Treatment of waste material

Abstract

To provide ways in which useful work can be extracted from plastics waste materials for example mixed and / or contaminated waste plastic materials and vehicle tyres.SOLUTION: There is provided a method of treating a comminuted waste material, the method comprises: a) feeding a comminuted waste material into a heating chamber (28); b) introducing steam into the heating chamber (28); c) contacting the steam and comminuted waste material; d) heating the steam and comminuted waste material to generate a combustible gas; and e) altering or controlling the ratio of steam to comminuted waste material such that the generated combustible gas contains a target amount (e.g. value or percentage) of a component thereof.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates generally to methods of treating waste and to apparatus for treating waste. More particularly, but not exclusively, the present invention relates to methods of treating comminuted waste and to apparatus for treating comminuted waste. [Background technology]

[0002] It is known to heat biomass materials to produce syngas. Syngas is a gaseous mixture containing, among other substances, hydrogen, carbon monoxide, and methane. The treatment process typically involves heating granular or otherwise comminuted biomass waste in a kiln. The kiln is typically heated by a heating system. It is also known to add steam to the contents of the kiln to, for example, provide a reducing atmosphere in which syngas can be more easily produced and / or the ratio of components in the syngas can be controlled. Steam is typically pre-produced by heating water using an additional heating system before the steam is introduced into the kiln. The produced syngas can then be sent for further processing.

[0003] As will be appreciated by those skilled in the art, equipment for producing synthesis gas (and for its further processing) is relatively complex. Furthermore, the treatment process is typically run continuously, e.g., 24 hours a day. Accordingly, relatively large amounts of energy are required for heating systems, compression systems, etc. As a result of these relatively high energy requirements, such equipment can be relatively expensive to operate. However, in order for hydrogen produced from biomass waste (for example) to be economically competitive with hydrogen produced from other sources, the processing method must necessarily be as inexpensive as possible. Therefore, it would be advantageous to minimize the running costs of such equipment for treating waste.

[0004] It would also be beneficial to increase the efficiency of the process, for example, relative to prior art processes. It would be beneficial to increase the relative efficiency of the kiln heating process, the steam production process, the gasification process, and / or the production of components of the product gas (e.g., hydrogen).

[0005] In recent years, the proliferation of plastic products and packaging has resulted in (and continues to result in) the generation of large amounts of waste. Plastic waste has traditionally been delivered to landfills for natural decomposition. However, such plastic waste can take a long time to decompose naturally, for example, hundreds of years. Therefore, it has been proposed to process waste plastic materials instead of delivering them to landfills, so that the by-products of the treated waste can be used. It would be advantageous to separate and recycle plastic materials so that they can be reprocessed to produce useful products.

[0006] Unfortunately, recycling and recycling technologies are not universal for plastic waste. Furthermore, it is relatively expensive and difficult to treat contaminated waste plastic materials or mixed plastic waste streams. In fact, there are some plastic materials that are currently impossible (or prohibitively expensive) to recycle. Unfortunately, when a waste stream is contaminated, separating recyclable plastic materials from non-recyclable ones tends to prove too expensive, so the entire waste stream may not be treated.

[0007] Plastic packaging, such as the plastic barrier films used in food packaging, is a major source of plastic material that is typically difficult to recycle due to the functional properties of plastics. Tires are also a difficult waste product to process.

[0008] In situations where the waste stream cannot be recycled, the waste stream typically ends up in a landfill. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-83310 [Patent Document 2] Japanese Patent Application Laid-Open No. 2003-113381 Summary of the Invention [Problem to be solved by the invention]

[0010] It is an object of the present invention to provide a method by which useful works can be extracted from plastic waste, for example mixed and / or contaminated waste plastic material and vehicle tyres. [Means for solving the problem]

[0011] Accordingly, a first aspect of the present invention provides a method for treating ground waste, the method comprising: a) contacting steam with ground waste material in a heating chamber; b) heating the steam and the pulverized waste material to produce a combustible gas; c) The amount of flammable gas produced is determined by the target amount of its component (C T Varying or controlling the ratio of steam to milled waste to include (e.g., value or percentage); Includes:

[0012] As used herein, the term "comminuted" means material that has been reduced to small particles or fragments.

[0013] The method may further include the step a') of feeding the ground waste material into the heating chamber. The method may further include the step a'') of introducing (e.g., injecting) steam into the heating chamber. Step a') may occur before, after, or together with (i.e., simultaneously or overlapping with) step a'').

[0014] Another aspect of the present invention provides a method for treating ground waste, the method comprising: a) feeding pulverized waste material into a heating chamber; b) introducing (e.g., injecting) steam into the heating chamber; c) contacting steam with the pulverized waste material; d) heating the steam and the pulverized waste material to produce a combustible gas; e) varying or controlling the ratio of steam to milled waste so that the combustible gas produced contains a target amount (e.g., value or percentage) of that component; Includes:

[0015] The method may further include the preceding step of heating the steam (e.g., superheating the steam).

[0016] The method may include the step f) of varying or controlling the location within the heating chamber where steam is introduced.

[0017] The steam can be generated and / or heated in a steam generator or heat exchanger (e.g., a boiler). The steam can be generated and / or heated by recovered heat. Excess heat from heating the heating chamber (e.g., flue gas) can be supplied to the steam generator or heat exchanger. Steam or water can be supplied to the heat exchanger. The flow rate of the steam or water supplied to the heat exchanger can be monitored or monitored. The flow rate of the steam or water supplied to the heat exchanger can be controlled or controllable. The heating of the steam or water can be via heat recovered from heating the steam and pulverized waste in the heating chamber. The flow rate of steam introduced to the heating chamber can be monitored or monitorable. The flow rate of steam introduced to the heating chamber can be controlled or controllable.

[0018] The temperature of the steam introduced into the heating chamber can be monitored or can be monitored. The temperature of the steam introduced into the heating chamber can be controlled or can be controlled. The amount of heat supplied to the heat exchanger can be controlled or can be controlled. The amount of heat supplied to the heat exchanger can be varied or can be varied to control the temperature of the steam introduced into the heating chamber.

[0019] Steam may be introduced into the heating chamber continuously or discontinuously, for example intermittently (eg, pulsed).

[0020] The temperature and / or flow rate of the steam introduced into the heating chamber may be controlled or controllable so that the combustible gas produced contains a target amount (eg, value or percentage) of that component.

[0021] In an embodiment, varying or controlling the ratio of steam to milled waste material may include, for example, adjusting (e.g., increasing or decreasing) the amount of steam (e.g., mass flow rate) introduced into the heating chamber.

[0022] In embodiments, varying or controlling the ratio of steam to pulverized waste material may include, for example, increasing or decreasing the amount (e.g., mass flow rate) of pulverized waste material delivered into the heating chamber.

[0023] In an embodiment, varying or controlling the ratio of steam to ground waste material may include, for example, adjusting (e.g., increasing or decreasing) the amount of steam (e.g., mass flow rate) introduced into the heating chamber, and / or, for example, increasing or decreasing the amount of ground waste material (e.g., mass flow rate) delivered into the heating chamber.

[0024] In embodiments, the method may include manually or (e.g., at least partially) automatically varying or controlling the ratio of steam to milled waste. In embodiments, adjusting (e.g., increasing or decreasing) the amount of steam (e.g., mass flow rate) may be accomplished automatically or manually (e.g., by an operator). In embodiments, increasing or decreasing the amount of milled waste (e.g., mass flow rate) may be accomplished automatically or manually (e.g., by an operator).

[0025] In an embodiment, the method may include monitoring or determining the amount (eg, mass flow rate) of steam introduced into the heating chamber.

[0026] In an embodiment, the method further comprises monitoring or determining the amount (e.g., mass flow rate) of steam introduced into the heating chamber (S M ) to the steam target amount (S T )

[0027] In an embodiment, the steam target amount (S T ) can be set prior to steps a), b), and / or c) of the method. In an embodiment, the steam target (S T ) can be set (e.g., at least partially) simultaneously with one or more of steps a), b), and c) of the method. In an embodiment, the steam target (S T ) can be fixed, e.g., set only once for the duration of the method or for this use. Alternatively, the steam target (S T ) can be dynamic, for example, the steam target (S T ) can be changed one or more times (e.g., simultaneously with one or more steps of the method). In an embodiment, the steam target (S T ) can be set according to the operation schedule. For example, the steam target (S T) can be set or changed according to one or more external factors. In an embodiment, the one or more external factors can include a determination to produce a relatively greater amount of one or more components of the flammable gas produced (e.g., a relatively greater amount of hydrogen).

