Biodesulphurized subbituminous coal by different fungi and bacteria studied by reductive pyrolysis

One of the perspective methods for clean solid fuels production is biodesulphurization. In order to increase the effect of this approach it is necessary to apply the advantages of more informative analytical techniques. Atmospheric pressure temperature programming reduction (AP-TPR) coupled with different detection systems gave us ground to attain more satisfactory explanation of the effects of biodesulphurization on the treated solid products. Subbituminous high sulphur coal from “Pirin” basin (Bulgaria) was selected as a high sulphur containing sample. Three different types of microorganisms were chosen and maximal desulphurization of 26% was registered. The following biodesulphurization treatments were performed: three types of fungi – “Trametes Versicolor” – ATCC №200801, “Phanerochaeta Chrysosporium” – ME446, Pleurotus Sajor-Caju and Mixed Culture of bacteria – ATCC №39327. A high degree of inorganic sulphur removal (79%) was established and consecutive reduction by ~ 13% for organic sulphur (Sorg) was achieved. To follow the Sorg changes a set of different detection systems i.e. AP-TPR coupled “on-line” with mass-spectrometry (AP-TPR/MS), on-line with potentiometry (AP-TPR/pot) and by the “off-line” AP-TPR/GC/MS analysis was used. In order to reach more precise sulphur balance, oxygen bomb combustion followed by ion chromatography was used