An OLED display for improving white light emitting efficiency and simplifying a manufacturing process includes a plurality of pixels, each of the pixels having a transistor unit, a color filter unit and an organic light emitting device unit. The system also includes second storage vessel for storing the decomposed heat storage material, and heat generating device for generating heat by recombining the heat storage material stored in the second storage vessel and for heating a heating medium. When used together, the componentsreduce emissions of elemental and oxidized mercury;increase the level of Hg, As, Pb, andor Cl in the coal ash;decrease the levels of leachable heavy metals in the ash, preferably to levels below the detectable limits; andmake a highly cementitious ash product.