[0028] In an embodiment, the steam target amount (S T ) may be set (e.g., at least in part) manually, for example, by an operator. In an embodiment, the steam target (S T ) can be set (e.g., at least partially) automatically. In an embodiment, the steam target (S T ) can be set remotely, for example, from a location away from the heating chamber. T ) can be set locally, for example, locally relative to the heating chamber (for example, adjacent or immediately adjacent to the heating chamber).

[0029] In an embodiment, the step of varying or controlling the ratio of steam to milled waste material may involve (e.g., automatically) adjusting the amount of steam introduced into the heating chamber to, for example, adjust the amount to a steam target amount (S T ) or approximately the steam target amount (S T ) or the steam target amount (S T ) within the predetermined range.

[0030] In an embodiment, the method may include monitoring or determining the amount (eg, mass flow rate) of ground waste material delivered into the heating chamber.

[0031] In an embodiment, the method includes monitoring or determining the amount (e.g., mass flow rate) of ground waste material delivered into the heating chamber (W M ) to the target amount of waste (W T )

[0032] In embodiments, the amount of ground waste delivered into the heating chamber (e.g., mass flow rate) can be remotely monitored, e.g., from a location remote from the heating chamber. In embodiments, the amount of steam introduced into the heating chamber (e.g., mass flow rate) can be remotely monitored, e.g., from a location remote from the heating chamber. In embodiments, the target amount of waste (W T ) can be set prior to steps a), b), and / or c) of the method. In embodiments, a target waste amount (W T ) can be set (e.g., at least partially) simultaneously with one or more of steps a), b), and c) of the method. In embodiments, the waste target amount (W T ) can be fixed, e.g., set only once for the duration of the method or for this use. Alternatively, the target waste amount (W T ) can be dynamic, e.g., the waste target amount (W T ) can be changed one or more times (e.g., simultaneously with one or more steps of the method). In embodiments, the target waste amount (W T ) can be set according to the operation schedule. For example, the target amount of waste (W T ) can be set or changed according to one or more external factors. In an embodiment, the one or more external factors can include a determination to produce a relatively greater amount of one or more components of the flammable gas produced (e.g., a relatively greater amount of hydrogen).

[0033] In the embodiment, the target amount of waste (W T ) can be set (e.g., at least in part) manually, for example, by an operator. In an embodiment, the target waste volume (W T ) can be set (e.g., at least partially) automatically. In an embodiment, the target waste amount (W T ) can be set remotely, for example, from a location away from the heating chamber. T) can be set locally, for example, locally relative to the heating chamber (for example, adjacent or immediately adjacent to the heating chamber).

[0034] In the embodiment, the target amount of waste (W T ) can be set according to an operating schedule.

[0035] In an embodiment, the step of varying or controlling the ratio of steam to pulverized waste material may involve (e.g., automatically) adjusting the amount of pulverized waste material delivered into the heating chamber, e.g., adjusting the amount to a target amount of waste material (W T ) or approximately the target amount of waste (W T ) or waste target amount (W T ) within the predetermined range.

[0036] In embodiments, this component may be one or more of hydrogen, methane, or a further combustible gas.

[0037] In an embodiment, the method comprises: T ) (e.g., a value or a percentage). In an embodiment, T ) can include a range of values ​​or percentages. Alternatively, the target amount can include a value or percentage.

[0038] In embodiments, the steam and pulverized waste material may initially be contacted at least partially outside the heating chamber, for example, the steam and pulverized waste material may be contacted before steps a') and a'').

[0039] In an embodiment, the target amount (C T) can be set prior to steps a), b), and c) of the method. In embodiments, the target amount can be set simultaneously (e.g., at least partially) with one or more of steps a), b), and c) of the method. In embodiments, the target amount can be fixed, e.g., set only once for the duration of or use of the method. Alternatively, the target amount (C T ) can be dynamic, e.g., a target quantity (C T ) can be changed one or more times (e.g., simultaneously with one or more steps of the method). In embodiments, the target amount (C T ) can be set according to the operation schedule. For example, the target amount (C T ) can be set or changed according to one or more external factors. In an embodiment, the one or more external factors can include a determination to produce a relatively greater amount of one or more components of the flammable gas produced (e.g., a relatively greater amount of hydrogen).

[0040] In an embodiment, the target amount (C T ) may be set (e.g., at least in part) manually, for example, by an operator. In embodiments, the target amount may be set (e.g., at least in part) automatically. In embodiments, the target amount (C T ) can be set remotely, for example, from a location away from the heating chamber. T ) can be set locally, for example, locally relative to the heating chamber (for example, adjacent or immediately adjacent to the heating chamber).

[0041] In embodiments, the step of contacting the steam with the pulverized waste material may include (e.g., at least partially) mixing the steam with the pulverized waste material. The mixing may be active (e.g., may be at least partially achieved by a mixing means or mixer) or passive (e.g., may be at least partially the result of contact between the steam and the pulverized waste material).

[0042] In some embodiments, the method may include scrubbing the generated flammable gas.

[0043] In embodiments, the heating chamber may be rotatable (e.g., rotatable about an axis of rotation) during use. The method may include rotating the heating chamber. Steam may be introduced offset from the axis of rotation.

[0044] The steam may be introduced at a temperature between about 400°C and 800°C, such as between about 500°C and 700°C, such as between about 550°C and 650°C, such as about 600°C.

[0045] In some embodiments, the method can include further processing the generated flammable gas, which can include removing or separating one or more components of the generated flammable gas, such as removing or separating hydrogen from the generated flammable gas.

[0046] The ground waste can include plastic waste, such as polyethylene terephthalate, high density polyethylene, low density polyethylene, linear low density polyethylene, polyvinyl chloride, polypropylene, etc. The ground waste can include rubber, biomass, tire dust, etc. The ground waste can include any suitable combination of plastics and / or other materials.

[0047] The combustible gas can include a combustible hydrocarbon, such as methane or another alkane. The combustible gas can form a component of a gaseous mixture, such as a generated gaseous mixture. The gaseous mixture can include synthesis gas. The synthesis gas can include hydrogen, methane, and carbon monoxide. The synthesis gas can include one or more additional substances.

[0048] In embodiments, the method may include providing at least a portion of the generated combustible gas to a generator, for example to generate electrical energy. The generator may provide electrical energy to control or operate one or more components or machines associated with the method steps. Additionally or alternatively, the generator may provide electrical energy to a power grid. Additionally or alternatively, the generator may provide electrical energy to one or more additional components or machines.

[0049] In embodiments, at least a portion of the generated flammable gas may be delivered or supplied to a gas grid. In embodiments, at least a portion of the generated flammable gas may be processed into one or more additional chemicals. In embodiments, components or at least a portion of the generated flammable gas may be stored, for example, in a storage means or storage system (such as, for example, a storage tank). In embodiments, the stored components or a portion of the generated flammable gas may be further processed.

[0050] The method can be a continuous or discontinuous method. For example, one or more of the steps of the method can be performed at least partially simultaneously with one or more of the other steps of the method. In embodiments, one, some, or each of the steps of the method can be performed continuously or discontinuously.

[0051] Contacting the ground waste with steam may include contacting the ground waste with superheated steam, which may be heated to a temperature greater than 200°C, for example, greater than 300°C, 400°C, or 500°C.

[0052] In an embodiment, the step of altering or controlling the ratio of steam to milled waste may include a feedback loop, including, for example, monitoring or determining and altering or controlling.

[0053] A further aspect of the present invention provides an apparatus for treating ground waste, the apparatus comprising: a heating chamber including an inlet for delivery of comminuted waste material into the heating chamber and an outlet for exhaust of generated combustible gases from the heating chamber; steam introduction means or a steam introduction system for introducing steam into the heating chamber; a heating means or heater for, in use, heating the mixture of steam and pulverized waste material within the heating chamber to produce a combustible gas; a controller configured to, in use, vary or control the ratio of steam to pulverized waste material in the heating chamber so that combustible gases produced from the steam and pulverized waste material contain a target amount (e.g., value or percentage) of that component; Includes:

[0054] The apparatus may include an adjustment means or adjuster or lance for varying or controlling the location within the heating chamber where the steam is introduced.

[0055] The apparatus may include a steam generator or heat exchanger (e.g., a boiler). Steam may be generated or heated in the steam generator or heat exchanger. Steam may be superheated in the steam generator or heat exchanger. Recovered heat may be used to generate and / or heat steam. Excess heat from heating the heating chamber (e.g., flue gas) may be supplied to the heat exchanger. Steam or water may be supplied to the heat exchanger.

