Experimental Research For The Co-Combustion And Co-Pyrolysis Of Sewage Sludge And Coal

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 final objective of sewage sludge is to meet the requirements of decrement, stabilization, detoxification, and the main tendency is energy and resources recycle. To conform to the new trend, combustion (incineration) and pyrolysis has become two promising disposal methods. Whereas, sewage sludge is high moisture and low caloric fuel, which weakens the feasibility and economics of incineration and pyrolysis. In order to spread the application of these new technologies, the co-combustion and co-pyrolysis with coal is being considered. So it's necessary to study on the characteristics of sewage sludge co-combustion and co-pyrolysis with coal. In this paper one kind of sludge and two kinds of coal are select and mixed in different ratio, every sample is investigated through a series of co-combustion and co-pyrolysis experiments using an advanced TGA-FTIR co-operation. According to the TGA curves obtained from mono-combustion and co-combustion, the basic mono-combustion characteristics between sludge and coal are studied, and the influence of different ratio and different coal on co-combustion are explored. Determine the combustion mechanism of sludge, coal, and their mixture and get the kinetic parameters A and E using differential method combined with integral method through disposing the test data. The co-combustion experiment proved that co-combustion is more effective than mono-combustion in some facts, which provide the academic base for the application of co-combustion. According to the TGA curves obtained from mono-pyrolysis and co-pyrolysis, the basic mono-pyrolysis characteristics between sludge and coal are studied, and the influence of different ratio and different coal on co-pyrolysis characteristics and gaseous product are explored. Determine the pyrolysis mechanism of sludge, coal, and their mixture and get the kinetic parameters A and E using differential method combined with integral method through disposing the test data. The co-combustion experiment proved that co-pyrolysis is more effective than mono-pyrolysis which provide the feasibility of co-pyrolysis. There is an optimization of mixture ratio, which is different for different coal. The conclusion from above experiments and analysis are helpful to the development of co-combustion and co-pyrolysis disposal methods of sewage sludge and supply valuable reference data for more research about sewage sludge co-combustion and co-pyrolysis with coal.