Depyritization of US Coal Using Iron-Oxidizing Bacteria: Batch Stirred Reactor Study

Authors: Ashish Pathak, Dong-Jin Kim, Haragobinda Srichandan, Byoung-Gon Kim

Abstract:

Microbial depyritization of coal using chemoautotrophic bacteria is gaining acceptance as an efficient and eco-friendly technique. The process uses the metabolic activity of chemoautotrophic bacteria in removing sulfur and pyrite from the coal. The aim of the present study was to investigate the potential of Acidithiobacillus ferrooxidans in removing the pyritic sulfur and iron from high iron and sulfur containing US coal. The experiment was undertaken in 8L bench scale stirred tank reactor having 1% (w/v) pulp density of coal. The reactor was operated at 35ºC and aerobic conditions were maintained by sparging the air into the reactor. It was found that at the end of bio-depyritization process, about 90% of pyrite and 67% of pyritic sulfur was removed from the coal. The results indicate that the bio-depyritization process is an efficient process in treating the high pyrite and sulfur containing coal. 

Keywords: At. ferrooxidans, Batch reactor, Coal desulfurization, Pyrite.

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1089022

References:

[1] Acharya, C., Sukla, L.B., Misra, V.N. Biodepyritisation of coal. Journal of Chemical Technology and Biotechnology 79 (1) 1–12 (2004).
[2] Li, Z.L., Sun, T.H., Jia, J.P. An extremely rapid, convenient and mild coal desulfurization new process: sodium borohydride reduction. Fuel Processing Technology 91 (9) 1162–1167 (2010).
[3] Cara, J., Vargas, M., Morán, A., Gomez, E., Martínez, O., García, F.J. Biodesulfurization of a coal by packed-column leaching. Simultaneous thermogravimetric and mass spectrometric analyses. Fuel 85: 1756–1762 (2006).
[4] Cardona, I.C., Marquez, M.A. Biodesulfurization of two Colombian coals with native microorganisms. Fuel Processing Technology 90: 1099–1106 (2009).
[5] Ivanov, I.P. Main trends in the biotechnological processing of coals: a review. Solid Fuel Chemistry 1: 3–10 (2007).
[6] Acharya, C., Kar, R., Sukla, L. Bacterial removal of sulfur from three different coals. Fuel 80: 2207–2216 (2001).
[7] Kargi, F., Robinson, J.M. Biological removal of pyritic sulphur from coal by the thermophile organisms Sulfolobus acidocaldarius. Biotechnology and bioengineering 27:41-49 (1985).
[8] Larsson, R.T. Licentiate thesis. University of Lund, Lund, Sweden (1982).
[9] Clark, T.R., Baldi, F., Olson, G.J. Coal depyritization by thermophilic archaeon metallosphaera sedula. Applied and Environmental Microbiology 59 (8): 2375-2379 (1193).
[10] Hu, J., Zheng, B., Finkleman, R.B., Wang, B., Wang, M., Li, S., Wu, D. Concentration and distribution of sixty-one elements in coals from DPR Korea. Fuel 85:679-686 (2006).