[0056] The apparatus can include a sensor for monitoring the flow rate of steam or water supplied to the heat exchanger. The apparatus can include a valve for controlling the flow rate of steam or water supplied to the heat exchanger. Heating of the steam or water can be via heat recovered from heating the steam and pulverized waste material in the heating chamber.

[0057] The apparatus may include a sensor in the heating chamber for monitoring the temperature of the steam introduced into the heating chamber. The temperature of the steam introduced into the heating chamber may be controlled or controllable. The amount of heat supplied to the heat exchanger may be controlled or controllable. The amount of heat supplied to the heat exchanger may be varied or variable to control the temperature of the steam introduced into the heating chamber.

[0058] The valves can supply steam or water to the heat exchanger intermittently (e.g., in pulses). Steam can be introduced into the heating chamber intermittently (e.g., in pulses).

[0059] Steam can be introduced into the heating chamber so that the resulting combustible gas contains a target amount (eg, value or percentage) of that component (eg, by controlling the flow rate and / or temperature of the steam).

[0060] In embodiments, the apparatus may include a vapor sensing means or vapor sensor, which may for example be configured or configurable to monitor the amount (e.g. mass flow rate) of vapor (e.g. introduced into the heating chamber during use). The vapor sensing means or vapor sensor may include one or more sensors, which may for example be configured or configurable to monitor or measure (e.g. directly or indirectly) the amount (e.g. mass flow rate) of vapor (e.g. introduced or injected into the heating chamber). The one or more sensors may include a flow rate sensor.

[0061] In an embodiment, the controller may measure the amount (e.g. mass flow rate) of steam introduced into the heating chamber (S M ) to the steam target amount (S T ) can be configured to be compared with

[0062] In an embodiment, the controller may (e.g., automatically) adjust the amount of steam introduced into the heating chamber during use, for example to set the amount to a steam target amount (ST ) or approximately the steam target amount (S T ) or the steam target amount (S T ) can be configured to maintain the

[0063] In embodiments, the apparatus may include a waste sensing means or material sensor, for example, which measures the amount (e.g., mass flow rate) of ground waste (e.g., delivered into the heating chamber) (W M ). The waste sensing means or waste sensor may include one or more sensors, which may for example be configured or configurable to monitor or measure (e.g. directly or indirectly) the amount of waste (e.g. mass flow rate) (e.g. into the heating chamber). The one or more sensors may be configured or configurable to monitor or measure a feeding means or feeder arranged or arrangeable to feed the ground waste into the heating chamber. Where the feeding means or feeder includes a feed screw, the one or more sensors may be configured or configurable to monitor or measure operating parameters of the feed screw, for example (e.g. electrical) force applied to or consumed by it and / or angular velocity of the feed screw. The one or more sensors may include an encoder.

[0064] In an embodiment, the controller adjusts the amount (e.g., mass flow rate) of steam introduced into the heating chamber to a steam target rate (S T ) can be configured to be compared with

[0065] In an embodiment, the controller adjusts the amount (e.g., mass flow rate) of ground waste delivered into the heating chamber during use to a target amount (W T ) can be configured to be compared with

[0066] In an embodiment, the controller may (e.g., automatically) adjust the amount of ground waste delivered into the heating chamber during use, for example, to match the amount to a target waste amount (WT ) or approximately the target amount of waste (W T ) or waste target amount (W T ) can be configured to maintain the

[0067] The heating means or heater may include one or more combustion heating means or heaters. The one or more combustion heating means or heaters may include one or more combustion heaters, for example, one or more heaters that use a fuel source such as gas. The one or more combustion heating means or heaters may include one or more gas heaters, for example, one or more gas burners. In an embodiment, the one or more combustion heating means or heaters may be located outside the heating chamber during use. The one or more combustion heating means or heaters may be positioned to heat the heating chamber.

[0068] In embodiments, the one or more combustion heating means or combustion heaters include multiple combustion heating means or combustion heaters. The first combustion heating means or combustion heater can be configured or configurable to heat the pulverized waste in a first zone of the heating chamber, e.g., to a first temperature T1 (if multiple zones are defined within the heating chamber). The second combustion heating means or combustion heater can be configured or configurable to heat the gasifiable material in a second zone of the heating chamber, e.g., to a second temperature T2. The third combustion heating means or combustion heater can be configured or configurable to heat a third zone of the heating chamber, e.g., to a third temperature T3. In embodiments, the first zone can be located at or adjacent to the inlet. The third zone can be located at or adjacent to the outlet. The second zone can be located between the first zone and the third zone.

[0069] The first temperature T1 can be sufficiently high to at least partially gasify the pulverized waste material. The first temperature T1 can be sufficiently high to completely gasify the pulverized waste material.

[0070] The temperature of the heating chamber can be greater than 250° C. throughout. For example, the temperature of the heating chamber can be greater than 250° C., e.g., greater than 275° C., 300° C., 325° C., 350° C., 375° C., 400° C., 425° C., 450° C., 475° C., 500° C., 525° C., 550° C., 575° C., 600° C., 625° C., or 650° C., in each of the zones, e.g., in each of the three zones.

[0071] Steam can be introduced or injected into any one of the three zones. Steam can be introduced into the first zone and / or the second zone and / or the third zone. Steam can be introduced into one or more of the three zones. Steam can be introduced upstream of the first zone (e.g., together with the milled waste).

[0072] In an embodiment, the apparatus may include a scrubbing system for scrubbing combustible gases generated, for example, in the heating chamber.

[0073] In some embodiments, the apparatus can include a kiln, such as a rotary kiln. The rotary kiln can be of the direct or indirect type. The heating chamber can be provided or defined within the kiln. The heating chamber (e.g., the kiln or a portion thereof) can be positioned or configured to be rotatable during use. The heating chamber can include a heat conversion chamber.

[0074] In some embodiments, the apparatus can include a steam delivery means or system, which can be configured or configurable to introduce steam into the heating chamber. The steam delivery means or system can include a water source. The steam delivery means or system can include, for example, a boiler and / or heat exchanger arranged or arrangeable to boil water (e.g., from a water source).

[0075] The vapor delivery means or vapor delivery system may include a heater or heat exchanger capable of superheating the vapor, for example a heater capable of heating the vapor to a temperature greater than 200°C, for example greater than 300°C, 400°C or 500°C.

[0076] A further aspect of the present invention provides a method for treating ground waste, the method comprising: a) heating water using one or more combustion heating means or heaters to produce steam; b) introducing the generated steam into a heating chamber; c) heating the pulverized waste material in the presence of the generated steam in the heating chamber to generate a combustible gas; d) supplying at least a portion of the combustible gas to one or more combustion heating means or heaters to heat the water; Includes:

[0077] In embodiments, waste heat (eg, from a kiln exhaust system) may be used, in whole or in part, to heat water and generate steam.

[0078] For the avoidance of doubt, any of the features described herein apply equally to any aspect of the invention, for example the apparatus may include any one or more features of the method associated with the apparatus, and / or the method may include any one or more features or steps associated with one or more features of the apparatus.

[0079] A further aspect of the present invention provides a computer program element comprising computer readable program code means or a computer readable program code system for causing a processor to execute procedures for performing one or more steps of the methods described above.

[0080] Yet another aspect of the present invention provides a computer program element embodied on a computer-readable medium.

[0081] Yet another aspect of the present invention provides a computer-readable medium having stored thereon a program configured to cause a computer to execute procedures for performing one or more steps of the above-described method.

[0082] A further aspect of the invention provides a control means or a control system or a controller including a computer program element or a computer readable medium as described above.

[0083] Within the scope of this application, it is expressly intended that the various aspects, embodiments, examples, and alternatives described in the preceding paragraphs, in the claims, and / or in the following description and drawings, and in particular their individual features, may be construed independently or in any combination. That is, the features of all embodiments and / or any embodiment may be combined in any manner and / or combination, provided such features are not incompatible. To avoid doubt, the terms "may," "and / or," "e.g.," "for example," and similar terms as used herein should be construed as open-ended, such that any feature so described does not need to be present. Indeed, any combination of optional features, whether or not they are explicitly claimed, is expressly contemplated without departing from the scope of the present invention.

