A novel microalgal lipid extraction method using biodiesel (fatty acid methyl esters) as an extractant

Enhanced isolation of lipids from microalgal biomass with high water content for biodiesel production

In present study, lipids were extracted from unbroken microalga Chlorella vulgaris with high water content (50% microalgal solution) through three-phase partitioning (TPP). The method was found to extract around 15.9% of total lipid transformable to methyl esters (LTMEs) from unbroken microalgal cells which is two times of Bligh and Dyer method. We investigated the effects of various parameters on TPP performance and were optimised through response surface methodology. The results indicated that incubation duration, temperature and extraction time were positively correlated with LTME extraction efficiency. The optimum temperature was 60 °C, incubation duration was 120 min, extraction time was 60 min, ratio of solvent to DKP was 1:1. The FAME yield was calculated as 12.05% and major fatty acids together accounted for 71.33% which indicated the great potential of the proposed lipid extraction procedure for microalga-based biodiesel production.

Fast and simple transesterification of epoxidized soybean oil to prepare epoxy methyl esters at room temperature

Epoxidized soybean oil methyl esters were prepared via transesterification of epoxidized soybean oil (ESBO) with methanol catalyzed by cheap and stable sodium hydroxide (NaOH). The transesterification could be completed in only 5 min at room temperature (25 °C) without loss of the epoxide function and the transesterification rate was promoted significantly while the utilization of 5% acetone as co-solvent. The afforded products epoxidized methyl esters represent a renewable substrate that is readily converted into surfactants, fuel additives and other valuable industrial products.

One-step production of biodiesel from wet and unbroken microalgae biomass using deep eutectic solvent

One-step and Two-step methods were studied for lipid extraction from wet and unbroken (water content is 65-67%) Chlorella sp. and Chlorococcum sp. (GN38) using deep eutectic solvent (DES) treated microalgae cells. Further we optimized the extraction process and studied on its underlying mechanism. Among all DES, Choline chloride-Acetic acid (Ch-Aa) DES treatment showed optimal conditions at the mass ratio of DES: methanol-H₂SO₄ (2.00%) mixture: algae biomass was 60:40:3 with reaction time was 60min, and the optimum temperature was 110°C (Chlorococcum sp.) and 130°C (Chlorella sp.) respectively. The total content of FAME by One-step method with DES treatment was improved by 30% compared with Two-step method. This process is effective on wet and unbroken paste of microalgae biomass, so the FAME extracted using one-step with DES process is feasible for microalgae based biodiesel production.

Simultaneous cell disruption and lipid extraction in a microalgal biomass using a nonpolar tertiary amine

A simultaneous cell disruption and lipid extraction method is developed for microalgal biodiesel production using a triethylamine/methanol solvent system. Individually, the pure solvents, i.e. triethylamine and methanol, do not exhibit significant enhancement in lipid extraction, but a 3:7 (v/v) triethylamine/methanol mixture exhibits the highest lipid extraction, corresponding to 150% of the conventional chloroform/methanol (2:1, v/v) solvent extraction. This extraction is equivalent to 92.5% of the total lipids, even when extracted from a wet microalgal biomass with a water content of 80%. The cell surfaces of the microalgae are significantly disrupted without using additional cell disruption reagents and without requiring energy-intensive equipment. The lipid mass transfer coefficient is 1.6 times greater than that of the chloroform/methanol solvent system. It is clearly demonstrated that triethylamine and methanol cooperate well for the cell disruption and lipid extraction.