Recycle Trash into Power
Managing domestic, industrial and commercial waste has traditionally consisted of collection, followed by disposal. Depending upon the type of waste and the area, a level of processing may follow collection. This processing may be to reduce the hazard of the waste, recover material for recycling, produce energy from the waste or reduce it in volume for more efficient disposal.
The other important waste disposal methods are briefed below. Of these, anaerobic digestion/biomethanation is comparatively a new method.
Landfills. Disposing of waste in a landfill is the most traditional method commonly practised in most countries. Few people want a landfill in their local neighbourhood because of adverse environmental impact.
Incineration. It is the process of destroying waste material by burning it. It involves high temperatures of 870°C to 1200°C (1400°F to 2200°F), to volatilise and combust (in the presence of oxygen). It is recognised as a practical method of disposing of hazardous waste materials (such as biological medical waste). The levels of chemical compounds released into the atmosphere when burning mixed waste, cause environmental pollution.
Anaerobic digestion/biomethanation. In this process, the organic fraction of the waste is segregated and fed into a closed container (biogas digester). In the digester, the segregated waste undergoes biodegradation in the presence of methanogenic bacteria under anaerobic conditions, producing methane-rich biogas and effluent.
The biogas can be used either for cooking/heating applications, or for generating motive power or electricity through dual-fuel or gas engines, low-pressure gas turbines or steam turbines. The sludge from anaerobic digestion, after stabilisation, can be used as a soil conditioner (manure) depending upon its composition, which is determined mainly by the composition of the input waste.
Biomethanation is the most widely used technology all over the world, more so in Europe. The Main Advantage is that it is environment-friendly and reliable. The only disadvantage is that it cannot treat non-biodegradable organic fractions.
What is plasma?
Plasma is the fourth state of matter (the other three states being solid, liquid and gas). It is an ionised gas that exists in nature, for example, during lightning. Much of the universe exists in plasma state. The sun, stars and the interstellar matter are plasma manifestations. The gas in the upper parts of the ionosphere (say, above 400 km altitude) is completely ionised. On cosmological scales, plasma is entirely dominating the universe, with safe estimates giving that at least 99 per cent of all matter is in the plasma state.