TWI547554B - Method of extracting oil from algae - Google Patents

Description

Method for extracting oil from algae

The present invention relates to a method of extracting oils and fats from algae, and more particularly to a recycling process for an oil extraction process.

At present, most of the world's energy supply comes from fossil fuels such as coal, oil, natural gas, etc., but the natural reserves of fossil fuels are decreasing. If there is no reduction in dependence on fossil fuels, there will always be a depletion day. In recent years, the development of alternative energy sources is a very important issue due to the sharp increase in energy demand for global economic development.

Microalgae is a biomass energy with great development potential. Among various biomass materials, microalgae have the characteristics and advantages of rapid growth, absorption of CO ₂ , non-toxicity, and no competition with food crops, and are very suitable for development as a biomass fuel resource crop. Microalgae can be used as a source of raw diesel, biomass alcohol, or biofuel. Although the use of microalgae to produce biomass fuel is technically feasible, it has not yet reached the stage of commercial production in the world, mainly because of the high cost and energy consumption of microalgae in farming and downstream processes. To.

Therefore, there is an urgent need to improve the oil extraction efficiency of microalgae and reduce the energy consumption required to recover the solvent of the extraction oil, so as to solve the problem of excessive energy consumption of the microalgae extraction process.

A method for extracting oil in algae according to an embodiment of the present invention, Including: (a) mixing algae with amines, causing amines to dissolve the oil in the algae to form a first solution; (b) mixing the hydrophobic ionic liquid with the first solution and then layering to form an oil layer and an amine plus hydrophobic ionic liquid layer (c) after separating the oil layer and the amine-added hydrophobic ionic liquid layer, carbon dioxide or sulfur dioxide is introduced into the amine hydrophobic ionic liquid layer, so that the amine forms ammonium amide ammonium salt, ammonium hydrogencarbonate salt, ammonium amide sulfonate Salt, or ammonium hydrogen sulfate, after stratification with the hydrophobic ionic liquid; and (d) separating the hydrophobic ionic liquid from ammonium urethane, ammonium bicarbonate, ammonium sulfonate, or ammonium hydrogen sulfate, The air or inert gas is passed to an ammonium urethane salt, an ammonium hydrogencarbonate salt, an ammonium sulfonate ammonium salt, or an ammonium hydrogen sulfate salt to convert it back to an amine, wherein the amine is a primary amine, a secondary amine, or a third Amine.

Fig. 1 is a flow chart showing a method of extracting fats and oils from algae in an embodiment of the present invention.

Fig. 1 is a flow chart showing a method of extracting fats and oils from algae in an embodiment of the present invention. In the step (a), the algae and the amine are mixed (a) first, and the amine is dissolved in the algae to form a first solution. In an embodiment of the invention, the algae liquid (such as microalgae) containing a large amount of water is directly mixed with the amine without first drying or dehydrating the algae. Conventional methods for extracting oil from algae usually require drying the algae. Compared with the conventional process method, the method of the invention for omitting dry algae can save energy and time. The above amines are primary amines, secondary amines, or tertiary amines. In one embodiment of the invention, the amine has a log K _ow (octanol-water partition coefficient) value between 0.5 and 2.5. If the logK _ow value of the amine is too low, it is too hydrophilic and the oil extraction rate is poor. If the logK _ow value of the amine is too high, it is too hydrophobic to enter the algae to extract the oil. For example, the amines may be N-methylcyclohexylamine, N-isopropyl-cyclohexylamine, dipropylamine, cyclohexylamine, tert-butylamine, piperidine, N,N-dimethylcyclohexane. Amine, triethylamine, other suitable primary amines, secondary amines, tertiary amines, or combinations thereof. In an embodiment of the invention, the weight ratio of algae to amine is between 1:20 and 1:1. If the amount of amines is too high, the extraction cost is increased. If the amount of the amine is too low, the oil in the algae cannot be effectively extracted.

