Food waste is currently managed through a range of systems. Larger scale municipal methods include: council food waste collection and composting using ‘in-vessel’ composting, ‘open windrow’ composting, or ‘anaerobic digestion’. A variety of popular smaller-scale domestic composting methods have been developed also. Each method has its advantages and disadvantages depending on where you want to compost, how much space you have available, the amount of compost you would like to make, the cost of buying or making the composter, and the time you have available to maintain or harvest your compost.

Industrial-Scale Composting

Open windrow composting is used for processing garden waste (such as grass cuttings, pruning, and leaves) in either an open-air environment or within large covered areas where the material can break down in the presence of oxygen.

Size
 
Open windrow composting is large-scale and needs lots of space for storing and processing waste.
 
Process
 
Feedstock is shredded, mixed, and formed into windrows (long lines) along a non-permeable surface.
Windrows are turned on a regular basis to regulate their oxygen, heat, and moisture content.
The final step involves the screening of the compost and removal of contaminants such as plastics or metals, as well as grading the compost for various end uses. Oversized materials are also removed and fed back into the composter until they have sufficiently composted.
 
Suitability for processing biodegradable or compostable plastics
 
It is not yet known whether biodegradable and compostable plastics can degrade in open windrow composting.
Types of waste processed
 
Windrow composting is only suitable for garden waste. It cannot be used to process organic materials, which include catering and animal wastes. Under Animal By-Products Regulations (ABPR), any organic waste, including catering and animal waste, must be processed using in-vessel composting or anearobic digestion (AD).
 

Advantages

Open windrow composting can process large volumes of green or garden waste.

Processing Time
 
The whole process takes approximately 12–20 weeks.
 
Types of waste processed
 
Can process council food waste collections, either separately or mixed with garden waste, as well as commercial and industrial sources.
 
Advantages
 
  • Can process a large volume of mixed organic waste.
  • The processing of all animal by-products, including municipal kitchen waste, must comply with the ABPR (Animal By-Products Regulations, introduced in 2003).
In-Vessel Composting
 
Industrial in-vessel composting (IVC) describes a large-scale process of composting food waste using vessels or containers. This system ensures that composting takes place in an enclosed and controlled environment to ensure that any pathogens present in the waste material are destroyed. This technique is commonly used to convert organic waste, including food and garden waste mixtures, to a suitable state for use as a soil conditioner.
 
Process
 
Stage 1 (1–3 weeks): The local authority food waste collection arrives at an enclosed reception area. It is then shredded and placed into a bay/tunnel were naturally occurring micro-organisms begin to break down the food waste, releasing nutrients and, in doing so, increasing the temperature within the composter to the 60–70℃ needed to kill pathogens and weed seeds, and meet the regulations for processing Animal Bi-Product (ABP) material.
 
Stage 2 (1–3 weeks): The composting material is transferred to a second bay/tunnel where the composting process continues. Processing in three stages ensures that all parts of the composting mass reach the required temperature. The oxygen level, moisture, and temperature are carefully monitored and controlled during both composting stages to ensure the material is fully sanitized.
 
Stage 3 (10–14 weeks): Once the sanitization process is complete, the compost is left to mature in either an enclosure or an open windrow to fully mature.
Anaerobic Digestion
 
Anaerobic digestion (AD) is the process whereby organic matter, including food waste, animal waste, and sewage sludge, is broken down in the presence of microorganisms to produce biogas and digestate fertiliser. This process happens in the absence of oxygen in a sealed, oxygen-free tank called an anaerobic digestor.
 
Size
 
AD composters vary in size; industrial-scale composters require significant machinery and storage space.
 
Process
 
  • Organic waste arrives at an anearobic digestor facility and is screened for contaminants. A wide range of organic waste can be processed, including food and green waste, animal slurries, and sewage.
  • The organic waste it then treated to ensure a smooth fluid consistency in preparation for transfer to a digestion unit. Digestion units run at either mesophilic (around 20–45℃) or thermophilic (around 50–60℃) temperature ranges depending on the type of microorganisms present.
  • Once in the digestion unit, the organic waste undergoes several processes of decomposition, including hydrolysis, acidogenesis, acetogenesis, and methanogenesis. The resulting by-products are methane biogas, which can be supplied to the grid or converted to biofuel, and a concentrated nutrient-rich fertiliser called digestate.
Processing time
 
The whole process takes approximately 2–6 weeks depending on the system temperature.
 
Types of waste processed
 
A wide range of food waste, green waste, animal slurry, and sewage can be processed owing to the controlled closed-system environment of anaerobic digestion.
 
Advantages
  • AD can process a wide range of organic material.
  • Biogas and digestate, two useful by-products of AD, can be harvested from the process.

TMK produces a wide variety of different models of food waste recycling machines, from 2kgs to 300 tons, in order to meet the composting needs of your large or small business.

TMK Composting Machine

TMK composter is committed to helping the globe achieve zero food waste by providing automatic organic waste composting solutions and systems for all kinds of businesses and homes. Our goal is to help achieve sustainability, allowing the food waste from the farms, restaurants, hotels, food processing plants, etc. to go back to the farms as fertilizer for future food.
 
TMK composting accelerators are machines that are used to convert organic waste such as vegetable waste, meat waste, bakery waste, leaves, fruits, fruit skins, and flowers into valuable compost that can be used for organic farming activities. Our compost converters also can transfer waste to energy – bio fuel and animal feed.
 
Food waste recycling machine increases the speed of the composting process to produce rich, healthy, organic compost in as little as 24 hours. This solution is an alternative to traditional methods of organic waste disposal such as landfill dumping and incineration. Converters reduce environmental pollution and they produce valuable end products in the form of compost.