For the extraction of oil from algae which is obtained from open pond system. solvent extraction method recovers almost all the oil and leaves behind only %. Oil extraction from algae is a hotly debated topic currently because this process is one of the more costly processes which can determine the sustainability of. Microalgae biomass can be used to produce numerous value added products such as biodiesel, bioethanol, biogas, biohydrogen, fish feed, animal feed, human.
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The use of microwaves to disrupt cells and increase efficiencies of vegetable lipid and algae oil extraction is a promising development, though applications outside of analytical labs are unclear.
Recent work on extraction of lipids from three different types of oleaginous microalgae compared bead beating, sonication, autoclaving, osmotic shock, and microwaves and suggested that microwave disruption prior to solvent extraction algae oil extraction the most efficient method.
The concept behind the earliest and well-known co-solvent extraction procedure. After the extraction reaction is complete, water which is not miscible with chloroform is added to the co-solvent mixture until a two-phase system develops in which water and chloroform separate into two immiscible layers.
The lipids mainly separate to the chloroform layer and can then be recovered for analysis. Nitrate was found to be the preferred source of nitrogen, in regards to amount of biomass grown.
Urea is a readily available source that shows comparable results, making it an economical substitute for nitrogen source algae oil extraction large scale culturing of algae.
In one study  nitrogen deprivation for 72 hours caused the total fatty acid content algae oil extraction a per cell basis to increase by 2.
It is vital for the lipid content algae oil extraction algal cells to be of high enough quantity, while maintaining adequate cell division times, so parameters that can maximize both are under investigation. Wastewater treatment facility A possible nutrient source is waste water from the treatment of sewage, agricultural, or flood plain run-off, all currently major pollutants and health risks.
How Algae Biodiesel Works
However, this waste water cannot feed algae directly and must first be processed by bacteria, through anaerobic digestion.
If waste water is not processed before it reaches the algae, it will contaminate the algae in algae oil extraction reactor, and at the very least, kill much of the desired algae algae oil extraction. In biogas facilities, organic waste is often converted to a mixture of carbon dioxide, methaneand organic fertilizer.
Organic fertilizer that comes out of the digester is liquid, and nearly suitable for algae growth, but it must first be cleaned and sterilized.
Algae Oil Extraction: Small and Commercial Scale -
However, heavy metals, trace metals, and other contaminants in wastewater can decrease the ability of cells to produce lipids biosynthetically and also impact various other workings in the machinery of algae oil extraction. The same is true for ocean water, but the contaminants are found in different concentrations.
Thus, agricultural-grade fertilizer is the preferred source of nutrients, but heavy metals are again a problem, especially for strains of algae that are susceptible to these metals. In open pond systems the use of strains of algae that can deal with high concentrations of heavy metals could prevent other organisms from infesting these systems.
Varying beads and bead sizes have different impact on the dispersion efficiency [ 43 ]. Doucha and Livansky [ 26 ] found that zirconium dioxide beads 0. The algae oil extraction variation in power algae oil extraction is a result of varying microalgae species and operation parameters.
Algae Biodiesel Engineering: Extracting Oil from Algae | HowStuffWorks
The advantages of using bead beating are the simplicity, rapidness of the method, reproducibility of results and low labor intensity requirement [ 4849 ]. However, pre-treatment of microalgae cells using bead milling can be difficult to scale up and requires the use of a algae oil extraction jacket in order to prevent algae oil extraction degradation of the desired product [ 10254850 ].
Additionally, bead mill pretreatment is not a selective product recovery technique, which requires further processing to remove the undesired compounds [ 49 ].
The biomass undergoing bead disruption techniques must be dry and concentrated in order to achieve high disruption efficiency [ 4951 ]. Ultrasonication Algae oil extraction is another mechanical method that can be used for pre-treatment of microalgae prior to lipid extraction.
In this method, algae are exposed to high intensity ultrasonic waves, creating algae oil extraction cavitation bubbles around the cells. The bubbles collapse and emit shockwaves that shatter the cell walls causing the intracellular lipids to enter the bulk of the solution as shown in Figures 9 and 10 [ 2452 - 54 ].
Ultrasonic assisted microalgae lipid extraction has been noted to significantly increase the yields and reduce the extraction time [ 102455 ].
Pernet and Tremblay [ algae oil extraction ] concluded that the ultrasonic method for oil extraction from Chaetoceros gracilis increased the extraction rate which affects the recovery of lipid extracts.
There are some contradictions in the literature regarding scale up. Micrographs of microalgae before and after ultrasound treatment .
Schematic of cell disruption using ultrasound energy . Prabakaran and Ravindran [ 32 ] found that the lipid recovery from Chlorella sp. De Souza Silva [ 60 ] tested the pre-treatment of microalgae culture using microwave, autoclaving and ultrasonication technology for lipid extraction and found that ultrasound resulted in the algae oil extraction yields.