comprise radiation of the first frequency. The first type of radiation may be selected to excite primarily water molecules as opposed to hydrocarbon bonds whilst the second type may be selected primarily to excite hydrocarbon bonds rather than water molecules. The hydrocarbon bonds excited by radiation of the second type may for example be C-C, C-H and/or C-0 bonds. The unit may be operable to irradiate material in the reactor vessel with radiation of the first and not the second type upon initial heating of the material to a temperature below a first prescribed temperature to evolve water vapour thereby to dry the material, subsequently to irradiate material in the reactor vessel with radiation of the second type thereby to heat the material to a temperature in excess of the first prescribed temperature thereby to evolve hydrocarbons.

This feature has the advantage that the material may first be dried, before hydrocarbons are evolved, reducing a risk that unwanted reactions between water and hydrocarbons take place.

The unit may be operable to irradiate material in the reactor vessel with radiation of the second type once a rate of change of weight of the reactor vessel has fallen below a prescribed value during heating of the material with radiation of the first type.

Advantageously the unit may comprise means for mechanically agitating material contained within the reactor vessel. The means for mechanically agitating material contained within the reactor vessel may comprise at least one movable blade. At least a portion of the reactor vessel to which material in the reactor vessel is exposed may comprise a catalytic material.

Advantageously the means for mechanically agitating material contained within the reactor vessel may comprise a catalytic material to which material to be pyrolysed in the reactor vessel may be exposed.

The catalytic material may be arranged to promote at least one selected from amongst decomposition of evolved hydrocarbons and reaction of evolved hydrocarbons. The catalytic material may comprise at least one selected from amongst aluminium, alumina, tantalum, tungsten, silver, and nickel.

The unit may advantageously be operable to heat material in the first and second reactor vessels substantially in the absence of oxygen.

The unit may be operable to flood the reactor vessel with a gas thereby to displace oxygen.

For example, the unit may be operable to flood the vessel with an inert gas such as nitrogen.

Advantageously the reactor vessel may be provided with thermoelectric generator means over at least a portion of an external surface thereof, the generator means being operable to generate electricity when the reactor vessel is heated.

The unit may be operable to use electricity generated by the generator means to recharge a rechargeable power storage device of the unit.

The unit may be operable to supply electricity generated by the generator means to an external sink, optionally a domestic power load or a mains electricity grid. The unit may be provided in a casing.

The casing may be suitable for installation of the unit in a domestic environment. It is to be understood that the casing may be arranged to form a housing of the unit, components of the unit such as the reactor vessel and control means being contained within the housing. Optionally one or more hydrocarbon storage tanks of the unit may be provided within the casing. The casing may be arranged not to exceed a temperature of one selected from amongst 30 °C, 40 ^< €, 50 °C, 60 ^< €, 70 °C, 80 ^< €, and 90 ^< € when the unit is used to pyrolyse material, the unit being provided in an environment that is at standard ambient temperature and pressure (SATP) conditions, i.e. 298.15K and an absolute pressure of 100 kPa.

The casing may be arranged to fit within a space of dimensions 1 m by 1 m by 1 m.

Optionally the casing is arranged to fit within a space of dimensions 600mm by 800mm by 800mm.

In a further aspect of the invention for which protection is sought there is provided a method of extracting hydrocarbons from hydrocarbon-containing material by pyrolysis by means of a substantially self contained waste processing unit, the method comprising: heating the material in a reactor vessel of the unit by irradiating the material with microwave radiation produced by a source of microwave radiation thereby to evolve hydrocarbon compounds therefrom; and

providing a flow of evolved hydrocarbons from pyrolysed material to a storage means. In an aspect of the invention for which protection is sought there is provided a substantially self contained waste processing apparatus for performing pyrolysis of hydrocarbon-containing material, the unit comprising:

a reactor vessel arranged to receive material to be pyrolysed;

a source of microwave radiation; and

control means for controlling the unit, the unit being operable by means of the control means to irradiate material contained within the reactor vessel with microwave radiation thereby to heat the material to evolve hydrocarbon compounds therefrom, the unit being operable to provide a flow of evolved hydrocarbons from pyrolysed material to a storage means.

In a further aspect of the invention for which protection is sought there is provided apparatus for performing pyrolysis of hydrocarbon-containing material, the apparatus comprising:

a reactor vessel arranged to receive material to be pyrolysed;

a source of microwave radiation; and

control means for controlling the apparatus,

the apparatus being operable by means of the control means to irradiate material contained within the reactor vessel with microwave radiation thereby to heat the material to evolve hydrocarbon compounds therefrom, the apparatus being operable to provide a flow of evolved hydrocarbons from pyrolysed material to a storage means.

In a further aspect of the invention for which protection is sought there is provided a substantially self contained waste processing unit for performing pyrolysis of hydrocarbon-containing material, the unit comprising:

a reactor vessel arranged to receive material to be pyrolysed;

heating means; and

control means for controlling the unit,

the unit being operable under the control of the control means to heat material contained within the reactor vessel by means of the heating means to evolve hydrocarbon compounds therefrom, the unit being operable to provide a flow of evolved hydrocarbons from pyrolysed material to a storage means.

