Enhancing environmental sustainability through utilization of CFBC ash

UTILIZING CFBC ASH FOR ENVIRONMENT SUSTAINABILITY

Abstract

Circulation fluidized bed combustion (CFBC) technology is an efficient combustion technique for combustion of high sulfur containing fuels like petcoke which results in generation of CFBC ash as by-product. This poses environmental risks and presents challenges in utilization due to significantly higher levels of CaO, SO₃ etc. CFBC ash has different chemical composition, mineralogy and morphology as compared to conventional coal based fly ash due to different combustion process with combustion temperature of about 900ºC. CFBC ash was characterized using XRF, XRD, SEM, Particle Size Distribution etc. In this study, CFBC ash based mortar cube, concrete cube and pavers block were developed. It was found that the strength of CFBC ash concrete got enhanced by the interfacial bonding of CFBC ash and other raw materials. The mineralogical and morphological studies of concrete confirm the formation of hydration products like Calcium Silicate Hydrate, Tricalcium Silicate, Gypsum, Portlandite and Ettringite which are extremely important for strength development and durability. The leachability results showed that the developed product is non-toxic and safe from environmental and leaching aspects. The study recommended the use of CFBC ash as a sustainable building material for broad application spectrum.