Sulfur functionalities and physical characteristics of the Maritza Iztok Basin lignite

Abstract

The use of selective functional group modification procedures has been investigated for the determination sulfur forms in low-rank coals. A Bulgarian lignite from the Maritza Iztok Basin was submitted to a variety of chemical treatments. The fresh lignite and residues were studied by atmospheric pressure temperature-programmed reduction (AP-TPR) and sulfur K-edge X-ray absorption near-edge structure (XANES) analysis to investigate the distribution of sulfur forms. The impact on the physical characteristics of the lignite following each treatment was studied by thermal analysis (d.t.a.) and scanning electron microscopy (SEM-EDX). The results have demonstrated the ability of selective procedures to simplify sulfur functionality determination by AP-TPR and have provided a clear insight into the impact of treatments on the thermal characteristics of the lignite. Copyright (C) 1996 Elsevier Science Ltd.