Hydrogen production by microorganisms in solar bioreactor

Download
2008
Uyar, Başar
The main objective of this study is exploring the parameters affecting photobiological hydrogen production and developing anaerobic photobioreactor for efficient photofermentative hydrogen production from organic acids in outdoor conditions. Rhodobacter capsulatus and Rhodobacter sphaeroides strains were used as microorganisms. EU project “Hyvolution” targets to combine thermophilic fermentation with photofermentation for the conversion of biomass to hydrogen. In this study, the effluent obtained by dark fermentation of Miscanthus hydrolysate by T. neapolitana was fed to photobioreactor for photofermentation by R. capsulatus. Hydrogen yield was 1.4 L/Lculture showing that the integration of dark and photofermentation is possible. Innovative elements were introduced to the photobioreactor design such as removal of argon flushing. An online gas monitoring system was developed which became a commercial product. It was found that the light intensity should be at least 270 W/m2 on the bioreactor surface for the highest hydrogen productivity and the hydrogen production decreased by 43 % if infrared light was not provided to the bioreactor. Scale-up of photofermentation process to 25L was achieved yielding 27L hydrogen in 11 days by R. capsulatus on acetate/lactate/glutamate (40/7.5/2 mM) medium. The outdoor application of the system was made. Shading and water spraying were adapted as cooling methods for controlling the temperature of the outdoor bioreactor. It was found that uptake hydrogenase deleted mutant of R. capsulatus show better hydrogen productivity (0.52 mg/L.h) compared to the wild type parent (0.27 mg/L.h) in outdoor conditions. It was also shown that the hydrogen production depended on the sunlight intensity received.

Suggestions

Ultrasound assisted extraction of lipids and antioxidants from wheat germ
Melikoğlu, Mehmet; Kıncal, Suzan; Department of Chemical Engineering (2005)
The aim of this thesis work was to extract lipids and antioxidants from wheat germ using an ultrasonic bath. Alternative solvents: Ethanol, isopropanol and acetone were used for the extraction purposes and for the fat content determination hexane was used. Alternative solvents dissolve wax, phospholipids and some other proteins because of their polar nature which increased the yield. Since waxes and some proteins can be added to the soaps and creams which were made from carrier oils, obtaining these substan...
Biochemical monitoring of toxic and carcinogenic organic pollutants along the İzmir Bay after the great canal project and possible health effects
Boyuneğmez, Tuğba; Arınç, Emel; Department of Biochemistry (2004)
The induction of hepatic cytochrome P4501A1 and its monooxygenase activity 7-ethoxyresorufin O- deethylase, (EROD) in fish by PAHs, PCBs and dioxins has been suggested as an early warning system أmost sensitive biochemical responseؤ for assessing environmental contamination conditions. In this study, the degree of induction of cytochrome P4501A1 protein as determined immunochemically and CYP1A1 associated EROD activity in fish were utilized as biomarkers of exposure to PAHs, PCBs and related organic polluta...
Water content controlled instead of suction controlled tests
Ahmadinaghadeh, Reza; Toker, Nabi Kartal; Ahmadiadli, Mohammad (2013-03-01)
Most soils that concern geotechnical engineering are in the state of partial water saturation. Current practice tries to predict engineering properties of cohesionless soils using data from tests on saturated specimens, regardless of the saturation in the field. Due to complexity of test setups and high technical requirements, unsaturated soil tests are not among the common equipment of soil mechanics laboratory. One of these problems is the existence of suction, which is a function of water content and aff...
Hemicellulose based biodegradable film production
Göksu, Emel Iraz; Bakır, Ufuk; Department of Chemical Engineering (2005)
Xylan was extracted from cotton waste, characterized by DSC and TGA analysis and used in biodegradable film production. Pure cotton waste xylan did not form film. The presence of an unknown compound, as an impurity, yielded composite films. The unknown compound was determined as a phenolic compound, and most probably lignin, by using DSC and TGA analysis and Folin-Ciocalteau method. The effects of xylan concentration of the film forming solutions, glycerol (plasticizer) and gluten additions on thickness, me...
Preliminary approch for the determination of fish exuded kairomone using fourier transform infrared spectroscopy
Kepenek, Ayşe Özge; Severcan, Feride; Department of Biology (2005)
Chemical communication in aquatic organisms has been topic of a large number of studies focusing interactions between organisms via info chemicals. Diel Vertical Migration (DVM) is commonly observed among zooplankton and consists of a single daily ascent with minimum depth reached between sunset and sunrise and a descent with maximum depth attained during the day. DVM was absent or reduced when predators were absent and well developed in their presence. Species of the Daphnia are one of the well investigate...
Citation Formats
B. Uyar, “Hydrogen production by microorganisms in solar bioreactor,” Ph.D. - Doctoral Program, Middle East Technical University, 2008.