Then proceeding to step (b), mixing the hydrophobic ionic liquid with the first solution After layering. In one embodiment, the upper layer is an oil layer (such as algal oil), the middle layer is a water-based algae liquid, and the lower layer is an amine-based hydrophobic ion liquid layer. In another embodiment, the algae are dried prior to dehydration, and in step (b), only the upper oil layer is layered, and the lower amine is added to the hydrophobic ionic liquid layer. The above hydrophobic ionic liquid is required to have the following characteristics: low melting point, hydrophobicity, compatibility with amines but insolubility with grease. For example, the hydrophobic ionic liquid can be 1-butyl-3-methylimidazolium hexafluorophosphate, 1-butyl-3-methylimidazolium bistrifluoromethanesulfonimide salt, N-butyl- N-methylpiperidine bistrifluoromethanesulfonimide salt, other suitable hydrophobic ionic liquids, or combinations thereof. In an embodiment of the invention, the weight ratio of the algae to the hydrophobic ionic liquid is between 1:20 and 1:1. If the amount of the hydrophobic ionic liquid is too low, the amines cannot be removed from the oil layer. If the amount of the hydrophobic ionic liquid is too high, the water in the first solution cannot be effectively separated.

Then proceeding to step (c), separating the oil layer (upper layer) and the amine plus the hydrophobic After the ionic liquid layer (lower layer), carbon dioxide (or sulfur dioxide) is introduced into the amine-added hydrophobic ionic liquid layer. Carbon dioxide (or sulfur dioxide) will react with amines such as formula 1 or 3 (or formula 2 or formula 4), the amine is formed into an ammonium amide ammonium salt or an ammonium hydrogencarbonate salt (or ammonium sulfamate or ammonium hydrogen sulfate salt) and then layered with a hydrophobic ionic liquid. In Formulas 1 to 4, R, R', and R" are determined depending on the actual structure of the amine. In one embodiment of the present invention, the above-mentioned carbon dioxide or sulfur dioxide is introduced into the amine-added hydrophobic ionic liquid layer. The flow rate is between 1 sccm and 100 sccm. If the flow rate of carbon dioxide or sulfur dioxide is too slow, it will prolong the time for the amine to form ammonium ammonium carbamate or ammonium hydrogencarbonate (or ammonium ammonium sulfonate or ammonium hydrogen sulfate). If the flow rate of carbon dioxide or sulfur dioxide is too fast, it will increase the gas dosage and cost without increasing the amine to form ammonium amide or ammonium hydrogencarbonate (or ammonium sulfonate or ammonium hydrogen sulfate). .

Following step (d), separating the hydrophobic ionic liquid from the urethane Ammonium salt or ammonium hydrogencarbonate (or ammonium sulfonate or ammonium hydrogen sulfate). Then, air or an inert gas is introduced into the ammonium amide or ammonium hydrogencarbonate (or ammonium sulfamate or ammonium hydrogen sulfate) to convert it back to the amine such as Formula 5 or Formula 7 (or Formula 6 or Formula 8) is shown. In the formulae 5 to 8, R, R', and R" are determined depending on the actual structure of the amine. In an embodiment of the invention, the inert gas may be nitrogen, helium, or a combination thereof. In an embodiment of the invention, the flow rate of the air or inert gas to the ammonium carbamate or ammonium hydrogencarbonate (or ammonium ammonate or ammonium hydrogen sulfate) is between 1 sccm and 100 sccm. If the flow rate of air or inert gas is too slow, the ammonium amide or ammonium hydrogencarbonate (or ammonium sulfonate or ammonium hydrogen sulfate) may be extended. Salt) The time to convert back to the amine. If the flow rate of air or inert gas is too fast, the amount of gas may be increased instead of increasing the ammonium amide or ammonium hydrogencarbonate (or ammonium sulfamate or ammonium hydrogen sulfate) to return to the amine. cost.