The heating means may comprise electrical heating means such as a source of microwave radiation. Alternatively or in addition the heating means may comprise a different form of electrical heating means such as one or more resistive heating elements. Alternatively or in addition the heating means may comprise a fuel burner such as a gas burner, a liquid fuel burner such as a petroleum spirits burner, a heavy oil burner or any other suitable heating means. In a further aspect of the invention for which protection is sought there is provided a substantially self contained waste processing module for performing pyrolysis of hydrocarbon-containing material, the module comprising:

a reactor vessel arranged to receive material to be pyrolysed;

heating means; and

control means for controlling the unit,

the module being operable under the control of the control means to heat material contained within the reactor vessel by means of the heating means to evolve hydrocarbon compounds therefrom, the module being operable to provide a flow of evolved hydrocarbons from pyrolysed material to a storage means.

BRIEF DESCRIPTION OF THE DRAWINGS

Aspects of the invention will now be stated and embodiments of the invention will be described with reference to the accompanying figures in which:

FIGURE 1 is a schematic diagram of a known plant for extracting hydrocarbons from hydrocarbon-containing raw materials such as plastics and rubber by pyrolysis; FIGURE 2 shows (a) a schematic illustration of a pyrolysis unit or module according to an embodiment of the present invention, (b) the module shown in (a) with a door open and (c) a module according to a further embodiment of the invention;

FIGURE 3 is a view from above of a main body portion of a reactor of the module of FIG. 2(a);

FIGURE 4 is a cross-sectional view of a portion of the reactor of the module of FIG. 2(a);

FIGURE 5 shows (a) a perspective view of the module of FIG. 2(a), (b) a plan view of the module of FIG. 2(a) and (c) a side view of the module of FIG. 2(a); and

FIGURE 6 shows a structure of a lid portion of the module of FIG. 2(a) showing a condenser conduit, vacuum pump and neutraliser. DETAILED DESCRIPTION

FIG. 2(a) shows an embodiment of the present invention in the form of a substantially self contained pyrolysis unit 100. The unit may also be referred to as a module 100, since it is in the form of a unitary apparatus that can be replaced by another unit, in a similar manner to another domestic unit or appliance such as a washing machine or cooker, in a modular manner. The module 100 has an outer shell or casing 101 in the form of a rectangular prism having a substantially square base although other arrangements are also useful. The dimensions of the casing 101 may be so as to allow the module 100 to be substituted for another domestic appliance of similar dimensions in a modular manner although other arrangements are also useful.

In the embodiment shown the base has a width w of 600cm and a depth d of 600 cm. A height h of the unit is around 800cm. It is to be understood that other values of w, d and h are also useful.

In the embodiment of FIG. 2(a) the module 100 has a control panel 105 and a door 1 10 through which material to be pyrolysed may be introduced into the module 100. The door 1 10 is a tilting door or 'chute'. In the configuration of FIG. 2(a) the door 1 10 is shown in a closed condition being the normal condition when pyrolysis is being performed. In the configuration of FIG. 2(b) the door 1 10 is shown in an open condition whereby it allows the introduction of material to the module 100. Material introduced through the chute 1 10 passes into a reactor 120 (FIG, 3). FIG. 2(c) shows a module 200 according to an alternative embodiment in which the door 210 is arranged to be slidable outwards away from a shell 201 of the module 200. As the door 210 so slides, a portion of a reactor vessel 220 in which material is pyrolysed emerges from the shell 201 of the module 200 allowing material to be introduced into the vessel 220.

The modules 100, 200 are primarily intended to receive domestic waste and other materials of a carbonaceous nature generated by a household. This may include plastic packaging, food waste and peelings, paper, board, garden waste, rubber, carpets, polymers, cotton and synthetic fabrics such as nylon and polyester. The modules 100, 200 are arranged to convert such material into fuels such as diesel and hydrocarbon gas and to produce a stable form of pyrolysed carbon as a by-product. It is to be understood that the following description of the module 100 of FIG. 2(a) is equally applicable to the module 200 of FIG. 2(c).

The module 100 is not designed to convert materials such as metal, glass and ceramics. Inclusion of such materials in the reactor 120 would not cause adverse reaction although the space occupied by such materials would not produce fuel and would likely lower the overall efficiency of the module 100.

The module 100 has several distinct sections illustrated in FIG. 3 to FIG. 6, each performing a separate function in the processing of carbonaceous material into fuel.

Thus the module 100 has a reactor 120 as noted above and shown in plan view in FIG. 3 in which waste material is heated and hydrocarbon vapours evolved. A gas pump 135 (shown in FIG. 4) is arranged to draw vapour evolved from the waste material out from the reactor 120 through a condenser conduit 131 . The condenser conduit 131 is oriented at an angle of from around 30° to around 60° to the vertical in some embodiments although other angles are also useful.

