The present invention relates to an apparatus and method for processing food waste, and in particular relates to an apparatus and method for processing Category 1 International Catering Waste.

There are many issues surrounding waste, such as catering wastes generated within the aviation sector, and with the recycling thereof. In particular, food waste from catering on aircrafts is particularly difficult and costly to deal with. Where the products, and/or waste thereof, have travelled into or through certain geographical areas, for example leaving and/or returning to European Union (EU) airspace, the waste may be classed as unsuitable for standard recycling for a number of reasons including potential contamination and/or other risks. In the EU, such waste is classed as International Catering Waste, or Category 1 ICW, and is strictly regulated by EU regulations that are enforced across Europe, such as in the UK by the Animal By-product Regulations, which impose stringent restrictions on how such waste can be dealt with. Where any Category 1 ICW is present in any container, the whole container is considered contaminated and so the entire contents of the container and the container itself must be processed as Category 1 ICW. Further to this, it is extremely difficult to distinguish between waste from EU and non-EU flights in most airports once it has been off-loaded by the cleaning companies, and therefore the restrictions on Category 1 ICW tend to be applied to all of the food waste acquired by the relevant airport for ease of processing. The waste can also contaminate potentially recyclable products, such as bottles, waste bags/boxes and/or other food containers, which then must also be processed in accordance with the same stringent requirements.

The Regulations require that the Category 1 ICW be destroyed by incineration or disposed directly into authorised landfill sites. In principle the Regulations could allow for Category 1 ICW to be used as a fuel for combustion, although formal Rules have not yet been formulated and this is therefore not yet carried out.

There are numerous problems with these current processes. Incineration requires a huge input of heat energy to simply burn the food waste away, making it both a costly process and an environmentally harmful process as greenhouse gases and toxins are released into the air. Even more energy and cost is required when the waste is damp or wet. With both incineration and landfill disposal, the food waste requires transportation to the appropriate site. Whilst in transit, particularly for Category 1 ICW, any leakages or spillages of the waste, and/or animals including vermin coming into contact with the waste, poses a risk for the spread of bacteria and infection. The risk from animals is also apparent whilst the waste is stored on the appropriate site waiting for processing. Particularly in hot countries, storing such waste prior to and during processing can also be problematic as the waste produces gases and lingering foul odours amongst other things.

Further to this, incinerating the waste or disposing of it in landfill is wasteful of the potential energy in the food waste. Food waste, including Category 1 ICW, can be used as a combustion fuel to generate energy. Since so much other food waste is also classified as Category 1 ICW due to any potential cross-contamination, for example in airports as discussed above, this also increases the amount of food waste not being used efficiently. Clearly if more of the food waste could be used as a combustion fuel, recycling the energy in this way would be far more energy efficient and environmentally friendly.

It is an object of embodiments of the present invention to address all or some of the above problems.

According to a first aspect of the present invention there is provided a method for processing food waste, comprising the steps of:

(i) feeding food waste into a vessel;

(ii) heating the food waste in the vessel to form dried solid materials and fluid;

(iii) condensing the fluid to form a liquid; and

(iv) treating the liquid under pre-determined conditions.

This method provides an effective way of producing dried solid material which can be used as a combustion fuel to generate energy and ensures that the resulting liquid obtained can be re-used or disposed of in a convenient manner, potentially even when the input food waste is classed as Category 1 , or Category 1 ICW, and so the strict EU Regulations apply. The method is simple to carry out, not necessitating much equipment, and can be easily performed on site. The method, therefore, reduces the need for transporting the potentially bacteria-ridden food waste between sites for processing, to either an approved landfill site or site for incineration. This helps reduce the chances of bacteria spreading during transportation and also reduces the levels of harmful gases released from the transporting vehicles. The method reduces the need for landfill sites and sites for incineration to be used, again reducing the harmful effects these can have on the environment. The method preferably also generates enough energy to keep the system working self-sufficiently, as well as surplus energy for re-use elsewhere, such as on site. This may be further advantageous as, for example, in the UK the Government's Renewable Heat Incentive (RHI) grants could be provided to companies for inputting such systems on site. The method also more efficiently uses the material in the food waste since the moisture removed from the food waste can be re-used as well as the dried components.

The method may also help reduce costs, by saving energy costs and also preventing the need to landfill or incinerate unprocessed and potentially wet food waste. Typically, food waste costs approximately £150 per tonne for disposal to an incineration or suitable land fill facility. In comparison, the energy required to start and/or potentially help maintain this process typically costs approximately £15 / tonne, and so this process is substantially cheaper. For each tonne of waste processed, approximately 300kg of highly calorific fuel (5kW/kg) is produced. Further to this, once the waste has been converted into a biomass fuel, the RHI can typically be claimed for such apparatus up to a cost of approximately 5 pence per kW/hour, meaning owners of such apparatus are potentially eligible for access into the scheme.

