Emission Characteristics of Pollution Gases from the Combustion of Food Waste

Abstract

The emission characteristics of pollution gases produced via the combustion of food waste were studied through a laboratory-scale electrically heated tube furnace. The results showed that the pollution gases generated from the combustion of food waste were CO, H2 and NOx. Each emission curve of CO had a peak. When the combustion temperature rose from 400 °C to 1000 °C, the peak first increased (from 400 °C to 700 °C) and then decreased (from 800 °C to 1000 °C). However, the burnout time shortened with the increase in temperature. Therefore, food waste should be combusted at a higher temperature than 700 °C from the perspective of reducing CO emissions. The emissions of H2 were similar to those of CO. In other words, if CO emissions increased, H2 emissions also increased in the same temperature range. Some NOx emission curves had two peaks (the combustion of cooked rice at 1000 °C; the combustion of vegetable leaves in the temperature range of 600 °C to 1000 °C). The higher the combustion temperature, the higher the second NOx emission peak. NOx emissions from the combustion of cooked rice were greater in the temperature range of 400 °C to 500 °C, whereas for vegetable leaves, that temperature range was from 600 °C to 700 °C. Hence, from the viewpoint of reducing pollution gases, food waste should be combusted at a higher temperature than 700 °C.