TGA-FTIR analysis of Upper Assam oil shale, optimization of lab-scale pyrolysis process parameters using RSM

Abstract

This paper presents a comprehensive study on the in line analysis of products formed during pyrolysis of oil shale from Upper Assam, India and optimization of lab-scale pyrolysis parameters. Thermogravimetric analysis coupled with Fourier transform infrared spectroscopy (TGA-FTIR) was used to determine the decomposition zones and investigate the products evolved during pyrolysis. Study of the evolved gases showed the presence of CH stretching, CC aromatic bending, OH, CO2, and SO2. Response surface methodology (RSM) was employed using central composite design (CCD) model to setup the lab-scale experiment using TGA data, and optimization of process parameters viz. heating rate, temperature and particle size. The pyrolytic shale oil obtained at optimum condition was subjected to characterization using gas chromatography and mass spectrometry (GC–MS) and nuclear magnetic resonance spectroscopy (NMR). The produced shale oil showed an abundance of aliphatic compounds corresponding to high energy density.