A Japanese government agency hired NEA to accurately estimate drying times for brown coals in a fluidized stream drying technology. NEA’s drying model explicitly accounts for the three moisture forms – monolayer, multilayer, and bulk – as a basis to predict the distinctive drying behavior and energy requirements of individual low rank coal samples. The mass loadings of the moisture forms are estimated from a database of equilibrium moisture contents that we correlated to parameters derived from a coal’s proximate and ultimate analyses. In accord with data, the predicted drying time is not solely a function of the total moisture content of the coal. One key aspect is whether or not the target moisture level requires removal of any monolayer moisture at all. Coals with little bulk moisture and relatively abundant monolayer moisture will require relatively long drying times simply because monolayer moisture is always released much slower than multilayer moisture. Learn More.
A boiler manufacturer in Japan was concerned about excessive corrosion in its full-scale PFBC. They hired NEA to develop a computer simulator to identify which coals are likely to have excessive alkali vapor emissions. After the predictions satisfied evaluations against lab-scale test data, NEA delivered a software package that accurately predicted the alkali emissions from the pilot-scale PFBC, and was used to screen coals for the 230 MW Karita PFBC.
A Japanese utility OEM routinely uses NEA’s PC Coal Lab® to develop small, distributed gasifiers for biomass and low-rank coals. These calculations are used to manage the different product gas compositions with various forms of biomass and coal, and also tar-related problems, such as sticky deposits and diminished fuel conversion efficiencies.