The fluidized bed combustion of a heavy liquid fuel

Abstract

Fluidized bed combustion as a flexible facility has been applied to burn liquid fuel. In the present work, a heavy oil (mazut) has been successfully dispersed and efficiently burnt with in situ desulfurization in a fluidized bed combustor. An atmospheric bubbling fluidized bed combustor of 300-mm inner diameter has been used. The liquid fuel has been injected into the bed using a multi-nozzle pneumatic injector. Measurements have been carried out under steady state operation. Results of experiments indicated that the in-bed combustion of fuel has been enhanced with increasing bed temperature, bed height, excess air and mass flow rate of dispersing air. Fortunately, the later trends improved both combustion efficiency and sulfur retention. High combustion efficiency has been obtained up to 99.7%. Sulfur retention up to 90% has been achieved by adding limestone particles. On the other hand, NO x has been slightly promoted with increasing the mentioned operating parameters, however, the obtained NO x emission was usually <130 ppm.