Flue gas drying of bagasse

Technical data on commercial systems using boiler flue gas to dry bagasse, the fibrous byproduct of milled sugarcane that fuels sugar factory boilers, will be presented in this article. The results of this study are based primarily on four systems installed in Hawaii during the late 1970s and early 1980s. Even though the temperatures of the flue gases available for bagasse drying in Hawaiian sugar factories are generally much lower than in factories elsewhere, the improvements in boiler efficiencies in Hawaii due to flue gas bagasse drying were found to be roughly 5 percentage points which is substantial. The heat loss from the dryer system and the related ducting was generally found to be minimal, = 0.5% of the heating value of the bagasse fuel. Carbon monoxide concentration (and the associated loss) was significantly lower and boiler stack emissions and opacity usually improved substantially when the bagasse was dried prior to being burned in the boiler.