In an embodiment of the invention, air or an inert gas is passed into the amine When the ammonium formate or ammonium hydrogencarbonate (or ammonium sulfonate or ammonium hydrogen sulfate) is heated, the ammonium amide or ammonium hydrogencarbonate (or ammonium sulfamate or ammonium sulphate is heated to Between 40 ° C and 90 ° C to further accelerate the conversion of ammonium amide or ammonium hydrogencarbonate (or ammonium sulfonate or ammonium hydrogen sulfate) back to the amine. If the heating temperature of the above steps is too high, then The recovery of energy consumption is too high, but the cost is increased. The amine formed in the above step (d) can be mixed with the next batch of algae as in step (a) for the subsequent cycle of the oil extraction process. In other embodiments, the amine The class can be used for other purposes and is not limited to the application of oils in the extraction of algae.

The above and other objects, features, and advantages of the present invention will become more apparent and understood.

Example Example 1

30 g of algae solution having a water content of 85% was added, and 52.08 g (about 60 mL) of N-methylcyclohexylamine was added thereto, and the mixture was extracted by magnetic stirring at room temperature, and then the algae were removed by filtration. Next, 86.16 g (about 60 mL) of hydrophobic ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate ([C ₄ -mim][PF ₆ ]) was added to the filtrate and magnetically stirred at room temperature. After mixing, the layers are allowed to stand. The upper layer of the liquid phase is algae oil, the middle layer of the liquid phase is an algae liquid, and the lower layer of the liquid phase is a mixed layer of N-methylcyclohexylamine and an ionic liquid [C ₄ -mim][PF ₆ ]. After taking the algae oil and the algae liquid, the lowermost mixed solution is passed through a carbon dioxide gas, and N-methylcyclohexylamine is formed into an ammonium hydrogencarbonate salt to be separated from [C ₄ -mim][PF ₆ ], that is, the ionic liquid is completed. Recycling. Next, an ammonium hydrogencarbonate layer was taken, and nitrogen gas was introduced at 50 ° C to remove carbon dioxide from the ammonium hydrogencarbonate to form N-methylcyclohexylamine. The oil extraction rate of the above procedure is about 90%, the recovery rate of [C ₄ -mim][PF ₆ ] is about 98%, and the recovery rate of N-methylcyclohexylamine is about 85%.

Example 2

30 g of algae solution having a water content of 85% was added, and 52.08 g (about 60 mL) of N-methylcyclohexylamine was added thereto, and the mixture was extracted by magnetic stirring at room temperature, and then the algae was removed by filtration. Then 82.80g (about 60mL) of hydrophobic ionic liquid 1-butyl-3-methylimidazolium bistrifluoromethanesulfonimide salt ([C ₄ -mim][NTf ₂ ]) was added to the filtrate in the chamber After mixing under magnetic stirring, the mixture was allowed to stand for stratification. The upper layer of the liquid phase is algae oil, the middle layer of the liquid phase is an algae liquid, and the lower layer of the liquid phase is a mixed layer of N-methylcyclohexylamine and an ionic liquid [C ₄ -mim][NTf ₂ ]. After taking the algae oil and the algae liquid, the lowermost mixed solution is introduced into carbon dioxide gas, and N-methylcyclohexylamine is formed into an ammonium hydrogencarbonate salt to be separated from [C ₄ -mim][NTf ₂ ], that is, the ionic liquid is completed. Recycling. Next, an ammonium hydrogencarbonate layer was taken, and nitrogen gas was introduced at 50 ° C to remove carbon dioxide from the ammonium hydrogencarbonate to form N-methylcyclohexylamine. The oil extraction rate of the above procedure is about 85%, the recovery rate of [C ₄ -mim][PF ₆ ] is about 95%, and the recovery rate of N-methylcyclohexylamine is about 70%.

