Batch waste gasification technology: Characteristics and perspectives

The problem of municipal solid waste (MSW) disposal is expanding rapidly in all the countries as a consequence of the habits and lifestyles of modern consumers that cause a continuous increasing volume of waste. To date, landfills are still the primary destination of waste. However, with landfill tipping fees rising and their proven negative environmental impacts, cleaner and less costly alternatives for municipal waste disposal should be identified and implemented. The energy recovery from MSW, known as "waste-to-energy" (WTE), is one of such alternatives. Waste-to-energy reduces the amount of materials sent to landfills, prevents air/water contamination, improves recycling rates and lessens the dependence on fossil fuels for power generation. The centrality of thermal processes in the WTE practice, makes strongly necessary the evaluation of the problems associated with both the release and formation of contaminants and the degree of pre-processing required in conversion of MSW into a suitable feed material. Among the currently WTE technologies, one that is finding some interest in Italy is the so called "Molecular Dissociation". This technology developed by Energo is claimed for some advantages, the main of which are the possibility to use as feed material unsorted MSW, the low emission level, and particularly the high flexibility due to its modular design that makes the process well adaptable to the seasonal changes and population growth. An experimentation conducted in a pilot plant greatly contributed to understand the behaviour of the process. On the basis of the obtained experimental results, the paper illustrates advantages and disadvantages of this technology. © 2010 WIT Press.