ABSTRACT
The utilization of microalgal biomass for the production of environmentally friendly chemicals and polymers in industrial-scale plants is presently inhibited by several technical and economic barriers. Thus, the applied (thermo)chemical, enzymatic, microbial, etc., technologies for the conversion of microalgal biomass to valuable products should be designed and analyzed to optimize the efficiency of the related process steps and minimize the relevant production cost. In this chapter, the economic potential of two Botryococcus braunii strains to produce high added value metabolites, as well as their derivatives, are thoroughly discussed. The conceptual design and optimization of several flowsheets led to the identification of eight scenarios for the production of exopolysaccharides, hydrocarbons, 1,4-pentanediol, poly(ethylene 2,5-furandioate), adipic acid and ethylene/propylene. The model-based simulation and sensitivity analysis of the eight scenarios disclosed the importance of both biomass cultivation and metabolites separation steps. These process steps are the clear ‘hotspots’ for both capital and operation expenditures. Overall, the scenarios that consider exopolysaccharides and hydrocarbons as the final products are more promising than the ones that employ their further conversion to chemicals and polymers. Taking into account that the optimization of all the involved process steps is a prerequisite and that the targeted products should be of higher than commodities value, the developed microalgal conversion pathways present a strong potential to operate in the near future under economic sustainability.
