Analytical Investigation of Sulfur Capture and Slag Rejection in Cyclone Coal Combustors. Final Report, September 20, 1982-February 28, 1983

摘要

This report describes the results of an analytical study of the combustion phenomena and environmental control functions, specifically sulfur capture and slag rejection, in a commercial scale horizontal cyclone coal combustor. The study was divided into three tasks, a literature review, an analysis of the combustion and sulfur capture processes in the combustion gas stream, and an analysis of the combustion and sulfur-slag phenomena in the liquid slag layer covering the inside of the cyclone combustor. The primary emphasis in the study was on the combustion aspects because they are the necessary prelude to a proper description of the sulfur capture process. A specific size cyclone combustor, namely a 150 MMBtu/h horizontal, air cooled unit with end injection of coal/limestone and air, and based in part on prior commercial experience, was selected as the model for much of the analysis in this project. The results of the study showed that a 3-dimensional model for the coal particle trajectories is required to properly model the coal ignition process. This process can be primarily accomplished by internal radiative heating. It was found that under fuel rich conditions, an appropriate coal particle size distribution will allow devolatilization and char gasification of a substantial part of the coal mass in suspension in the gas stream. The various models for gasification of char on a slag layer substantially under-predict experimental observations. 54 references, 6 figures, 10 tables. (ERA citation 10:012224)