[0084] Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which: [Brief explanation of the drawings]

[0085] [Figure 1] 1 is a generalized schematic diagram of an apparatus for processing pulverized waste according to one embodiment of the present invention; [Figure 2] FIG. 2 is a detailed schematic diagram of the indirect rotary kiln, heating system, and steam system shown in FIG. 1. [Figure 3] FIG. 3 is an enlarged view of the indirect rotary kiln shown in FIG. 2. [Figure 4] FIG. 3 is an enlarged view of the heating system shown in FIG. 2. [Figure 5] FIG. 3 is an enlarged view of the steam system shown in FIG. 2. [Figure 6] FIG. 3 illustrates the syngas removal and pressure relief system shown in FIG. 2. [Figure 7] 1 is a flow diagram of a method for treating ground waste according to one embodiment of the present invention. [Figure 8] FIG. 10 is a flow diagram of a method for treating ground waste according to a further embodiment of the present invention. [Figure 9] FIG. 10 is a flow diagram of a method for treating ground waste according to a further embodiment of the present invention. [Figure 10] FIG. 10 is a flow diagram of a method for treating ground waste according to a further embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0086] 1, there is shown a schematic diagram of an apparatus 1 for processing comminuted waste according to one embodiment of the present invention. In use, the apparatus 1 converts waste material, such as granular plastic, into synthesis gas (as described in more detail below).

[0087] As shown in FIG. 3 , the apparatus 1 includes a heating chamber 28, which in this embodiment is provided within the indirect rotary kiln 2. The apparatus 1 further includes a waste feed system 3, a heating system 4, a steam system 5, a cleaning system 6, a storage system 7, and a further processing system 8. The heating system 4 includes a plurality of fired heaters 40. The plurality of fired heaters 40 are arranged to heat the contents of the indirect rotary kiln 2 during use. The waste feed system 3 is arranged to introduce pulverized waste into the indirect rotary kiln 2 during use. The steam system 5 is arranged to introduce steam into the indirect rotary kiln 2 during use. The indirect rotary kiln 2 is fluidly connected to the heating system 4 by a supply system S. The supply system S includes the cleaning system 6 and the storage system 7 in this embodiment. However, in some embodiments, the supply system S may be absent from one or each of the cleaning system 6 and the storage system 7.

[0088] The scrubbing system 6 is arranged to receive, in use, the produced syngas from the indirect rotary kiln 2. The storage system 7 is arranged to receive, in use, the cleaned syngas from the scrubbing system 6. The storage system 7 is arranged to pass at least a portion of the cleaned syngas to a further processing system 8.

[0089] 2 through 6, there are shown detailed schematic diagrams of portions of the apparatus for processing ground waste shown in FIG.

[0090] As shown in FIG. 3, the indirect rotary kiln 2 includes an inlet 21 and an outlet 22. In this embodiment, the inlet 21 and the outlet 22 are located at opposite ends of the indirect rotary kiln 2. The indirect rotary kiln 2 includes a drum 23. The drum 23 includes an outer shell 23a. The outer shell 23a surrounds a layer of insulating refractory bricks 23b. The insulating refractory bricks 23b surround a rotatable tube 23c. The rotatable tube 23c extends beyond the ends of the outer shell 23a at both ends. A heating space 23d is defined between the insulating refractory bricks 23b and the rotatable tube 23c. During use, the outer shell 23a and the insulating refractory bricks 23b remain stationary while the rotatable tube 23c rotates. The rotatable tube 23c may have a diameter of approximately 1.5 m and a heating length of approximately 10 m.

[0091] For use, the indirect rotary kiln 2 is positioned at an angle of approximately 1.5° to the horizontal. The indirect rotary kiln 2 is positioned so that the inlet 21 is higher than the outlet 22. A variable speed drive motor 26a is provided, which in this embodiment is positioned adjacent the inlet 21 of the indirect rotary kiln 2. A mechanical drive chain 26b is also provided. The mechanical drive chain 26b connects the variable speed drive motor 26a to the rotatable tube 23c. During use, operation of the variable speed drive motor 26a moves the mechanical drive chain 26b, thereby rotating the rotatable tube 23c. The rotary kiln 2 is supported on water-cooled bearings (not shown). The rotatable tube 23c is sealed using a nitrogen-purged spring-loaded seal (not shown).

[0092] A discharge hood 22a is provided adjacent to the outlet 22 of the indirect rotatable kiln 2. The discharge hood 22a is in fluid communication with the outlet 22. An inspection hatch 22b is provided above the discharge hood 22a.

[0093] A heating chamber 28 is defined within the rotatable tube 23c. The heating chamber 28 is divided into a first zone 28a, a second zone 28b, and a third zone 28c. The first zone 28a is adjacent to the inlet 21. The third zone 28c is adjacent to the outlet 22. The second zone 28b is disposed between the first zone 28a and the third zone 28c. In this embodiment, each of the zones 28a, 28b, and 28c is of approximately equal length and / or volume. However, in some embodiments, this need not be the case, and one or more of the zones 28a, 28b, and 28c may be of different lengths and / or volumes.

[0094] Apparatus 1 includes an array 29 of temperature sensors, which in this embodiment include temperature sensors 29a, 29b, 29c, 29d, 29e, and 29f disposed inside rotatable tube 23c. Two of temperature sensors 29a, 29b, 29c, 29d, 29e, and 29f disposed inside rotatable tube 23c are disposed inside each of zones 28a, 28b, and 28c in this embodiment. Array 29 also includes temperature sensors 29g, 29h, 29i, 29j, 29k, and 29l disposed in heated space 23d.

[0095] The apparatus includes a pressure sensor 29m configured or arranged to monitor the pressure within the heated space 23d.

[0096] The heating space 23d includes three exhaust ports 25a, 25b, and 25c that are provided through the outer shell 23a and are in fluid communication with the heating space 23d, one of which is located adjacent to each of the zones 28a, 28b, and 28c of the heating chamber 28.

[0097] The apparatus 1 further includes a first nitrogen supply 21a. The first nitrogen supply 21a is in fluid communication with the inlet 21 of the indirect rotary kiln 2. The apparatus 1 further includes a second nitrogen supply 22c. The second nitrogen supply 22c is in fluid communication with the discharge hood 22a. A check valve 21b is provided between the first nitrogen supply 21a and the rotatable tube 23c. A check valve 22d is provided between the second nitrogen supply 22c and the discharge hood 22a.

[0098] In this embodiment, the feed system 3 includes a feed screw (not shown). However, in some embodiments, the feed system 3 may include any suitable means for feeding waste material into the indirect rotary kiln 2, as would be understood by one of ordinary skill in the art. As shown in Figure 1, a flow sensor 30 is positioned to monitor the amount (e.g., mass flow rate) of ground waste material into the heating chamber 28.

[0099] Referring now to FIG. 4, heating system 4 includes a plurality of fired heaters 40, which in this embodiment are gas burners 40a, 40b, 40c, 40d, 40e, and 40f. Gas burners 40a, 40b, 40c, 40d, 40e, and 40f are positioned to heat heating space 23d during use. Gas burners 40a, 40b, 40c, 40d, 40e, and 40f are lean-burn, high-efficiency gas burners. Gas burners 40a, 40b, 40c, 40d, 40e, and 40f are configured to be individually controllable (as described in more detail below). In this embodiment, two of gas burners 40a, 40b, 40c, 40d, 40e, and 40f are positioned adjacent each of zones 28a, 28b, and 28c. The gas burners 40a, 40b, 40c, 40d, 40e, and 40f are equally spaced along the length of the indirect rotary kiln 2. Each gas burner 40a, 40b, 40c, 40d, 40e, and 40f is provided with a respective monitoring device 40g, 40h, 40i, 40j, 40k, and 40l, which in this embodiment are flame detectors.

[0100] The heating system 4 includes a natural gas supply 41. The natural gas supply 41 is in fluid communication with gas control valves 44a, 44b, 44c, 44d, 44e, and 44f via a natural gas pipeline 41a. The natural gas pipeline 41a has parallel branches 41b, 41c, 41d, 41e, 41f, and 41g. Each branch 41b, 41c, 41d, 41e, 41f, and 41g is provided with a gas control valve 44a, 44b, 44c, 44d, 44e, and 44f, respectively. A flow sensor 41h is also provided. The flow sensor 41h is positioned to monitor flow through the natural gas pipeline 41a, for example, flow between the natural gas supply 41 and the first branch 41b.

[0101] The heating system 4 also includes a syngas supply pipeline 42a in fluid communication with a storage 42 of generated syngas (as described in more detail below). The syngas supply pipeline 42a is in fluid communication with gas control valves 44a, 44b, 44c, 44d, 44e, and 44f. The syngas pipeline 42a has parallel branches 42b, 42c, 42d, 42e, 42f, and 42g. A pressure sensor 42h is also provided. The pressure sensor 42h is configured to measure or determine the pressure of gas in the syngas pipeline 42a, for example, between the distal branch 42g and the syngas storage 42.

