Development and validation of a sampling and analysis method to determine biogenic sulfur in a desulfurization bioreactor by gas chromatography coupled with a pulsed flame photometric detector (GC-PFPD).

Abstract

Suspended biomass bioreactors can be operated to remove H2S from biogas under anoxic conditions and produce elemental sulfur, the commercial value of which has been demonstrated. In the present paper, a novel methodology comprising the optimization of a determination method performed in a gas chromatograph equipped with a pulsed flame photometric detector (GC-PFPD), combined with a simple preparation based on filtration and extraction with toluene, is proposed. The injector temperature and carrier gas flow rate (QHe) values were optimized using a response surface methodology based on a face-centred composite central design. This optimization revealed that the optimum conditions were an injector temperature and carrier gas flow rate of 222°C and 7mLmin-1, respectively. The chromatographic method shows an analysis time of 48min, a detection limit of more than 5.9mgL-1, a relative standard deviation of less than 3.71%, and a sulfur recovery percentage of more than 98%. These values provide excellent linearity and a reasonable concentration range (10-200mgL-1). Finally, a measurement error of 4.45% was obtained when using the present method in a selectivity test. Copyright © 2021 The Authors. Published by Elsevier B.V. All rights reserved.