Multi-component extraction process of high added value compounds from microalgae with supercritical CO2: A technical and economic study

Abstract

In this work a multicomponent extraction process of high added value compounds (principally omega-3 fatty acids and carotenoids) from a microalgal matrix (Chlorella vulgaris), using supercritical CO2, was studied. Chlorella's metabolites were analyzed singularly, not as a pseudocomponent, and their affinities to the solvent were explored. The Simplified Broken and Intact Cell model was implemented in order to represent the extraction yields and to define the best conditions in terms of operative variables, ensuring the preservation of the bioactive and thermolabile properties of the extracted metabolites. Moreover, these conditions were chosen also for keeping carotenoids’ solubility in supercritical CO2 very low, in order to separate them (residue stream) from fatty acids (extract stream) without further purification steps. All of these informations were used to implement a simulation of the process, optimizing the daily cycles and increasing the productivity. As last step, calculations of the energy and utilities’ consumption for the estimation of the Operating Expense (OPEX) and Capital Expenditure (CAPEX), as starter point for a future industrial implementation of the process, were carried out.