A condenser coil 132 is provided within the condenser conduit 131 upstream of the pump 135, between the pump 135 and reactor 120. The condenser coil 132 is arranged to cool the evolved vapour thereby to condense a fraction of the vapours corresponding to diesel oil. These condensed vapours drain into an oil storage tank 141 via a conduit 133. When the waste material is initially heated, water may be evolved and any such water is condensed by the condenser coil 132 into a water storage tank 145. In some arrangements condensing water is arranged to flow out from the module 100, for example into a drain. Valves are provided to prevent draining of evolved water into the oil storage tank 141 and prevent draining of condensed oil into the water tank 145, the valves being opened and closed when required.

Gases that are not condensed by the condenser coil 132 are pumped by the pump 135 through a neutraliser 137 (FIG. 6) that is arranged to neutralise or remove certain gases such as NOx, SOx, C02 and CO. The pump 135 is also arranged to compress the remaining gas into a gas storage tank 143. The module 100 has a battery 150 of rechargeable cells for storing electricity generated by the module 100 (see below).

The reactor 120 is of substantially cylindrical shape in the embodiment of FIG. 2(a) although other arrangements are also useful. As shown in FIG. 3, the reactor 120 has a rotating mixing arm 125 emanating from a centre of a base 120B along a cylinder axis of the reactor 120. A pair of blades 125A, 125B are arranged to be rotated by the arm 125, the blades 125A, 125B being arranged to rotate in opposite directions. In some embodiments the blades and/or an inner surface of the reactor 120 are coated with or formed from aluminium and/or another material arranged to catalyse decomposition of waste material to form useful hydrocarbon compounds. The material from which the reactor is formed (such as aluminium or an aluminium alloy) may be impregnated with or contain one or more other elements or materials for catalysing decomposition of material during pyrolysis.

Waste material contained within the reactor 120 is heated by microwave generators 127A-D sited underneath the reactor 120. In some arrangements the microwave generators 127A-D are provided to a side of, above and / or in an upper portion of the reactor 120. The generators 127A-D are arranged to generate microwaves and direct the microwaves inwards into the reactor 120. In some embodiments in which the reactor is formed from a metallic material, microwave transparent windows may be provided in a wall of the reactor 120 to allow microwave radiation to pass into the reactor. In some embodiments a waveguide is arranged to guide microwave radiation from each generator 127A-D into the reactor 120 at a suitable position, for example through an aperture formed in a sidewall of the reactor 120.

In the embodiment shown respective generators 127A-D are arranged to generate microwave radiation of different respective prescribed frequencies. The generators are arranged to generate the different frequencies one after the other although in some arrangements the generators 127A-D are arranged to generate two or more of the frequencies substantially simultaneously.

In the arrangement shown one or more of the generators 127A-D initially generate one or more frequencies or radiation arranged to excite the O-H bond of water molecules comprised in the waste material, This allows drying of the material in the reactor 120 to take place.

Subsequently the generators 127A-D generate one or more frequencies arranged to excite C-C, C-H, C-N, C-CI, C-O, C-S, N-H and S-H bonds of hydrocarbon molecules comprised in the waste material thereby to vapourise the molecules.

Material remaining in the reactor 120 following heating of the material is expected to be substantially pure carbon together with non-vapourised materials such as metals, glass, ceramics and the like.

It is to be understood that the reactor 120 and mixing arm 125 may be manufactured from aluminium or a similar metal arranged to act as a catalyst and encourage volatilisation of hydrocarbon gases at relatively low temperatures and/or microwave energy levels. Other hydrocarbons of relatively low molecular weight (low mol wt) such as diesel, olefins, limonenes and other materials that comprise petroleum and diesel fuels / spirits are also vapourised.

An inner surface 120C of the reactor 120 comprises zeolites and bentonite clay. Other materials for catalysing the breakdown of hydrocarbon-bearing vapours in the reactor 120 and the formation of high energy / high calorific value low mol wt gases such as methane, ethane, propane, butane and/or other condensable volatile compounds such as olefins and limonenes are also useful. In the module 100 of FIG. 2(a), (b) an inside of the reactor 120 is accessed by means of a hinged door 1 10. In the module 200 of FIG. 2(c) the door 120 is arranged to slide in and out by means of a rail-type arrangement whereby the reactor 120 or a portion thereof may be slid out to a position allowing the reactor 120 to be emptied or filled. In the module 100 of FIG. 2(a) the reactor 120 has a lid portion 120L (FIG. 4) that can be raised above a main body portion 120M of the reactor 120 to allow filling of the reactor 120 with waste material. The lid portion 120L has a skirt portion 120LS that may be lowered over and around a free end of the body portion 120M to form an air and water tight seal between the lid portion 120L and body portion 120M. The lid portion 120L may be raised and lowered by an electrical actuator or by energy supplied by a person using the reactor 120. For example the act of opening the door 1 10, 210 may cause the lid portion 120L to be moved to allow material to be placed inside the reactor 120.

