Process development for continuous photofermentative hydrogen production

Boran, Efe
By the integration of dark and photo fermentative hydrogen production processes, higher yields of hydrogen can be obtained from biomass. In the first step, biomass is utilized for hydrogen production by dark fermentation and in the second step, the effluent of dark fermentation is further utilized for hydrogen production by photofermentation using photosynthetic purple non-sulfur bacteria. The purpose of this study was to develop a solar pilot scale tubular photobioreactor (PBR) for continuous photo fermentative hydrogen production from the effluent of dark fermentation. This study demonstrated the implementation of the solar pilot tubular PBR for this new technology for the first time and successful continuous operations were performed in different seasons. Two different strains of Rhodobacter capsulatus were used for the operations. It was showed that even in winter, pure hydrogen could be produced in the pilot PBR with an average productivity of 0.3 mol H2/m3.h, when circulation of the PBR was continuous. Productivity obtained by the mutant strain was 0.2 mol H2/m3.h with periodical circulation. The integration between dark and photo fermentation was proven at pilot scales by using real dark fermenter effluents of molasses and thick juice. DFE of thick juice yielded a maximum productivity of 0.27 mol H2/m3.h whereas the maximum productivity obtained from DFE of molasses was 0.12 mol H2/m3.h. The most important factor affecting productivity is found to be the total received light energy and a yield factor (mmol H2/g dry cell weight) was correlated with total received light energy. Acetic acid consumption rates were found to be first order for daytime and zero order for nights. Furthermore acetic acid utilization for different metabolic pathways were estimated and by-product, poly- β- hydroxybutyrate, specific rates of product formation were determined.


Carbon dioxide removal in steam reforming : adsorption of CO2 onto hydrotalcite and activated soda
Fıçıcılar, Berker; Doğu, Timur; Department of Chemical Engineering (2004)
Conversion of natural gas and other light hydrocarbons via steam reforming is currently the major process for hydrogen production. However, conventional hydrogen production technologies are not cost effective and therefore, cost is the biggest impediment to use hydrogen in fuel cell applications. In order to optimize and overcome cost problems in hydrogen production, sorption and membrane enhanced reaction processes are the two novel technologies for in situ operation of reforming and removal of carbon diox...
Development of organic-inorganic composite membranes for fuel cell applications
Erdener, Hülya; Baç, Nurcan; Department of Chemical Engineering (2007)
Hydrogen is considered to be the most promising energy carrier of the 21st century due to its high energy density and sustainability. The chemical energy of hydrogen can be directly converted into electricity by means of electrochemical devices called fuel cells. Proton exchange membrane fuel cells (PEMFC) are the most preferred type of fuel cells due to their low operating temperatures enabling fast and easy start-ups and quick responses to load changes. One of the most important components of a PEMFC is t...
Chemical vapor deposition of boron carbide
Karaman, Mustafa; Özbelge, Önder; Department of Chemical Engineering (2007)
Boron carbide was produced on tungsten substrate in a dual impinging-jet CVD reactor from a gas mixture of BCl3, CH4, and H2. The experimental setup was designed to minimise the effect of mass transfer on reaction kinetics, which, together with the on-line analysis of the reactor effluent by FTIR, allowed a detailed kinetic investigation possible. The phase and morphology studies of the products were made by XPS, XRD,micro hardness and SEM methods. XPS analysis showed the existence of chemical states attrib...
Sorption enhanced ethanol reforming over cobalt, nickel incorporated mcm-41 for hydrogen production
Gündüz, Seval; Doğu, Timur; Department of Chemical Engineering (2011)
The interest in hydrogen as a clean energy source has increased due to depletion of limited fossil resources and environmental impact related to CO2 emissions. Hydrogen production from bio-ethanol, which already contains large amount of water, by steam reforming reaction, has shown excellent potential with CO2 neutrality. However, steam reforming of ethanol reaction is a highly complex process including many side reactions which decrease hydrogen yield and have a negative effect on process economy. Also, th...
Biological hydrogen production on acetate in continuous panel photobioreactors using rhodobacter capsulatus
Androga, Dominic Deo; Eroğlu, İnci; Department of Chemical Engineering (2009)
Photobiological hydrogen production from organic acids occurs in the presence of light and under anaerobic conditions. Stable and optimized operation of the photobioreactors is the most challenging task in the photofermentation process. The main aim of this study was to achieve in long term, a stable and high hydrogen production on acetate, using the photosynthetic bacteria Rhodobacter capsulatus in continuous panel photobioreactors. Rhodobacter capsulatus (DSM 1710), heat adapted Rhodobacter capsulatus (DS...
Citation Formats
E. Boran, “Process development for continuous photofermentative hydrogen production,” M.S. - Master of Science, Middle East Technical University, 2011.