Algae Culture in a Photobioreactor NEEDS Specific Growth MEDIA, LIGHT Distribution and Operational Aspects of Chemical Engineering

Cultivation of Algae has shown recently an important role in the field of Energy, Food and Health care. Macro-and Micro-algae propagations have shown two different industrial applications. Macro-algae are efficient in CO₂ capture and for energy source as bio-mass and are cost effective in open pond culture. Micro-algae on the other hand provides the source for food in presence of light and CO₂ i.e. Spirulina, Blue Green Algae and or Cyan bacteria species involved in productions of bio-fuel and food. To study biological and physico-chemical properties of Algae, differentiated by cellular properties of micro and macro-Algae, different cultural methods, were applied to optimize their growths. By changing the increase residence time i = V_R/ V^o (i.e. taw = volume of the reactor / flow of nutrient), proper light distribution, the growth of algae cells were monitored in PBR, as shown in figures. To increase the growth rate of algae and to reduce the lag// induction- phase, a hybrid reactor system is proposed, where spiral tube and tapered fluidized mixing column are included. To maintain the growth process continuous, a control panel based many valve systems are used. Based on algal mass productions, the sparging of air and CO₂, into reactor was optimized. Light distribution into transparent glass based reactor is designed; figure bottom left. A combined reactor model has been proposed to design the process in continuous mode, figure, bottom extreme right. Glass reactor photo-bioreactors (PBR) has been used primarily to study all such growth propagation of algae collected from local sources. To increase and to differentiate the growth potential of unicellular/ monoculture algae from multicellular algal weeds, water circulating open pond has also been used. Controlled photoreaction has been found to be essential to optimize the changing variations of lipid (oil), protein (food), carbohydrate (fertilizer) profiles. Unicellular algae are of interest for the production of polysaccharides, pigments, polyunsaturated fatty acids, and enzymes (proteins), supposed to be efficient in a monoculture of algae, aseptically grown, at fixed pH, viscosity, temperature, and salt constituents. Figure bottom extreme left shows the light distribution of one lab- PBR and the middle shows the growth of algae, at side wall of our Lab-PBR. The temperature control both by a chiller and by thermo stating water  bath have been reproduced, as shown in figure, top lab-(PBR). To maintain aseptic environment inside the reactor a magnet stirrer is used. To achieve average photon flux, various hollow glass tube (heat and shell) and spiral tubes are proposed, where light will be placed inside the reactor. It has been proved from our experiment, that the changing properties of algae could also be varied both by external open sun-light and internal LED light. We will study these properties in future both by algal cellular and biochemical properties, enzymes, fats and oils.. The algae (unknown) were collected from the local ponds of Badu- Madhyamgram-Kolkata- India.