Method for extracting microalga oil under assistance of carbonate and absorbing carbon dioxide for circulated culture

Abstract

The invention provides a method for extracting microalga oil under the assistance of carbonate and absorbing carbon dioxide for circulated culture, which comprises the following steps: (1) obtained microalga culture solution is concentrated into microalga concentrate, carbonate and basic ionic liquid are then added, heating is carried out for wall-breaking treatment, and thereby the cell walls ofmicroalgae are lysed; (2) organic reagent is added for salting-out extraction, and oil is separated from a water phase, and gets into an organic phase; (3) after carbon dioxide is introduced into thewater phase rich in carbonate until the pH value is 6.5 to 10.0, the water phase is then mixed with corresponding microalga medium to culture microalgae, and steps (1) to (3) are repeated. Because themethod directly adopts wet algae to extract oil, compared with the conventional dry alga oil extraction method, the method can reduce energy consumption cost brought by the spray-drying technique. Inaddition, the treated water phase can carry out the circulated culture of microalgae, and carbonate and water in the process of breaking the walls of microalgae to extract oil can be effectively recycled.

Description

technical field [0001] The invention relates to a method for extracting oil from microalgae and recycling of waste water, in particular to a method for extracting oil from wet algae and using the extracted waste water to circulate and cultivate microalgae. Background technique [0002] Microalgae are photosynthetic microorganisms that have great potential applications in biofuel production. The oil yield per unit area of ​​microalgae is 130 times that of soybean and 10 times that of palm, and large-scale cultivation does not occupy arable land, so it has great potential in the production of biodiesel instead of petroleum. At the same time, it also has the advantages of high photosynthetic efficiency and short growth cycle. At present, the most important problem restricting the development of microalgae biodiesel is cost. One is to reduce the cost of microalgae cultivation, and the other is to improve the production process. [0003] Many processes for the production of bio...

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Problems solved by technology

[0005] 1. Most of the cells containing microalgae have thicker cell walls, so it takes a long time to directly use organic solvents and acid-base methods to extract oil, and the extraction efficiency is low

[0006] 2. At present, most of the industrial microalgae production of biodiesel adopts in-situ extraction, which will have strict requirements on the water in the system

Therefore, these processes need to use dry algae powder as a raw material for oil extraction, which will inevitably increase the cost of spray drying and energy loss

[0007] 3. Using wet algae to directly extract biodiesel will reduce the cost and energy loss caused by spray drying, but at the same time will generate a large amount of waste liquid, which will increase environmental pressure

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