The food waste may comprise organic food waste. The food waste may comprise Category 1 waste, as categorised by the Animal By-Products Regulations. The food waste may comprise Category 1 International Catering Waste. The processing may remove and/or destroy substantially all of the bacteria from the food waste. By substantially all of the bacteria, it is meant that at least 95%, preferably at least 98%, preferably at least 99% of the bacteria in the untreated food waste is removed and/or destroyed. This means that the food waste and resulting dried solid, or biomass, material and liquid may be re-usable and/or recyclable in accordance with EU Regulations. The step of treating the liquid under pre-determined conditions may remove and/or destroy substantially all of the bacteria in the food waste.

The step of heating the food waste may comprise applying heat using a heat source comprising at least one of hot water, hot gases, thermal oil, electricity, gas and steam, or any combination thereof.

The dried solid materials may comprise biomass. Biomass is a combustive fuel and so may be used to generate energy.

The step of condensing the fluid may comprise condensing the fluid in a condenser and/or feeding the fluid through one or more pipes having a temperature suitable for condensing the fluid. This may mean that the fluid can be condensed in transit between where the food waste is heated and where the resultant liquid is then treated.

The step of treating the liquid may comprise storing the liquid for a pre-determined time period at a pre-determined temperature. The pre-determined temperature may be at least approximately 50 °C. The pre-determined temperature may be between approximately 50 and 100°C. The pre-determined temperature may be between approximately 50 and Τδ .ΤΙιβ pre-determined temperature may be between approximately 50 and 60 °C. The pre-determined time period may be at least 20 minutes. The pre-determined time period may be between approximately 20 and 120 minutes. The pre-determined time period may be between approximately 20 and 70 minutes. The pre-determined time period may be approximately 70 minutes. The higher temperatures may allow for shorter durations to be used. The shorter durations may be between approximately 20 and 60 minutes. The pre-determined temperature may be approximately 120^ and the pre-determined time period may be approximately 50 minutes. These conditions are sufficient to allow the liquid to be re-used or disposed of according to the standards and restrictions put on Category 1 ICW by EU Regulations; treatment under these conditions is sufficient to ensure that substantially no bacteria remains in the condensed material, even the bacteria dominant in causing African Swine Fever.

The step of treating the liquid may comprise treating the liquid under pressure. The pressure may be between approximately 1 bar (100,000 Pa) and 5 bar (500,000 Pa), preferably between approximately 2 bar (200,000 Pa) and 4 bar (400,000 Pa), preferably approximately 3 bar (300,000 Pa). The pressure may be at least approximately 3 bar (300,000 Pa), so at least approximately 2 bar (200,000 Pa) above normal atmospheric pressure. This may require the liquid to be stored at a higher predetermined temperature, but it may also allow the liquid to be stored for a shorter predetermined time period. The pre-determined temperature may be between approximately 100°C and 150 ^< €, preferably between approximately 1 10°C and 140 ^< €, preferably between approximately 125^ and 135^. The pre-determined time period may be approximately 20 minutes. The pre-determined time period may be at least approximately 20 minutes. The pre-determined time period may be between 20 and 30 minutes. The step of treating the liquid may comprise storing the liquid at a pressure of approximately 3 bar (300,000 Pa) at a pre-determined temperature of approximately 130°C, preferably approximately ~\ 33 °C, for approximately 20 minutes. These conditions are sufficient to allow the liquid to be re-used or disposed of according to the standards and restrictions put on Category 1 ICW by EU Regulations; treatment under these conditions is sufficient to ensure that substantially no bacteria remains in the condensed material, even the bacteria dominant in causing African Swine Fever.

The step of treating the liquid may comprise treating the liquid under vacuum. This may allow the liquid to be stored at a lower pre-determined temperature. The predetermined temperature may be between approximately 50 °C and 70 °C. A lower predetermined temperature may be beneficial. These conditions are sufficient to allow the liquid to be re-used or disposed of according to the standards and restrictions put on Category 1 ICW by EU Regulations; treatment under these conditions is sufficient to ensure that substantially no bacteria remains in the condensed material, even the bacteria dominant in causing African Swine Fever.

