PRODUCCIÓN DE BIODIESEL POR MICROALGAS, COMO UNA ESTRATEGÍA DE FUENTES ALTERNAS DE ENERGÍA

Abstract

In the last four decades, the society has decided to reduce its dependence on oil and coal. This problem makes renewable energy to look with a heightened visibility in the future. Within this category is bioenergy, which is the conversion of biomass into fuels (biodiesel and bioethanol) for power generation. Nowadays the idea to use microalgae biomass creates expectations and confidence in a short-term to be considered the first economical way to produce biomass, collection of oils and biodiesel production because it costs less than conventional processes. Initially it was evaluated the growth of the microalgae Chrorella protothecoides in different culture media, finding that the modified Bold Basal Medium is the most suitable for cultivation the microalgae. Subsequently it was evaluated the growth of microalgae Chlorella vulgaris and Chlorella protothecoides at scaling level, starting from the purification of the strain, growth in test tube, Erlenmeyer Flasks with the capacities of 100, 500 y 1000 mL up to a 20 liter jug. Results for both species of microalgae showed good growth, with an increased in total solids (greater biomass productivity). Chlorella protothecoides culture, began with a cell density of 1, 00 X 105 cell mL-1 (flask and jug). The growth showed a similar trend (flask and jug), with a lag phase, which ended on day 7 (5,95 X 105 cell mL-1) for flask and 1,42 X105 cell mL-1 in the day 3 for jug; the exponential phase lasted 29 days (9,48 X 106 cell mL-1) (flask) and de 1,10 X106 cell mL-1 of 16 days for jug. The stationary phase appeared after 30 days (9.42 X106 cell mL-1) (flask) and of 2,80 X 106 cell mL-1 from day 24 (jug). For Chlorella vulgaris culture, initiated with a cell density of 5,00 X 104 cell mL-1 for flask and 1,00 X 105 cell mL-1 for jug. The growth showed a similar trend with a lag phase which ended on day 2 (5,28 X 105 cell mL-1) (flask) and 1,16 X105 cell mL-1 in day 4 (jug); The exponential phase lasted 13 days (2,50 X 107 cell mL-1) (flask) and 1,11 X 107 cell mL-1 after 33 days (jug). The stationary phase occurred after 14 to 18 days (2,12 X107 cell mL-1) (flask) and 1,09 X 107 cell mL-1 after 38 days (jug). Finally the last phase of experimentation consisted of the standardization of the methodology to assessing of the growth of the microalgae C. vulgaris and C. protothecoides at massive scale (jugs of 20 liters) through the monitoring of growth kinetics, physicochemical parameters and biomass production. Finally, was assessed the number of carbons obtained from the oil produced in the three systems (carboy 1, 2 and 3) of C. protothecoides, while for C. vulgaris only the carboy 2. Therefore, in this research are given the necessary foundation for the cultivation of microalgae, oil extraction and production of biomass for energy purposes.