System and method for recycling waste materials with improved cleaning - Patents.com

Abstract

An integrated method and system for recycling waste materials including waste paper is provided, the method including treating the waste material in a pressure vessel at an elevated processing temperature and elevated processing pressure to form a treated waste material including substantially repulped waste paper, discharging the treated waste material from the pressure vessel, and then separating and diluting the treated waste material to dilute the portion including substantially repulped waste paper to about 1% to about 20% solids by weight, and introducing at least a portion of the dilution water into a screening device via a plurality of auxiliary dilution water inlets. The recovered paper pulp portion and substantially fiber-free recoverable / recyclable plastics and metals may be further separated and used as feedstock in various subsequent processes.

Description

[Technical field]

[0001] (CROSS REFERENCE TO RELATED APPLICATIONS) This application claims priority to U.S. Provisional Application No. 63 / 268,996, filed March 8, 2022, which is incorporated by reference in its entirety.

[0002] FIELD OF THEINVENTION FIELD OF THE DISCLOSURE This application relates generally to methods for recycling waste materials, including waste paper, into useful products. More specifically, this application relates to methods and systems for recycling waste materials including a post-processing wash trommel. [Background technology]

[0003] Recycled waste paper is a major source of feedstock for the manufacture of paper products. Recycled waste paper can be produced from a variety of waste sources that often contain other recoverable and recyclable materials. For example, common sources of waste materials often contain polymeric materials, such as plastics, and metals, such as aluminum.

[0004] These recoverable and recyclable materials can be obtained from a variety of waste sources and can be used as feedstock for the manufacture of a variety of products, but existing methods of recovering these materials are inefficient and subject to the economics of labor-intensive recovery, sorting, and cleaning processes. For example, many existing methods of recovering these reusable materials require sorting the materials at the source or at an intermediate facility before they can be later processed into useful products. Thus, there remains a need for more efficient methods of processing waste materials to increase the recovery and recycling of more waste materials in a more economical process. Summary of the Invention

[0005] SUMMARY OF THE DISCLOSURE Embodiments of the present application address the above-mentioned needs by providing methods and systems for recycling waste materials, including waste paper.

[0006] In one aspect, a method is provided that includes introducing waste material into a pressure vessel, treating the waste material in the pressure vessel at a high treatment temperature and a high treatment pressure to form a treated waste material comprising substantially repulped waste paper, discharging the treated waste material from the pressure vessel, and then separating the treated waste material into a first portion and a second portion with a screening device. The first portion may comprise substantially repulped waste paper and the second portion may comprise large debris. The screening device may include multiple dilution water inlets, at least one of which is an auxiliary dilution water inlet located inside the screening device distal from the waste material inlet, and the step of introducing dilution water includes introducing at least a portion of the dilution water into the screening device via the at least one auxiliary dilution water inlet. In an embodiment, the screening device may be a washing trommel, and the washing trommel may be configured to introduce dilution water at several points, such as, for example, a dilution water inlet located proximal to the waste material inlet and at least one auxiliary dilution water inlet located inside the washing trommel. In some embodiments, the separating step can further include showering the exterior of the wash trommel with additional dilution water to facilitate separation.

[0007] In another aspect, an integrated system for recycling waste materials including waste paper is provided. The integrated system may include a pressure vessel configured to receive the waste material in the pressure vessel and process it at a high processing temperature and high processing pressure to form a treated waste material including substantially repulped waste paper, a screening device for receiving the treated waste material, the screening device configured to pass dilution water through the screening device at several points to separate the treated waste material into a first portion and a second portion, the first portion including substantially repulped waste paper and the second portion including large debris, and a water supply device configured to supply dilution water to a plurality of points of the screening device and wash the first portion through the screening device. The screening device may include at least one auxiliary dilution water inlet disposed inside the screening device distal from the waste material inlet and for introducing at least a portion of the dilution water into the screening device. In an embodiment, the screening device may be a washing trommel, and the washing trommel may be configured to introduce the dilution water at several points.

[0008] These and other features, aspects, and advantages of the present invention and embodiments thereof will be better understood from the following detailed description when taken in conjunction with the accompanying drawings, in which components are not necessarily to scale and in which corresponding reference numerals indicate corresponding parts throughout the drawings. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic diagram of a waste material baling system according to one embodiment. [Figure 2A] 1 is a schematic diagram of a waste material recycling system for receiving waste materials according to one embodiment. [Figure 2B] 1 is a schematic diagram of a waste material recycling system discharging treated waste material according to one embodiment. [Diagram 3] FIG. 1 is a side view of an autoclave used in one embodiment. [Figure 4] FIG. 4 is a partial cross-sectional view of the vessel of FIG. 3 showing the rotating drum and showing the closure panel of the autoclave in an open position. [Diagram 5] FIG. 4 is an elevated end view of the pressure vessel of FIG. 3, showing the drive belt and motor used to rotatably drive the drum. [Figure 6] FIG. 4 is an end view of the autoclave of FIG. 3 showing the operation of the closure panel. [Figure 7] FIG. 4 is a side view of the apparatus of FIG. 3 showing lifting paddles spaced around the interior of the rotating drum, with the location of the spiral baffle indicated in dashed lines. [Figure 8A] FIG. 8 is a cross-sectional view taken along line 8a-8a in FIG. 7. [Figure 8B] FIG. 8 is a cross-sectional view taken along line 8b-8b in FIG. 7. [Figure 9] FIG. 8C illustrates the relationship of lifting paddles to a spiral baffle disposed about the inner surface of the rotating drum of FIGS. 3-8B. [Figure 10] FIG. 2 is an enlarged scale view of a typical lifting paddle utilized in connection with one embodiment, with the adjacent portion of the drum also shown in cross section, with the closure panel end of the drum facing toward the left as viewed in this view. [Figure 11] FIG. 1 is a schematic diagram of a vacuum system used in connection with one embodiment. [Figure 12] FIG. 1 is a process flow diagram of a wet processing and separation system according to one embodiment. [Figure 13] FIG. 1 is a process flow diagram of a separation system for separating non-cellulosic solids according to one embodiment. [Figure 14A] FIG. 1 is a process flow diagram of a screening device according to one embodiment. [Figure 14B] FIG. 1 is a process flow diagram of a screening device according to one embodiment. [Figure 15] FIG. 1 is a schematic diagram of a screening device for use in connection with an embodiment. [Figure 16] 1 is a photograph of the interior of a screening device used in connection with one embodiment. [Figure 17] 1 is a graph of single versus dual auxiliary dilution water inlets. [Figure 18]13 is a graph of short versus staggered auxiliary dilution water inlets. [Figure 19] 1 is a graph of dilution water versus municipal solid waste fiber recovery. [Figure 20] 1 is a graph of dilution water versus old cardboard fiber recovery. [Figure 21] FIG. 2 is a schematic diagram of a washing trommel used in connection with one embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] The present application provides a system and method for efficiently recycling waste materials, including waste paper. Generally described, the method includes introducing waste materials, including waste paper, into a pressure vessel, treating the waste materials in the pressure vessel at high treatment temperatures and high treatment pressures to form treated waste materials, including substantially repulped waste paper, discharging the treated waste materials from the pressure vessel, and then separating the treated waste materials into a first portion and a second portion using a screening device configured to introduce dilution water at several points arranged in series. The first portion may include substantially repulped waste paper, and the second portion may include large debris. The screening device may include multiple dilution water inlets, at least one of which may include an auxiliary dilution water inlet disposed inside the screening device distal from the waste material inlet, and the step of introducing dilution water includes introducing at least a portion of the dilution water into the screening device via the at least one auxiliary dilution water inlet. In an embodiment, the screening device may be a washing trommel, and the washing trommel may be configured to introduce dilution water at several points. In some embodiments, the separating step can further include showering the exterior of the wash trommel with additional dilution water to facilitate separation.

[0011] Advantageously, the substantially repulped waste paper and non-cellulosic solids separated from the treated waste wood provide a clean feedstock that can be used as a feedstock for a variety of different processes. For example, the substantially repulped waste paper may be used to produce post-consumer paper-containing products or may be converted to one or more organic acids, organic acid decomposition products, etc. Additionally, cleaned and essentially fiber-free recyclable plastics and metals may be recovered from the second portion and either marked for sale or used to produce waste-derived fuels, pyrolyzed to produce one or more products suitable for use as fuels, or converted to polymer flakes or films (i.e., polyethylene terephthalate flakes or films). The liquids and solubilized organics may also be used in subsequent processes, such as anaerobic digesters to produce biogas.

