Waste management: Some energy recovery processes

Abstract

Biomass energy is one of humanity's earliest sources of energy particularly in rural areas where it is often the only accessible and affordable source of energy. The use of biomass fuels provides substantial benefits as far as the environment is concerned. Biomass can be converted into liquid, solid and gaseous fuels with the help of some physical, chemical and biological conversion processes. Wastes are indispensable elements of human life. Solid wastes comprise garbage, paper, plastics, metals, wood and synthetic materials. A natural part of the life cycle, the waste occurs when any organism returns substances to the environment. Waste management is required to prevent deterioration of the ecological balance. Solid waste management was one of the most significant environmental issues encountered in developing countries. The natural wastes are disposed of by the ecological system. Important is the elimination of waste of natural artificial. There are various options available to convert solid waste to energy. Mainly, the following types of technologies are available: pyrolysis, gasification, anaerobic digestion, sanitary landfill, incineration, and other types. The gasification of biomass is a thermal treatment, which results in a high production of gaseous products and small quantities of char and ash. The pyrolysis process consists of the thermal degradation of the wastes in the absence of oxygen/air. The biogas production is the process conversion of a cellulosic material to methane gas in anaerobic conditions.