Waste Recycling using Superheated Steam and Its Environmental Evaluation

A practical superheated steam drying system is introduced to process high-moisture waste to solid fuel. Energy consumption and CO2 emissions with this system are evaluated and compared with the result from a conventional waste incinerator. In this paper, used paper disposable diapers are processed by the drying system as high-moisture waste. If the solid fuel is used as an auxiliary fuel to generate superheated steam and results in an efficient waste thermal recycle system, the energy consumption and CO2 emissions become considerably low. However, much energy is consumed to heat the drying chamber before high-moisture waste processing, and time and energy are lost by the superheated steam drying system. In this paper, first the advantages of introducing the new superheated steam drying system for high-moisture waste to produce a solid fuel are shown. Then second, a procedure to reduce the energy consumption during pre-processing for heating the drying chamber is proposed. As a result, this new superheated steam drying system for processing high-moisture waste and the obtained solid fuel provides a promising environmentallyfriendly waste recycle system.