Example 3

30 g of algae solution having a water content of 85% was added, and 51.54 g (about 60 mL) of N-isopropylcyclohexylamine was added thereto, and the mixture was extracted by magnetic stirring at room temperature, and then the algae were removed by filtration. Next, 86.16 g (about 60 mL) of a hydrophobic ionic liquid [C ₄ -mim][PF ₆ ] was added to the filtrate, and the mixture was stirred under magnetic stirring at room temperature, and then allowed to stand for stratification. The upper layer of the liquid phase is algae oil, the middle layer of the liquid phase is an algae liquid, and the lower layer of the liquid phase is a mixed layer of N-isopropyl-cyclohexylamine and an ionic liquid [C ₄ -mim][PF ₆ ]. After taking the algae oil and the algae liquid, the lowermost mixed solution is passed through a carbon dioxide gas, and N-isopropyl-cyclohexylamine is formed into an ammonium hydrogencarbonate salt to be separated from [C ₄ -mim][PF ₆ ], that is, completion. Recovery of ionic liquids. Next, an ammonium hydrogencarbonate layer was taken, and nitrogen gas was introduced at 60 ° C to remove carbon dioxide from the ammonium hydrogencarbonate to form N-isopropyl-cyclohexylamine. The oil extraction rate of the above procedure was about 85%, the recovery of [C ₄ -mim][PF ₆ ] was about 95%, and the recovery of N-isopropyl-cyclohexylamine was about 80%.

Example 4

30 g of algae solution having a water content of 85% was added, and 44.28 g (about 60 mL) of di-n-propylamine was added, and the mixture was extracted by magnetic stirring at room temperature, and then the algae were removed by filtration. Next, 86.16 g (about 60 mL) of a hydrophobic ionic liquid [C ₄ -mim][PF ₆ ] was added to the filtrate, and the mixture was stirred under magnetic stirring at room temperature, and then allowed to stand for stratification. The upper layer of the liquid phase is algae oil, the middle layer of the liquid phase is algae liquid, and the lower layer of liquid phase is a mixed layer of dipropylamine and ionic liquid [C ₄ -mim][PF ₆ ]. After the algae oil and the algae liquid are taken out, the mixed solution of the lowermost layer is introduced into carbon dioxide gas, and the dipropylamine is formed into an ammonium hydrogencarbonate salt to be separated from [C ₄ -mim][PF ₆ ], that is, the recovery of the ionic liquid is completed. Next, an ammonium hydrogencarbonate layer was taken, and nitrogen gas was introduced at 90 ° C to remove carbon dioxide from the ammonium hydrogencarbonate to form dipropylamine. The oil extraction rate of the above process is about 75%, the recovery rate of [C ₄ -mim][PF ₆ ] is about 95%, and the recovery rate of dipropylamine is about 70%.

Example 5

30 g of algae solution having a water content of 85% was added, and 51.88 g (about 60 mL) of cyclohexylamine was added, and after magnetic stirring at room temperature for 1 hour, the algae were removed by filtration. Next, 86.16 g (about 60 mL) of a hydrophobic ionic liquid [C ₄ -mim] [PF ₆ ] was added to the filtrate, and stirred magnetically at room temperature for 1 hour, and then allowed to stand for stratification. The upper layer of the liquid phase is algae oil, the middle layer of the liquid phase is algae liquid, and the lower layer of liquid phase is a mixed layer of cyclohexylamine and ionic liquid [C ₄ -mim][PF ₆ ]. After the algae oil and the algae liquid are taken out, the mixed solution of the lowermost layer is introduced into carbon dioxide gas, and cyclohexylamine is formed into an ammonium hydrogencarbonate salt to be separated from [C ₄ -mim][PF ₆ ], that is, the recovery of the ionic liquid is completed. Next, an ammonium hydrogencarbonate layer was taken, and nitrogen gas was introduced at 90 ° C to remove carbon dioxide from the ammonium hydrogencarbonate to form cyclohexylamine. The oil extraction rate of the above process is about 80%, the recovery rate of [C ₄ -mim][PF ₆ ] is about 90%, and the recovery rate of cyclohexylamine is about 65%.

