Food waste recycling

Abstract

A process for producing animal feed having a defined nutritional profile from food waste includes accumulating successive batches of macerated and dehydrated food waste, where each batch of the plurality of food wastes is sourced from the same batches of a plurality of categorized producers of food waste and is always maintained separate from other batches of the plurality of food wastes; independently mixing each of the accumulated batches of macerated and dehydrated food waste to produce a plurality of homogenized ingredients for the animal feed; analyzing each of the homogenized ingredients to determine one or more nutritional parameters of the ingredient; and blending two or more of the homogenized ingredients to produce the animal feed having the defined nutritional profile.

Description

[Technical field]

[0001] The present invention relates to food waste recycling, and in particular to processes, methods and apparatus for use in recycling food waste into premium animal feed. [Background technology]

[0002] It is estimated that almost one-third of the food produced for human consumption is wasted, at enormous economic and environmental costs. Disposal of food waste on a commercial scale has become increasingly problematic as it is no longer generally acceptable to send all food waste to landfills. Many creative solutions have been proposed to the problem of food waste, but few of these solutions have achieved commercial success.

[0003] In one such solution, one of the inventors made an invention regarding a unique method for recycling food waste. The present invention is described in International (PCT) Application No. PCT / AU2017 / 051130, the contents of which are incorporated herein in their entirety. However, further problems became apparent in implementing the invention on a commercial scale. Summary of the Invention

[0004] The present invention relates to an apparatus, process and method for recycling food waste for maximum environmental and economic benefit, such as when the food waste is used to produce premium animal feed. As will become apparent from the disclosure set forth below, an overarching objective of the present invention is to enable the recycling of virtually all food waste into a saleable product with little or no waste. The environmental benefits of the present invention are significant, both in terms of reducing the amount of food waste sent to landfills and in terms of allowing products such as premium animal feeds to be produced without the need to use other raw material sources (e.g., grains and protein sources) that could be more beneficially used as human food.

[0005] In a first aspect, the present invention provides a process for producing animal feed with a defined nutritional profile from food waste. The process includes accumulating successive batches of macerated and dehydrated food waste, where each batch of the plurality of food wastes is sourced from the same batches of multiple categorized producers of food waste and is always maintained separate from other batches of the plurality of food wastes; independently mixing each of the accumulated batches of macerated and dehydrated food waste to produce a plurality of homogenized ingredients for animal feed; analyzing each of the homogenized ingredients to determine one or more nutritional parameters of the ingredient; and blending two or more of the homogenized ingredients to produce an animal feed having a defined nutritional profile.

[0006] As described in PCT / AU2017 / 051130, the inventors have discovered that certain categories of food waste can be processed to produce ingredients for animal feed that have relatively consistent nutritional profiles. For example, food waste from a bakery, a cafe, and a butcher can be processed separately to produce ingredients with different nutritional profiles for the resulting animal feed. Such ingredients offer countless blending opportunities to produce animal feeds with nutritional content that allows them to command premium prices.

[0007] The present invention, which is the subject of PCT / AU2017 / 051130, has resulted in the production of animal feeds, such as chicken feed, shrimp feed, and fish feed. However, the inventors have found that there is slight variation between batches of categorized food waste, even when taken from the exact same producer of food waste. In some applications, these variations are acceptable. However, premium animal foods (eg chicken feed) have very strict requirements and these variations are not compatible with such foods. The homogenization, analysis, and blending steps in the process of the present invention have been found to provide an elegant solution to this problem. The process of the present invention allows the production of animal feed with a precisely defined nutritional profile from food waste. Furthermore, due to the variety of food waste sources that can be utilized, the ingredients produced by the process of the present invention have a corresponding variety in nutritional parameters. The wide variety of readily available sources of ingredients provides numerous blending opportunities to produce animal feeds having virtually any given composition. In fact, animal feed (eg, chicken feed) meeting rigorous standards can be produced without the need for any ingredients other than those derived from food waste. The advantages, both in terms of cost and security of supply of raw materials, are clear.

[0008] In a second aspect, the present invention provides a method for dewatering macerated food waste. The method includes mixing a material having a moisture content different from the moisture content of the macerated food waste into the macerated food waste proximate an inlet of the dehydrator, wherein the added material and the macerated food waste are mixed such that the mixture at the inlet of the dehydrator has a defined and substantially uniform moisture content. The mixture can then be dehydrated.

[0009] In a third aspect, the present invention provides an apparatus for dewatering macerated food waste. The apparatus includes a hopper, the outlet of which communicates with the inlet of the dehydrator; a moisture detector proximate the outlet of the hopper and configured to detect a moisture content; a conduit through which a material having a moisture content different from the moisture content of the macerated food waste can be added to the macerated food waste proximate the outlet of the hopper; and a mixer for mixing the material and the macerated food waste such that the resulting mixture is presented to the inlet of the dehydrator having a defined and substantially uniform moisture content.

[0010] The second and third aspects of the invention overcome the problems associated with dehydrating macerated food waste that has variable water content or is either too wet or (less common) too dry. When fed into the dehydrator used in our tests, the macerated food waste quickly breaks down into small particles. Relatively dry particles will be damaged by excessive heat, while relatively wet particles will not dehydrate adequately.