The lid 120L and main body portion 120M are arranged to be sealed together in a substantially airtight manner by means of a seal that may be formed from a plastic or rubber compound or a polymer. The seal is arranged not to decompose or react when in contact with compounds generated during pyrolysis of the waste material, for example volatile acidic gases such as HCI, S02, HS etc. The seal may be formed from a silicone material or other suitable high temperature rubber or other polymeric material.

The seal is also capable of withstanding exposure to microwave radiation generated by the microwave generators 127A-D.

As shown in FIG. 4, an internal diameter of the skirt portion 120LS of the lid portion 120L is slightly wider than an external diameter of the body portion 120M. This allows the lid portion 120L to slide down and over the body portion 120M. A seal may be formed between a bottom rim of the lid portion 120L and the body portion 120M by means of a seal member 120S.

A further seal in the form of a ring seal 120R is provided around an outer surface of the body portion 120M to allow a seal to be formed between the body portion 120M and lid portion 120L. Other positions are also useful for the ring seal 120R which may be in the form of an '0' ring seal.

An outer skin 120A of the reactor 120 is provided with a thermoelectric generator structure. The structure is configured to generate electrical energy due to heating of the reactor 120 during pyrolysis.

The thermoelectric generator structure may be in the form of a sandwich arrangement of materials configured to exploit the Peltier effect.

Thus a difference in temperature between the reactor 120 and external environment is exploited to generate an electrical current between respective elements (such as plates) of the thermoelectric generator structure which are held at different respective temperatures.

Incorporation of a thermoelectric generator structure allows generation of not insignificant amounts of electrical energy when the reactor 120 is operating. The energy may be stored in the battery 150 or used to supplement an electrical utility supply.

Furthermore in such an arrangement an outer surface of the reactor 120 is maintained in a relatively cool condition by the insulating effect of the thermoelectric generator structure, presenting a reduced safety hazard to an operator of the module 100.

The module 100 is arranged not to allow leakage of gases or microwave radiation therefrom. Sensors are provided for detecting leakage of gases. In the event a leakage is detected the module 100 is configured to shut down. In some arrangements a heat detector (such as a temperature sensor) is provided for detecting overheating of a portion of the module 100. In some embodiments a microwave detector is provided for detecting leakage of microwave radiation.

It is to be understood that in use the temperature inside the reactor 120 may rise to between 300 and 900 'Ό. Nevertheless an outer surface of the reactor 120 may be maintained substantially at ambient environmental temperature.

A safety interlock system is also provided to ensure that operation of the module 100 terminates in the event the reactor 120 is opened or a malfunction occurs.

Operation is also terminated if any portions of the module 100 are not correctly sealed or positioned.

Thus, the module 100 is arranged not to allow heating of material in the reactor 100 unless the lid portion 120L is correctly sealed to the body portion 120M and all outer surfaces of the reactor 120 are intact. A pressure test may be performed by the module 100 before heating of material commences. For example in some embodiments gas pump 135 may be used to draw gas initially contained in the reactor (such as air) out from the reactor. A pressure gauge may be employed to verify that a pressure of gas in the reactor 120 falls below a prescribed value, verifying that the reactor 120 is substantially airtight, before heating of material in the reactor 120 can commence. The reactor 120 is mounted on load cells 129A-D arranged continuously to monitor a mass of the reactor 120 during processing of materials. Pressure and temperature sensors are provided inside the lid portion 120L to allow monitoring of conditions inside the reactor 120.

In one embodiment the module 100 performs a predetermined series of operations as follows: 1 . The reactor 120 is opened and filled with organic waste materials from the home or factory via door 1 10.

2. The door 1 10 is closed and the module 100 energised. The lid portion 120L is urged against the body portion 120M to form a seal therebetween.

3. A controller of the module 100 records the starting temperature, weight of the reactor 120 and pressure inside the reactor 120. An absolute measurement of weight is not performed in some embodiments; rather, data corresponding to an output of one or more of the load cells 129A-D may be stored.

4. The vacuum pump 135 is started in order to pump air from the inside of the reactor 120 to the outside environment through an exhaust.

5. When the module controller notes that the weight of the reactor 120 is substantially constant as air is pumped from the reactor the controller closes an exhaust valve to the outside environment. The module 100 switches the outlet to a tank 145 for water collection. In some alternative embodiments the controller closes the exhaust valve once a prescribed pressure is reached in the reactor 120; in some further alternative embodiments the controller closes the exhaust valve a prescribed period after pumping has begun.

6. One or more of the microwave generators 127A-D are then started and arranged to generate radiation to excite O-H bonds of water contained in the material within the reactor 120. The water is converted to steam relatively rapidly under the partial vacuum conditions, the pressure being between 0.8 and 0.1 atm in some embodiments. The water leaves the reactor as a gas and passes through the condenser conduit 131 .

