Biodesulfurization of a Coarse-Grained High Sulfur Coal in a Full-Scale Packed-Bed Bioreactor

Abstract:

Biodesulfurization of a high-sulfur and medium-ash coal product was carried out in a 5-m tall packed bed bioreactor using a mixed culture of iron- and sulfur- oxidizing microorganisms. The feed coal (4 tones) was obtained from a heavy media cyclone product from Takht-Zeitoon coal mine (Tabas, Iran) with a density of -1.4 g/cm³ and a grain size of 0.5-25 mm, having the ash and sulfur contents of 14.92% and 2.46%, respectively. The pilot scale process was performed in a semi-continuous mode with a solution injection rate of 2.5-4.5 lit/min/m², aeration rate of 4-12 m³/h/m² and solution pH of 1.7-2, over a period of 190 days. Iron and sulfate ions were controlled during the process in two 1500-L stirred tank reactors by goethite and gypsum precipitation processes, respectively. The column biodesphurization in a period of 170 days was followed by a washing step with HCl to remove sulfate precipitates. Results showed that the total sulfur and ash contents reached to 1.69% and 11.04%, respectively, which were corresponded to 31% sulfur removal and 26% ash removal. It was indicated that biodesulfurization has a good industrial potential to treat coarse-grained high sulfur coals.

• Periodical: Solid State Phenomena (Volume 262)
• Pages: 207-210
• DOI: https://doi.org/10.4028/www.scientific.net/SSP.262.207
• Online since: August 2017
• Authors: Ahmad Doodkanlou Milan, Ali Ahmadi*, Seyed Mohammad Raouf Hosseini
• Keywords: Biodesulfurization, CoAl, Packed-Bed Bioreactor, Pilot Scale

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