The optimization of biohydrogen production by bacteria using residual glycerol from biodiesel synthesis

Abstract

In this research the production of hydrogen by Klebsiella pneumoniae BLb01 using residual glycerol discharged from a biodiesel fuel production plant was investigated. Klebsiella pneumoniae BLb01 was isolated from a bacteria-rich sludge of an upflow anaerobic sludge blanket reactor (UASB) of a soybean processing plant. A Plackett–Burman design (P-B) and Response Surface Methodology (RSM) were employed to determine the optimal condition for enhanced hydrogen production. The maximal hydrogen production, which was 45.0 mol % and with 98% of glycerol degradation, was achieved with the optimized medium with the following composition: 30 g L⁻¹ glycerol; 3 g L⁻¹ yeast ex tract 3 g L⁻¹ K₂HPO₄; 1 g L⁻¹ KH₂PO₄; temperature 39°C and pH 9.0. These results show the ability of this new strain of effectively converting residual glycerol into value-added energy products.

Keywords:

• Hydrogen production
• biodiesel
• residual glycerol
• Klebsiella pneumoniae

Acknowledgments

The authors gratefully acknowledge the financial support of CNPQ and CAPES.