[0012] According to an embodiment, the waste material may be municipal solid waste or commercial solid waste, etc. The term "municipal solid waste" refers to all waste material discarded for disposal by households, including single-family and multi-family homes, and hotels and motels. The term also includes waste material generated by commercial, institutional, and industrial sources to the extent that such waste is essentially the same as waste normally generated by households, or is collected and disposed of with other municipal solid waste as part of a regular municipal solid waste collection service. Examples of municipal solid waste include food and yard waste, paper, plastic, metal, clothing, electronics, consumer product packaging, disposable diapers, office supplies, cosmetics, glass and metal food containers, and household hazardous waste.

[0013] The term "residential waste" means waste generated by the normal activities of a household, including, but not limited to, food waste and other organic materials, waste materials such as paper, metals, and plastics, ash, and bulk waste.

[0014] The term "commercial solid waste" means any type of solid waste generated by stores, offices, restaurants, warehouses, educational and institutional facilities, and other non-manufacturing activities, excluding residential and industrial waste. This waste material is high in paper and therefore has a higher paper fiber content as well as a higher polyethylene terephthalate (PET) plastic content than municipal solid waste. Commercial solid waste also contains plastics and metals, but has less yard waste, polyvinyl chloride (PVC) plastics, building materials, electrical appliances, cosmetics, household hazardous waste, and large metal items than municipal solid waste. Commercial solid waste is typically collected at locations such as airports, restaurants, office buildings, educational institutions, and amusement or theme parks.

[0015] The term "re-pulp" means to pull apart or at least partially separate fibers that are attached, bonded or entangled with each other, such as the cellulose fibers in paper. In the context of this specification, re-pulping paper means at least partially separating the cellulose fibers of the paper from each other to form free cellulose fiber pulp.

[0016] 1. Disposal of waste materials According to one embodiment, there is provided a process for recycling waste material, particularly waste material comprising a mixture of waste paper and polymer waste material such as plastics, utilizing a generally cylindrical pressure vessel mounted for tilted rotation about its longitudinal axis, the process comprising the steps of: a) introducing the waste material and dilution water through an inlet of the pressure vessel; b) applying thermal energy to the waste material in the pressure vessel to subject the waste material in the pressure vessel to high processing temperatures and high processing pressures to levels above atmospheric pressure; c) rotating the pressure vessel about its longitudinal axis to agitate the waste material to achieve re-pulping of the fibrous paper fraction; and d) rotating the pressure vessel about its longitudinal axis to agitate the waste material to achieve re-pulping of the fibrous paper fraction. The method includes the steps of: depressurizing the vessel by venting steam through a condenser followed by pulling a vacuum on the condenser to begin cooling the material and reduce odors emitted by the treated waste material; e) then optionally introducing cooling water into the pressure vessel to cool the treated waste material in the pressure vessel below the discharge temperature achievable in the previous step to further reduce odors emitted by the treated waste material; and f) discharging the treated waste material from the pressure vessel, wherein the paper portion is substantially repulped and substantially separated from the polymeric or plastic waste material and other contaminants in the waste material. In one embodiment, the polymeric waste material serves to concentrate contaminants, including color bodies, from the waste material.

[0017] According to one embodiment, a process is provided in which a rotating device, referred to in the art as an autoclave, is used. A desired amount of waste material is placed in the inner drum of the autoclave by allowing the rotational movement of an auger blade in the drum to further draw the waste material into the drum. The door of the pressure vessel is closed and sealed, a vacuum is drawn in the chamber to eliminate the effect of the partial pressure of air trapped in the vessel, and dilution water is added. Steam is then introduced through a steam inlet valve until a desired treatment temperature and pressure is reached. The autoclave drum is rotated while the waste material is contained in the drum at the desired treatment temperature and pressure for a preset reaction time to form treated waste material. Steam is used to maintain the temperature and pressure through the preset reaction time. After the preset reaction time, the steam valve for introducing steam into the drum is closed and the drum is vented to atmospheric pressure, which also reduces the temperature in the chamber. Following the first venting step, a vacuum is drawn to further reduce the temperature of the treated waste material.

[0018] The drum is then again vented to the atmosphere, cooling water is optionally introduced into the chamber to further cool the treated waste material to a discharge temperature and dilute one or more odorous compounds, and the chamber is opened. The treated material in the drum is then removed by reversing the rotation of the drum so that the auger blades deliver the treated material to the front of the drum where it exits onto a discharge conveyor or trough for further screening to remove coarse materials.

[0019] [Pressure vessel] According to one embodiment, the autoclave pressure vessel may be an elongated vessel of generally cylindrical configuration mounted to be driven in rotation about its longitudinal axis, and provided with agitation means comprising an array of fixed lifting paddles present inside the vessel. Agitation of the waste material may include movement of the lifting paddles within the vessel simultaneously with rotation of the vessel. According to one embodiment, the vessel may comprise a helically configured member.

[0020] Any suitable pressure vessel capable of producing the required effect in processing the waste material may be used in connection with the systems and methods provided herein. However, according to one embodiment, the pressure vessel may advantageously be equipped with suitable agitation means to facilitate suitable agitation of the waste material. A suitable pressure vessel according to one embodiment is a pressure vessel of generally cylindrical configuration mounted to be driven in tilted rotation about its longitudinal axis, as disclosed in U.S. Pat. Nos. 5,119,994, 4,974,781 and 6,458,240, and U.S. Patent Application No. 14 / 256,652, filed with the U.S. Patent Office on April 14, 2014, entitled "Method For Recycling Waste Material With Reduced Odor Emission," the disclosures of which are incorporated herein by reference in their entirety. Such a pressure vessel is equipped with suitable agitation means to homogenously mix the waste material and to break down the plastic-containing waste material and the paper-containing waste material. Examples of suitable agitation means include mechanical, hydrodynamic or electrical devices. Examples of mechanical devices include mechanical agitators, shakers, blenders, tumblers, etc. An array of fixed lifting paddles and a helically configured member mounted on an interior section of the pressure vessel have been found to work together as examples of agitation means for embodiments of the present invention. According to one embodiment, the agitation means is provided within a drum that is rotatably mounted at an angle within the pressure vessel.

[0021] Thus, an autoclave for the treatment of waste materials according to one embodiment comprises a substantially cylindrical container mounted at a slight inclination angle to the horizontal plane, the inclination angle being in an embodiment about 7°, the upper end of the container having an opening for receiving the waste material and the lower end of the container being closed. The container may be designed with a highly effective closing device on the opening, which when closed, seals the container from the atmosphere, allowing a pressure build-up to occur in the container during its operation, or alternatively allowing a vacuum to be maintained in the container by the functioning of a suitable vacuum system.

[0022] With reference to Figures 3-11, an autoclave for carrying out a process according to an embodiment disclosed in U.S. Patent No. 6,458,240 is shown. The apparatus includes a thick-walled processing pressure vessel A that is generally cylindrical in configuration. Heavy walls are used in the construction of pressure vessel A to enable it to operate under conditions of high internal pressure, as well as sometimes under vacuum conditions as described above. Pressure vessel A is non-rotatably mounted on a sturdy fixed support 26 and has a sufficiently wide base to provide sufficient stability. Support 26 may utilize structural steel members designed to effectively transfer the weight of the processing equipment and waste material to a foundation below the processing equipment.

[0023] The rotating drum, which will now be described, utilized within the shell of vessel A, transfers its forces to the carrier and support bearings which in turn transfer their loads to the shell of vessel A, becoming part of the load supported by the structural supports of the shell, and thus to the foundations beneath the processing equipment.

[0024] A closure device or dome-shaped door 40 with a seal 41 is hinged adjacent the entrance 30 to the vessel A so that a substantial pressure or vacuum can be established within the vessel at selected times, as previously described.

[0025] Disposed inside the non-rotating vessel A is a generally cylindrical drum D mounted for rotation in either direction about an axis coincident with the axis of vessel A. Drum D is provided with a riding or support ring 12 adjacent its front end 50 and a roller or trunnion bearing 58 is disposed inside vessel A in contact with ring 12 and thus providing support for the front end 50 of drum D. The front end 50 of drum D is open whilst the rear or lower end 56 of the drum is closed and watertight.

[0026] A drive shaft 16 is fixed to the rear or lower end 56 of drum D and is arranged to support and rotatably drive the rear end of drum D. The shaft is rotatably supported by roller or ball bearings 17 which are in turn supported from a structural member 19 attached to vessel A. This support arrangement is designed to fix the position of drum D as far as its horizontal positioning within vessel A is concerned.

[0027] The drive shaft 16 of drum D passes through the shell of vessel A and is sealed from the atmosphere by a seal 33, enabling a selected pressure or a selected vacuum to be maintained within vessel A, and of course within drum D, from time to time.

[0028] A typical rotational speed of the drum D is between 2 and 30 rpm, preferably between about 8 and 15 rpm, to facilitate uniform force application to the drive mechanism 14 utilized to drive the drum in rotation.