Example 6

30 g of algae solution having a water content of 85% was added, and 41.75 g (about 60 mL) of tert-butylamine was added, and the mixture was extracted by magnetic stirring at room temperature, and then the algae was removed by filtration. Next, 86.16 g (about 60 mL) of a hydrophobic ionic liquid [C ₄ -mim][PF ₆ ] was added to the filtrate, and the mixture was stirred under magnetic stirring at room temperature, and then allowed to stand for stratification. The upper layer of the liquid phase is algae oil, the middle layer of the liquid phase is an algae liquid, and the lower layer of the liquid phase is a mixed layer of a third butylamine and an ionic liquid [C ₄ -mim][PF ₆ ]. After the algae oil and the algae liquid are taken out, the mixed solution of the lowermost layer is introduced into carbon dioxide gas, and the third butylamine is formed into an ammonium hydrogencarbonate salt to be separated from [C ₄ -mim][PF ₆ ], that is, the recovery of the ionic liquid is completed. Next, an ammonium hydrogencarbonate layer was taken, and nitrogen gas was introduced at 70 ° C to remove carbon dioxide from the ammonium hydrogencarbonate to form a third butylamine. The oil extraction rate of the above process is about 80%, the recovery rate of [C ₄ -mim][PF ₆ ] is about 90%, and the recovery rate of third butylamine is about 70%.

Example 7

30 g of algae solution having a water content of 85% was added, 51.72 g (about 60 mL) of piperidine was added, and the mixture was extracted by magnetic stirring at room temperature, and then the algae were removed by filtration. Next, 86.16 g (about 60 mL) of a hydrophobic ionic liquid [C ₄ -mim] [PF ₆ ] was added to the filtrate, and stirred magnetically at room temperature for 1 hour, and then allowed to stand for stratification. The upper layer of the liquid phase is algae oil, the middle layer of the liquid phase is algae liquid, and the lower layer of liquid phase is a mixed layer of piperidine and ionic liquid [C ₄ -mim][PF ₆ ]. After the algae oil and the algae liquid are taken out, the mixed solution of the lowermost layer is introduced into carbon dioxide gas, and the piperidine is formed into an ammonium hydrogencarbonate salt to be separated from [C ₄ -mim] [PF ₆ ], that is, the recovery of the ionic liquid is completed. Next, an ammonium hydrogencarbonate layer was taken, and nitrogen gas was introduced at 70 ° C to remove carbon dioxide from the ammonium hydrogencarbonate to form piperidine. The oil extraction rate of the above process is about 70%, the recovery rate of [C ₄ -mim][PF ₆ ] is about 90%, and the piperidine recovery rate is about 60%.

Example 8

30 g of algae solution having a water content of 85% was added, and 77.40 g (about 90 mL) of N-methylcyclohexylamine was added thereto, and the mixture was extracted by magnetic stirring at room temperature, and then the algae was removed by filtration. Next, 129.94 g (about 90 mL) of a hydrophobic ionic liquid [C ₄ -mim] [PF ₆ ] was added to the filtrate, and the mixture was stirred under magnetic stirring at room temperature, and then allowed to stand for stratification. The upper layer of the liquid phase is algae oil, the middle layer of the liquid phase is an algae liquid, and the lower layer of the liquid phase is a mixed layer of N-methylcyclohexylamine and an ionic liquid [C ₄ -mim][PF ₆ ]. After taking the algae oil and the algae liquid, the lowermost mixed solution is passed through a carbon dioxide gas, and N-methylcyclohexylamine is formed into an ammonium hydrogencarbonate salt to be separated from [C ₄ -mim][PF ₆ ], that is, the ionic liquid is completed. Recycling. Next, an ammonium hydrogencarbonate layer was taken, and nitrogen gas was introduced at 70 ° C to remove carbon dioxide from the ammonium hydrogencarbonate to form N-methylcyclohexylamine. The oil extraction rate of the above procedure was about 98%, the recovery rate of [C ₄ -mim][PF ₆ ] was about 90%, and the recovery rate of N-methylcyclohexylamine was about 75%.

