(204t) Integrated Microalgae Biorefinery for the Production of Biodiesel and Value Added Products

Integrated microalgae biorefinery
for the production of biodiesel and value added products

Carla Valeria García Prieto, Vanina Estrada,
María Soledad Díaz, Chemical Engineering,
Planta Piloto de Ingeniería Química (PLAPIQUI), CONICET- Universidad Nacional del
Sur, Bahía Blanca, Argentina.

The
production of biofuels has been studied in the last
years as a solution for the increased demand of crude based fuels.
First-generation biofuels appear unsustainable
because of the potential stress that their production places on food
commodities, resulting in
the development of second and third generation biofuels, where lignocellulosic and algae biomass are considered as raw materials. Microalgae perform
oxygenic photosynthesis and live in freshwater, marine and terrestrial
environments while showing a wide diversity of morphologies, metabolisms and
cell structures. They have several features that make them attractive to obtain
products in farmaceutical, nutraceutical,
biofuels, and other industries. Microalgae reach high
cellular densities in culture and have simple growth requirements: light,
carbon dioxide, and other inorganic nutrients to grow. Carbon dioxide can be
obtained from waste streams from other plants. Many researchers have focused
their investigations on improving productivity of algae culture for ethanol,
hydrogen and biodiesel, based on control of the environmental conditions such
as light intensity, salinity, temperature, pH (Christy, 2007; Estrada et al., 2012) and on metabolic
engineering (Deng and Coleman, 1999; Paulo et
al., 2011). However, for cost-effective production of biofuels,
value added co-products need to be considered.

In this work, we formulate a
mixed-integer nonlinear programming model for the design of an integrated
microalgae-based biorefinery for the production of
biodiesel and co-products that include nutritional supplements, omega-3 fatty
acids, carotenoids, fertilizers, etc., depending on
the particular microalgae species considered. The production of biogas by anaerobic
digestion of the oil cake together with liquid waste streams is also included
in the superstructure. The model has been implemented in GAMS (Brooke et al., 2011) and solved with DICOPT.
Numerical results provide useful insights on the design of integrated biorefineries that use carbon dioxide as carbon source, as
well as quantitative information on economical benefits.

References

Brooke, A., Kendrick,
D., Meeraus, A., Raman, R. (2011), GAMS, A User
Guide. Washington, DC, USA.

Christi, Y. (2007). Biodiesel from Microalgae. Biotechnology Advances. 25: 294-306
Deng M., Coleman, J. (1999). Ethanol
synthesis by genetic engineering in cyanobacteria. Applied & Environmental
Microbiology. 65: 523-528.

Estrada, V., Vidal Vidal, R.,
Florencio, F. J., García Guerrero, M. and Díaz, M.S. (2012). Parameter estimation of bioethanol
production model by a genetic engineered cyanobacterium. AIChE Annual
Meeting, Pittsburg, USA.

Paulo, C., Di Maggio,
J., Estrada, V., Díaz, M.S. (2011). Optimizing
cyanobacteria metabolic network for ethanol production. Computer Aided Chemical Engineering. 29, 1366-1370.