Implementation of Control Systems on a Photobioreactor for Large-Scale Cultivation of the Microalgae Rhodomonas salina

摘要

This master thesis is about control of microalgae production in a photobioreactor. It is a part of the Copepod egg Mass production in Aquaculture (COMA) project, where the goal is to produce 100 million copepod eggs per day in an automated facility. Experiments was conducted to see if the photobioreactor is a good facility for culturing the microalgae as feed for the copepod Acatia tonsa using parameters such as growth rate, harvest, light, pigment content, fatty acid content and nutritional content in the culture medium. Furthermore two semi-automatic controller types was implemented on the photobioreactor for determining which is best suited for controlling microalgae production. The controller types was a Standard Dilution control, using an applied dilution strategy and a Proportional Integral control. The photobioreactor is located in Taarstrup, Denmark owned by AKVAgroup. The results indicated that the photobioreactor investigated is an acceptable facility for cultivating the microalgae Rhodomonas salina for the purpose of producing live feed for copepods. The results indicated furthermore that the Standard Dilution Control system is preferred at this time, but the potential of using a Proportional Integral Control system is acknowledge. Further investigations on this is recommended.