Cultivation and energy efficient harvesting of microalgae using thermoreversible sol-gel transition

Abstract

Microalgae represent a promising source of renewable biomass for the production of biofuels and valuable chemicals. However, energy efficient cultivation and harvesting technologies are necessary to improve economic viability. A Tris-Acetate-Phosphate-Pluronic (TAPP) medium that undergoes a thermoreversible sol-gel transition is developed to efficiently culture and harvest microalgae without affecting the productivity as compared to that in traditional culture in a well-mixed suspension. After seeding microalgae in the TAPP medium in a solution phase at 15 °C, the temperature is increased by 7 °C to induce gelation. Within the gel, microalgae are observed to grow in large clusters rather than as isolated cells. The settling velocity of the microalgal clusters is approximately ten times larger than that of individual cells cultured in typical solution media. Such clusters are easily harvested gravimetrically by decreasing the temperature to bring the medium to a solution phase.

Characterization of Core Microbiomes and Functional Profiles of Mesophilic Anaerobic Digesters Fed With Chlorella vulgaris Green Microalgae and Maize Silage

“…Benefits of a microalgal biomass include versatility of utilization for energy purposes such as biohydrogen, bioethanol, biodiesel, and biogas production (Posten and Schaub, 2009;Harun et al, 2010;Klassen et al, 2016;Uggetti et al, 2016), and complex biorefinery applications (Yen et al, 2013). The main technological disadvantages, i.e., requirement for large land area and efficient harvesting, are addressed in ongoing research (Estime et al, 2017;Ummalyma et al, 2017).…”

Phycoremediation of aquaculture wastewater and algal lipid extraction for fuel conversion

“…whereas for macroalgae simple technique such as drying and storing is basically preferred but however few techniques from microalgae harvesting techniques are also operated [34]. Thermo reversible gel transition [35,36] characterized with either agar or sol gel for harvesting of algae where clustered cells are settled at bottom and collected the biomass. Flocculation is another technique of harvesting.…”

Material Balance

“…For instance, the medium is usually water but growth medium modifications with other gels have been tested (e.g. by encapsulating them within gel-based biomaterial such as hydrogel) (Estime et al 2017).…”

“…In fact, to meet the growing interest on microalgae renewable biomass, it is crucial to increase their production. However, obtaining energy efficient cultivation and harvesting technologies are necessary steps to improve their economic viability (Estime et al 2017).…”