Rotating photobioreactor for hydrogen producing Chlamydomonas cultures
Csaba Litkei and Vince Ördög
Faculty of Agricultural and Food Sciences of the University of West Hungary, Institute of Plant Biology
 
Under specific conditions Chlamydomonas reinhardtii is able to split the water and produce hydrogen gas via biophotolysis. It is a great challenge to develop photobioreactors for hydrogen production which are able to ensure the requirements of Chlamydomonas strains concerning light intensity, temperature, composition of nutrient media, carbon supply, etc. Unusual photobioreactors have to be constructed with separated aerobic and anaerobic modules which are using different nutrient media and are working simultaneously. The optimal light absorbance in the aerobic modul and the thermal regulation of the whole phorobioreactor should be achieved with maximum efficiency and minimum energy consumption.
In laboratory experiments 9 Chlamydomonas strains are investigated to measure and optimize their hydrogen production and to select the best strain for mass production. A microcontroller regulated automatic photobioreactor is developed for hydrogen production, which can operate in artificial and sunlight as well. It includes aerobic and anaerobic modules and is equipped with a concave background surface that is reflecting the light through the glass tubes so the cells are able to absorb more light. Rotating mechanism ensures the optimal light intensity and temperature in the culture suspension. The optimal conditions are maintained by evaluating the pH, temperature and turbidity, which are measured by integrated sensors.
The present paper demonstrates a newly developed photobioreactor and some preliminary results concerning the hydrogen production of 9 selected Chlamydomonas strains. The results showed that the use of tubular photobioreactor made from glass, stainless steel, plastic and aluminium for photobiological hydrogen production is currently not economically feasible. Further developments are necessary in this direction.
 
 
 
e-mail address of presenting author: csaba.litkei@explora.hu