Mathematical modeling of methane combustion in a fluidized bed

Abstract

In this paper, the homogeneous combustion of methane in a fluidized bed in described using three increasingly complex reactor models which can be identified by their key features: two phases with constant bubble size, three phases with constant bubble size, and three phases with bubble growth. A simple plug flow model is used to describe the freeboard region separately. To compare the predicted methane concentration profiles with measured values, existing theory for in-bed gas sampling is considered. Without resorting to the use of adjustable parameters, the third model provides the best agreement between theory and experiment. Two factors were identified as crucial to the success of this model: the accurate treatment of the time gas in the bubble needs to reach the bed temperature and the change in the rate of mass transfer between the bubble and dense phases as the bubbles grow.