Additional fuel is required to incinerate refuse that contains what percentage of moisture?

Additional fuel is typically required to incinerate refuse when it contains a high percentage of moisture. Moisture in refuse affects the efficiency of the incineration process because water absorbs heat, making it more difficult to reach and maintain the high temperatures necessary for effective combustion.

When refuse contains 50 percent or more moisture, a significant portion of energy produced by the incineration process is used to evaporate the water rather than combusting the waste material. This necessitates more fuel to maintain the required temperatures for efficient burning.

Conversely, refuse with 30 percent or less moisture generally does not require additional fuel to the same extent, as it is closer to an optimal moisture content for combustion. Therefore, it is the high moisture content in conjunction with low levels of other combustible materials that dictates additional fuel needs.

The correct choice reflects the understanding that both refuse with 50 percent or more moisture and, conversely, the more favorable conditions in which only 30 percent or less moisture is present influence fuel requirements. However, the critical concern is that refuse with high moisture content (50 percent or more) demands significant additional fuel for effective incineration. This links to the importance of understanding how moisture levels directly affect fuel requirements in the waste management process.