title: Implementation and analysis of temperature control strategies for outdoor photobiological hydrogen production.
abstract: For outdoor photobiological hydrogen production, the effective control of temperature in photobioreactors is a challenge. In this work, an internal cooling system for outdoor tubular photobioreactors was designed, built, and tested. The temperatures in the reactors with bacteria were consistently higher than those without bacteria, and were also strongly influenced by solar irradiation and ambient air temperature. The cooling protocol applied successfully kept the reactor temperatures below the threshold limit (38 °C) required for the bioprocess and provided a uniform distribution of temperature along the reactor tube length. The biomass growth and hydrogen production were similar in the reactors cooled co-currently and counter-currently. The biomass growth rate was 0.1 l/h, the maximum hydrogen production rate was 1.28 mol/m3/h, and the overall hydrogen yield obtained was 20 %. The change in the biomass was fitted using the logistic model while cumulative hydrogen production was fitted using the modified Gompertz equation.
authors: Department of Biotechnology, Middle East Technical University, 06800, Ankara, Turkey.
authors: Dominic Deo
authors: DD
authors: Androga
authors: Department of Chemical Engineering, Kocaeli University, 41380, Kocaeli, Turkey. basaruyar@gmail.com.
authors: Basar
authors: B
authors: Uyar
authors: Department of Chemical Engineering, Middle East Technical University, 06800, Ankara, Turkey.
authors: Harun
authors: H
authors: Koku
authors: Department of Chemical Engineering, Middle East Technical University, 06800, Ankara, Turkey.
authors: Inci
authors: I
authors: Eroglu
mesh_terms: D018533:Biomass; D019149:Bioreactors; D006358:Hot Temperature; D006859:Hydrogen / Q000378:metabolism*; D008954:Models, Biological; D016354:Rhodobacter capsulatus / Q000254:growth & development*
chemical_list: D006859:Hydrogen
keywords: Biohydrogen; Photofermentation; Rhodobacter capsulatus; Temperature control; Tubular reactor