[0029] The drum D can be rotated in either direction on its horizontal axis by a drive assembly 14, shown in Figure 3, which may utilize, for example, a reversible electric motor 20 and appropriate reduction gearing 18 connected to the drum's drive shaft 16 to rotate the drum D in the selected direction. As shown in Figures 3 and 5, it may be preferable to use a heavy duty chain 22 passing through sprockets 23 and 24 to transfer the motor rotation to the drive shaft, in a configuration well known to those skilled in the art.

[0030] By locating drum D within pressure vessel A, it is possible to have the same advantages of unhindered agitation of materials that one would have in a freestanding rotating drum. By designing the drum to have suitable containment walls, the waste materials being processed and any additives inserted into those materials are contained within the drum during processing. According to this embodiment, because the drum is located within a pressure vessel, the materials of construction of the drum are significantly lighter than would be required for a freestanding rotating drum, which would have required structural integrity to withstand the forces of pressure as well as the forces associated with the vacuum sometimes utilized in the process.

[0031] The interior of drum D is equipped with a series of lifting paddles 70 and helical blades 80 to facilitate agitation and movement of the waste material as a result of rotation of drum D. The lifting paddles and blades used in the present invention are described in more detail below.

[0032] Vessel A, according to one embodiment, is preferably operated at an incline. One suitable inclination angle is 7° from horizontal, with the front or inlet end 30 being higher than the closed lower end 36 of the vessel. The inclination angle helps contain the waste material being processed within drum D in that as the drum rotates, the waste material moves through drum D towards the rear end, at least in part under the influence of gravity.

[0033] Lifting paddles 70 are mounted on the interior of drum D and positioned to minimize disruption of material flow within the drum. The lifting paddles are distributed in sections along the horizontal dimension of the drum and are staggered at approximately 45° intervals from one section to the next, as shown in FIG.

[0034] Lifting paddles 70 are mounted on the inner periphery of drum D perpendicular to the shell of the drum, as shown in FIGS. 8A and 8B, and are oriented longitudinally to correspond to the longitudinal dimension of the drum, as shown in FIGS.

[0035] As best seen in FIG. 10, the vertical leg 72 is attached to the interior sidewall of the drum, and the angled member 74 is attached to the radially inner portion of the vertical leg at its midline 77. The angled member 74 has outer surfaces 75 and 76, with surface 75 at an angle of about 45° from the vertical leg 72 of the lifting paddle, and surface 76 at a similar angle to leg 72. Surface 76 is preferably considered the first portion, and surface 75 of the paddle is considered the second portion. The midline 77 of the angled member 74 may be at an angle of about 52° to the interior surface of the drum D, and as shown in FIG. 10, the midline 77 is disposed in a direction toward the higher end of the drum D. Stated somewhat differently, the inner portion 78 of the lifting paddle faces the closed end 56 of the drum D, which is to the left as viewed from the perspective of FIG. 10.

[0036] In one embodiment, the inclination angle of the drum is approximately 7° with respect to the horizontal, and therefore the inclination angle of the lifting paddle angle portions 75 and 76 is 52° with respect to the shell wall of drum D, which results in the lifting paddle angle portions 75 and 76 operating at an angle of 45° with respect to the horizontal.

[0037] The helical vanes or baffles 80 are mounted on the inner circumference of the drum D so as to minimize disturbance to the flow of waste material within the drum, and may be at a frequency corresponding to one complete cycle of the helix at a distance equal to the diameter of the drum measured along the length of the drum. The angle of the helical vanes is such that when the drum D is rotated in the so-called first direction of rotation, the waste material to be processed is moved forward towards the closed lower end 56 of the drum, while rotation of the drum in the second direction of rotation moves the material backwards towards the inlet opening 50 of the drum. The helical vanes are continuous, which means that the paddles 70 must be eliminated, lifting from time to time at certain positions to allow for production.

[0038] Referring to Figure 3, vessel A is equipped with piping 90 for the selective addition of steam, and piping 92 for the selective addition of both dilution water and cooling water, with appropriate valves utilized to control the flows. The steam and water piping are combined into a single injection pipe 94 as shown in Figure 3, allowing the steam and water to be directed through the side wall of vessel A and then injected into the open end of drum D through a curved fixed pipe 95.

[0039] During one phase of operation of the apparatus, a vacuum can be induced in vessel A by a vacuum system, such as the types manufactured by Nash Engineering Company of Norwalk, Connecticut, or Croll-Reynolds Company, Inc. of Westfield, New Jersey, connected to the vessel by vacuum connection 46. NOTE FIG.

[0040] [Introduction of waste materials] Waste materials suitable for use in the embodiments may be in the form of municipal solid waste, commercial solid waste, residential waste, sanitary waste, industrial waste, etc., and include waste paper. Non-limiting examples of waste paper present in such waste materials include newspapers or other inked paper products, magazines, cartons, containers, cups, plates, tissues, paper towels or other absorbent paper products, leaflets, flyers, envelopes, corrugated boards, boxes, bags, printed and non-printed paper sheets, posters, etc. Waste materials may also include one or more odorous compounds or materials that form one or more odorous compounds during repulping or upon storage, non-limiting examples of which include organic materials such as food waste and / or beverage waste, and possible polymer waste materials such as plastic cups, plastic bottles, plastic containers, etc. Organic materials means materials composed of organic compounds of or associated with animal or plant components or products that are primarily carbon-based, including those derived from the remains of dead organisms such as plants and animals and their waste products in the environment. Non-limiting examples of organic materials include food, beverages, yard waste, agricultural waste, human waste, biological waste, medical institution waste such as hospital or clinic waste, hydrocarbons, oils, solvents or industrial chemicals, and the like, and combinations thereof.

[0041] In embodiments, the waste feedstock may include waste paper and polymer waste (e.g., coated feedstocks provided with latex coatings, fillers, etc.). The coating or polymer component may include synthetic polymers such as acrylates and vinyl acetates, or pastes of natural polymers and starches or organic pastes, as well as natural and synthetic adhesives. The polymeric material may be in the form of a coating, a binder, or may simply be bound to the paper fiber component, as in the case of packaging having a paperboard component and a plastic film component. According to certain embodiments, the waste feedstock may include both cellulosic fiber-containing paper and a resinous polymer component that is agglomerated during the process and serves to separate other contaminants from the loose papermaking fibers.

[0042] Further examples of difficult waste materials that can be processed according to some embodiments include single and double sided plastic coated board with wet strength resin, single and double sided plastic coated board without wet strength resin, double sided glossy printer trimmings, ultraviolet (UV) cured ink coated stock, and mixtures thereof. Further examples of plastic coated board include double sided coated (C2S) plastic food board with wet strength resin, such as milk cartons or other cartons used for dry food storage and the like. Further examples of plastic coated board without wet strength resin include ice cream containers, various other frozen food packages, and the like. Further examples include double sided glossy photo trimmings, ice cream tops, unprinted colored paper, newsprint, and the like.

[0043] Referring again to Figures 1-9, according to one embodiment, waste materials including paper waste and optionally plastic-containing waste, along with odor or odor generating compounds, are conveyed by a suitable conveyor and introduced into the open end 50 of the drum D through the entrance opening 30 when the door 40 is moved to the open position.

[0044] Drum D is rotated in a first rotational direction while waste material is being transported into the drum, and the helical blades 80 and the tilt angle of the drum cause a sufficient amount of material, although not free-flowing, to be loaded into the drum for processing.

[0045] When drum D is filled with a sufficient amount of material to be processed, closure device 40 is closed and secured by a locking ring 42 such as the type manufactured by Klinge Products Company of Denmark.

[0046] Generally, the weight percent of waste solids (i.e., non-pulpable materials) in the waste wood ranges from about 1% to about 80% by weight based on the total dry weight of the waste wood, whereas the weight percent of waste solids in the waste wood may range from about 20% to about 70% by weight based on the total dry weight of the waste wood.

[0047] Typically, waste paper contains about 80% or less by weight of waste polymer, based on the total weight of the paper pulp and waste polymer. In some cases, the waste paper contains less than about 10 percent of waste polymer, based on the total weight of the pulp and waste polymer.

[0048] As used herein, the terms "polymer", "plastic", "polymers" and similar terms refer to and include all organic, synthetic, natural or engineered natural polymeric materials, such as cellulose acetate, including resins, adhesives, foams, films, sheets and alloys (composites) that are molded, cast, extruded, stretched or laminated or otherwise applied onto or into objects or films. Such application can be carried out by any of the techniques known in the art using either water or oil based lattices. Examples of coating techniques include blade coating, dip coating, spray coating, and the like. Specific examples of polymeric materials include addition polymers such as vinyl polymers including acrylates and vinyl acetates, their latexes, condensation polymers such as polyolefins, polyesters or polycarbonates, and the like.

