The combustion of fuel derived from municipal solid waste is a promising cheap retrofitting technique for coal power plants, having the added benefit of reducing the volume of waste disposal in landfills. co-combustion of waste-derived fuel (WDF) and coal, rather than switching to WDF combustion alone in dedicated power plants, allows power plant operators to be flexible toward variations in the WDF supply. Substituting part of the coal feed by processed high calorific value waste could reduce the NOx, SO2, and CO2 emissions of coal power plants. However, the alkaline content of WDF and its potentially harmful interactions with the coal ash, as well as adverse effects from the presence of chlorine in the waste, are important drawbacks to waste-derived fuel use in large-scale power plants. This chapter reviews these points and gives a centralized review of co-combustion experiments reported in the literature. Finally, this chapter underlines the importance of lab-scale experiments previous to any large-scale application and introduces the idea of combining waste and additives dedicated to the capture of targeted pollutants.
Part of the book: Developments in Combustion Technology
The first fluidized bed thermogravimetric analyzer (FBTGA) has been developed. The proof of concept of the FBTGA has been carried out on the thermal decomposition of calcium hydroxide. The kinetics and modeling of coal pyrolysis and gasification were investigated in the FBTGA. The obtained activation energies for the individual gases that are produced from coal pyrolysis are 19 to 21% lower than those found for similar coals in the literature. This decrease in the activation energies is explained by a temperature gradient of 185 to 209°C. For the CO shift reaction, the resulting activation energy is 46.6 kcal/mol, increasing by 20% from the one used in the literature. The second reactor presented in this work is a TGA powered by electromagnetic irradiation. As an application for this reactor, a novel kinetic model based on a dual attempt to predict not only the yield but also the composition of bio-oil is presented. The validation of the developed models demonstrated an excellent capability of predicting the yield and quality of the produced oil. The third reactor is a saddle reactor, which consists of two V-shaped pairs of arms and minimizes the impact of the heat and mass transfer limitation on chemical reactions.
Part of the book: Gasification for Low-grade Feedstock