[0011] However, in these embodiments, the blending of a second (usually drier) material into the macerated food waste at a particular location in the hopper ensures that proper mixing occurs and that the material presented to the dehydrator has both a relatively consistent moisture content as well as a target moisture content (e.g., 50% moisture). Thus, the dewaterer can be operated to dewater the substance of the mixture, reducing the risk of any damage to the material occurring. As can be appreciated, excessive heat is detrimental to the nutritional content of many categories of foods.

[0012] In a fourth aspect, the present invention provides a method for producing a dehydrated granular powder from macerated food waste. The method includes dehydrating the macerated food waste to produce a dehydrated product, and then agitating the dehydrated product as it cools, thereby preventing agglomeration and producing a dehydrated granular powder.

[0013] This aspect has been found to prevent agglomeration of granular particles of food waste that occurs when some categories of food waste are cooled (which has been found to be a particular problem when treating food waste streams having a relatively high fat content).

[0014] The method of the fourth aspect also includes a biosecurity treatment. For example, the method includes a biosecurity treatment in which the dehydrated product produced in the dehydrator is maintained at a temperature of at least 100° C. for at least 30 minutes. Heating to this temperature for this period of time ensures that any pathogens (eg, microorganisms and viruses) present in the dehydrated granular powder are destroyed. Post processing, the dehydrated granular powder is completely biosecure and therefore is not a source of bacterial, viral, fungal or any other pathogenic contamination, none of which are desirable in an industrial environment or would cause downstream spoilage. The bio-secure granular powder of macerated and dehydrated food waste produced by this method is shelf stable and sterile and therefore can be stored for long periods without spoilage issues.

[0015] In a fifth aspect, the present invention provides a macerator assembly including a macerator having an inlet and an outlet, the inlet being matable with the outlet of a storage vessel, the macerator being movable between a plurality of storage vessels.

[0016] Such macerator assemblies reduce capital costs for industrial applications of the present invention and enable efficiencies that may not otherwise be obtainable.

[0017] Additional features and advantages of various aspects of the invention are described below with reference to specific embodiments. However, such additional features have more general applicability in the present invention than those described in these specific embodiments. [Brief description of the drawings]

[0018] Embodiments of the invention are described in further detail below with reference to the following drawings:

[0019] [Figure 1] 1 illustrates a schematic of a process for producing animal feedstock from multiple categorized waste streams and incorporates various embodiments of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] As stated above, the present invention relates to a process by which animal feed can be produced from multiple categories of food waste that are separately collected, maintained and processed.

[0021] As used herein, terms such as "food waste" are intended to encompass all types of food waste, including, but not limited to, coffee grounds, vegetable matter, dairy products, bakery waste, meat trimmings and bones, and seafood shells (e.g., oysters, mussels, lobsters, etc.).

[0022] As used herein, the terms "food waste producer," "food waste producer," and the like are intended to encompass any facility that generates a reasonable amount of food waste on a regular basis. Food waste producers include, but are not limited to, restaurants, cafes, pubs / clubs, nursing homes, hospitals, supermarkets, grocery stores, greengrocers, delicatessens, butchers and bakeries.

[0023] As used herein, terms such as "food waste categories," "categorized producers of food waste," and the like refer to different streams of food waste and sources of these wastes that, due to their common origin, have a relatively consistent composition between successive batches. The food waste categories include those listed immediately above, generated by each of the food waste producers listed in the preceding paragraph. As an example, one category of food waste is bread products (obtained as waste from bakeries) and another category of food waste, which is collected, maintained and processed separately from bakery waste, is meat off-cuts (obtained as waste from butchers).

[0024] In a first aspect thereof, there is provided a process for producing animal feed having a defined nutritional profile from food waste. The process then includes accumulating successive batches of macerated and dehydrated food waste, where each batch of the plurality of food waste is sourced from the same batches of multiple categorized producers of food waste and always maintained separate from other batches of the plurality of food waste; independently mixing each of the accumulated batches of macerated and dehydrated food waste to produce a plurality of homogenized ingredients for the animal feed; analyzing each of the homogenized ingredients to determine one or more nutritional parameters of the ingredient; and blending two or more of the homogenized ingredients to produce an animal feed having a defined nutritional profile.

[0025] In the present invention, food wastes are classified based on their source. The nutritional characteristics of food waste collected from different types of food waste producers are expected to vary considerably. For example, bakeries generate food waste that is unlikely to be as high in protein content as the waste from butchers. However, it has been discovered that a category of food waste collected only from bakeries (and similar) and processed independently from other categories of food waste results in processed food waste with a remarkably consistent nutritional profile from batch to batch. Similarly, food waste collected from sources such as restaurants / cafes, greengrocers, or butchers will all have a relatively consistent nutritional profile from batch to batch. Thus, each of these categories of food waste can be processed independently of other categories of food waste (i.e., combined with other batches of the same category of food waste (e.g., collected one day later from the same source) to produce multiple ingredients with different nutritional profiles. These ingredients allow for a wide variety of blending opportunities, thereby producing animal feeds with tailored nutritional compositions.

[0026] In contrast, in many prior art applications, food waste is mixed and processed into animal feed with non-specific and highly batch-variable nutritional content. Such animal feeds cannot simply command a premium price while still providing nutrition to the animals.

[0027] As mentioned above, the inventors have recently discovered that there is slight variation between batches of categorized food waste, even when taken from the exact same producer of food waste. While such variability may be acceptable in some applications, premium animal foods (eg chicken feed) have very stringent requirements and variability in nutritional content is simply not acceptable. The homogenization, analysis, and blending steps of the process described herein enable the production of animal feed with a precisely defined nutritional profile from food waste. Such products can command a premium price.