[0049] 3-11, according to one embodiment, plastic wrapped waste material is transported by a suitable conveyor and introduced into the open end 50 of drum D through entrance opening 30 when door 40 is moved to the open position. The entrance opening 30 of container A and the opening 50 to the drum are sufficiently large and free of obstructions so that the waste material can be introduced directly into the processing equipment.

[0050] Drum D is rotated in a first rotational direction while waste material is being conveyed into drum D, and the helical blades 80 and the tilt angle of the drum load a sufficient amount of waste material into the drum for processing.

[0051] When drum D is filled with a sufficient amount of waste material to be processed, closure device 40 is closed and secured by a locking ring 42 such as the type manufactured by Klinge Products Company of Denmark.

[0052] [Dilution water] Returning to the embodiment shown in Figures 1-9, a significant amount of dilution water is added to the waste material being treated, which is accomplished by injecting the dilution water through pipe 92 so that sufficient dilution water is brought into contact with the waste material in the drum through curved stationary pipe 95. Typically, dilution water is added to pressure vessel drum D such that the water content in drum D is between 30% and 75% by weight of the total waste material and water in the drum, with about 70% by weight being an amount according to certain embodiments. According to another embodiment, dilution water is introduced into pressure vessel drum D through pipe 92 in an amount of up to about 3 parts by weight of dilution water to about 1 part by weight of waste material, or up to about 7 parts by weight of dilution water to about 3 parts by weight of waste material, or from about 0.43 parts by weight to about 3 parts by weight of dilution water to about 1 part by weight of waste material.

[0053] According to embodiments, the dilution water may be substantially pure water, but may be potable or non-potable water. The dilution water may contain additives, such as chemical auxiliaries, which are described in more detail below.

[0054] Drum D is typically rotated in a first rotational direction during dilution water addition to enhance contact between the waste material and the dilution water.

[0055] Once all materials are loaded into the vessel, the pressure vessel door is closed and sealed. Drum D is then rotated in a first rotational direction while a vacuum is briefly drawn in the chamber for approximately 1-5 minutes or 5-10 minutes, and dilution water can be optionally introduced during the evacuation. In some embodiments, dilution water may be added to the Drum D chamber during the evacuation. One purpose of applying a vacuum at this stage is to prevent pressure build-up due to trapped non-condensable gases. At the end of the evacuation period, the vacuum is shut off and the system is isolated by closing the valves. After the evacuation period is completed, additional dilution water can optionally be added to the Drum D chamber in addition to or instead of the dilution water added during the evacuation period.

[0056] [Chemical Auxiliary Agents] According to this embodiment, the addition of suitable chemical auxiliaries during the agitation process can improve the quality of the pulped paper portion. The degree of repulping can be increased from the use of chemical auxiliaries. In addition, pulp formed in the presence of certain chemical auxiliaries can be shinier, reducing the degree of additional process steps. The chemical auxiliaries may be introduced into the pressure vessel before or after the drum door is closed and locked, and may be added to the pressure vessel before, with, or after the waste material, or with the dilution water.

[0057] Thus, according to one embodiment, at least one chemical auxiliary selected from the group consisting of alkaline agents, buffers, bleaching agents, detergents, surfactants, solvents, dispersants, chelating agents, sequestering agents, and mixtures thereof may be included. These chemical auxiliary agents may be used either alone or in combination, in their bulk form or as solutions, preferably aqueous solutions. Any amount of these chemical auxiliary agents may be used to provide the intended benefits. However, preferred chemical auxiliary agents and amounts are described in more detail below.

[0058] According to some embodiments, various other chemical aids, such as detergents, surfactants, solvents, dispersants, chelating agents, sequestering agents, etc., may be added alone or in combination to the waste wood for use during repulping. All of these chemical aids now known or hereafter developed for such purposes may be used in amounts sufficient to provide the intended benefits. However, these chemical aids are only used if the pulp formed therefrom exhibits acceptable quality.

[0059] According to some embodiments, the preferred chemical aid is sodium hydroxide alone or in combination with hydrogen peroxide.

[0060] [Repulping conditions] According to an embodiment, the treatment of waste material, including waste paper, is accomplished by applying heat and mechanical energy to fully re-pulp and concomitantly sterilize the waste material. Due to the added dilution water, which increases the conduction of heat to the waste material being treated, the waste material, which may otherwise have an insulating effect on itself and other materials, is completely and quickly penetrated by the required heat, thus avoiding the creation of pockets in which infectious materials may be protected from sufficient heat to achieve complete re-pulping. As mentioned above, due to the reduction in size of the pulpable parts of the waste material as it is treated, and also due to the heat of the process causing the thermal deformation and collapse of the plastic parts of the waste material, if any, into a more compact form, the entire amount of the waste material is more thoroughly agitated and therefore most completely contacted with the heat.

[0061] Returning to the embodiment shown in Figures 3-11, in a first rotation direction, assumed to be clockwise when viewed from the open end of the drum, the waste material is intercepted by the directional vanes 80 and moved through the drum towards the rear or closed lower end 56 of the drum. At the same time, the bidirectional lifting paddles 70, by virtue of the angular portion of each paddle, direct a portion of the waste material countercurrently towards the inlet end of the drum as each of the paddles contacts the material during the rotation of the drum. This simultaneous backward and forward movement of the material in the drum by the action of the helical vanes 80 and the surfaces 72 and 76 of the novel lifting paddles 70 during the rotation of the drum D in the desired direction results in an advantageous and very complete agitation of the material being processed. Due to these actions and the added dilution water, repulping of the waste pulpable material is achieved very effectively.

[0062] In some embodiments, the rotating drum device is rotated at a speed of at least about 6 revolutions per minute (rpm), or at least about 8 rpm, or at least about 10 rpm.

[0063] According to some embodiments, heat is added to the pressure vessel during the treatment of the waste material. In this case, steam can be advantageously added to the vessel by steam line 90 and injected into the waste material by injection line 94 while the drum D is rotating in a first rotational direction. Note FIG. 3. As explained above, the application of heat allows the plastic material, if present, to soften and separate while the drum is rotating, thus allowing the paper parts in intimate contact with the plastic to be thoroughly agitated and brought into contact with the added moisture and the added heat. According to some embodiments, the desired pressure is maintained in the vessel A by suitable use of valves of the pressure control system associated with the pressure pipe 60 and the vent connection 62. Valve 61a controls the pressure pipe 60 and valve 61b controls the vent pipe 62. Pipe 68 forms the connection to the interior of the vessel A. Chemical auxiliaries, as mentioned above, can be added as liquid or vapor to the steam line or additionally to the water line. According to some embodiments, the desired pressure is controlled through the control of the temperature.

[0064] According to some embodiments, a sufficient amount of steam is introduced during the agitation step to provide an internal temperature in the range of about 212° F. to about 285° F. and a pressure in the range of about 0 psig to about 50 psig or about 10 psig to about 50 psig. According to some embodiments, a temperature of at least about 230° F. and a pressure of at least about 15 psig are preferred to reduce the time required to achieve pulping.

[0065] According to some embodiments, the conditions are controlled such that the time required to achieve repulping is generally about 30 to 90 minutes, and typically the time required to achieve repulping may be about 60 minutes.

[0066] [Pressure drop after repulping] After the waste material has been treated for a sufficient time and at a sufficiently high temperature, steam injection into the system is shut off, the pressure vessel drum is vented to atmospheric pressure, and then the vacuum system 46 shown in FIG. 11 is activated while continuing to rotate the drum in the first rotational direction to induce a vacuum in the pressure vessel chamber to cool the treated waste material within the pressure vessel. As the vacuum is induced, the treated waste material is cooled from the repulping processing temperature to a lower temperature. According to some embodiments, the induced vacuum ranges from about -5 psig to about -15 psig or about -10 psig, reducing the temperature of the treated material to as low as about 170°F or about 160°F or as low as about 150°F.

[0067] [Cooling water] According to some embodiments, cooling water is introduced into the pressure vessel to continue to cool the treated waste material in the pressure vessel to a discharge temperature that is lower than the high repulping processing temperature, reducing odors emitted by the treated waste material. The addition of cooling water reduces or eliminates odors that would be released when the treated waste material is discharged or would otherwise be released. The water and treated waste material in the pressure vessel form a treated waste material slurry in the pressure vessel. Without wishing to be bound by theory, it is believed that the cooling water reduces odors by lowering the temperature of the treated material, or by diluting the treated material slurry, or both. It is also believed that the cooling water absorbs odorous compounds in the treated material that would otherwise be released into the surrounding atmosphere. Such odorous compounds may be present in the waste material or are generated during repulping of the treated waste material slurry, or both. In some embodiments of the present invention, the source of odorous compounds includes food waste or beverage waste, or both.

