Potential Applications of High Temperature Air Combustion Technology to Other Systems - High Temperature Air Combustion: From Energy Conservation to Pollution Reduction - page 351

FIGURE 6.8 Approximate energy balance for an RDF manufacturing process.

of RDF includes a variety of steps and consumes a large amount of energy. To utilize
RDF effectively as a fuel, it is very important to identify clearly the differences
between the thermal energy obtained from RDF and the energy originally contained
in the waste. According to the figure, the net amount of available energy is about
40%. Nagata and Ureshino 10 conducted an energy balance analysis of RDF power
generation with respect to the life cycle of RDF. The analysis revealed that the drying
process is the key to making RDF power generation reasonable with respect to life
cycle assessment (LCA). In summary, it is advantageous to have low water content
in industrial wastes from the viewpoint of energy balance and RDF production.

6.2.1.4 Problems with Waste Derived Fuel Production and

Combustion

RDF technology was originally developed to cope with the problem of high levels
of dioxins emitted from “batch type” small-size incinerators. The RDF manufactur-
ing process needs to overcome the following problems to achieve the full practical
use of RDF:

• Seasonal changes in the shape of the fuel and the amount of waste
collected as well as local calorific value fluctuations of the wastes
•Treatment of odor and contaminated water at RDF manufacturing plants
• Energy saving considerations in the RDF manufacturing process (involv-
ing both the drying and pulverization processes)