[0028] An embodiment of the process of the present invention is zero waste, with all incoming food waste becoming a final saleable product, such as animal feed.

[0029] The process of the present invention involves storing successive batches of macerated and dehydrated multiple categorized food waste, each batch of the multiple food waste being sourced from the same batch of multiple categorized producers of food waste and always maintained and stored separately from other batches of the multiple food waste. The categorized producers of food waste are independently selected from, for example, restaurants, cafes, supermarkets, grocery stores, greengrocers, delicatessens, butchers, bakeries, etc.

[0030] Apparatus, methods and systems for collecting and keeping separate multiple categories of food waste are described in PCT / AU2017 / 051130 and will not be repeated here. Macerators and dehydrators for macerating and dehydrating products such as food waste are known, and specific examples of such are described below in embodiments of the present invention.

[0031] The process also includes independently mixing each of the accumulated batches of macerated and dehydrated food waste to produce a plurality of homogenized ingredients for animal feed.

[0032] The accumulated batches of macerated and dehydrated food waste are then mixed at any convenient time. For example, when the amount of accumulated batches reaches a certain threshold, the accumulated batches are mixed. Alternatively, if the animal feed being produced requires ingredients with a nutritional profile that is likely to be provided by a particular category of food waste, any accumulated batches of that food waste may be immediately processed to produce the respective homogenized ingredients (albeit likely in smaller amounts than in the previous embodiment). Mixing can occur in any suitable device.

[0033] Given that the macerated and dewatered food waste typically exists as a granular powder, pneumatic loading is conveniently used to transfer material between the storage vessel for the macerated and dewatered food waste and the storage vessel for the homogenized ingredients, and vice versa. In fact, pneumatic loading is conveniently used to transport granular powders through any of the "dry" areas of the overall process.

[0034] The process also includes analyzing each of the homogenized ingredients to determine one or more nutritional parameters of the ingredient. A sample having a predetermined weight or volume (e.g., 1 L) of homogenized components is removed from the bulk material and transported to a laboratory (e.g., an on-site laboratory) for testing; any suitable equipment may be used for such analysis. Examples of nutritional parameters that may be determined include protein content, fat content, amino acid content, and specific gravity.

[0035] The process also includes blending two or more of the homogenized ingredients to produce an animal feed having a defined nutritional profile.

[0036] Blending involves determining the relative amounts of each of the homogenized ingredients needed to produce an animal feed with a defined nutritional profile. An analysis of the nutritional properties of each ingredient can be entered into a computer system, for example, along with the desired resulting nutritional content of the animal feed. The computer system can then process this information and provide the exact proportions (typically on a volume basis) of each ingredient needed to produce the animal feed.

[0037] Any need to add micro ingredients to the blended homogenized ingredients can also be determined at this point.

[0038] The resulting animal feed is processed into any suitable form appropriate for its end use. For example, the process may further include processing the blended homogenized ingredients into an animal feed in the form of pellets, flakes, or mash.

[0039] The homogenized ingredients can be recycled back into each accumulated batch of macerated and dewatered food waste. For example, if only a small amount of a particular homogenized ingredient remains after an animal feed production run, it is more efficient to return it upstream in the process rather than storing it until it can be used in another animal feed that requires only a small amount of that ingredient. Returning homogenized ingredients to the appropriate pooled batches should not result in any significant variation in the nutritional properties of that batch (which is in fact the "average" of those batches).

[0040] Given the nature of food waste and the stringent requirements of animal feed, macerated and dehydrated food waste has also been subjected to biosecurity treatment. Biosecurity processes are described in more detail below.

[0041] The animal feed produced according to the present invention contains meat products and is therefore only suitable for feeding animals that are capable of eating animal feed that potentially contains meat. Animals that can eat such feed include most omnivores, such as chickens and ducks, game birds, such as pheasants, and crustaceans, such as crayfish.

[0042] While recycling of food waste is an important feature of the present invention, the inventors note that other edible materials can be incorporated into the process and doing so does not adversely affect the performance of the present invention. For example, products such as Maltings, Malt Combings, Hominy Meal or Mill Mix sold by Castlegate James may be used as co-blend materials as described below or to contribute in some other advantageous way to the invention. Other edible products, such as, for example, microingredients, may also be incorporated at appropriate stages of the process if it is advantageous to do so.

[0043] In its second aspect, there is provided a method for dehydrating macerated food waste (or, indeed, any moisture containing material). The method includes mixing a material having a moisture content different from the moisture content of the macerated food waste into the macerated food waste proximate an inlet of the dehydrator, wherein the added material and the macerated food waste are mixed such that the mixture fed to the dehydrator has a defined and substantially uniform moisture content.

[0044] As mentioned above, mixing ingredients (usually relatively dry ingredients) into the macerated food waste just before the resulting mixture is fed to the dehydrator ensures that the material presented to the dehydrator has not only a moisture content appropriate for the dehydrator, but also a relatively consistent moisture content throughout. Thus, the dehydrator can be operated to dehydrate the substance of the mixture, reducing the risk of heat damage to the material occurring.

[0045] As with other aspects of the present invention, the macerated and dehydrated food waste is sourced from one of multiple categorized producers of food waste and is always kept separate from other categories of food waste. Again, however, this need not be the case for all embodiments of the invention.