[0068] According to some embodiments, the treated waste material in the pressure vessel is introduced into a discharge trough prior to discharge into the screening device. In some embodiments, cooling water is introduced into the discharge trommel in addition to or instead of introducing cooling water into the pressure vessel.

[0069] Returning to the embodiment shown in Figures 3-11, a quantity of cooling water is added to the treated waste material, which is accomplished by injecting cooling water through pipe 92 so that sufficient cooling water contacts the waste material in drum D through curved stationary pipe 95. Cooling water is added to pressure vessel drum D such that the total water content in drum D is between 78% and 95% by weight of the total waste material and water in the drum, with about 80% being an amount according to certain embodiments. According to another embodiment, cooling water is introduced into pressure vessel drum D through pipe 92 in an amount such that the total amount of water present in the pressure vessel after the cooling step is at least about 3.5 parts by weight for about 1 part by weight of treated waste material, or at least about 3.8 parts by weight for about 1 part by weight of treated waste material.

[0070] According to embodiments, cooling water is added to the treated waste material in an amount sufficient to reduce the temperature of the treated waste material in the pressure vessel by at least about 10° F., or by about 10° F. to about 50° F., or by about 10° F. to about 30° F. According to embodiments of the present invention, cooling water is added to the treated waste material in an amount sufficient to reduce the temperature of the treated waste material in the pressure vessel from a temperature of at least about 170° F. to a temperature of about 140° F. or less, or from a temperature of at least about 160° F. to a temperature of about 140° F. or less, or from a temperature of at least about 160° F. to a temperature of about 130° F. or less.

[0071] According to embodiments, cooling water is added to the treated waste material at a temperature of up to about 130°F, or up to about 120°F, or from about 70°F to about 130°F, or from about 70°F to about 120°F, or from about 70°F to about 115°F.

[0072] According to embodiments, cooling water is added to the treated waste material in an amount sufficient to increase the total water content in the pressure vessel by at least about 5% by weight of the total water content and waste material content of the pressure vessel, or by at least about 10% by weight of the total water content and waste material content of the pressure vessel, or by between about 5% by weight and about 40% by weight of the total water content and waste material content of the pressure vessel.

[0073] According to an embodiment, the cooling water may be substantially pure water, but may be potable or non-potable water. The cooling water may contain additives such as odor control agents and / or biocides.

[0074] [Discharge of treated waste] After cooling with cooling water, the treated waste material is discharged from the rotating vessel for recovery of repulped materials and plastics for recycling. According to some embodiments, the discharged treated waste material contains solids in an amount of about 5% to about 50% by weight based on the total wet weight of the discharged treated waste material. Preferably, the solids concentration of the discharged treated waste material is in an amount of about 10% to about 40% by weight based on the total wet weight of the discharged treated waste material, about 10% to about 25% by weight based on the total wet weight of the discharged treated waste material, about 10% to about 20% by weight based on the total wet weight of the discharged treated waste material, or about 30% to about 40% by weight based on the total wet weight of the discharged treated waste material.

[0075] Additionally, as discussed above, the waste paper present in the treated waste material is substantially repulped. According to some embodiments, the waste paper is at least about 80 percent repulped, or the waste paper is at least about 90 percent repulped.

[0076] Returning to the embodiment of Figures 3-11, the closure device 40 is opened and the drum D is rotated in a second rotational direction. In the second rotational direction, assuming a counterclockwise rotation, the treated waste material is intercepted by the helical vane 80 and directed by the action of the helical vane 80 towards the inlet end of the drum D. As the drum D continues to rotate, the treated waste material is also lifted and directed towards the inlet end of the vessel by the surface 75 of the "Y" shaped lifting paddle 70 as previously described.

[0077] The angular surfaces 75 and 76 on either side of the vertical plane of the paddle function equally well in either direction of rotation, and are of course assisted in each case by the vertically disposed member 72.

[0078] It should be noted that lifting paddle 70 functions in a countercurrent or countercurrent manner relative to helical blade 80 during processing, with surface 76 acting in a primary manner at such time. Only after the waste material has been completely processed is the direction of rotation of drum D reversed to allow helical blade 80 to discharge the material over drum lip 51 into a suitable discharge system. During this discharge, surface 75 of paddle 70 functions primarily and actually cooperates with the action of helical blade 80.

[0079] Thus, the treated waste material is discharged from the bin by the combined action of the helical blades 80 and the surfaces 72 and 75 of the lifting paddles 70 during rotation of the drum D in the second direction of rotation. Because the outer lip 51 of the drum D projects beyond the outer rim of the bin A, the discharged treated waste material falls from the bin. Repulping of the paper material reduces the volume of the treated waste material to approximately one-third of its original volume.

[0080] The discharge rate of the treated waste material will depend on the rotational speed of the drum D, the size and frequency of the helical blades 80, and the size and number of lifting paddles 70, which, as will be apparent to those skilled in the art, depend on the amount of material being treated in a given time, and is not limited to a single combination of these variables.

[0081] The drain connection 64 is provided with a suitable valve 66 which can be opened to allow water to be drained from the shell (pressure vessel A) in the event of excessive water accumulation.

[0082] The treated waste material is then sent to one or more screening devices for separation and recovery of the repulped paper fraction, and further collection of the separated plastic materials, as described herein below. Although the above-described embodiments of pressure vessels suitable for use in the integrated recycling systems and methods of the present application are batch processes, one skilled in the art will understand that pressure vessels configured for continuous use may also be used.

[0083] 2. Wet processing and separation of treated waste materials The treated waste material is further diluted during and optionally prior to separation of the treated waste material by one or more substantially non-destructive separation processes. "Substantially non-destructive" refers to a process that does not cause significant size reduction or material decomposition. For example, a separation process can be characterized as substantially non-destructive if the median diameter of the treated waste material after separation is at least 85% of the treated waste material before separation. Non-limiting examples of various separation processes include density separation, size separation, optical separation, and metal separation.

[0084] An exemplary embodiment of a wet processing and separation system 100 for the processed waste material 110 discharged from the autoclave 102 is shown in FIG. 12. The processed waste material 110 is separated into two or more portions using one or more screening devices 112. Non-limiting examples of such screening devices include trommels, coarse screens, fine screens, vibrating flat screens, finger screens, ballistic separators, drum repulpers, magnets, eddy current, optical sorters, and the like. In a preferred embodiment, the screening device includes a washing trommel. The first portion 114 can include material that can pass through the openings of the screening device, non-limiting examples of which include a repulped waste paper portion, small debris such as pieces of plastic, metal, glass, grit, and the like, and an aqueous mixture of liquid and solubilized organic matter. In embodiments, the solids of the first portion may comprise the repulped waste paper portion in an amount of about 20% to about 90% by weight of the solids of the first portion, about 50% to about 90% by weight of the solids of the first portion, about 50% to about 80% by weight of the solids of the first portion, about 50% to about 70% by weight of the solids of the first portion. In some embodiments, the first portion comprises solids present in the first portion of 0.5% to about 4% by weight of the discharged waste material. In some embodiments, the dewatered substantially repulped waste paper comprises cellulosic material in an amount of greater than about 95% of the dewatered substantially repulped waste paper. For example, the repulped waste paper portion comprises about two-thirds of the solids of the first portion and plastics comprise about one-third of the solids of the first portion. The second portion 116 of the separated processed waste material can include oversized material (also referred to as waste) that cannot pass through the trommel, non-limiting examples of which include dewatered large debris such as rags, cans, and large pieces of plastic and metal.

[0085] An exemplary embodiment of the screening apparatus 112 is illustrated in Figures 14A and 14B. The screening apparatus 112 is divided into zone 1140 and zone 2142 by the internal baffle 144. The treated waste material 110 enters zone 1140 with dilution water. Supplemental dilution water is added to the screening apparatus 112 to aid in separation. In the embodiment of Figure 14A, the supplemental dilution water is added at both the internal baffle 144 and zone 2142. In the embodiment of Figure 14B, the supplemental dilution water is added only to zone 2142. Figure 21 depicts another embodiment of the screening apparatus, including two supplemental dilution water inlets and two dilution water showers. In some embodiments, the internal baffle is adjustable from a first position along the longitudinal axis of the screening apparatus to a second position along the longitudinal axis of the screening apparatus, allowing the size of zone 1 and zone 2 to be changed.

[0086] Water may be added to the screening device along with the treated waste material at or near the waste material inlet to dilute the treated waste material as it enters the screening device. During separation, additional dilution water is added via at least one auxiliary dilution water inlet to help wash the first portion through the openings in the screening device 112. In some embodiments, the multiple dilution water inlets comprise a first dilution water inlet located distal and upstream from the at least one auxiliary dilution water inlet.