[0102] The natural gas pipeline 41a is fluidly connected to each of the gas burners 40a, 40b, 40c, 40d, 40e, and 40f by gas pipes 45a, 45b, 45c, 45d, 45e, and 45f, respectively. The synthesis gas supply pipeline 42a is fluidly connected to each of the gas burners 40a, 40b, 40c, 40d, 40e, and 40f by gas pipes 45a, 45b, 45c, 45d, 45e, and 45f, respectively. Each of the gas pipes 45a, 45b, 45c, 45d, 45e, and 45f includes a gas control valve 44a, 44b, 44c, 44d, 44e, and 44f. Each gas pipe 45a, 45b, 45c, 45d, 45e, 45f includes a temperature control valve 42aa, 42bb, 42cc, 42dd, 42ee, 42ff.

[0103] The gas control valves 44a, 44b, 44c, 44d, 44e, and 44f are arranged between the respective branches 41b, 41c, 41d, 41e, 41f, and 41g of the natural gas pipeline 41a and the respective gas pipes 45a, 45b, 45c, 45d, 45e, and 45f. The gas control valves 44a, 44b, 44c, 44d, 44e, and 44f are arranged between the respective branches 42b, 42c, 42d, 42e, 42f, and 42g of the synthesis gas pipeline 42a and the respective gas pipes 45a, 45b, 45c, 45d, 45e, and 45f.

[0104] The heating system 4 further includes a combustion air supply 43. The combustion air supply 43 is in fluid communication with a combustion air fan 46 via a combustion air pipeline 43a. The combustion air fan 46 includes an electrically driven motor 46a. The combustion air pipeline 43a is fluidly connected to each of the gas burners 40a, 40b, 40c, 40d, 40e, and 40f, for example, via branches 43b, 43c, 43d, 43e, 43f, and 43g, respectively. Air control valves 43h, 43i, 43j, 43k, 43l, and 43m are provided on lines between each of the gas burners 40a, 40b, 40c, 40d, 40e, and 40f and their respective branches 43b, 43c, 43d, 43e, 43f, and 43g. Each branch 43b, 43c, 43d, 43e, 43f, 43g of the combustion air pipeline 43a is connected to a gas pipe 45a, 45b, 45c, 45d, 45e, 45f between the temperature control valves 42aa, 42bb, 42cc, 42dd, 42ee, 42ff and the gas burners 40a, 40b, 40c, 40d, 40e, 40f, respectively.

[0105] 5, steam system 5 includes a water source 51. Water source 51 is in fluid communication with steam superheater 52 via steam pipeline 51a. A flow sensor 51b is positioned to measure the flow of water from water source 51 to steam superheater 52. A flow control valve 51c is positioned in steam pipeline 51a. Steam superheater 52 is in fluid communication with inlet 21 of rotatable tube 23c via steam pipeline 51a.

[0106] Steam superheater 52 is heated by excess heat from heating space 23d. Exhaust outlets 25a, 25b, and 25c are in fluid communication with and provide excess heat to superheater 52. The excess heat heats water to provide superheated steam to inlet 21 of rotatable tube 23c.

[0107] Referring now to FIG. 6 , exhaust hood 22a is in fluid communication with syngas fan 60, for example, via outlet pipe 61. Exhaust hood 22a is in fluid communication with pressure control valve 62, for example, via outlet pipe 61. Pressure control valve 62 is in fluid communication with a pressure relief system (not shown). Syngas fan 60 is in fluid communication with scrubbing system 6. Syngas fan 60 includes a variable speed electric drive motor 60a. A pressure sensor 63 is positioned to monitor the pressure inside rotatable tube 23c at and / or adjacent its outlet 22. A pressure sensor 64 is positioned to monitor the pressure inside exhaust hood 22a. A temperature sensor 65 is positioned to monitor the temperature of gas flowing from exhaust hood 22a to syngas fan 60 during use. A pressure sensor 66 is positioned to monitor the pressure of gas flowing from syngas fan 60 to scrubbing system 6 during use.

[0108] 2, the apparatus includes a residue removal system 9 positioned to receive residue from the exhaust hood 22a, which may be sent for further processing in a residue treatment system (not shown).

[0109] The apparatus 1 further includes a control system (not shown). The monitoring devices 40g, 40h, 40i, 40j, 40k, and 40l are wired to the control system. The check valves 21b and 22d are in wired communication with the control system. The pressure transmitter 29m is in wired communication with the control system. The temperature transmitters 29a, 29b, 29c, 29d, 29e, 29f, 29g, 29h, 29i, 29j, 29k, and 29l are in wired communication with the control system. The variable speed drive motor 26a is in wired communication with the control system. The gas control valves 44a, 44b, 44c, 44d, 44e, and 44f are in wired communication with the control system. The flow sensor 41h is in wired communication with the control system. The pressure sensor 42h is in wired communication with the control system. Temperature control valves 42aa, 42bb, 42cc, 42dd, 42ee, and 42ff are in wired communication with the control system. Electric drive motor 46a is in wired communication with the control system. Air control valves 43h, 43i, 43j, 43k, 43l, and 43m are in wired communication with the control system. Flow sensor 51b and flow control valve 51c are in wired communication with the control system. Variable speed electric drive motor 60a is in wired communication with the control system. Pressure control valve 62 is in wired communication with the control system. Pressure sensor 64 is in wired communication with the control system. Pressure sensor 63 is in wired communication with the control system. Temperature sensor 65 is in wired communication with the control system. Pressure sensor 66 is in wired communication with the control system. Flow sensor 30 is in wired communication with the control system. In some embodiments, one, some, or each of the above components can additionally or alternatively communicate wirelessly with the control system.

[0110] Referring now to Figure 7, there is shown a method of treating ground waste according to one embodiment of the present invention using the apparatus shown in Figures 1-6.

[0111] In a first step S1, an apparatus 1 is provided which includes a heating chamber 28 and a plurality of gas burners 40a, 40b, 40c, 40d, 40e, 40f. The rotatable tube 23c is rotated.

[0112] In a second step S2, the ground waste material is fed by the feeding system 3 through the inlet 21 into the rotatable tube 23c and thus into the heating chamber 28. Without wishing to be bound by any theory, it is believed that the inclination angle of the indirect rotary kiln 2 encourages the feed material to move along the rotatable tube 23c towards the outlet 22, for example by gravity feed.

[0113] In a third step S3, steam is injected into the heating chamber 28 by the steam system 5. The steam is introduced into the rotary tube 23c through the inlet 21 by the steam pipeline 51a. The steam is superheated and introduced into the rotary tube 23c at about 600°C.

[0114] Hot water is provided from hot water source 51 to steam superheater 52. The flow rate of the hot water to steam superheater 52 is monitored by flow sensor 51b, and the measurements are sent to a control system. By adjusting flow control valve 51c, the control system can adjust the flow rate of the hot water to steam superheater 52. The hot water is heated to steam in steam superheater 52 for introduction into rotatable tubes 23c.

[0115] Advantageously, the steam provides a reducing atmosphere for the production of synthesis gas. Thus, without wishing to be bound by any particular theory, it is believed that the waste material in the heating chamber 28 is more easily and efficiently gasified into synthesis gas in the presence of steam. Furthermore, the steam acts to transfer heat directly to the waste material inside the heating chamber 28. Advantageously, the heat required from the gas burners to reach the required temperatures in the zones 28a, 28b, 28c can therefore be relatively reduced.

[0116] In a fourth step S4, the pulverized waste material in the heating chamber 28 is heated using gas burners 40a, 40b, 40c, 40d, 40e, 40f.

[0117] As the waste material travels along the rotatable tube 23c, it passes through three zones 28a, 28b, and 28c. In one embodiment, the first temperature T1 in the first zone 28a is about 700°C, the second temperature T2 in the second zone 28b is about 900°C, and the third temperature T3 in the third zone 28c is about 1100°C. The temperature near the outlet 22 of the heated space 23d may be about 1200°C. However, in some embodiments, the first temperature T1, the second temperature T2, and / or the third temperature T3 may be different.

[0118] In the fifth step S5, synthesis gas is generated in the heating chamber 28. The synthesis gas includes a mixture of hydrogen, methane, and carbon monoxide. Additional gaseous substances, such as carbon dioxide and oxygen, may also be present. The ratio of hydrogen to methane in the generated synthesis gas can be adjusted by adjusting various operating parameters of the apparatus 1. For example, it has been found that heating to a relatively high temperature in the second zone 28b and / or the third zone 28c can produce a relatively large ratio of hydrogen to methane. Such a relatively high temperature can be, for example, in the range of 1000°C to 1200°C. In this manner, maximum hydrogen production can be achieved. Conversely, a relatively low temperature in the second zone 28b and / or the third zone 28c can result in a relatively high ratio of methane to hydrogen in the generated synthesis gas. Such a relatively low temperature can be, for example, in the range of 850°C to 950°C. At such a relatively low temperature, a relatively high amount of methane can be present in the synthesis gas removed from the rotatable tube 23c. It may be advantageous to send at least a portion of the generated syngas to a gas burner for heating the heating chamber 28. Additionally or alternatively, at least a portion of the generated syngas can be sent to a generator for producing electrical energy that can be used to power at least a portion of the apparatus and / or sent to a power grid and / or to power other machinery.