[0046] The method includes adding, adjacent an inlet of the dehydrator, into the macerated food waste, a material having a moisture content different than the moisture content of the macerated food waste. Typically, relatively dry ingredients are added to the relatively moist macerated food waste, although this need not be the case.

[0047] With the present invention in mind, any material may be added to the macerated food waste. For example, a stockpile of pre-dried material such as bread crumbs or spent brewer's grains is maintained for this purpose. Commercially available products, such as those sold by Castlegate James and described above, may also be used, albeit at additional cost. Alternatively, macerated and dried food waste is used from downstream of the process of the present invention, for example from a food waste producer in the same category as the macerated food waste going to the dehydrator.

[0048] The amount, relative moisture content, and mixing technique all affect the properties of the resulting mix going into the dehydrator. The amount of material added to the macerated food product can be adjusted, for example, to achieve a particular moisture content. Similarly, the rate at which ingredients are added to the macerated food product can be adjusted to achieve a particular moisture content.

[0049] The method also includes mixing the added ingredients and the macerated food waste such that the resulting mixture for feeding to the dehydrator has a defined and substantially uniform moisture content. Such mixing is accomplished using any conventional technique, preferably one that compresses the materials into a macerated food waste material, thus causing rapid moisture exchange between the relatively wet / dry materials. In the embodiment described herein, a screw auger is used to mix the added ingredients and the macerated food waste, although other devices can be used chilled to achieve a similar effect.

[0050] The defined moisture content (i.e., the moisture content of the mixture fed to the dehydrator) is about 5%-80%, about 20%-70%, about 30%-60%, more preferably about 50% (w / w).

[0051] Dehydration of the mixture can be accomplished using any commercially available dehydrator. Much of the inventor's testing has been carried out using a dehydrator sourced from AKT International, for example as described in International (PCT) Patent Application No. PCT / AU89 / 00475, the contents of which are incorporated herein in their entirety.

[0052] Typically, dewatering the mixture involves agitating the mixture in a current of hot air. Typically, the hot air has a temperature of about 350° C. and dehydration takes less than 10 seconds. Specific embodiments of the dewaterer are described in further detail below.

[0053] The method further includes measuring the moisture content of the dehydrated macerated food waste. Such measurements can advantageously provide feedback on the operating parameters of the dewaterer (eg, the temperature of the dewaterer, the feed rate of the material to the dewaterer, and the residence time of the material within the dewaterer). For example, if the moisture content of the dewatered granular powder exiting the dewaterer is deemed to be too high, the operating parameters of the dewaterer can be adjusted (preferably automatically by a computerized operating system controlling the process) to cause a greater amount of dewatering. Similarly, if the moisture content of the dewatered granular powder exiting the dewaterer is deemed to be too low, the operating parameters of the dewaterer can be adjusted to cause a lesser amount of dewatering.

[0054] The moisture content of the dewatered particulate material exiting the dehydrator is approximately 1% to 12%. Materials with a moisture content greater than 12% are highly susceptible to microbial growth during storage. Thus, the dewatered particulate material exiting the dewaterer has a moisture content of less than about 10% or about 8%. And materials having a moisture content below 8% are generally not susceptible to the growth of microbial growth during storage.

[0055] In a third aspect, there is provided an apparatus for dewatering macerated food waste (or, more generally, any moisture containing material). The apparatus comprises a hopper, the outlet of the hopper communicating with the inlet of the dehydrator; a moisture detector configured to detect a moisture content of a material proximate the outlet of the hopper; a conduit through which a material having a moisture content different from the moisture content of the macerated food waste can be added to the macerated food waste proximate the outlet of the hopper; and a mixer for mixing the material and the macerated food waste such that the resulting mixture is presented to the inlet of the dehydrator having a defined and substantially uniform moisture content.

[0056] The apparatus of the third aspect is configured to, but is not so limited to, carry out the method of the second aspect. And, the apparatus includes additional features that enable it to perform any and all of the embodiments of the method.

[0057] The assembly includes a hopper, the outlet of which communicates with the inlet of the dewaterer. Specific embodiments of the hopper and dewaterer are described in further detail below.

[0058] The apparatus also includes a moisture detector adjacent the hopper outlet / dehydrator inlet configured to detect the moisture content of the macerated food waste. Moisture detectors such as the MCT460 Online Smart NIR Sensor series produced by KPM Analytics are suitable for this purpose. The detector configured to detect moisture may also be configured to detect other properties of the material under analysis. Such characteristics include its fat and / or protein content. Moisture detectors which are more expensive but offer such enhanced functionality offer advantages in the performance of the present invention.

[0059] The apparatus also includes a conduit through which material having a moisture content different from that of the macerated food waste can be added to the macerated food waste proximate the outlet of the hopper. The conduit may be provided in any suitable form, such as a pipe that extends to the hopper with its outlet adjacent the outlet of the hopper.

[0060] The apparatus also includes a mixer for mixing the material and the macerated food waste such that the resulting mixture is presented to the inlet of the dehydrator having a defined and substantially uniform moisture content. Again, in view of the present invention, any device capable of providing this functionality may be used for such mixing. In the embodiments described below, for example, a screw auger is used to mix the macerated food waste and other materials as the macerated food waste is fed into the dehydrator. Those skilled in the art will recognize other suitable devices for this purpose.