Example 9

30 g of algae solution having a water content of 85% was added, and 52.08 g (about 60 mL) of N-methylcyclohexylamine was added thereto, and the mixture was extracted by magnetic stirring at room temperature, and then the algae was removed by filtration. Next, 172.22 g (about 120 mL) of a hydrophobic ionic liquid [C ₄ -mim] [PF ₆ ] was added to the filtrate, and the mixture was stirred under magnetic stirring at room temperature, and then allowed to stand for stratification. The upper layer of the liquid phase is algae oil, the middle layer of the liquid phase is an algae liquid, and the lower layer of the liquid phase is a mixed layer of N-methylcyclohexylamine and an ionic liquid [C ₄ -mim][PF ₆ ]. After taking the algae oil and the algae liquid, the lowermost mixed solution is passed through a carbon dioxide gas, and N-methylcyclohexylamine is formed into an ammonium hydrogencarbonate salt to be separated from [C ₄ -mim][PF ₆ ], that is, the ionic liquid is completed. Recycling. Next, an ammonium hydrogencarbonate layer was taken, and nitrogen gas was introduced at 50 ° C to remove carbon dioxide from the ammonium hydrogencarbonate to form N-methylcyclohexylamine. The oil extraction rate of the above procedure was about 98%, the recovery rate of [C ₄ -mim][PF ₆ ] was about 87%, and the recovery rate of N-methylcyclohexylamine was about 80%.

Example 10

30 g of algae solution having a water content of 85% was added, and 52.08 g (about 60 mL) of N-methylcyclohexylamine was added thereto, and the mixture was extracted by magnetic stirring at room temperature, and then the algae was removed by filtration. Next, 82.72 g (about 60 mL) of hydrophobic ionic liquid N-butyl-N-methylpiperidine bistrifluoromethanesulfonimide salt [PI _1,4 ][NTf ₂ ] was added to the filtrate at room temperature. The mixture was stirred under magnetic stirring and allowed to stand for stratification. The upper layer of the liquid phase is algae oil, the middle layer of the liquid phase is algae liquid, and the lower layer of liquid phase is a mixed layer of N-methylcyclohexylamine and ionic liquid [PI _1,4 ][NTf ₂ ]. After taking the algae oil and the algae liquid, the lowermost mixed solution is passed through a carbon dioxide gas, and N-methylcyclohexylamine is formed into an ammonium hydrogencarbonate salt to be separated from [PI _1,4 ][NTf ₂ ], that is, the ionic liquid is completed. Recycling. Next, an ammonium hydrogencarbonate layer was taken, and nitrogen gas was introduced at 60 ° C to remove carbon dioxide from the ammonium hydrogencarbonate to form N-methylcyclohexylamine. The oil extraction rate of the above process is about 90%, the recovery rate of [PI _1,4 ][NTf ₂ ] is about 78%, and the recovery rate of N-methylcyclohexylamine is about 60%.

Example 11

Take 30g of algae solution with 85% moisture content, add 76.41g (about 90mL) of N,N-dimethylcyclohexylamine, extract with magnetic stirring at room temperature, and remove by filtration. Algae body. Next, 129.06 g (about 90 mL) of hydrophobic ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate ([C ₄ -mim][PF ₆ ]) was added to the filtrate and magnetically stirred at room temperature. After mixing, the layers are allowed to stand. The upper layer of the liquid phase is algae oil, the middle layer of the liquid phase is algae liquid, and the lower layer of liquid phase is a mixed layer of N,N-dimethylcyclohexylamine and ionic liquid [C ₄ -mim][PF ₆ ]. After taking the algae oil and the algae liquid, the lowermost mixed solution is passed through a carbon dioxide gas to form N,N-dimethylcyclohexylamine to form an ammonium hydrogencarbonate salt to be separated from [C ₄ -mim][PF ₆ ], that is, Complete the recovery of the ionic liquid. Next, an ammonium hydrogencarbonate layer was taken, and nitrogen gas was introduced at 50 ° C to remove carbon dioxide from the ammonium hydrogencarbonate to form N,N-dimethylcyclohexylamine. The oil extraction rate of the above process is about 80%, the recovery rate of [C ₄ -mim][PF ₆ ] is about 95%, and the recovery rate of N,N-dimethylcyclohexylamine is about 70%.