[0119] Heating of the waste material in the heating chamber 28 leads to the production of synthesis gas (which includes combustible gas) in the heating chamber 28, eg, fifth step S5.

[0120] The generated syngas may have a residence time within the kiln 2 of approximately 10 seconds. The residence time of the generated syngas may be changed by increasing or decreasing the suction created by the syngas fan 60. Increasing the power to the syngas fan 60 may act to relatively increase the flow of syngas from the rotatable tubes 23c.

[0121] In a sixth step S6, at least a portion of the generated syngas is supplied from the heating chamber 28 to the plurality of gas burners 40a, 40b, 40c, 40d, 40e, and 40f. In some embodiments, the fuel used by the plurality of gas burners 40a, 40b, 40c, 40d, 40e, and 40f can be provided mostly or entirely by the generated syngas. In embodiments, the generated syngas (or at least a portion thereof) can be processed before being supplied to the plurality of gas burners 40a, 40b, 40c, 40d, 40e, and 40f. For example, one or more components (e.g., hydrogen) of the generated syngas can be removed before being supplied to the plurality of gas burners 40a, 40b, 40c, 40d, 40e, and 40f.

[0122] The time from when the ground waste enters the rotatable tube 23c until the associated residue is removed by the residue removal system 9 ranges from 10 to 20 minutes.

[0123] The generated syngas exits the rotatable tube 23c through the outlet 22. The syngas is drawn from the rotatable tube 23c by the action of the syngas fan 60. The syngas then enters the exhaust hood 22a. From the exhaust hood 22a, the syngas is then drawn into the scrubbing system 6. Additionally, an internal distributor (not shown) assists in transporting solid residues through the heating zone 28 to the exhaust hood 22a. These solid residues are then removed and processed in the residue removal system 9. Additionally, advantageously, the internal distributor also introduces turbulence into the gas and vapor within the heating zone 28. While not wishing to be bound by any theory, it is believed that this turbulence increases the efficiency of syngas production, for example, by enhancing mixing of the gasified waste with the vapor. The generated syngas is cleaned in the scrubbing system 6. The cleaned syngas is then sent to the storage system 7. At least a portion of the syngas is then sent from the storage system 7 to the gas burners 40a, 40b, 40c, 40d, 40e, and 40f.

[0124] Advantageously, the above-described method and apparatus 1 provide a relatively more efficient system than prior art systems. For example, by utilizing the syngas produced by apparatus 1 as a fuel source for the plurality of gas burners 40a, 40b, 40c, 40d, 40e, 40f, the amount of external fuel required is relatively reduced. The cost of heating the heating chamber 28 can therefore be relatively reduced relative to prior art apparatus and methods.

[0125] As will be appreciated by those skilled in the art, the various steps described above can occur simultaneously. For example, waste can be fed into the indirect kiln 2 at the same time that previously fed waste is being heated by the gas burner.

[0126] The pressure in the rotatable tube 23c is monitored by a pressure sensor 63. The temperature in the outlet pipe 61 is monitored by a temperature sensor 65. A control system receives the monitored pressure and temperature. If the monitored pressure is greater than a predefined threshold, the control system is configured to operate the pressure control valve 62 to allow the synthesis gas to escape from the rotatable tube 23c. For example, a pressure increase can be caused by an accident such as a blockage in the rotatable tube 23c. If the monitored pressure is less than the predefined threshold, the control system increases the suction of the fan 60. The pressure in the rotatable tube 23c can be set to about 1 bar, for example, atmospheric pressure.

[0127] The residue removal system 9 removes solid residue from the exhaust hood 22a for proper disposal.

[0128] The control system can periodically provide a nitrogen purge from the first nitrogen supply 21a to the inlet of the rotatable tube 23c by opening check valve 21b. The control system can also provide a nitrogen purge from the second nitrogen supply 22c to the exhaust hood 22a by opening check valve 22d.

[0129] Referring now to Figure 8, there is shown a method of treating ground waste according to a further embodiment of the present invention.

[0130] In a first step S11, the pulverized waste material in the heating chamber 28 is heated using gas burners 40a, 40b, 40c, 40d, 40e, 40f.

[0131] In a second step S12, the temperature within the heating chamber 28 is measured by temperature sensors 29a, 29b, 29c, 29d, 29e, 29f, 29g, 29h, 29i, 29j, 29k, and 29l. The measured temperatures are sent to the control system. The temperature inside the heating space 23d is measured by temperature sensors 29g, 29h, 29i, 29j, 29k, and 29l. The measured temperatures are sent to the control system. As will be appreciated, the temperatures in each of the zones 28a, 28b, and 28c of the heating chamber 28 can be measured or determined individually. Additionally or alternatively, the temperatures within the heating spaces adjacent to each of the zones 28a, 28b, and 28c can also be measured or determined individually.

[0132] Additionally, monitoring devices 40g, 40h, 40i, 40j, 40k, and 40l record the presence or absence of a flame at each gas burner 40a, 40b, 40c, 40d, 40e, and 40f, respectively. Pressure sensor 42h measures the pressure of the synthesis gas in supply pipeline 42a. Flow sensor 41h measures the flow rate of natural gas through natural gas pipeline 41a.

[0133] In a third step S13, the control system compares the monitored or determined temperatures within the heating chamber 28 with predetermined temperature ranges. In particular, the monitored or determined temperature in the first zone 28a of the heating chamber 28 is compared with the predetermined temperature range for the first zone 28a. The monitored or determined temperature in the second zone 28b of the heating chamber 28 is compared with the predetermined temperature range for the second zone 28b. The monitored or determined temperature in the third zone 28c of the heating chamber 28 is compared with the predetermined temperature range for the third zone 28c.

[0134] Additionally, the control system monitors the operation of the heating system 4 using data received from monitoring devices 40g, 40h, 40i, 40j, 40k, 40l, pressure sensor 42h, and flow sensor 42h.

[0135] In a fourth step S14, if the measured or determined temperature within the heating chamber is outside a predetermined temperature range, the control system adjusts the amount of heat added to the heating chamber 28 by one or more of the gas burners 40a, 40b, 40c, 40d, 40e, 40f. For example, if the measured or determined temperature in the first zone 28a of the heating chamber 28 is below a predetermined temperature range, the control system adjusts one or each of the gas burners 40a and 40b to increase the amount of heat they add to the first zone 28a.

[0136] The predetermined temperature range in the first zone 28a can be between 650°C and 750°C, e.g., between 660°C, 670°C, 680°C, or 690°C and 710°C, 720°C, 730°C, or 740°C. The predetermined temperature range in the second zone 28b can be between 850°C and 950°C, e.g., between 860°C, 870°C, 880°C, or 890°C and 910°C, 920°C, 930°C, or 940°C. The predetermined temperature range in the third zone 28c can be between about 1050°C and 1150°C, e.g., between about 1060°C, 1070°C, 1080°C, or 1090°C and 1110°C, 1120°C, 1130°C, or 1140°C. The predetermined temperature range can be varied or set depending on the composition of the waste material (eg, the waste material being fed into heating chamber 28).

[0137] The temperature in each of the zones 28a, 28b, and 28c of the heating chamber 28 is controlled by controlling the heat applied by each of the gas burners 40a, 40b, 40c, 40d, 40e, and 40f. The heat applied by each of the gas burners 40a, 40b, 40c, 40d, 40e, and 40f is independently controlled by a control system. For example, the control system can increase or decrease the mass flow rate of air supplied to one, some, or each of the gas burners 40a, 40b, 40c, 40d, 40e, and 40f. The control system can also increase or decrease the mass flow rate of fuel to one, some, or each of the gas burners 40a, 40b, 40c, 40d, 40e, and 40f. The fuel can include a mixture of natural gas and syngas. Additionally or alternatively, the control system can change the ratio of natural gas to syngas in the fuel mixture. Each gas control valve 44a, 44b, 44c, 44d, 44e, 44f can vary the amount of natural gas supplied to its respective gas burner 40a, 40b, 40c, 40d, 40e, 40f, or can prevent any natural gas from being supplied to its respective gas burner 40a, 40b, 40c, 40d, 40e, 40f. Each gas control valve 44a, 44b, 44c, 44d, 44e, 44f can vary the amount of syngas supplied to its respective gas burner 40a, 40b, 40c, 40d, 40e, 40f, or can prevent any syngas from being supplied to its respective gas burner 40a, 40b, 40c, 40d, 40e, 40f. In embodiments, only syngas may be supplied to one, some, or each of gas burners 40a, 40b, 40c, 40d, 40e, and 40f. In embodiments, only natural gas may be supplied to one, some, or each of gas burners 40a, 40b, 40c, 40d, 40e, and 40f. For example, when insufficient syngas is available, only natural gas may be supplied to gas burners 40a, 40b, 40c, 40d, 40e, and 40f. This situation may occur during initial startup and operation of apparatus 1.

