Ultrasonic-assisted cleaning of Indian low-grade coal for clean and sustainable energy

In this study, the ability of ultrasound was described in cleaning Indian low-grade coal in the presence of leaching reagent particularly emphasizing the role of ultrasound in demineralization. Moreover, the focus has been made on the development of a novel technique for coal cleaning and the possibilities of scaling-up of the proposed process. It was proved that there is the superiority of ultrasonic leaching over pressure leaching under the optimized conditions. This superiority was supported by employing studies on leached coals using different techniques such as X-ray Diffract ion (XRD), Fourier Transform Infrared (FT1R) Spectroscopy, Raman Spectroscopy, Scanning Electron Microscopy (SEM), and Thermogravimetric Analysis (TGA). The fuel properties of coals were determined in term of fixed carbon content, ash composition, degree of demineralization, Carbon-Hydrogen-Nitrogen-Sulphur (CHNS) content, gross calorific value (GCV), and ash fusion temperature (AFT). Comments and discussions are also made on the feasibility of scaling-up of the process addressing various technological limitations and their possible solutions. (C) 2018 Elsevier Ltd. All rights reserved.