7. Water condensing in the condenser conduit 131 is arranged to flow into the water collection tank 145.

8. The weight of the reactor 120 is continually measured by the controller by means of load cells 129A-D until the weight is substantially constant. At this point the material inside the reactor 120 is determined to be substantially dry. Drying of the material is advantageous since there is then a reduced risk of unwanted reactions between water and/or oxygen within the water and other compounds such as carbohydrates and C02 products in the evolved gases and liquids once the material in the reactor 120 is heated further.

9. When the module controller notes that the weight of material in the reactor 120 is substantailly constant (due to evolution of water vapour) the one or more microwave generators 127A-D generating radiation to excite O-H bonds may be shut down and microwave radiation for exciting other bonds is generated. Thus one or more of the generators 127A-D are arranged to generate microwave radiation for exciting bonds of carbonaceous materials such as C-C bonds, C-H bonds etc as described above.

10. When this stage of the process begins, the valve to the water tank 145 is closed and lines to the oil storage tank 141 and gas storage tank 143 are opened. The materials inside the reactor 120 start to heat up and hydrocarbons are evolved.

1 1 . The gases start to pass through the condenser conduit 131 and the fractions of relatively high mol wt or high condensation point start to liquefy against the cold surface of the condenser coil 132. Relatively light gases such as methane and ethane etc. continue on through the condenser conduit 131 and through a neutraliser 137 (FIG. 6). The neutraliser 137 may contain alkaline liquid or absorbent crystals in a tube to neutralise or absorb acidic gases. The neutraliser 137 may contain alkaline crystals but may in addition or instead contain carbon black generated by pyrolysis of waste material, for example material produced by the module 100.

12. The gases that pass through the neutraliser may then be compressed by a compressor into the gas storage tank 143. The compressor may compress the neutralised hydrocarbon gases to around 50 to 350 psi. The gas storage tank 143 has an inlet pipe 136 and an outlet pipe (not shown). The outlet pipe is connected to a mixing valve to allow mixing of gas from the tank 143 with gas in a gas utility line such as natural gas. Thus, a mixture of gases that is fed to an appliance such as a boiler, a cooker or an industrial unit can be adjusted from 0% to 100% of gas generated within the module 100. The mix may be adjusted in dependence on the amount of gas within the gas storage tank 143, or the mix may be a substantially constant mix when sufficient gas is within the tank 143. Other arrangements are also useful. 13. Condensable gas passing out of the reactor 120 along conduit 131 condenses in the conduit 131 and is directed by conduit 133 into the oil storage tank 141 . A valve is provided to prevent condensing oil from flowing into the water storage tank 145. Similarly, when water is condensing at the earlier stage of the process a valve is provided to prevent flow of condensing water into the oil storage tank

141 .

14. When the module controller determines that the weight of the reactor 120 has stopped dropping as vapour is evolved in the reactor the controller shuts down the microwave generators 147B-D and allows the reactor 120 to cool. The valves to the gas storage tank 143 and the compressor 135 close and the valve to the oil storage vessel 141 also closes.

15. A temperature sensor inside the reactor lid 120L provides a signal to the controller and opening of the reactor 120 is prevented until the temperature falls below 60 °C. Other temperatures are also useful.

16. A pressure sensor inside the reactor 120 will shut off the reactor 120 and the microwave generators 127A-D if a leak is detected in the system at any time due to an unexpected drop in pressure.

17. The temperature sensor inside the reactor 120 stops the microwave generators 127A-D if the temperature inside the reactor 120 exceeds 900 °C or the temperature inside a casing of the module 100 but outside the reactor 120 exceeds 40 ^. Other temperatures are also useful.

18. Hydrocarbon sensors inside the module 100 are arranged to shut down the module 100 if such gases are detected outside of the internal environment of the reactor, conduits 131 , 133, 134, 136 and storage tanks 141 , 143, 145. Thus if a leak is detected the module 100 is shut down.

19. When the temperature inside the reactor 120 falls to 60°C a catch on the lid portion 120L is released allowing it to be opened. The oil storage tank 141 is also allowed to be removed from the module 100 for emptying.

20. In one embodiment the gas storage tank 143 is permanently fixed inside the module 100 and permanently connected to the domestic utility gas supply of a house, factory or other facility in which the module 100 is located.

21 . When the reactor 120 is reopened, the products of the pyrolysis process including carbon black / carbon char remaining inside the reactor 120 may be removed with a vacuum cleaner or taken out with a scoop and the module 100 is then ready to be used again. 22. The carbon waste product can then be used for example in agriculture, in a refuse bucket for absorbing waste organic liquids or gases or sold to industry for further processing. Alternatively, it can be used in the neutraliser 137 as the absorbent material to absorb acidic gases, dioxins and syngas.

23. Throughout the heating, evolution of the volatile gases and the cooling period the thermoelectric materials around the reactor 120 continue to generate electricity. This can be exported to the domestic household or an external power grid or stored in the battery 150. The stored power may be used to power the module 100 when it is next used. As noted above the gas pump 135 (or vacuum pump) for drawing gases out from the reactor 120 may also be employed to compress gases into the gas tank 143. Alternatively a vacuum pump 135 and separate compressor for compressing gas into the gas tank 143 may be employed. In some embodiments a single pump 135 may initially extract air and water vapour from the reactor 120 and subsequently compress gas and volatile compounds evolved during pyrolysis.