[0138] The temperatures in the three temperature zones 28a-28c can additionally be controlled by varying the rotational speed of the rotatable tube 23c by a control system configured to control the variable speed drive motor 26 to rotate the rotatable tube 23c at a desired rotational speed.

[0139] Combustion air fan 46 can be operated (e.g., by a control system) at a constant or variable speed. Electric drive motor 46a can be controlled by the control system. Because the combustion air flow rate to gas burners 40a, 40b, 40c, 40d, 40e, and 40f is determined by combustion air control valves 43h, 43i, 43j, 43k, 43l, and 43m, variable control of electric drive motor 46a on combustion air fan 46 is provided solely to improve the operating efficiency of heating system 4.

[0140] Referring now to Figure 9, there is shown a method of treating ground waste according to a further embodiment of the present invention.

[0141] In a first, optional step S21, the ratio of the mass flow rate of steam to the mass flow rate of pulverized waste is calculated. In embodiments, this may be calculated by or using a control system. This ratio is calculated to provide a target amount of the components of the syngas produced in the heating chamber 28. In embodiments, this ratio is calculated to provide a target amount of methane or hydrogen. This ratio may be calculated based on historical operating data. This ratio may be based on theoretical analysis or may be modeled in proprietary process modeling software. This ratio may be calculated based on a combination of historical operating data and theoretical analysis. This ratio is calculated based on the specific geometry and operating conditions of the indirect rotary kiln 2 and the type and particle size of the pulverized waste.

[0142] In a second step S22, the ground waste material is fed into the heating chamber 28 in a manner similar to that described with respect to step S2 of the method described with respect to Figure 7. In a third step S23, steam is introduced into the heating chamber 28.

[0143] In a second step S22, steam contacts the comminuted waste material, which in this embodiment includes mixing. The comminuted waste material is fed into the heating chamber 28 in a manner similar to that described with respect to step S2 of the method described with respect to Figure 7. Steam is introduced into the heating chamber 28. In this embodiment, mixing of the steam and the comminuted waste material occurs inside the heating chamber 28. However, in some embodiments, mixing (and indeed contacting) can occur at least partially outside the heating chamber 28.

[0144] In a third step S23, the steam and pulverized waste material are heated inside the heating chamber 28 to produce synthesis gas, which then exits the heating chamber 28 and enters the scrubbing system 6 for further processing, as described above.

[0145] In a fourth step S24, the ratio of the mass flow rate of steam to the mass flow rate of the pulverized waste is adjusted so that at one or more given temperatures in zones 28a, 28b, 28c of heating chamber 28, the produced synthesis gas contains a target amount of its component (e.g., methane or hydrogen).

[0146] The mass flow rate of the comminuted waste material fed into heating chamber 28 is measured or determined. In embodiments, this is accomplished by monitoring the mass of comminuted waste material fed into heating chamber 28 by the feed screw. This may be accomplished by measuring or determining the angular velocity of the feed screw. In embodiments, the angular velocity of the feed screw may be measured directly (e.g., by measuring or knowing the angular velocity of the motor that drives the rotation of the feed screw) and / or may be measured indirectly (e.g., using an encoder).

[0147] The mass flow rate of steam into heating chamber 28 is measured or determined in this embodiment by monitoring the flow of water via flow sensor 51b. However, in some embodiments, any suitable means for monitoring the mass flow rate of steam into heating chamber 28 may be used.

[0148] The feed rate of the pulverized waste material into heating chamber 28 can then be controlled by adjusting the angular velocity of the feed screw. Additionally, or alternatively, the mass flow rate of steam into heating chamber 28 can be controlled by adjusting (e.g., automatically or manually) flow control valve 51c. In this manner, the mass flow rate of pulverized waste material into heating chamber 28 can be adjusted to reach a calculated ratio of the mass flow rate of steam to the mass flow rate of pulverized waste material. In this manner, a target amount of a component (e.g., hydrogen or methane) of the produced synthesis gas is achieved.

[0149] As will be appreciated by those skilled in the art, the first, optional step S21 can be performed (e.g., at least in part) at any time prior to or simultaneously with any of the other steps of this method. Steps S22, S23, S24, and S25 can, in embodiments, be continuous (or substantially continuous) during the processing of the ground waste. The first, optional step S21 can be performed one or more times during the processing of the ground waste. For example, different target amounts of components of the synthesis gas to be produced can be set. Additionally or alternatively, different components of the synthesis gas to be produced can be set. Additionally or alternatively, one or more operating characteristics of the heating chamber (e.g., one or more temperatures therein and / or its rotation speed) can be changed, and / or the composition and / or type of ground waste (e.g., different plastics or mixtures of plastics, and / or different sizes or size ranges of ground particles of the waste) can be used. When a new calculation is performed, it can be based on any one or more of the characteristics and / or target component amounts identified above. In embodiments, the optional step S21 can be performed after one or more of the other steps have already begun. In an embodiment, the sixth step S26 may, for example, be performed subsequent to the optional step S21 and may be based on the results from the optional step S21.

[0150] (Example) A theoretical analysis was performed using proprietary process modeling software to provide a calculation of the ratio of steam mass flow rate to milled waste mass flow rate required to provide the target amounts of components of the synthesis gas produced (e.g., optional first step S21).

[0151] In one example, the pulverized waste material was polypropylene and the operating temperature in the heating chamber 28 was set at 1150° C. The target component was set to methane, with the target amount set to 35% v / v of the synthesis gas produced.

[0152] Using theoretical analysis, the ratio of steam mass flow rate to milled waste mass flow rate was determined to be 0.6.

[0153] Surprisingly, it was found that increasing the ratio of steam to mill waste between 0 and 0.6 resulted in a decrease in the amount of hydrogen produced (as a percentage of syngas produced v / v). However, increasing the ratio of steam to mill waste between 0.6 and 1 resulted in an increase in the amount of hydrogen produced (as a percentage of syngas produced v / v).

[0154] Referring now to Figure 10, there is shown a method of treating ground waste according to a further embodiment of the present invention.

[0155] The first three steps S31, S32, S33 of the method shown in FIG. 10 are similar to the first three steps S21, S22, S23, respectively, of the method shown in FIG.

[0156] The method shown in Figure 10 includes a fourth step S34 that includes a feedback loop (eg, a closed loop) for controlling the amount of components contained in the synthesis gas produced.

[0157] The fourth step S34 includes a first stage S35 of measuring the amounts of components in the generated syngas. This measurement can be performed outside or inside the kiln 2 and / or can be achieved through the use of a gas analysis means or system (not shown). The gas analysis means or system can include a gas chromatograph and / or can use gas chromatography and / or any other suitable technique as known to those skilled in the art. In embodiments, one or more other components of the generated syngas can be measured (e.g., additionally).

[0158] In a second step S36, the controller determines or calculates the difference between the target amount of the component of the synthesis gas to be produced and the measured amount of the component. If there is a difference, the controller calculates changes to the angular velocity of the feed screw and / or changes to the flow control valve 51c to adjust the feed rate of the ground waste material and the mass flow rate of steam into the heating chamber 28, respectively, to produce the target amount of the component. This calculation can be at least partially automated or can be performed by an operator.

[0159] In a third step S37a, S37b, adjustments are made to the flow control valve 51c to increase or decrease the mass flow rate of steam entering the heating chamber and / or adjustments are made to the angular velocity of the feed screw to increase or decrease the feed rate of the pulverized waste material into the heating chamber. The adjustments are made in response to the calculations performed in the second step S36. In one embodiment, only the mass flow rate of steam is adjusted. In another embodiment, only the feed rate of the pulverized waste material is adjusted.

[0160] The above-described feedback loop of the fourth step S34 provides for monitoring and control of the synthesis gas produced so that the target amounts of the components are produced. Advantageously, this allows the target amounts of the components of the synthesis gas produced to be maintained during operation. Even more advantageously, this allows the target amounts and / or components to be changed during operation of the method. In this way, changes to end-use requirements can be more quickly and easily met.

