Organic sulphur alterations in biodesulphurized low rank coals

► Coal biodesulphurization approach for organic/inorganic sulphur removal is applied. ► Prior to biodesulphurization processing, samples are chemically treated. ► The used microorganisms are “P. chrysosporium” and “S. solfataricus”. ► Extra maximal total and organic sulphur decreases of ∼24% are achieved. ► TPR-MS techniques are used for sulphur alteration assessment.