It is to be understood that components such as a vacuum pump that can be easily and quickly replaced may be advantageously employed. Components allowing quiet operation are also advantageous.

A position of the pump 135 and neutraliser 137 may be swapped with one another in some arrangements.

On exiting the reactor 120 the volatile gases enter the condenser conduit 131 . The condenser coil 132 may be formed from coiled glass, metal or plastic tube and positioned inside the conduit 131 . Alternatively the coil may be positioned external to the conduit 131 and arranged to cool the conduit 131 . The conduit 131 may be oriented so that it is inclined away from the reactor 120, for example from the top of the reactor 120. The coil 132 may be arranged such that volatile products from the reactor 120 that have a condensing point above -5 degrees centigrade condense on the surface of the coil 132 and drip from there onto the inner lining of the conduit 131 . The condensed liquid then runs down the inside of the conduit 131 and into the oil storage tank 141 . The lid portion 120L of the reactor 120 has a tapered upper inner surface 120LI (FIG. 6) arranged to promote expulsion of evolved gases out from the reactor 120 and into the condenser conduit 131 . Coolant flowing through the condenser coil 132 to cool the coil may be a brine solution. Any suitable salt may be employed to form the brine solution. NaCI, KCI and/or MgCI may be employed.

It is to be understood that the presence of salt in the coolant lowers the freezing temperature of the coolant and allows cooling of the gases in the conduit 131 to a lower temperature than in the case that water alone is used. The coolant draws heat from the volatile gases to allow them to condense. The coolant is itself cooled by means of a heat exchanger provided in a different portion of a coolant circuit of the module 100. A coolant pump and coolant recirculating system may be provided that is similar to that found inside a conventional refrigerator.

The coolant pump may be in the form of a relatively small peristaltic or diaphragm pump similar to those used in freezers or refrigerators where one half of the coolant circuit will be at high pressure and the other at low pressure. When the coolant is pumped from the low pressure side to the high pressure side the pressure difference causes relatively hot coolant to dump heat energy in order to equalise the pressure inside that half of the circuit. When this is done, the coolant becomes cooler again and ready to be pumped back to the condenser coil 132. After passing through the condenser conduit 131 without condensing the incondensable gases such as methane and ethane etc, together with any undesirable syngas and acidic gases must then be treated to remove the acidic and syngas.

This is because these gases cause unwelcome combustion products such as H2S03 and C02 and CO etc. Furthermore some of the gases may be particularly toxic such as chlorine gas.

To remove them from the useful gas mixture the gases are passed through a neutraliser 137 as described above. In some arrangements the neutraliser 137 contains a solution of alkaline and complexing agents that will neutralise and extract the problematic gases whilst allowing the useful gases to progress and be compressed into the gas storage tank 143.

The neutraliser 137 may also be referred to as a gas scrubber. In some arrangements the gas is "pulled" through this portion by a compression pump acting also as a vacuum pump to empty the system of gas but also to pull it through the gas scrubber, which may employ liquid or crystal technology.

Where a liquid solution is employed, the solution may have a pH meter / sensor to sense when the solution is exhausted, for example by sensing when a fall in pH occurs.

The module 100 may be arranged to provide an alert in the event the pH falls below a prescribed value. In an alternative arrangement crystals within the conduit are arranged to absorb unwanted gases, a change in appearance of the crystals signalling that replacement or recharging of the crystals is required.

A sensor may also be provided within the crystals to measure the pH of the crystals or of the gas as it exits the neutraliser 137, to ensure gases entering the gas storage tank 143 are neutralised.

Sensors may also be provided upstream of the compressor and downstream of the neutraliser 137 to detect chlorine, sulphur and/or nitrogen molecules. In some embodiments the sensors simply determine a pH of the gas flowing therepast.

If the pH of the gas is low then the module 100 may be arranged to terminate processing. In some arrangements the gas is bubbled through or passed over a volume of pure / demineralised water downstream of the neutraliser 137, and the pH of the water measured to determine whether the gas is excessively acidic.

An indicator may also be provided that changes colour in the presence of an acidic or alkaline material. Alternatively or in addition an electrical or electronic sensor may be provided to sense the presence of undesirable gases such as corrosive gases. In some embodiments materials such as carbon tubes and/or nanotubes including carbon nanotubes and the like may be employed to capture one or more gases such as H2S, HCI and/or dioxins. The material may be provided in a flow of gas from the reactor 120 to the gas tank 143. In some embodiments the material is supported by a membrane or a matrix such as a honeycomb structure, for example a honeycomb of carbon arranged to expose the material to gas flowing to the gas tank 143. The material may be provided downstream of the neutraliser 137. In some arrangements the material may be provided upstream of a compressor arranged to pump gas into the gas tank 143.

