ANAEROBIC DIGESTION

Similar in some respects to composting, but in tanks from which oxygen is excluded, anaerobic digestion is the breaking down of organic material (i.e. from plants and animals) to simpler chemicals by bacteria. While the bacteria of composting use oxygen to produce carbon dioxide from plant material, the anaerobic bacteria create methane (an energy-rich gas) in addition to carbon dioxide. After digestion, the remaining material consists of nutrient-rich fertiliser suspended in water. This can be used for soil improvement, or optionally the dry material can be separated from the water for resale and the water can be used as grey water or cleaned further to be potable.

The anaerobic digestion process creates biogas, consisting mainly of methane (approximately70%) and carbon dioxide. This can be used in stationary engines to generate electricity, for instance, but it is not suitable as a vehicle fuel.

It is possible to separate the methane from the carbon dioxide, each of which is a valuable gas. The methane is then known as Renewable Natural Gas or Biomethane, which is virtually identical to natural gas and can be used for heating, cooling, as a source of chemicals, fertiliser or hydrogen. When used as a vehicle fuel, biomethane is, without doubt, the world's cleanest and most environmentally friendly fuel.

Carbon dioxide is valued for its properties as an inert gas, for heat transfer, and as a solvent. In addition to carbonating soft drinks, it is used in fire extinguishers, chilling food products, to increase food production in greenhouses and (in its supercritical form) as the most environmentally friendly solvent.

The remaining solids are suspended in water and are a most effective soil improver. The Maltin® System ensures thorough and complete treatment, so all the material is broken down into its most basic chemical components with no contaminants, no smell and no pathogens or weed seeds.

In the Maltin® System there is no waste product.

THE MALTIN® SYSTEM

British engineer Christopher Maltin spent over 18 years in worldwide research of all of the methods available to generate renewable energy. He recognised that the anaerobic digestion of waste offered the most effective solution and he has designed a system with a number of innovative features that overcome practically all of the issues of current systems.

• The system consists of a patented tank shape that promotes thorough and continuous mixing with minimum use of energy. Its design allows for eight tanks in a sequence, ensuring that all feedstock is properly digested and eliminating pathogens from the output.
• The tanks are sunk in a lagoon of water, providing insulation and a heat sink for the process, reducing heating bills. This also allows for visually unobtrusive installations. Since the tanks are suspended in water, they can be made out of simple plastic or similar recyclable materials, and are protected from the elements to ensure a long life.
• With no internal moving parts, the tanks are virtually maintenance free. Traditional plants use paddles for stirring, requiring the process to be stopped when maintenance is required. The Maltin® System uses a patented curtain of gas bubbles for stirring, so the moving parts are external to the tank and can be maintained without opening the tanks.

Combining greater efficiency and effectiveness than current systems, the Maltin® System opens markets that have not been available before, such as the manufacture of bio-methane to replace natural gas in the gas grid. It is now a cost-effective competitor to other sources of renewable energy, such as wind and solar. Bio-methane is also able to replace petrol and diesel in vehicles.