[0087] In embodiments, water is added to the treated waste material in the screening device in an amount sufficient to dilute the first portion to about 0.5% to about 20% by weight solids, about 1% to about 10% by weight solids, about 1% to about 6% by weight solids, about 2% to about 5% by weight solids, about 3% to about 5% by weight solids, or any range therebetween.

[0088] In a preferred embodiment, water is added at multiple points arranged in series, for example, a first portion of dilution water is first added to the screening device along the waste material at or near the waste material inlet, and then additional dilution water is added at one or more points distal to the waste material inlet.

[0089] In some embodiments, the screening device includes an internal baffle configured to separate the screening device into a first zone proximal to the waste material inlet and a second zone distal to the waste material inlet.

[0090] In some embodiments, the screening device is a rotating cylindrical drum having a longitudinal axis. The internal baffle may be located at a midpoint along the longitudinal axis such that the first and second zones have the same size, or the internal baffle may be located at another point along the longitudinal axis such that the first and second zones have unequal volumes. Any positioning of the internal baffle may be utilized depending on the needs of the waste recovery process and the composition of the treated waste material.

[0091] In some embodiments, there may be at least one auxiliary dilution water inlet. For example, a first auxiliary dilution water inlet may be disposed at a first circumferential location within the screening apparatus, and a second auxiliary dilution water inlet may be disposed at a second circumferential location within the screening apparatus. As used herein, "circumferential location" refers to a point around the circumference of the cylindrical wash trommel.

[0092] In some embodiments, the first auxiliary dilution water inlet and the second auxiliary dilution water inlet are disposed at a common position on the longitudinal axis of the screening apparatus. In other embodiments, the first auxiliary dilution water inlet is disposed at a first longitudinal position on the longitudinal axis of the screening apparatus, and the second auxiliary dilution water inlet is disposed at a second longitudinal position on the longitudinal axis of the screening apparatus. As used herein, "longitudinal position" essentially refers to the length of the piping that delivers the auxiliary dilution water within the screening apparatus. In other words, two auxiliary dilution water inlets disposed at the same longitudinal position can refer to two inlets that are disposed at different circumferential positions, but have the same length and extend the same distance into the screening apparatus along the longitudinal axis.

[0093] In some embodiments, the auxiliary dilution water inlet is in the form of a perforated shower bar configured to deliver dilution water at several points along the length of the shower bar.

[0094] Traditionally, dilution water is added to the screening device at a single point, and the screening device is agitated to mix the treated waste material with the dilution water and cause separation through openings in the screening device. It has been unexpectedly discovered that introducing dilution water at multiple locations, such as first with the waste material and then again at one or more locations within the screening device, lowers overall water consumption, increases the yield of recovered repulped waste paper, and reduces batch times.

[0095] In some embodiments, the first auxiliary dilution water inlet is configured to deliver dilution water at the internal baffle. In other words, the first auxiliary dilution water is delivered through piping having a length such that the dilution water is delivered to the same point along the longitudinal axis as the internal baffle. The second auxiliary dilution water inlet may be positioned at the same point such that the first and second auxiliary dilution water inlets deliver dilution water to a point in the screening device that coincides with the internal baffle, or the second auxiliary dilution water inlet may be positioned beyond the internal baffle such that the dilution water is delivered to the second zone. In some embodiments, both the first and second auxiliary dilution water inlets deliver dilution water to the second zone.

[0096] In some embodiments, the screening apparatus includes a plurality of dilution water showers located external to the screening apparatus configured to spray water onto an exterior surface of the screening apparatus to prevent clogging of the screening apparatus.

[0097] A schematic diagram of an exemplary screening apparatus 112 is shown in Figure 15. Waste material and dilution water are added to the screening apparatus 112 at or near the waste material inlet 150, while supplemental dilution water is added to the supplemental dilution water inlet 152. In some embodiments, the supplemental dilution water inlet 152 may have different lengths and deliver supplemental dilution water to zone 1154 and / or zone 2156. A shower 158 may be present to deliver water from outside the screening apparatus 112 to prevent clogging of the openings.

[0098] The openings of the one or more screening devices may be adjusted depending on the size of the material desired in the first portion and may be the same or may vary along the length of the screening device. For example, in embodiments, the screening device may be about 20 to about 400 mm. 2 The aperture may have a plurality of holes / openings having an average area of

[0099] The first portion may undergo further processing to separate the repulped waste paper portion from the majority of the non-cellulosic solids. A variety of separation processes may be used, including size separation, density separation, coarse screening, fine screening, dissolved air flotation, washing, clarification, forward cleaner, reverse cleaner, dispersion, drying, or combinations thereof. For example, in embodiments, a second screening device, such as a second trommel, vibrating screen, air separator, magnet, eddy current, ballistic separator, density separation, or optical sorting, may be used to separate the majority of the non-cellulosic solids from the repulped waste paper portion of the first portion to produce a highly washed substantially fiber-free non-cellulosic solids portion, optionally including non-cellulosic solids from the second portion and the first portion. By "substantially fiber-free" it is meant that less than about 20% by weight of the solids are cellulosic solids, and more preferably less than about 5% by weight of the solids are cellulosic solids. For example, the substantially fiber-free non-cellulosic solids portion recovered from the first and / or second portions may include cellulosic solids in an amount of about 1% to about 5% by weight on a dry basis.

[0100] The non-cellulosic solids portion may optionally be sorted using further separation processes to recover recyclable plastics and metals. For example, metals may be separated by using magnets to recover ferrous metals, eddy current to recover non-ferrous metals and aluminum, and optical sorting techniques. Plastics can be separated using optical sorting techniques to separate recyclable plastics such as polyethylene (including both high and low density), polypropylene, polyethylene terephthalate, polyvinyl chloride, polyamide, and polystyrene. If it is desired to reduce the moisture content of the recovered recyclable material, further techniques can be used, for example, by mechanically dewatering the recovered recyclable material. Non-limiting examples of techniques for mechanical dewatering include screw presses and belt presses.

[0101] The second portion can undergo further processing to recover suitable treated water from the waste and recycle the treated water to the autoclave.

[0102] In the exemplary embodiment shown in FIG. 12, a high density cleaner 118 is used to remove at least a portion of the small non-cellulosic solids 122 (e.g., metals, grit, glass, etc.) from the first portion 114. The remainder of the first portion 120 may then undergo further processing using one or more screening processes 124 to separate other non-cellulosic solids 128 (e.g., plastics) from the repulped wastepaper portion 126. The repulped wastepaper portion 126 may then be mechanically dewatered 130, for example, using a screw press or belt press, to remove at least a portion of any liquids and solubilized organic matter 134 and provide an at least partially dewatered repulped wastepaper portion 132 having an increased solids concentration. For example, the dewatered repulped wastepaper portion 132 may be about 50 to about 90% solids by weight, with the solids comprising greater than about 95% cellulosic material (e.g., cellulose, hemicellulose, etc.) by weight.

[0103] Advantageously, the dewatered repulped wastepaper fraction produced by such methods is significantly cleaner than that produced by prior art methods, characterized by a biochemical oxygen demand (BOD) content of less than about 50 or lb / t dry fiber. In addition, the majority of the cellulosic material is recovered in the repulped wastepaper fraction, and the liquid and solubilized organic matter removed during dewatering of the repulped wastepaper fraction (i.e., the filtrate) contains less than about 1.0% suspended solids by weight, with about 90% soluble BOD in the repulped wastepaper fraction. In some embodiments, the present methods may be characterized by a reduction in the BOD of the dewatered repulped wastepaper fraction compared to untreated wastewood. For example, the BOD of the repulped waste paper portion may be less than 50% of the BOD of the untreated waste wood, about 5% to about 40% of the BOD of the untreated waste wood, about 5% to about 20% of the BOD of the untreated waste wood, or about 5% to about 10% of the BOD of the untreated waste wood.

[0104] Non-cellulosic solids recovered from the second and / or first portions of the treated waste material may also undergo one or more processes to recover recyclable plastics and metals. In an exemplary embodiment, a process 200 for separating non-cellulosic solids 210 from the treated waste material is shown in FIG. 13. For example, metals may be separated from the first or second portions of the treated waste material 210 by using one or more magnets 212 to separate ferrous metals 214 and using eddy currents 216 to separate non-ferrous metals and aluminum 218. Plastics 222 may be optically separated 220 from the first or second portions of the treated waste material to recover one or more of polyethylene, polypropylene, polyethylene terephthalate, polyvinyl chloride, polystyrene, etc. 224. The separated recyclable metals and plastics may then be used as feedstock in one or more subsequent processes to produce other useful products.

[0105] 3. Post-processing In embodiments, the repulped paper portion (either before or after mechanical dewatering) may be used as at least a portion of the cellulosic feedstock in the production of post-consumer paper-containing products such as tissue paper, paper towel products, or as part of the production of paper plates, absorbent paper sheets, and the like.

