What’s it all about?
The MHT process produces a range of sustainable fuels from materials that have traditionally been sent to landfill. These alternative fuels can be used to produce renewable electricity, green heat and sustainable road transport fuels. This helps to decarbonise the environment by reducing our dependence on coal, crude oil and natural gas.
The MHT process treats heavily contaminated waste which generally has a high organic content, such as food, away from landfill into alternative fuels. The process revolves around four distinct phases:
- Waste Feed Preparation. General Waste to the required specification is tipped from collection vehicles into the reception hall, inspected and bulky items removed. Waste is loaded into a rotating screen (trommel) and separated into -150mm and +150mm streams. The +150mm then passes to a shredder. Both streams are then conveyed to a mixing (homogeneous) stockpile ready for the next stage.
- The Process. The mixed waste is ram fed continuously into the rotating wet preparation drum where it is agitated, conditioned and moisture added and evenly distributed. The waste is then ram fed into the patented Orchid Processor (a rotary hot air dryer). This further agitates the moist waste and a steamy environment is generated which sanitises all materials including metals, plastics, glass and rubble. The cellulose fibres from paper, cardboard, food and green waste ('organics') are transformed into a fibrous unrefined biomass fuel - intermixed with the other products.
- Post Treatment Separation. Having been screened into two size fractions, +50mm and -50mm, both streams are now subject to a whole series of mechanical and physical separation processes resulting in distinct products - ferrous metals, non-ferrous metals, mixed plastics - sent to reprocessors in addition to a small amount of residual unrefined fuel. Plastic film and large card recovered is granulated and eventually blended in with the fuel. The unrefined fuel, together with glass and stones/fines is then passed to stage four.
- Biomass Density Separator. The unrefined fuel from stage three which contains plastics fragments, broken glass and stones/rubble is then subjected to a patented separation and blending process to take out impurities and take out or leave in/add more plastic to meet the specific needs of combustion processes such as co-firing in power station boilers, fluidised bed boilers, gasification, pyrolysis, and cement kilns.
The Good Stuff
- Full recycling of heavily contaminated waste including organics (food, semi solids, meat (cooked), jars and cans of food stuffs. This is a Landfill free solution.
- Types of waste streams accepted for MHT: Paper, cardboard, plastics, food (loose and in jars or cans), dairy products, clothing
Not so Good
- Treatment in line with current landfill disposal rates. Limited nationwide coverage until new plants become available.
- Materials not accepted as MHT: Wooden or plastic pallets, banding tape, liquids, chemicals or hazardous waste.
Top Tips
- Recycle as much as possible before producing waste for the MHT process.
- Check if your service provider offers onsite training to assist staff in understanding what waste can be included
FAQs
Q. Can I recycle raw meat and fish in the MHT process?
A. At this present time raw meat and fish must be treated via approved ABP routes
Q. How sustainable is MHT?
A. MHT is a proven process similar to autoclave and will become the forefront for the treatment and recycling of contaminated organic bound waste streams.
Q. What products are made from the MHT process?
A. A bio fuel pellet is produced as well as recovering glass, plastics and metal cans from the input waste. Nothing is wasted.
Q. Does the MHT process produce toxic fumes?
A. No, only hot air (steam) is used to sanitise the waste. Any emissions are strictly controlled using state of the art cleaning filters that results in only steam reaching the atmosphere.
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