Method for extracting and purifying microalgae biodiesel

Abstract

The invention relates to a method for extracting and purifying microalgae biodiesel. The method comprises the following steps: crushing microalgae, namely, introducing an algae liquid into a crushing tank, crushing microalgae with ultrasonic waves, feeding into a settling pond, performing natural precipitation to form an upper layer and a lower layer, and sucking algae slurry of the lower layer into a reaction tank, wherein the upper layer is water, and the lower layer is algae slurry; performing in-situ extraction, namely, adding a reaction agent and an extraction agent into the reaction tank with the algae slurry, heating till the temperature is 60-70 DEG C, and stirring all the time; performing separation purification, wherein n-hexane is adopted as an extraction agent; the volume ratio of the reaction agent to the extraction agent is 1:1; the volume ratio of the reaction agent to the algae slurry is (1-2):1; and the extraction agent needs to be replaced once every 4-6 hours; and after extraction is completed, sucking the upper liquid obtained after extraction into a collecting tank, stirring while heating, and evaporating the extraction agent into a condenser, thereby obtaining the biodiesel which is left in the reaction tank. The method has the advantages that material consumption is reduced, the steps are simple, the operation is simple and convenient, and the yield can be approximate to 100%.

Description

technical field [0001] The invention relates to the field of bioenergy, in particular to a method for refining microalgae biodiesel. Background technique [0002] With the development of modern industry and the rapid increase of population, the world's demand for energy is increasing, and the exploitation and utilization of earth resources are also increasing. Energy and environmental issues have become the focus of human attention. According to relevant assessment reports, according to the current speed, the world's traditional oil resources will be exhausted in 40 years. With the depletion of oil and coal resources and the air pollution caused by their combustion, countries around the world are actively developing and utilizing renewable new resources. [0003] The common method for producing biodiesel is the transesterification method, which is a process in which oil and methanol are heated and reacted under acid or base catalysis to form fatty acid methyl esters and the...

AI Technical Summary

Problems solved by technology

Because the environment with high water content is conducive to the growth of microalgae, the water content of the harvested microalgae is usually high, and it must be fully dried before oil extraction, and the drying operation costs a lot, which can account for the amount of microalgae biodiesel. One-third to one-half of the production cost