Method for wet extraction of purified microalgae oil

Abstract

The invention provides a method for wet extraction of purified microalgae oil. The method comprises the following steps: (1) adding an ethanol solution into ooze of collected microalgae, quickly stirring the mixture uniformly, carrying out centrifugation, and collecting sediments to obtain dehydrated algae ooze; (2) adding non-toxic or slightly-toxic organic solvent of a water solution of the organic solvent into the dehydrated algae ooze obtained in the step (1), carrying out cell disruption on the algae ooze, and extracting coarse oil in the microalgae; (3) carrying out centrifugation, collecting the coarse oil obtained in the step (2), adding water and inorganic salt into the coarse oil, stirring the mixture uniformly to form a coarse oil-water solution, adding n-hexane into the coarse oil-water solution, carrying out standing layering or centrifugal layering after uniform mixing to form three layers which are the upper solution layer, the middle solid matter layer and the lower solution layer, and collecting the solution on the upper layer; (4) carrying out desolvation on the solution on the upper layer to obtain the microalgae oil. According to the method for wet extraction of the purified microalgae oil, the yield of esterified grease is high, operation is easy, and energy consumption is low.

Description

technical field [0001] The invention relates to the field of energy and microalgae biotechnology, in particular to a method for obtaining purified microalgae oil through ethanol dehydration-wet oil extraction-n-hexane extraction. Background technique [0002] With the growth of population and the improvement of living standards, the demand for energy, especially transportation energy, is increasing worldwide; at the same time, the problems of global warming and the reduction of oil reserves are becoming increasingly prominent. As an energy source that can be supplied locally, is easily biodegradable, and can be directly applied to existing diesel engines and reduce exhaust emissions, biodiesel is widely considered to be the most promising alternative to petroleum. [0003] A major obstacle currently facing biodiesel development is the availability of renewable feedstocks. It is estimated that raw material cost accounts for 45-58% of the total production cost of biodiesel (E...

AI Technical Summary

Problems solved by technology

But this method has the following disadvantages: 1. Other components such as protein are also extracted in the oil extraction process, resulting in a waste of nutrients; 2. Due to the low solubility of oil in water, the oil extraction rate of acid-base water extraction is often only 40-70%; 3. The resulting acid-base wastewater treatment costs are relatively high

However, ionic liquids are expensive and difficult to recycle

[0010] Membrane separation in-situ extraction method uses biocompatible solvents (such as dodecane, d-limonene, and p-cymene, etc.), and extracts oil while microalgae are cultivated, and can extract microalgae in the culture pool without destroying the cell wall. Oil in algal cells (Bioresource Technology, 2013, 134(2013): 271-275), but the extraction efficiency of this method is low, and further research is needed to determine whether it has long-term effects on microalgal cell viability and oil synthesis

[0011] In most of the current methods of wet extraction of microalgae oil, or require high energy consumption of microalgae drying process, or require high equipment and energy input, or cannot use other nutrients in microalgae except oil, or oil low extraction rate

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