Photofermentative hydrogen production from molasses: Scale-up and outdoor operation at low carbon-to-nitrogen ratio. (28th June 2018)

• Record Type: Journal Article
• Authors: Savasturk, Dilan; Kayahan, Emine; Koku, Harun
• Is Part Of: International journal of hydrogen energy. Volume 43:Number 26(2018)
• Page Start: 11676
• Page End: 11687
• Publication Date: 2018-06-28
• Subjects: Photofermentation -- Rhodobacter capsulatus -- Molasses -- Carbon-to-nitrogen ratio -- Scale-up -- Outdoor; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2018.01.014
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: Photofermentative hydrogen production was carried out under outdoor conditions with a Rhodobacter capsulatus strain on molasses, a renewable and sustainable feedstock. An existing photobioreactor design was scaled-up from 9 L to 20 L. The decreased carbon-to-nitrogen (C/N) ratio of 13.0, compared to our previous work, accelerated growth and resulted in a reduced lag period for hydrogen production as well as higher productivities in the exponential phase. However, the low C/N ratio also promoted a high optical density due to growth, limiting light transmission. Still, the maximum productivity was found as 0.47 mol H2 /(m 3 ·h), significantly higher than our result with the smaller reactor volume. High rates of production could not be maintained presumably due to the combined effects of cloudy periods, the aforementioned C/N ratio and decreasing pH. These results suggest that the scale-up was successful and there is potential for further improvement using optimal C/N ratio and cell concentration values. Highlights: Outdoor photofermentative hydrogen production carried out from diluted molasses. An existing photobioreactor design was scaled-up to 20 L from 9 L. The low C/N ratio promoted growth and reduced the lag time for hydrogen production. Adverse weather conditions and high optical density decreased productivity. Maximum productivity was 0.47 mol H2 /(m 3 ·h).