[0061] The apparatus further comprises a second moisture detector configured to detect the moisture content of the dehydrated macerated food waste exiting the dehydrator. Similar to that described above in the second embodiment, the operating parameters of the dehydrator (e.g., temperature, material feed rate, and residence time) are adjusted based on the measured moisture content of the dehydrated macerated food waste exiting the dehydrator.

[0062] In a fourth aspect, there is provided a method for producing a dehydrated granular powder from macerated food waste (or indeed any other moisture containing material). The method involves dehydrating the macerated food waste to produce a dehydrated product (while still warm / hot) and then agitating the dehydrated product as it cools. In this way, agglomeration of the dehydrated product is prevented and a granular powder is produced.

[0063] This aspect has been found to prevent agglomeration of granular particles of food waste, which occurs when some categories of food waste cool after heating. Dehydrating the macerated food waste may be accomplished using any suitable technique, such as those disclosed herein (although it will be understood that the invention is not so limited).

[0064] After dehydration, the still warm dehydrated product is agitated as it cools to prevent clumping of the product from occurring. In an embodiment described in more detail below, the dewatered product is cooled in a screw auger and is constantly turned over by the screw as it moves through the (optionally cooled) sleeve. However, it will be appreciated that many other devices provide similar functionality.

[0065] The cooled, dehydrated granular powder has a particle size of about 1-3 mm.

[0066] The inventors note that agglomeration occurs in some dehydrated granular powders as they exit the dehydrator at a temperature of about 50-70° C. and begin to cool. However, this has been found to be more problematic in processes that also include a biosecurity step (described below), where higher temperatures and longer residence times are required.

[0067] The method of the fourth embodiment also includes a biosecurity treatment prior to the dehydrated granular powder cooling step. Biosecurity steps can be implemented at different stages of the overall process, but operational efficiencies are gained when the still-warm material is presented for biosecurity processing.

[0068] Food biosecurity is of paramount importance when food is sold to consumers, but there is little such regulation when it comes to food waste. However, when using food waste in the production of animal feed, it is essential that it is biologically safe, as many threats to animal welfare are present in unsafe feed. By way of example, such threats include African swine fever, Aujeszky's disease, and Brucella suis in pigs, arboviruses, avian adenoviruses, avian influenza in poultry, and foot and mouth disease in livestock.

[0069] Biosecurity heat treatment requires that the material be heated to a temperature and for a time effective to kill all pathogens (including all microorganisms such as bacteria and fungi) and all viruses. Biosecurity heating protocols are governed by regulations based on scientific evidence or empirical judgement, but all result in complete inactivation of pathogens. The inventors have found that heating the dehydrated granular powder of food waste for at least 30 minutes (e.g., 30-35 minutes) at a temperature of at least 100°C (this is the temperature experienced by the powder, not necessarily the chamber temperature) is effective in killing all potential microorganisms. Higher temperatures may be used, however, heating to such temperatures adversely affects the nutrient content of the resulting biosecure product.

[0070] Once the biosecure heat treatment has been carried out, the biosecure product is allowed to cool. Any relevant measurements, such as the weight of the biosecure product, are then taken at this point. Cooling occurs naturally due to exposure to ambient conditions or is controlled using a coolant (eg, a cooling sleeve on the auger, as described above). Cooling may take a suitable amount of time and occurs over a period of between about 3 and about 15 minutes.

[0071] The biosecurity treatment is carried out with any suitable equipment, such as a screw auger.

[0072] In a fifth aspect, there is provided a macerator assembly including a macerator having an inlet and an outlet. The inlet is connectable to the outlet of the storage vessel, and the macerator is movable between the multiple storage vessels.

[0073] Specific embodiments of the macerator assembly are described below. Generally speaking, however, the macerator assembly includes rails (or other moving devices, such as conveyor belts) along which the macerator can slide to align with the outlet of one of a number of storage vessels. The macerator assembly also includes a lifting assembly for lifting the macerator so that the outlet and inlet are coupled to one of the plurality of storage vessels.

[0074] A specific embodiment of a process for producing animal materials from multiple categorized food waste streams, incorporating various embodiments of aspects of the present invention, will now be described with reference to FIG.

[0075] FIG. 1 is a schematic / flow diagram of a process 10 in which starting material in the form of categorized food waste is processed to produce animal feed for sale in the market. The animal feed produced has a clearly defined nutrient content which is in line with customer requirements and can therefore command a high price. Furthermore, since the raw materials for this product are traditionally considered waste products, production costs are significantly lower than traditional animal feed production. Finally, the environmental benefits of using food waste to produce saleable products are significant.

[0076] In Figure 1, the following keys are used: JPEG2025510312000002.jpg40167

[0077] In a process 10, for example as described in PCT / AU2017 / 051130, the collected, stored and transported categorized food waste is delivered to a bank of categorized food waste bins 12. Bins 12A-12N are physically separated from one another and each receives the same category of food waste. As an example, bin 12A may be designated to receive waste from a bakery, bin 12B may be designated to receive waste from a butcher, and so on. As each successive delivery of recently collected food waste arrives, any bakery waste is added to bin 12A and any meat waste is added to bin 12B. As described in PCT / AU2017 / 051130, each of these categories of food waste has a similar nutritional composition.