The step of treating the liquid may comprise storing the liquid for a pre-determined time period under pre-determined pH conditions. The method may further comprise the step of adjusting the pH of the liquid to satisfy the pre-determined pH conditions. The pH of the liquid during storage may be between approximately 10 and 14. The pH of the liquid during storage may be greater than approximately 1 1 .5. The pre-determined time period may be at least 20 minutes. The pre-determined time period may be between approximately 20 and 120 minutes. The pre-determined time period may be between approximately 20 and 70 minutes. The pre-determined time period may be approximately 70 minutes. Shorter time periods may be used for higher pH values. The shorter durations may be between approximately 20 and 60 minutes. A time period of approximately 60 minutes may be used for a pH of approximately 12. The pH of the liquid during storage may be reduced to make the conditions more acidic. The pH of the liquid during storage may be between approximately 1 and 5. The pH of the liquid during storage may be between approximately 2 and 4. The pH of the liquid during storage may be approximately 3. The pH of the liquid during storage may be approximately 4. The pH of the liquid during storage may be less than 4. A time period of approximately 60 minutes may be used for a pH of approximately 4. These conditions are sufficient to allow the liquid to be re-used or disposed of according to the standards and restrictions put on Category 1 ICW by EU Regulations; treatment under these conditions is sufficient to ensure that substantially no bacteria remains in the condensed material, even the bacteria dominant in causing African Swine Fever.

The step of treating the liquid may comprise exposing the liquid to at least one of UV radiation and/or ozone. Any or all of these conditions may be sufficient to ensure all bacteria have been removed from the food waste according to EU Regulations. These conditions may ensure, for example, that the bacteria for causing African Swine Fever (ASF) are not present, the bacteria causing ASF potentially being classed as one of the most difficult to destroy. This may make the method suitable for processing Category 1 ICW in accordance with EU Regulations and Article 12 of the Animal By-product Regulations. This may make the resulting products re-usable and/or recyclable according to EU Regulations. The treated liquid may still go on to be incinerated.

The method may further comprise the steps of:

(v) burning the solid materials to generate energy; and

(vi) using at least a portion of the generated energy to heat the food waste in step (ii). The energy may preferably be in the form of heat.

Step (v) may be used to generate energy, for use on site or otherwise. This may mean that the material can be burnt, or combusted, on site to produce energy for use on site or otherwise. This may reduce the need for transportation of food waste and/or may reduce energy bills on site. Furthermore, step (vi) may allow for the method to be self- sufficient and fuel itself, in that the energy generated by the method is over and above that which the method uses, the generated energy keeping the method of processing the food waste going, and also producing surplus energy for additional uses.

The step of burning the solid materials may involve combusting the solid materials in a biomass boiler and/or in a biomass gasification process.

The portion of generated energy consumed according to step (vi) may be between approximately 10 and 100% of the entire energy generated according to step (v). It may be between approximately 10 and 90% of the entire energy generated. It may be between approximately 30 and 70% of the entire energy generated. It may be between approximately 30 and 50% of the entire energy generated. It may be approximately 50% of the entire energy generated. The percentage of the entire generated energy consumed may depend on the type of waste being processed. The percentage of generated energy consumed may be such that there is plenty of extra energy generated for use elsewhere.

The method may further comprise the step of filtering the solid materials between steps (v) and (vi). This may help to ensure that there are no larger and/or unprocessed particles of waste in the food waste. This may help ensure that the combustion process runs smoothly and efficiently. The step of filtering the solid materials may comprise filtering the solid materials with a screening or sieving process.

The method may be entirely or partially automated. This may reduce the need for user intervention.

According to another aspect of the present invention, there is provided an apparatus comprising a dryer, means for condensing a fluid and means for treating a liquid, the apparatus for carrying out the method according to the first aspect of the present invention. The apparatus may further comprise a burner for carrying out a method according to the first aspect of the present invention.

According to another aspect of the present invention there is provided an apparatus for processing food waste, comprising: a dryer for heating the food waste to produce dry solid components and fluid components; a condensing means for receiving and condensing the fluid components to form a liquid; and a treatment means for receiving the liquid and treating the liquid under pre-determined conditions.

The apparatus may have any one or more of the same advantages as discussed above for the method of the first aspect of the present invention.

The apparatus may comprise a shredder. The food waste may be shredded before being fed into the dryer. This may help ensure that all of the food waste can be more easily broken down and/or dried out in the dryer. This may help to produce a biomass material that is more easily and efficiently combusted.

The food waste may comprise organic food waste. The food waste may comprise Category 1 ICW. The processing may remove and/or destroy substantially all of the bacteria from the food waste. This means that the food waste and resulting biomass material and liquid may be re-usable and/or recyclable in accordance with EU Regulations. The treatment means may remove and/or destroy substantially all of the bacteria in the food waste. The entire apparatus may be of a reasonable size such that the apparatus could be stored on site by companies or otherwise.

