A STUDY ON THE FEASIBILITY OF CO-COMBUSTION OF SEWAGE SLUDGE AND COAL IN THE COAL-FIRED POWER PLANT

Urbanization development and sewage industry development have brought about a soaring increment of sewage sludge, how to dispose the ever-increasing sewage sludge and eliminate their hazard has become a serious problem with which people are currently confronted. The technologies of co-combustion of sewage sludge and coal can not only ease the problems in sewage sludge disposal in many big cities, but also can utilize the heat of waste sewage sludge for power generation. Based on the actual situation and need of the co-combustion of coal and sewage sludge in the power plant, one coal sample from a power plant and one sewage sludge sample from a sewage treatment plant were studied in this paper for the feasibility of co-combustion in the coal-fired power plant. Sewage sludge with different moisture contents and coal were mixed into different proportions. Thermal gravity analysis (TGA) and Drop Tube Furnace (DTF) experiments were used to study the characteristics of combustion, pollution gases emission and also heavy metal emission. It was found in this study that there was a comparatively large difference between combustion characteristics of sewage sludge and those of coal. However, the performance of co-combustion of sewage sludge with coal is generally expressing the joint action result of sewage sludge and coal, and sometimes better than the burning of single coal. This study will provide essential and fundamental research data for the feasibility and utilization of co-combustion of coal and sewage sludge in the power plant.