[0078] Once each bin 12 reaches a predetermined capacity (or after a predetermined period of time, keeping in mind the potential for spoilage of the food waste), a macerator and pump assembly, generally shown as macerator 14, is used to macerate the food waste in each bin 12 and pump the macerated food waste via line 16 to a hopper (not shown) and subsequently to a dehydrator 20. The macerator 14 is positioned on a track 22 which enables it to move laterally beneath successive bins 12 . In use, the macerator 14 can be moved into position adjacent a respective bin (eg, bin 12A) and coupled to an outlet (not shown) of the bin. When the outlet of the bin 12 is opened, the food waste within the bin falls into the macerator 14 where it is macerated and then pumped to the dehydrator 20. The macerator 14 can, for example, be raised to a position where this bonding occurs, but can, of course, perform other movements to the same effect.

[0079] A stationary macerator 18 is also provided in communication with a designated bin (eg, bin 12H). The macerator 18 is specifically configured to macerate larger or harder food waste materials. For example, smaller macerators may not be able to engage and therefore macerate relatively large items such as whole cabbages or cauliflowers. Also, oyster shells or bones require a more robust macerator. Providing a dedicated macerator 18 for such relatively large food waste further improves the capacity of the process.

[0080] As each bin 12 is emptied, flushing occurs. A small amount of water can be sprayed into the bottle 12 to wash and effectively clean its walls. The wash water, which may contain any remaining food waste, enters the macerator 14 and is then pumped to the dehydrator 20.

[0081] The dehydrator 20 is then operated under conditions to dehydrate the macerated food waste presented thereto. In the dehydrator used by the inventors in the tests described in PCT / AU89 / 00475, hot air (approximately 350°C) is blown through a chamber into which macerated food waste is introduced. Rotating arms dependent on a central shaft strike the macerated food waste, further breaking it up and propelling it through hot air. After just 10 seconds, a granular powder forms in the drying chamber and is entrained in the air stream and carried out of the chamber. A cyclone separator (not shown) is then used to separate the granular particles from the hot air and moisture. The granular powder exits the cyclone airlock valve via dewaterer outlet line 24 and is further processed as described below.

[0082] In the process 10, two dewaterers 20A and 20B are depicted, one larger than the other, approximately 1.0 m 3 / hour (20B) instead of about 1.5m 3 / hour (20A) maximum output. Dewaterer 20A and dewaterer 20B can be operated independently, separately or together, as desired to maximize the overall efficiency of process 10.

[0083] The operation of dewaterer 20 (both dewaterer 20A and dewaterer 20B operate in the same manner) involves the monitoring of a number of parameters, many of which the inventors anticipate may be automated. One of these parameters is the moisture content of the macerated food waste fed to the dehydrator 20, which is ideally about 50%. Dehydration is more efficient if the material entering the dehydrator 20 has a relatively consistent moisture content, which is not necessarily the case for food waste. Therefore, to better control the moisture content of the macerated food waste presented to the dehydrator 20, the dry co-blending operation described below is used.

[0084] The dewatered food waste in line 24 is directed via line 28 to silo 30 for temporary storage. If ground food waste having too high a moisture content is presented to the dehydrator 20, a quantity of dewatered food waste from the silo 30 is transferred via line 34 and provided to a hopper (not shown), typically in the form of a flexi-screw auger (not shown), for blending with the ground food waste so that the resulting mixture entering the dehydrator 20 has an overall reduced moisture content and a relatively consistent moisture content.

[0085] The inventors also note that spent brewer's grain is a food waste that contains large amounts of nutrients and is problematic to dispose of. Such food waste does not need to be macerated and is therefore stored separately in silo 34 and fed to dehydrator 20 at an appropriate time (e.g., when there is no other food waste in the bin 12 being dewatered). The inventors note that dewatered spent brewer's grains is also a suitable dry co-blend material and may be used solely for this purpose. Another food waste that is useful as a co-blend material is bread crumbs. Other products used include those sold by Castlegate James and described above, both of which are stored in silos 30 / 34.

[0086] The dehydrated and ground food waste exiting the dehydrator 20 is further processed to ensure that it is biologically safe. Such processing is carried out in the assembly described below. Biosecurity heat treatment involves heating the dehydrated granular powder to a temperature and for a time effective to kill all pathogens (including all microorganisms such as bacteria and fungi) and all viruses. In this embodiment, the material is heated to a temperature of at least 100° C. (this is not necessarily the chamber temperature, but the temperature experienced by the product) for at least 30 minutes (eg, 30-35 minutes).

[0087] Heating occurs in a first screw auger (not shown), the inlet of which is configured to receive the dewatered product from line 24 . A heater about the auger shaft heats the material therein to a desired temperature, and the screw is rotated at a speed that controls the residence time of the material within the auger. At the end of the biosecurity process the biosecure granular powder is cooled and the inventors have found that this cooling should ideally be controlled to prevent agglomeration of the powder (this is a particular problem for food waste that is relatively high in fat or protein). The inventors have found that stirring the material whilst cooling prevents agglomeration from occurring and results in a granular powder which is relatively easy to handle in downstream processes (having a substantially uniform particle size and which can be moved using pneumatic conveying techniques). In these embodiments, a second screw auger (not shown) is used and the hot biosecure granular powder exiting the first auger falls directly into the second auger, initiating the cooling process. Cooling may occur naturally or may be caused by applied cooling (eg, on the sleeve of the auger). Again, the cooling time depends on the speed at which the auger screw rotates. The inventors have found that the constant rotating action of the screw provides sufficient agitation to prevent agglomeration.