The dried solid materials may comprise biomass. Biomass is a combustive fuel and so may be used to generate energy. The dryer may comprise a fuel source comprising at least one of hot water, hot gases, thermal oil, electricity, gas and steam, or any combination thereof.

The condensing means may comprise a condenser and/or one or more pipes having a temperature suitable for condensing the fluid. The condensing means may condense the fluid in transit between the dryer and the treatment means. This may mean that the fluid could be condensed in transit between where the food waste is heated and where the resultant liquid is then treated

The treatment means may comprise a vessel. The treatment means may be programmable to keep the liquid at a set temperature and/or pH. The liquid may comprise condensed water. The liquid may consist substantially of condensed water.

The apparatus may further comprise: a burner for receiving the solid materials and combusting the solid materials to produce energy; and means for transporting the generated energy back to the dryer to heat the food waste. The burner may be a biomass boiler. The means for transporting the generated energy back to the dryer may comprise pipes.

Between approximately 10 and 100% of the entire energy generated by the burner may be transported back to the dryer. It may be between approximately 10% and 90% of the entire energy generated. It may be between approximately 30% and 70% of the entire energy generated. It may be between approximately 30% and 50% of the entire energy generated. It may be approximately 50% of the entire energy generated. The percentage of generated energy transported back to the dryer may depend on the type of waste being processed. The percentage of generated energy transported back to the dryer may be such that there is plenty of extra energy generated for use elsewhere. The apparatus may further comprise means for storing the remaining generated energy for use. The energy may be used elsewhere on site.

Gas may be produced during use of the biomass boiler and this may be extracted and/or passed through a filter prior to emission to the atmosphere. The filter may comprise ceramic. Filtration of the exhaust gases may be required depending on the types of fuel being combusted.

The apparatus may further comprise filtering means for filtering the solid components before they pass into the burner. The filtering means may comprise a screen or sieving process. The screen may be a vibratory screen. This may help to ensure that there are no larger and/or unprocessed bits of waste in the food waste. This may help to ensure that the combustion process runs smoothly and efficiently.

Discharge augers and/or conveyors may be used to transport the waste and/or dried solid materials between any parts of the apparatus. This may reduce the need for user intervention.

According to an alternative aspect, there is provided a method for processing waste; comprising the steps of:

(v) feeding waste into a vessel;

(vi) heating the waste in the vessel to form dried solid materials and fluid;

(vii) condensing the fluid to form a liquid; and

(viii) treating the liquid under pre-determined conditions.

In another aspect, there is provided an apparatus for processing waste comprising a dryer, means for condensing a fluid and means for treating a liquid, the apparatus for carrying out the method according to this alternative aspect.

Food waste and/or waste as referred to in any of the above aspects may comprise packaging, containers, bags or any other objects or articles associated with the food waste or waste. The food waste and/or waste may comprise wet contaminated plastics for example.

In relation to all of the above described aspects of the present invention, it is envisioned that any preferred features can be used in combination with any other aspect, except where it would specifically conflict with the disclosure to do so. Therefore aspects of the present invention are combinable as appropriate.

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

Fig. 1 shows a method according to an embodiment of the present invention;

Fig. 2 shows an apparatus according to an embodiment of the present invention;

Fig. 3 shows an apparatus according to an embodiment of the present invention;

Fig. 4 shows an apparatus according to an embodiment of the present invention.

Referring to figure 1 , there is a method for processing food waste, in particular for processing Category 1 ICW and/or for removing substantially all of the bacteria from the food waste for onward use and/or processing. The food waste may first be shredded to break the waste down into smaller pieces. The food waste is collected in a dryer. Heat is applied to the food waste in the dryer using a fuel source such as thermal oil, although the fuel source could also be gas, electricity and/or steam. Heating the food waste causes any moisture from the food waste to evaporate out forming a fluid component, which is mostly gaseous. The combination of removing the moisture from and heating the food waste causes a dried biomass material to form. The gaseous components and dried biomass material are then further processed separately.

The gaseous components are extracted and condensed by allowing the gas to escape through cooling pipes attached to the dryer. The pipes are cool enough to condense the fluid and so the gaseous components condense on travelling through the pipes and the resulting condensed liquid is directed into a vessel. The vessel is programmable to keep the interior and contents at a set temperature and/or set pH, and so the relevant pre-determined conditions are then set. The condensed liquid is then stored in the vessel at between 60 °C and 70 °C for at least 70 minutes, and/or it is kept at a pH of approximately 1 1 .5 for approximately 70 minutes. These conditions are sufficient to allow the liquid to be re-used or disposed of according to the standards and restrictions put on Category 1 ICW by EU Regulations; storage under these conditions is sufficient to ensure that substantially no bacteria remains in the condensed material, even the bacteria dominant in causing African Swine Fever.

