Supercritical CO2 extraction of hydrocarbons from Botryococcus braunii as a promising bioresource

- Supercritical CO2 extraction of hydrocarbons from Botryococcus braunii was carried out.
- The optimum conditions were elicited as 200 bar, 40 °C and CO2 flow rate of 8.71 g/min.
- The highest total extract and hydrocarbon yields were 1.74 g and 147.5 mg/g dry microalgae.
- Supercritical CO2 extraction can serve as a green and sustainable alternative.

Microalgae has been a sustainable resource for producing bio-based products and hydrocarbon rich varieties are significant sources for converting into green naphtha and further to ethylene and propylene. The objective of this study was to develop an optimized supercritical CO2 method for extracting hydrocarbons from Botryococcus braunii. A 3-level factorial design was used to evaluate the effects of pressure (125-200 bar) and CO2 flow rate (5-7 g/min) at a constant temperature of 40 °C to elicit the conditions maximizing total extract and hydrocarbon yields. Maximum total extract and hydrocarbon yields were obtained at a pressure of 200 bar, and a CO2 flow rate 8.71 g/min, yielding 1.74 g extract and 147.5 mg hydrocarbon/g dry microalgae. Considering the large diversity of microalgae species, the ability to effectively extract oil from cellular biomass is of prime importance and supercritical CO2 extraction can serve as a green and sustainable alternative.

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