[0088] The categorized, dewatered, ground, and biosecure food waste is then transported to an array of silos 26 (e.g., via pneumatic conveying, where all downstream steps in the process 10 are dry). Each silo (e.g., silo 26A) in the array of silos 26 holds a defined category of dewatered, ground, and biosecure food waste, and successive batches of similarly processed food waste of the same category (i.e., sourced from a producer of the same category of food waste, e.g., a bakery) are added to silo 26A. In this manner, a stratified mass of food waste is accumulated in each silo 26A, ready for further processing in the manner described below.

[0089] Each successive batch of properly categorized and processed food waste transferred to a particular silo (e.g., silo 26A) will have a similar nutritional profile, albeit with minor batch variations, because it comes from the same source. However, the nutritional profile of food waste accumulated in other silos (e.g., silo 26B), which are a different category of food waste and are sourced from a different category of food waste producer (e.g., a butcher), will be significantly different.

[0090] When the amount of material in any given silo 26 (e.g., silo 26A) reaches a certain level (e.g., as determined by the weight of the silo or a sensor within the silo), the contents of the silo are pneumatically conveyed to a batch mixer 36 where vigorous mixing occurs to thoroughly homogenize the material. The mixed material is then pneumatically conveyed to each silo in the array of silos 38 (e.g., silo 38A) where it defines the components or raw materials available for blending to produce animal feed. A physical sample (e.g., about 1 L of ingredient) is taken from one of the silos 38 (e.g., silo 38A) and analyzed for parameters such as its protein content, fat content, moisture content, specific gravity, and amino acid profile. Thus, the ingredient stored within each silo 38 is well characterized in terms of the qualities it adds to the animal ration.

[0091] Silo 38 therefore contains multiple homogenous ingredients, all with well-characterized nutritional profiles and similar physical morphology (ie, dry granular particles). These ingredients are readily available for blending together to produce the resulting animal feed. To that end, calculated proportions of the ingredients from the various silos 38 are pneumatically conveyed to a batch mixer 40 . If desired, the micro ingredient from silo 42 can also be added to the batch mixer at this point along with any other ingredients required. Although not shown, the micro ingredients are typically each stored in their own separate silo 42 for maximum blending opportunities.

[0092] The batch mixer 40 homogenizes the ingredients and any added micronutrients, thus producing an animal feed having the required specifications. The animal feed so produced is pneumatically conveyed to a storage silo 44 (if required) and then pneumatically conveyed to a packaging facility 46 . At this packaging facility 46 the animal feed is then pelleted and bagged (either in bulk or small (eg 20 kg) bags) as required. Alternatively, the animal feed is loaded into silos 48 for storage until it is then loaded onto trucks for transport off-site (eg, to a poultry farm requiring bulk feed).

[0093] This is what the inventors believe to be a major advantage of this aspect of the invention; the process uses only recycled food waste, with several components having significantly different nutritional profiles and available to be blended to produce a saleable product (e.g., animal feed). The inventors have not previously envisaged the potentially detrimental impact of batch variability between successive deliveries of the same category of food waste when used to generate animal feed, such as chicken feed, where any deviation from the precise nutritional profile is unacceptable. However, the homogenization, analysis, and blending processes described herein allow for the production of animal feeds with precise nutritional content on demand (as required for feeds such as chicken feed) to meet virtually any given requirement.

[0094] Process 10 also includes a recycle line 50 that can be used to recycle products within the process to any upstream stage of the process. For example, if only a small amount of an ingredient is in a particular silo 38 and that silo is needed for a new ingredient, the remaining ingredient may be pneumatically conveyed back to the appropriate silo 26, e.g., as a co-blend material, or even pneumatically conveyed back to the dewaterer 20.

[0095] It will be appreciated that the present invention provides new and useful advantages. For example, the present invention provides one or more of the following advantages: ● Less food waste is sent to landfills. • Saleable, high quality animal feed can be produced solely from the collected food waste, potentially at relatively low ongoing cost (i.e. due to a relatively cheap supply of food waste components). A wide variety of food wastes can be processed to result in ingredients with a wide variety of nutritional profiles, which can be blended to produce animal feed with virtually any nutritional profile. • The recycling line helps to utilise all the food waste in the process. • The environmental benefits of beneficially reusing food waste as ingredients for animal feed (that would otherwise be put to more beneficial use, such as human food), instead of requiring commercially sourced ingredients.

[0096] It will be apparent to those skilled in the art of the present invention that many modifications can be made without departing from the spirit and scope of the invention. All such modifications are intended to fall within the scope of the following claims.

[0097] In the following claims and the preceding description of the invention, unless otherwise required by express language or necessary implication, the term "comprise" or variations such as "comprises" or "comprising" are used in the inclusive sense, i.e., to specify the presence of the specified features, but not to preclude the presence or addition of further features.

[0098] Any prior art document referred to in this specification is not an admission that the document forms part of the common general knowledge in the art.

Claims

1. 1. A process for producing animal feed having a defined nutritional profile from food waste, comprising: storing successive batches of macerated and dehydrated food waste, each batch of said plurality of food waste being sourced from the same batch of a plurality of categorized producers of food waste and always maintained and stored separately from other batches of said plurality of food waste; independently mixing each of the accumulated batches of macerated and dehydrated food waste to produce a plurality of homogenized ingredients for animal feed; analyzing each of the homogenized ingredients to determine one or more nutritional parameters of the ingredient; and blending two or more of said homogenized ingredients to produce said animal feed having a defined nutritional profile.