[0106] In embodiments, the repulped paper portion (either before or after mechanical dewatering) may undergo chemical treatment to form one or more furaldehydes, organic acids, organic acid decomposition products, etc. For example, the repulped paper portion may be converted to one or more furaldehydes, organic acids, organic acid decomposition products, or combinations thereof by hydrolyzing cellulose in the repulped paper portion to glucose and converting the glucose to one or more furaldehydes, organic acids, organic acid decomposition products, or combinations thereof (hereinafter, individually or collectively, referred to as "organic acid compounds"). Non-limiting examples of organic acid compounds include levulinic acid, formic acid, acetic acid, propionic acid, etc.

[0107] In embodiments, the plastics separated from other non-cellulosic solids may be used to produce reject-derived fuels, such as fuel cubes or pellets. In some embodiments, the waste-derived fuel can then be used to co-generate electricity for use in the processes and systems described herein.

[0108] In embodiments, the plastics (with or without polyolefin polymers) separated from other non-cellulosic solids may be pyrolyzed to produce one or more products suitable for use as fuel. Such systems generally include a pyrolyzer configured to pyrolyze the plastic feedstock. Such processes may result in the production of useful hydrocarbon liquids (e.g., crude oil, diesel fuel, etc.).

[0109] In embodiments, polyethylene terephthalate (PET) optically separated from other non-cellulosic solids can be used to produce PET flakes for film. For example, PET can be shredded to produce shredded PET flakes using methods known in the art. Alternatively, PET can be formed into PET film using methods known in the art. Advantageously, the methods and systems provided herein eliminate the need for separate pre-treatments that are commonly required in the prior art. For example, prior art methods require processes for label removal, sterilization, decapping, and densification before the PET is suitable for further processing.

[0110] In embodiments, at least a portion of the liquid and solubilized organic matter separated from the treated waste material may be introduced into an anaerobic digester to produce biogas suitable for electricity cogeneration. Non-limiting examples of biogas that may be produced by an anaerobic digester include carbon dioxide and methane. The anaerobic digester may also produce residual material suitable for use as a solid fuel and / or compost.

[0111] Various aspects of the above-mentioned systems and processes can be combined to provide an integrated recycling system for the treatment of waste materials. These systems and processes are particularly suitable for use in industrial plants that already have water treatment facilities in place. For example, the integrated recycling system can be co-located with an on-site water treatment facility (e.g., a pulp and paper mill, a waste-to-energy plant, a pyrolysis site, a gasification site, or a landfill) at a water treatment facility or any other industrial facility. The integrated recycling system and process can advantageously be at least an energy neutral process that does not require additional energy sources beyond those generated in the recycling process.

[0112] [Example] Example 1: Exemplary Process

[0113] The waste material recovery process was carried out as described herein. The weight of the waste material was based on an "oven dry" basis, i.e., zero moisture content. Material inputs and outputs were measured from (i) the autoclave, (ii) the autoclave discharge trough, (iii) the first zone of the washing trommel, and (iv) the second zone of the washing trommel. The process parameters for these four stages are shown in Tables 1-4 below. [Table 1] [Table 2] [Table 3] [Table 4] [Table 5]

[0114] Example 2: Comparison of single versus dual auxiliary dilution water inlets

[0115] Two waste material recovery processes were conducted as described herein. One waste material recovery process included a single auxiliary dilution water inlet, and the other included dual auxiliary dilution water inlets. Both municipal solid waste (MSW) and old cardboard waste (OCC) were recycled. The wash trommel was configured to rotate clockwise, and the single auxiliary dilution water inlet was tested in both the "north" position, where the dilution water was discharged along the upward moving wall of the wash trommel onto the rotating waste material, and the "south" position, where the dilution water was discharged along the downward moving wall of the wash trommel onto the rotating waste material. A photograph of the wash trommel 112 with the piping configuration showing the north pipe 160 and the south pipe 162 is displayed in FIG. 16. The results of the testing are shown in Table 6 below and in FIG. 17. [Table 6]

[0116] As shown in FIG. 17, the use of both north and south piping in the wash trommel results in an increased amount of fiber recovered even with approximately the same amount of dilution water.

[0117] Example 3: Comparison of short and staggered piping

[0118] Two waste recovery processes were run as described herein. One included an auxiliary dilution water inlet with "short" piping that extended to an internal baffle that separated a first zone from a second zone in the wash trommel, and the other included an auxiliary dilution water inlet with "staggered" piping, with one auxiliary dilution water inlet extending to the internal baffle and another extending into Zone 2. The results of the testing are shown in Table 7 below and in FIG. 18. [Table 7]

[0119] By staggering the piping as shown in FIG. 18, a substantial increase in the amount of fiber recovered is achieved with only a small increase in the amount of dilution water used.

[0120] Example 4: Dilution water vs. fiber recovery analysis.

[0121] Two waste material recovery processes with multiple dilution water inlets arranged in series along the wash trommel were conducted as described herein. One waste material recovery process was fed municipal solid waste (MSW) and the other was fed old corrugated cardboard (OCC). Different amounts of dilution water were fed to the wash trommel. The results are shown in Figures 18 and 19.

[0122] As shown in Figures 19 and 20, the amount of fiber recovered (measured as a percentage of the feed) has a sideways trend with respect to the amount of dilution water delivered to the wash trommel. A conventional screening apparatus that includes only a single supply of dilution water at the waste inlet has an upward trend between the amount of dilution water used and the percentage of fiber recovered. In other words, the conventional apparatus recovers a greater amount of fiber using a greater amount of dilution water. Unexpectedly, it was discovered that a greater amount of fiber can be recovered when multiple dilution water inlets are placed in series in the wash trommel and the overall amount of dilution water is less. Thus, by including one or more auxiliary dilution water inlets in the wash trommel, the ratio between fiber removal efficiency and overall water consumption can be improved, i.e., the fiber removal efficiency is improved over a conventional process using the same amount of water.

[0123] It should be noted that for purposes of describing and defining the present teachings, the term "substantially" is utilized herein to represent the inherent degree of uncertainty that may result from any quantitative comparison, value, measurement, or other representation. The term "substantially" is also utilized herein to represent the degree to which a quantitative representation may vary from the stated standard without resulting in a change in the basic functionality of the subject matter at issue.

[0124] While the present teachings have been described in terms of various embodiments, it will be understood that these teachings are also capable of a wide variety of further and other embodiments within the spirit and scope of the appended disclosure.

Claims

1. A method for recycling waste materials, including waste paper, comprising the steps of: introducing said waste material and water into a pressure vessel; treating the waste material in the pressure vessel at an elevated treatment temperature and elevated treatment pressure to form a treated waste material comprising substantially repulped waste paper; Discharging the treated waste material from the pressure vessel; and thereafter, introducing the treated waste material into a waste inlet of a screening device and using the screening device to separate the treated waste material into a first portion and a second portion, the first portion comprising the substantially repulped waste paper and the second portion comprising large debris; The method of claim 1, wherein the screening apparatus comprises a plurality of dilution water inlets, at least one of the dilution water inlets comprising an auxiliary dilution water inlet located within the screening apparatus distal from the waste material inlet, and the step of introducing the dilution water comprises introducing at least a portion of the dilution water into the screening apparatus via the at least one auxiliary dilution water inlet.

2. 10. The method of claim 1, wherein the at least one dilution water inlet comprises a dilution water inlet disposed proximate to the waste material inlet such that dilution water is introduced into the screening apparatus along with the treated waste material.

3. The method of claim 1 , wherein the plurality of dilution water inlets includes a first dilution water inlet distal and upstream from the at least one auxiliary dilution water inlet.

4. 10. The method of claim 1, wherein the separating step further comprises washing the first portion through the screening device with a sufficient amount of water to dilute the first portion to about 0.5% to about 20% solids by weight.

5. 10. The method of claim 1, wherein the elevated processing temperature is at least 212°F.

6. The method of claim 1 , wherein the elevated processing pressure is greater than atmospheric pressure.

7. The method of claim 1 , wherein the screening device further comprises an internal baffle configured to separate the screening device into a first zone proximate the waste material inlet and a second zone distal to the waste material inlet.

8. 8. The method of claim 7, wherein the internal baffle is adjustable from a first position along a longitudinal axis of the screening device to a second position along the longitudinal axis of the screening device.

9. 8. The method of claim 7, wherein the screening device comprises a rotating cylindrical drum having a longitudinal axis, the internal baffle is positioned at a midpoint along the longitudinal axis such that the first zone and the second zone have the same size, and the step of separating the processed waste material using the screening device comprises rotating the rotating cylindrical drum of the screening device.