The module 100 has a total of three storage tanks not including the reactor 120 itself, the tanks being an oil storage tank 141 , a gas storage tank 143 and a water tank 145. The amount of fluid in each tank may be monitored and an alert provided to an operator when a tank is full.

In some embodiments the water tank 145 is not provided, the water being arranged to drain out from the module 100.

The gas storage tank 143 may be made from stainless or mild steel or other suitable material impervious to methane and hydrocarbon gases and also strong enough to maintain a gas under high pressure - up to 9 bar / atm pressure - and not buckle or explode.

The tank 143 may be bolted permanently into the module 100 and not allowed to be removed or it may be a removable tank. For example it may be connected by means of clip or screw fastenings.

In some emodiments the tank 143 is of a similar design to known portable gas storage tanks such as those commonly used to store butane or propane gases for camping, acetalene gas tanks for welding or supply of oxygen and other gases to the health sector.

Thus similar fittings and inlet/outlet sizes may be employed allowing gas reclaimed by the module 100 to be readily used to fuel existing apparatus such as a stove or the like. The capacity of the cylinder can be any suitable volume but it is envisaged that the size will be approximately 25 litres to 40 litres as this is approximately the amount gas (at 9 atm / bar pressure) that a family of 4 might be expected to produce in one week from household waste.

The module 100 may have sensors and the compressor 135 would be rated to pressurise the tank 143 to the predetermined pressure. If this were not possible then an alarm would be activated to warn of a leak in the system or if the pressure increased beyond the predetermined and required pressure then the compressor 135 and module 100 would shut down immediately.

Also, when the removable gas tank 143 is full to capacity the module 100 is arranged to shut down until another empty tank 143 replaces the full tank 143 or some of the gas in the tank 143 is drawn away, for example by being used by a household / factory.

If the tank 143 is a permanent tank and not arranged to be readily removed, then load cells may be employed to note the increase in the weight of the bottle and warn the user when the capacity was nearly achieved or to shut down the unit when the weight of the tank 143 reached a predetermined level.

It would be possible to also use the weight difference in a replaceable tank (or bottle) 143 although allowance would need to be made for differences in weight between different tanks 143. In some embodiments, a liquid level sensor or gas pressure sensor may be provided to allow the controller to determine when a tank is full.

As noted above, in some embodiments the module 100 is arranged to supply gas from the tank 143 to a mixer valve arranged to mix gas from the module 100 with natural or other gas from a utility supply. A user may set a desired proportion of the respective gases to be supplied to a gas fired appliance.

The mixer valve may be a three-way valve with two inputs (the utility gas and the gas from the tank 143 of the module 100) and one output, the output being arranged to deliver a mixture of the gases delivered to the inputs. The module 100 may be arranged to set the outlet pressure of gas from the tank 143 to be the same as that of the utility gas. Gas may then be drawn from the respective inlets (utility gas and gas from the module 100) according to the desired mix. For example, if the mixer valve is set to deliver 100% gas from the gas tank 143 the valve will allow only gas from the tank 143 to be delivered to the appliance. However when gas in the tank 143 has been exhausted (or has fallen to a pressure where the required flow is too low) the mixer valve may be opened automatically to allow flow of gas from the utility supply.

Other arrangements are also useful. For example if another mix of gases is requested, such as a 50:50 mix, the mixer valve may be arranged to increase the proportion of utility gas supplied if the pressure of gas in the tank 143 falls below a prescribed value. A warning may be provided to indicate that the required mix is unattainable.

A non-return valve may be provided to the utility supply to ensure that gas from the gas tank 143 is unable to travel in a reverse direction upstream of the utility supply.

The oil storage tank 141 may be constructed of a hard plastics material and be substantially impervious to hydrocarbons. The tank 141 is arranged not to dissolve or soften in the presence of organic solvents.

In some arrangements the tank 141 is formed from a similar type of metal material to the gas tank 143 so as to avoid problems with corrosion or sacrificial oxidation between different metals.

The oil tank 141 is optionally fully removable from the module 100. Thus, when the tank 141 is installed in the module 141 a valve may be opened to allow oil to be drained into the tank. The valve may be closed automatically when the tank 141 is removed. In some embodiments the valve is actuated mechanically.

The tank 141 may alternatively be permanently installed in the module 100. The tank 141 may be made from the same materials as above but have a tap or other means for allowing oil to be dispensed from the tank 141 . Each tank 141 is provided with an electronic display indicating the amount of fuel contained in the tank 141 . The indication may state the actual amount of fluid (in litres, gallons, cubic metres etc) or the amount as a fraction or percentage of the capacity of the tank 141 .

The module 100 may have a display 105 indicating the historical amount of waste (e.g. in kg) that has been processed by the the reactor 120 and therefore the amount of carbon and fuel generated over a prescribed time period, for example the previous year / month / week etc. The display 105 may also provide an indication of the amount of fuel and/or carbon generated since the module 100 was switched on.