2. 10. The process of claim 1, wherein the blending comprises determining the relative amounts of each of the homogenized ingredients needed to produce the animal feed having a defined nutritional profile.

3. 3. The process of claim 1 or claim 2, wherein the one or more nutritional parameters of the ingredients are independently selected from one or more of protein content, fat content, amino acid content, and specific gravity.

4. 4. The process of claim 1, wherein each of the accumulated batches of macerated and dewatered food waste is mixed when the volume of the accumulated batch reaches a predetermined threshold.

5. 5. The process of any one of claims 1 to 4, wherein one or more of the homogenized components are recyclable back into one or more of the respective accumulated batches of macerated and dewatered food waste.

6. A process according to any one of claims 1 to 5, wherein the macerated and dewatered food waste has been subjected to a biosecurity treatment.

7. The process according to any one of claims 1 to 6, wherein each of the categorized producers of food waste is selected from a restaurant, a cafe, a supermarket, a grocery store, a greengrocer, a delicatessen, a butcher, and a bakery.

8. 8. The process of any one of claims 1 to 7, further comprising processing the blended homogenized ingredients into an animal feed in the form of pellets, flakes, or mash.

9. The process of any one of claims 1 to 8, further comprising adding a micro ingredient to the homogenized ingredient.

10. 1. A method for dehydrating macerated food waste, comprising: mixing a material having a moisture content different from that of the macerated food waste proximate an inlet of a dehydrator into the macerated food waste, the added material and the macerated food waste being mixed such that the mixture at the inlet of the dehydrator has a defined and substantially uniform moisture content; and dehydrating the mixture.

11. 11. The method of claim 10, wherein the amount of material added to the macerated food waste is adjustable to achieve the defined moisture content.

12. 12. The method of claim 10 or claim 11, wherein the rate at which the material is added to the macerated food waste is adjustable to achieve the defined moisture content.

13. A method according to any one of claims 10 to 12, wherein mixing comprises pressing the material and the macerated food waste together.

14. A method according to any one of claims 10 to 13, wherein a screw auger mixes the added material and the macerated food waste.

15. The method according to any one of claims 10 to 14, wherein the defined moisture content is about 50% (w / w).

16. A method according to any one of claims 10 to 15, wherein dewatering the mixture comprises agitating the mixture in a current of hot air.

17. 17. The method of claim 16, wherein the hot air has a temperature of about 350°C and the dehydration takes less than 10 seconds.

18. The method of any one of claims 10 to 17, further comprising measuring the moisture content of the dewatered mixture.

19. 20. The method of claim 18, wherein operating parameters of the dewaterer are adjustable based on the measured moisture content of the dewatered mixture.

20. 20. The method of claim 19, wherein the operating parameters are selected from one or more of the following: temperature of the dewaterer, feed rate to the dewaterer, and residence time in the dewaterer.

21. 21. The mixture of any one of claims 18 to 20, wherein the moisture content of the dehydrated mixture is from about 1 to about 12%.

22. A method according to any one of claims 10 to 21, wherein the macerated food waste is sourced from one of a number of categorized producers of food waste.

23. A mixture according to any one of claims 10 to 22, wherein relatively dry material is added to relatively wet macerated food waste.

24. 1. An apparatus for dewatering macerated food waste, comprising: a hopper, the outlet of which is connected to the inlet of a dehydrator; a moisture detector proximate the outlet of the hopper and configured to detect a moisture content; a conduit through which a material having a moisture content different from that of the macerated food waste may be added to the macerated food waste proximate the outlet of the hopper; and a mixer for mixing the material and the macerated food waste such that a resulting mixture is presented to an inlet of the dehydrator having a defined and substantially uniform moisture content.

25. 25. The assembly of claim 24, comprising a screw auger for mixing the material and the macerated food waste and feeding the resulting mixture to the dehydrator.

26. 26. The assembly of claim 24 or claim 25, further comprising a second moisture detector configured to detect the moisture content of dehydrated macerated food waste exiting the dehydrator.

27. 1. A method for producing a dehydrated granular powder from macerated food waste, comprising: dehydrating the macerated food waste to produce a dehydrated product; agitating the dehydrated product as it cools, thereby preventing agglomeration and producing the dehydrated granular powder.

28. 28. The method of claim 27, wherein the dehydrated product is cooled for a period of about 3 to about 15 minutes.

29. 29. The method of claim 27 or claim 28, wherein the cooled dehydrated granular powder has a particle size of about 1-3 mm.

30. A method according to any one of claims 27 to 29, wherein the dewatered product is cooled in a screw auger.

31. 31. The method of any one of claims 27 to 30, further comprising biosecurity treatment of the dehydrated product prior to cooling.

32. 32. The method of claim 31 , wherein the biosecurity treatment comprises maintaining the dehydrated product at a temperature of at least 100° C. for at least 30 minutes.

33. 33. The method of claim 31 or claim 32, wherein the biosecurity treatment is carried out in a screw auger.

34. A method according to any one of claims 27 to 33, wherein the macerated food waste is sourced from one of a number of categorized producers of food waste.

35. 1. A macerator assembly comprising: a macerator having an inlet and an outlet; the inlet is connectable to an outlet of a storage vessel; A macerator assembly, wherein the macerator is movable between a plurality of storage vessels.

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