[0161] Those skilled in the art will understand that several variations on the above-described embodiment are contemplated without departing from the scope of the present invention. For example, the control system can be automated or manually monitored and / or controlled. The control system can be located remotely or on the apparatus 1. Additionally or alternatively, while a natural gas source 41 is described, this can alternatively be another combustible fuel, such as oil or coal. Additionally or alternatively, while six gas burners are shown, there can alternatively be any suitable number, for example, more or less than six. Additionally or alternatively, while a single indirect rotary kiln is shown, there can alternatively be multiple indirect rotary kilns. If more than one indirect rotary kiln is provided, there can be a heating system, steam system, supply system, etc. for each indirect rotary kiln. Alternatively, if more than one indirect rotary kiln is provided, the heating system, steam system, supply system, etc. can be shared between two or more indirect rotary kilns.

[0162] Additionally or alternatively, although the apparatus 1 is described as including an indirect rotatable kiln 2, this need not be the case; instead, the kiln may be a direct kiln, for example a direct rotatable kiln.

[0163] Additionally or alternatively, although the pulverized waste and steam are described as being mixed, this mixing may result solely from the introduction of the pulverized waste into contact with the steam. Alternatively, mixing may include the use of a mixing means or mixer configured to assist or enhance mixing of the pulverized waste and steam. If provided, the mixing means or mixer may be provided inside the kiln 2, for example, inside the heating chamber 28. Alternatively, the mixing means or mixer may be provided at least partially outside the kiln 2 (e.g., at least partially outside the heating chamber 28).

[0164] It will also be appreciated by those skilled in the art that any number of combinations of the features set forth above and / or those shown in the accompanying drawings offer distinct advantages over the prior art and, therefore, are within the scope of the invention as described herein. [Explanation of symbols]

[0165] 1 device 2. Kiln 3. Supply System 4. Heating System 5. Steam System 6 Cleaning System 7. Storage System 8 Further Processing Systems 9. Residue Removal System 21 Entrance 21a First nitrogen supply unit 21b Check valve 22 Exit 22a Exhaust hood 22b Inspection hatch 22c Second nitrogen supply 22d Check valve 23 Drums 23a outer shell 23b Insulating firebrick 23c Rotatable Tube 23d heating space 25a~25c Exhaust port 26a Variable speed drive motor 26b Mechanical Drive Chain 28 Heating chamber 28a First Zone 28b Second Zone 28c Third Zone 29a~29l Temperature sensors 29m pressure sensor 30 Flow sensor 40 Combustion heater 40a~40f gas burner 40g~40l monitoring device 41 Natural Gas Supply Department 41a Natural Gas Pipeline 41b~41g Branch 41h Flow sensor 42 Storage Unit 42a Syngas Supply Pipeline 42b~42g Branch 42h Pressure Sensor 42aa~42ff Temperature control valve 43 Combustion air supply section 43a Combustion air pipeline 43b~43g Branch 43h~43m Air control valve 44a~44f Gas control valve 45a~45f Gas Pipe 46 Combustion air fan 46a Electric drive motor 51 Water source 51a Steam Pipeline 51b Flow sensor 51c Flow control valve 52 Steam superheater 60 Synthetic Gas Fan 60a variable speed electric drive motor 61 Outlet pipe 62 Pressure control valve 63 Pressure Sensor 64 Pressure Sensor 65 Temperature Sensor 66 Pressure Sensor

Claims

1. 1. A method for treating ground waste, comprising: a) continuously feeding comminuted waste material into an inlet of a rotatable heating chamber; b) introducing steam into the rotatable heating chamber through a steam introducer disposed within the inlet; c) contacting the steam with the pulverized waste material by flowing the steam into the rotatable heating chamber; d) heating the steam and pulverized waste material to produce a continuous discharge of combustible gas at an outlet of the rotatable heating chamber; e) automatically varying the ratio of steam to milled waste so that the resulting combustible gas contains a target amount (e.g., value or percentage) of that component; A method comprising:

2. 2. The method of claim 1, wherein automatically varying the ratio of steam to milled waste material comprises adjusting (e.g., increasing or decreasing) the amount of steam (e.g., mass flow rate) introduced into the rotatable heating chamber.

3. 3. The method of claim 1 or 2, wherein automatically varying the ratio of steam to pulverized waste material includes increasing or decreasing the amount (e.g., mass flow rate) of pulverized waste material delivered into the rotatable heating chamber.

4. The method of claim 1 , further comprising monitoring or determining the amount (e.g., mass flow rate) of the steam introduced into the rotatable heating chamber.

5. The method of claim 4 , including comparing the monitored or determined amount (e.g., mass flow rate) of steam introduced into the rotatable heating chamber to a steam target.

6. 6. The method of claim 5, wherein automatically varying the ratio of steam to milled waste material comprises automatically adjusting the amount of steam introduced into the rotatable heating chamber to maintain the amount at, approximately at, or within the steam target.

7. 7. The method of claim 1, further comprising monitoring or determining the amount (e.g., mass flow rate) of the pulverized waste material fed into the rotatable heating chamber.

8. The method of claim 7, including comparing the monitored or determined amount (e.g., mass flow rate) of ground waste material delivered into the rotatable heating chamber with a waste material target.

9. 9. The method of claim 8, wherein automatically varying the ratio of steam to pulverized waste material includes automatically adjusting the amount of pulverized waste material delivered into the rotatable heating chamber to maintain the amount at, approximately at, or within the waste material target.

10. 10. The method of any one of claims 1 to 9, wherein the component is hydrogen or methane.

11. The method of any one of claims 1 to 10, comprising the step f) of setting the target amount (e.g. a value or a percentage).

12. 12. The method of any one of claims 1 to 11, wherein step c) is performed inside the rotatable heating chamber.

13. 13. The method of any one of claims 1 to 12, wherein step c) is performed at least in part outside the rotatable heating chamber.

14. 1. An apparatus for treating crushed waste, comprising: a rotatable heating chamber including an inlet for continuous feeding of comminuted waste material into the rotatable heating chamber and an outlet for continuous exhaust of generated combustible gases from the rotatable heating chamber; steam introducing means for introducing steam into the rotatable heating chamber, the steam introducing means comprising a steam inductor for introducing steam into the rotatable heating chamber, the steam inductor being disposed within the inlet for continuously feeding pulverized waste material into the rotatable heating chamber and configured to contact the pulverized waste material as it enters the rotatable heating chamber; heating means for, in use, heating a mixture of steam and pulverized waste material within said rotatable heating chamber to produce a combustible gas; a controller configured, in use, to automatically vary the ratio of steam to pulverized waste material in the rotatable heating chamber so that combustible gases produced from the steam and the pulverized waste material contain target amounts (e.g., values ​​or percentages) of their components; 1. An apparatus comprising:

15. 15. Apparatus according to claim 14, including steam sensing means configured or configurable to monitor, in use, the amount (e.g. mass flow) of steam introduced into the rotatable heating chamber.

16. 16. The apparatus of claim 15, wherein the controller is configured to, during use, compare the amount of steam (e.g. mass flow rate) introduced into the rotatable heating chamber as measured by the steam sensing means with a steam target.

17. 17. The apparatus of claim 16, wherein the controller is configured, during use, to automatically adjust the amount of steam introduced into the rotatable heating chamber to maintain the amount at, approximately at, or within the steam target.

18. 18. Apparatus according to claim 14 or 17, including waste sensing means configured or configurable to monitor the amount (e.g. mass flow) of ground waste delivered into the rotatable heating chamber.

19. 20. The apparatus of claim 18, wherein the controller is configured to, in use, compare the amount of steam (e.g. mass flow rate) introduced into the rotatable heating chamber with a steam target.

20. 20. The apparatus of claim 19, wherein the controller is configured to, in use, compare the amount (e.g. mass flow rate) of the ground waste material delivered into the rotatable heating chamber with a waste material target.

21. 21. The apparatus of claim 20, wherein the controller is configured, during use, to automatically adjust the amount of ground waste material delivered into the rotatable heating chamber to maintain the amount at, approximately at, or within the waste material target.

22. 1. A method for treating ground waste, comprising: a) heating water using one or more combustion heating means to produce steam; b) directing the generated steam into a rotatable heating chamber; c) heating pulverized waste material in the presence of the generated steam within the rotatable heating chamber to generate a combustible gas; d) supplying at least a portion of the combustible gas generated in step c) to the one or more combustion heating means for heating the water to generate steam for step a); A method comprising:

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