The display 105 may also provide an estimate of the amount of money that has been saved by not having to buy an equivalent amount of fuel to that produced by the module 100.

For example, the module 100 may be arranged to calculate the amount of electricity produced by the unit via the thermoelectric generators and the amount exported from the unit to the home / factory and also back into a supply grid if there was an excess. The calculation would be performed by the controller so the user can input the cost per unit of energy from a utility bill, allowing the module 100 to calculate the saving that has been made.

The module 100 may also calculate the weight of waste processed, the weight of carbon manufactured and therefore the amount of C02 saved from going into the atmosphere.

The display 105 may also provide an indication of the amount of gas present in the gas tank 143, the amount of oil in the oil tank 141 and the amount of water in the water tank 145.

In use, the module 100 may provide an indication of the point in the processing cycle that the module 100 is at and an estimated time left for the unit to complete the cycle. This may be calculated by the module 100 based on the total weight of the waste at the start and the rate of loss of the carbon bearing materials. A plot of weight loss as a function of time may have a similar form for each load of material placed in the reactor 120. As noted above a battery 150 of charge storage cells is provided underneath the reactor 150 for storing charge generated by the thermoelectric generators of the module 100. The battery 150 may be arranged to supply electrical energy to the microwave generator 127A-D, stirring arm 125 and pump 135. The battery 150 may be a Nickel Cadmium rechargeable battery or any other suitable battery.

In some embodiments of the invention the module 100 is arranged to perform pyrolysis of waste material using heat generated by solar-powered electrical generators.

In some embodiments pyrolysis of a raw material may be performed within a period of around 12 hours, for example from around 8 hours to around 12 hours. Other periods are also useful.

It is to be understood that a wide range of materials may be processed by pyrolysis such as plastics and rubbers as noted above, plus carpets (wool and non-wool), wools from other waste sources, certain foodstuffs and other biological materials. The temperature at which certain organic compounds are evolved from different raw material sources may differ from source to source requiring conditions in a given reactor to be optimised for a given raw material type.

In some embodiments, material to be pyrolysed is first cooled to a temperature sufficiently low to kill bacteria and/or viruses of concern to the user.

For example, in some applications biomedical waste from medical and healthcare institutions such as body parts, organs, dressings, packaging and the like may be cooled to kill bacteria, viruses and like organisms that are capable of surviving at relatively high temperatures such as those encountered during pyrolysis of organic materials.

It is to be understood that such organisms might otherwise still be present in waste material from a pyrolysis reactor 120 such as in the carbon by-product. Thus in order to prevent spread of disease and other infections due to surviving organisms the waste material may be cooled to cryogenic temperatures in order to kill the organisms. In some embodiments the material may be cooled to around -δ'Ό, -Ι Ο 'Ό, -20 ^, -δΟ 'Ό, - l OO 'C or any other suitable temperature. In some embodiments the material may be cooled to liquid nitrogen temperatures, around 77K. Cooling to any other temperature at which the organisms of concern are unable to survive may also be useful. In some embodiments the material is cooled to a temperature around that of dry ice (freezing point of C02), around -78 ^< C.

In some processes, when the material is frozen it is more readily crushed into small pieces, for example into a powder making packaging (such as bagging) and handling of the material easier.

It is to be understood that in some arrangements cooling also kills moulds, fungi and the like. In some embodiments the feature of crushing the material before pyrolysis facilitates handling of the material when it is removed from the reactor 120 since it has already been broken into manageable pieces during the cryogenic process to kill organisms present in the material. It is to be understood that some organisms capable of withstanding cooling to the cryogenic temperatures may subsequently be killed in the low (or zero) oxygen, high temperature environment of the reactor during pyrolysis. In some arrangements a combination of low pressure (due to suction of air from the reactor 120) and heating is arranged to kill organisms that survive cooling to the cryogenic temperatures. For example, a combination of heat and low pressure may cause bacterial cells to shrink and detach from the cell walls, the cell walls then exploding, killing the bacteria.

In some embodiments the module 100 is provided with means for cooling and crushing waste as described above. The means for crushing may comprise hammers, rollers or the like.

In some embodiments of the invention the pyrolysis process involves freezing waste such as biomedical waste; and subsequently heating the waste in a reactor to evolve organic compounds by pyrolysis as described herein. The process optionally comprises crushing the frozen waste before pyrolysis. Throughout the description and claims of this specification, the words "comprise" and "contain" and variations of the words, for example "comprising" and "comprises", means "including but not limited to", and is not intended to (and does not) exclude other moieties, additives, components, integers or steps.

Throughout the description and claims of this specification, the singular encompasses the plural unless the context otherwise requires. In particular, where the indefinite article is used, the specification is to be understood as contemplating plurality as well as singularity, unless the context requires otherwise.

Features, integers, characteristics, compounds, chemical moieties or groups described in conjunction with a particular aspect, embodiment or example of the invention are to be understood to be applicable to any other aspect, embodiment or example described herein unless incompatible therewith.