10. 8. The method of claim 7, wherein the at least one auxiliary dilution water inlet includes a first auxiliary dilution water inlet disposed at a first circumferential location and a second auxiliary dilution water inlet disposed at a second circumferential location.

11. The method of claim 10 , wherein the first auxiliary dilution water inlet and the second auxiliary dilution water inlet are disposed at a common location on the longitudinal axis.

12. 11. The method of claim 10, wherein the first auxiliary dilution water inlet is disposed at a first longitudinal position on the longitudinal axis and the second auxiliary dilution water inlet is disposed at a second longitudinal position on the longitudinal axis.

13. the at least one auxiliary dilution water inlet includes a first auxiliary dilution water inlet disposed at a first circumferential location and a second auxiliary dilution water inlet disposed at a second circumferential location; the first auxiliary dilution water inlet has a first length to discharge dilution water at the internal baffle; 8. The method of claim 7, wherein the second auxiliary dilution water inlet has a second length to discharge dilution water in the second zone.

14. The method of claim 7 , wherein each auxiliary dilution water inlet in the at least one auxiliary dilution water inlet is configured to discharge dilution water into the second zone.

15. 8. The method of claim 7, wherein the at least one auxiliary dilution water inlet is a perforated shower bar configured to discharge dilution water at several points along a length of the shower bar.

16. 10. The method of claim 1, wherein the screening apparatus further comprises a plurality of dilution water showers located external to the screening apparatus and configured to spray water onto an exterior surface of the screening apparatus to prevent clogging of the screening apparatus.

17. 2. The method of claim 1, wherein the separating step further comprises separating the second portion into a waste stream and a recycle stream, the waste stream comprising dewatered large pieces and the recycle stream comprising excess dilution water removed from the large pieces.

18. 10. The method of claim 1, wherein the discharged treated waste material has a temperature of about 110 to about 220°F.

19. 10. The method of claim 1, wherein the discharged treated waste material comprises solids present in the discharged treated waste material in an amount of from about 5% to about 50% by weight of the discharged treated waste material.

20. 10. The method of claim 1, wherein the first portion comprises from 0.5% to about 4% by weight of the discharged treated waste material solids present in the first portion.

21. 2. The method of claim 1, wherein the first portion comprises substantially repulped waste paper present in the solids of the first portion in an amount of from about 20% to about 90% by weight of the solids of the first portion.

22. The screening device has a diameter of about 20 to about 400 mm ２ The method of claim 4 , further comprising a plurality of openings having an average area of

23. 13. The method of claim 1, wherein the method is performed on-site at an industrial facility having a water treatment facility.

24. 2. The method of claim 1, further comprising separating the substantially repulped waste paper from a majority of any non-cellulosic solids in the first portion using density separation, size separation, coarse screening, fine screening, dissolved air flotation, washing, clarification, forward cleaner, reverse cleaner, dispersion, drying, or combinations thereof.

25. 5. The method of claim 4, further comprising separating substantially fiber-free recoverable / recyclable plastics and metals from the second portion using a second separation device.

26. 26. The method of claim 25, wherein the second separation device comprises a trommel, a vibrating screen, an air separator, a magnet, an eddy current, a ballistic separator, density separation, or optical sorting.

27. 25. The method of claim 24, further comprising mechanically dewatering the separated substantially repulped waste paper to remove at least a portion of liquids and solubilized organic matter from the separated substantially repulped waste paper.

28. 28. The method of claim 27, wherein the dewatered substantially repulped waste paper comprises cellulosic material in an amount greater than about 95% of the dewatered substantially repulped waste paper.

29. 28. The method of claim 27, wherein the dewatered substantially repulped waste paper is characterized by a biochemical oxygen demand (BOD) content of less than about 50 or lb / t dry fiber.

30. 28. The method of claim 27, wherein the dewatered substantially repulped waste paper is characterized by a biochemical oxygen demand (BOD) content that is less than about 50% of the BOD content of the untreated waste wood.

31. 28. The method of claim 27, wherein the filtrate removed during dewatering of the substantially repulped waste paper comprises less than about 1.0% by weight suspended solids and about 90% soluble biochemical oxygen demand (BOD) as the substantially repulped waste paper.

32. 1. An integrated system for recycling waste materials, including waste paper, comprising: a pressure vessel configured to receive water and waste material and to treat the waste material in the pressure vessel at an elevated treatment temperature and an elevated treatment pressure to form a treated waste material comprising substantially repulped waste paper; a screening device having a waste material inlet for receiving the processed waste material and configured to separate the processed waste material into a first portion and a second portion, the first portion including the substantially repulped waste paper and the second portion including large debris; An integrated system, wherein the screening apparatus comprises a plurality of dilution water inlets, at least one of the dilution water inlets comprising an auxiliary dilution water inlet disposed within the screening apparatus distal to the waste material inlet.

33. 33. The system of claim 32, wherein at least one dilution water inlet comprises a dilution water inlet disposed proximate to the waste material inlet such that dilution water is configured to be introduced into the screening device along with the treated waste material.

34. 33. The system of claim 32, further comprising a water supply configured to wash the first portion through the screening device with a sufficient amount of water to dilute the first portion to about 0.5% to about 20% solids by weight.

35. The screening device has a diameter of about 20 to about 400 mm ２ 33. The system of claim 32, comprising a plurality of openings having an average area of

36. 33. The system of claim 32, wherein the screening device further comprises an internal baffle configured to separate the screening device into a first zone proximal to the first end of the screening device and a second zone distal to the first end of the screening device.

37. 37. The system of claim 36, wherein the internal baffle is adjustable from a first position along a longitudinal axis of the screening device to a second position along the longitudinal axis of the screening device.

38. 37. The system of claim 36, wherein the screening apparatus comprises a rotating cylindrical drum having a longitudinal axis, the internal baffle being located at a midpoint along the longitudinal axis such that the first zone and the second zone have the same size.

39. 37. The system of claim 36, wherein the at least one auxiliary dilution water inlet includes a first auxiliary dilution water inlet disposed at a first circumferential location and a second auxiliary dilution water inlet disposed at a second circumferential location.

40. 40. The system of claim 39, wherein the first auxiliary dilution water inlet and the second auxiliary dilution water inlet are disposed at a common location on the longitudinal axis.

41. 40. The system of claim 39, wherein the first auxiliary dilution water inlet is disposed at a first longitudinal position on the longitudinal axis and the second auxiliary dilution water inlet is disposed at a second longitudinal position on the longitudinal axis.

42. the at least one auxiliary dilution water inlet comprises a first auxiliary dilution water inlet disposed at a first circumferential position and a second auxiliary dilution water inlet disposed at a second circumferential position; the first auxiliary dilution water inlet has a first length to discharge dilution water at the internal baffle; 37. The system of claim 36, wherein the second auxiliary dilution water inlet has a second length to discharge dilution water in the second zone.

43. 37. The system of claim 36, wherein each auxiliary dilution water inlet in the at least one auxiliary dilution water inlet is configured to discharge dilution water into the second zone.

44. 37. The system of claim 36, wherein the at least one auxiliary dilution water inlet is a perforated shower bar configured to discharge dilution water at several points along a length of the shower bar.

45. 33. The system of claim 32, wherein the screening device further comprises a plurality of dilution water showers located external to the screening device configured to spray water on an exterior surface of the screening device to prevent clogging of the screening device.

46. 33. The system of claim 32, wherein the system is co-located at a pulp and paper mill, a waste-to-energy plant, a pyrolysis site, a gasification site, or a landfill site.

47. 41. The system of claim 40, wherein the water supply is integrated with an on-site water treatment facility.

48. 33. The system of claim 32, further comprising one or more separators for separating the substantially repulped waste paper from a majority of any non-cellulosic solids within the first portion.

49. 43. The system of claim 42, wherein the one or more separators include one or more of a density separator or a size separator.

50. 43. The system of claim 42, wherein the one or more separators include a second trommel, a coarse screen, a fine screen, or a combination thereof.

51. 43. The system of claim 42, wherein the one or more separators include a high density cleaner.

52. 43. The system of claim 42, wherein the one or more separators comprise a high density cleaner, a coarse screen, and a fine screen in series with each other.

53. 43. The system of claim 42, further comprising a dewatering device for removing at least a portion of solubilized organic matter and liquid from said separated substantially repulped waste paper.

54. 49. The system of claim 48, wherein the dewatering device comprises a screw press, a filter press, or a combination thereof.

55. 43. The system of claim 42, further comprising one or more secondary separators for separating substantially fiber-free recoverable / recyclable plastics and metals in the second portion, the one or more secondary separators being selected from the group consisting of a density separator, an optical separator, and a metal separator.

56. 51. The system of claim 50, wherein the one or more secondary separators comprise a metal separator comprising magnets for separating ferrous metals and eddy currents for separating aluminum and non-ferrous metals.

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