Intensive cultivation of microalgae (eukaryotic and prokaryotic) to produce biomass for energy purposes involving the biofiltration of CO2 from combustion gasses.
â€¢ To evaluate the intensive and integrated cultivation of microalgae (eukaryotic and prokaryotic) to produce (non-lipid) biomass for energy purposes, applying conventional fermentation technologies, associated with the biofiltration of CO2 from combustion gasses and with a biorefinery model.
a. Establish the suitability of strains selected by the Bioagramar Foundation (especially filamentous cyanobacteria) for fermentative energetic cultures (and start a program to identify new symbiotic strains, species or cultures) suitable for cultivation in simple media (conventional agricultural fertilizers) and under natural conditions (direct solar irradiation) in the following environments:
â€¢ fresh water
in 5- to 8-litre semi-open tubular vertical photobioreactors with scalable hydrodynamics (for the purpose of ensuring the possibility of being able to scale the cultivation of the selected strains in photobioreactors two to three orders of magnitude larger).
b. Verify and evaluate the induction of aggregates (between 0.5 mm to 2 cm in diameter/length) of the selected (unialgal and multialgal) strains by spontaneous autoflocculation (preferred) or induced by pH (chemical flocculants will be used if autoflocculating strains are not available) that allow harvesting through simple effluent filtration (through a mesh larger than 300-400 microns), even without the need to apply vibration to the harvest by means of mechanical filtration.
c. Determine the percentage of carbon fixed in biomass and excreted (DOM), especially in cultures of microalgae that excrete polysaccharides, so as to ascertain:
â€¢ The real percentage of fermentable photosynthetic carbon (in biomass harvestable by mess filtration)
â€¢ The possibility of formulating comprehensive fermentations of the entire culture medium.
â€¢ The possibility of carrying out a dual fermentation: aerobic (ethanol, in very dilute fermenters) and methanogenic (anaerobic).
d. Determine the behaviour of the strains (size, composition, production) best suited to cultivation in carbonated systems with:
â€¢ gasses from industrial combustion
e. Evaluate the energy behavior and efficiency (with no pre-analysis of composition, only post-analysis of the most productive strains) of the direct use of the microalgal paste (with no pre-processing vs. thermochemical pretreatment), cultivated in two phases (exponential vs. stationary), harvested by filtration (estimated at between 8-20% of PS) and loaded directly into standard (multicolonial) anaerobic fermenters to produce biogas from cultures grown in two types of salinity:
â€¢ Fresh water
f. Evaluate the potential industrial use of the (theoretically proteinous) residual pellet of the above fermentation processes by analysing its composition and nutrient content.