In some embodiments, the dried biomass material is extracted from the dryer via a discharge auger and then passed through a vibratory filter screen to remove any larger pieces of waste, such as pieces of packaging or otherwise. The filtered, or unfiltered, material is fed into a biomass boiler and incinerated to produce heat energy. Approximately half of this heat energy is re-used to heat the dryer in a continuous cycle. The system is self-sufficient in this way as the generated energy is re-used as input energy for the system. The remaining energy, approximately half of that heat energy generated, can be used on site as an energy source to generate electricity or otherwise. Gas can also be extracted or filtered off from the biomass boiler and passed through a ceramic filter or otherwise for onward processing and/or use.

Referring to figures 2 and 3, there is an apparatus for processing food waste, in particular for processing Category 1 ICW and/or for removing substantially all of the bacteria from the food waste for onward use and/or processing. In some embodiments, the apparatus comprises a hopper and shredder, and the food waste may be held in the hopper and then passed through the shredder to shred the food waste. In some embodiments, the apparatus comprises one or more auger conveyors for transporting the food waste between parts. The apparatus comprises a dryer for holding and heating the food waste, after being shredded or otherwise. Heat is applied to the dryer using a heat source which comprises one or more of thermal oil, electricity, gas and steam. Heating the food waste in the dryer causes the moisture to evaporate out forming a fluid, mostly gaseous, component and leaves dry solid components remaining. In this way, the dryer separates out the solid and fluid components.

The apparatus also comprises a condensing means for receiving and condensing the fluid components to form a liquid. In some embodiments, the condensing means comprises one or more cooling pipes having a temperature suitable for condensing the fluid to form a liquid, the pipes transporting the fluid components from the dryer to a treatment means. In some embodiments, the treatment means is a large storage vessel, which is programmable to achieve required pre-determined temperature and/or pH conditions or otherwise. The storage vessel receives the condensed liquid and the liquid is held for approximately 70 minutes or more at a temperature of between 60 °C and 70 °C. These conditions are sufficient to allow the liquid to be re-used according to the standards and restrictions put on Category 1 ICW by EU Regulations; storage under these conditions is sufficient to ensure that substantially no bacteria remains in the condensed material, even the bacteria dominant in causing African Swine Fever.

In some embodiments, the apparatus also comprises a vibratory screen. On extraction of the dry solid components from the dryer, the components are passed through the vibratory screen as it is vibrated to remove any larger and/or unprocessed parts of the food waste. The filtered dried components, or biomass, are then passed into a biomass boiler for incineration. Incinerating the biomass generates energy. Approximately half of the heat energy generated is then passed back into the dryer and used to heat the initial food waste in a cyclic process. The other half of the generated energy is stored for use in other operations and/or elsewhere on site. Additionally, gas may be produced during use of the biomass boiler and this may be extracted, and may be passed through a ceramic filter prior to emission to the atmosphere.

Referring to figure 4, in an embodiment of the present invention, a bin containing food waste is lifted by a bin lift and emptied into a dryer. The dryer holds the food waste and when the dryer contains a pre-determined quantity of food waste, the dryer is used to heat the food waste. Heat is applied to the dryer using a fuel source which comprises one or more of thermal oil, electricity, gas and steam. Heating the food waste in the dryer causes the moisture to evaporate out forming a fluid, mostly gaseous, component and leaves dry solid components remaining. In this way, the dryer separates out the solid and fluid components.

The fluid components are extracted from the dryer, passed through a condensing means and into a treatment means, according to any or all of the above described embodiments.

A discharge auger extracts the dry solid components, or biomass, from the dryer and filters the components by passing them through a vibratory screen. Once filtered, another discharge auger carries the biomass into a biomass hopper for holding there. Another auger transports the biomass into a biomass boiler where the biomass is incinerated. Incinerating the biomass produces heat energy, a fluid component, comprising smoke, and there may be ash/debris left behind. The ash/debris can be removed after each use or after two or more uses of the biomass boiler. The fluid component is passed through an exhaust gas filter before exiting the system through a flue stack. The heat energy generated by incineration of the biomass is transported to and stored in a thermal store. This heat energy can be transported to other components and used to heat the food waste in the dryer and/or the biomass in the boiler and/or it can be used elsewhere on site. In this respect the system and method can be made self sufficient.

The above embodiments are described by way of example only. Many variations are possible without departing from the scope of the invention as defined in the appended claims.