PYROLYSIS: AN ALTERNATIVE TECHNOLOGY FOR MUNICIPAL SOLID WASTE MANAGEMENT

Abstract

This paper reviews the process of pyrolysis with an aim of assessing its potential as an alternative technology formanaging municipal solid waste in Kenya. Pyrolysis is the thermo-chemical decomposition of organic matter, at high temperatures, in the absence of oxygen. Organic matter simultaneously undergoes a change in chemical and physical phase, forming a gas, liquid and carbon-rich solid residue, which can be used as fuels. Pyrolysis is one of the processes involved in charring of wood, burning of solid fuels and volcanic eruptions which bring lava into contact with vegetation. Pyrolysis has been applied widely in the chemical industry for production of charcoal, methanol, PVC, activated carbon and gasoline. The process has also been applied to convert solid waste into safelydisposable substances. In Kenya, pyrolysis has been widely applied in local production of charcoal. This continues to pose serious environmental challenges due to widespread deforestation and emission of greenhouse gases into the atmosphere. Meanwhile, Kenya continues to face serious municipal solid waste management challenges associated with urbanization and population pressure. Pyrolysis energy recovery from MSW has been successfully practiced in countries such as the UK, Turkey and Japan, where used tetra pak is now being used as a source of fuel, reducing its presence in Municipal Solid Waste by over 80%. Pyrolysis can also be used to convert plasticwaste and waste rubber, which pose a great environmental problem in Kenya, into useful energy. Pyrolysis is relatively insensitive to input material and prevents formation of dioxins and combustion materials associated with burnt waste. This guarantees my strong recommendation to Kenyan environmental management agencies to adopt pyrolysis to help manage plastics and tetra pak in Municipal solid waste and as an alternative source of energy.