Computer-aided solvent screening for the fractionation of wet microalgae biomass

Abstract

Computational solvent selection enables the screening of more than 8000 solvent candidates for the fractionation of wet microalgal cells.

Superstructure optimization of a microalgal biorefinery design with life cycle assessment‐based and economic objectives

“…After a desired extraction time, subsequently the water/organic solvent ratio is decreased by inserting additional organic solvent into Extr‐I to establish a separation into aqueous and organic liquid phases. Following the prediction as elaborated in an earlier work, 19 the two‐liquid phase system is expected to form an autonomous partition of carbohydrates and polar molecules. Based on computational predictions, 19 it could be expected that solid residual biomass is left over after Extr‐I.…”

“…Following the prediction as elaborated in an earlier work, 19 the two‐liquid phase system is expected to form an autonomous partition of carbohydrates and polar molecules. Based on computational predictions, 19 it could be expected that solid residual biomass is left over after Extr‐I.…”

“…2) is carried out for undisrupted, wet cells. As described in detail in our previous study, 19 the water/solvent ratio in Extr‐I is adjusted initially to establish only one liquid phase. After a desired extraction time, subsequently the water/organic solvent ratio is decreased by inserting additional organic solvent into Extr‐I to establish a separation into aqueous and organic liquid phases.…”

“…In the computational screening, 19 eight solvent candidates are identified for unit Extr‐I and three for Extr‐II. The solvent selection is challenging in the early stage process design, because a process flow sheet simulation requires the knowledge of thermodynamic properties to simulate the liquid–liquid equilibrium (LLE) for the solvent/water mixtures and the partition of the exploitable components between the phases.…”

“…The experimental LLE information, or reliable interaction parameters for mutual solubility estimation were lacking for a few solvent/water mixtures. We predicted the binary solvent/water phase equilibria computationally following the quantum chemical approach (COSMO‐RS, conductor like screening model for real solvents) similar to an earlier publication 19 . The solubility and the partition coefficients of the biomass constituents (neutral and polar lipids, fucoxanthin, protein, and carbohydrates) in the respective solvent‐mixtures were predicted using the COSMO‐RS and reference molecules were used as model compounds for protein and carbohydrate fractions.…”