Energy recovery opportunities from wastes

Energy recovery opportunities from wastes are discussed, together with asso ciated challenges on the environmentally benign energy recovery. The amount of waste generated worldwide has continued to increase in the current cent ury. Most of the wastes have significant energy potential. The utilization of wastes can save millions of dollars on the national scale. However, diff iculties exist for their utilization in propulsion and power systems in an environmentally acceptable manner. It is anticipated that the amount of was te generated will continue to grow in the next millenium, along with associ ated changes in its composition. The thermal destruction of wastes to the m olecular level allows one to more cleanly convert waste into usable energy. The challenges provide opportunities for combustion engineers, whose resea rch is now becoming even more important with new emphasis. Research in comb ustion-related areas has expanded significantly in recent years, particular ly in areas related to fossil fuels and wastes being used as fuels. The fie ld of combustion is further diversified by the complex nature of most react ion processes. Fuel chemistry, fluid mechanics, convective and radiative he at transfer, gas-phase elementary reactions, turbulence, and particle kinet ics and dynamics are relevant processes that often have a direct, and somet imes controlling, influence on the behavior of a particular combustion syst em. Sensors, diagnostics, and miniaturization of the system continue to be of major importance for successful implementation of this new technology.