Example 12

30 g of algae solution having a water content of 85% was added, and 43.53 g (about 60 mL) of triethylamine was added, and the mixture was extracted by magnetic stirring at room temperature, and then the algae were removed by filtration. Next, 86.16 g (about 60 mL) of hydrophobic ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate ([C ₄ -mim][PF ₆ ]) was added to the filtrate and magnetically stirred at room temperature. After mixing, the layers are allowed to stand. The upper layer of the liquid phase is algae oil, the middle layer of the liquid phase is algae liquid, and the lower layer of liquid phase is a mixed layer of triethylamine and ionic liquid [C ₄ -mim][PF ₆ ]. After the algae oil and the algae liquid are taken out, the mixed solution of the lowermost layer is introduced into carbon dioxide gas, and triethylamine is formed into an ammonium hydrogencarbonate salt to be separated from [C ₄ -mim] [PF ₆ ], that is, the recovery of the ionic liquid is completed. Next, an ammonium hydrogencarbonate layer was taken, and nitrogen gas was introduced at 50 ° C to remove carbon dioxide from the ammonium hydrogencarbonate to form triethylamine. The oil extraction rate of the above process was about 85%, the recovery rate of [C ₄ -mim][PF ₆ ] was about 88%, and the recovery rate of triethylamine was about 70%.

Example 13 (dry algae powder extraction)

30 g of the dried algal flour was added, and 26.04 g (about 30 mL) of cyclohexylamine was added, and the mixture was extracted by magnetic stirring at room temperature, and then the algae was removed by filtration. Next, 43.08 g (about 30 mL) of a hydrophobic ionic liquid [C ₄ -mim] [PF ₆ ] was added to the filtrate, and the mixture was stirred under magnetic stirring at room temperature, and then allowed to stand for stratification. The upper layer of the liquid phase is algae oil, and the lower layer of the liquid phase is a mixed layer of cyclohexylamine and ionic liquid [C ₄ -mim][PF ₆ ]. After the algae oil and the algae liquid are taken out, the mixed solution of the lowermost layer is introduced into carbon dioxide gas, and the cyclohexylamine is formed into an ammonium carbamate to separate from [C ₄ -mim][PF ₆ ], that is, the recovery of the ionic liquid is completed. Next, an ammonium carbamate salt was taken, and nitrogen is exchanged at 50 ° C to remove carbon dioxide from the ammonium carbamate to form cyclohexylamine. The oil extraction rate of the above process is about 98%, the recovery rate of [C ₄ -mim][PF ₆ ] is about 90%, and the recovery rate of cyclohexylamine is about 80%.

Comparative Example 1 (Extraction of wet algae with hydrophobic tertiary amine)

30 g of algae solution having a water content of 85% was added, and 50.94 g (about 60 mL) of N,N-dimethylcyclohexylamine was added thereto, and the mixture was extracted by magnetic stirring at room temperature, and then the algae was removed by filtration. The filtrate was allowed to stand after standing, and the upper layer of the liquid phase was algae oil and N,N-dimethylcyclohexylamine, and the lower layer of the liquid phase was an algal liquid layer. After the upper layer of the liquid phase is taken out, an equal volume of water is added, and carbon dioxide gas is introduced to form N,N-dimethylcyclohexylamine to form an ammonium hydrogencarbonate salt to be separated from the algal oil. Next, an ammonium hydrogencarbonate layer was taken, and nitrogen gas was introduced at 70 ° C to remove carbon dioxide from the ammonium hydrogencarbonate to form N,N-dimethylcyclohexylamine. The oil extraction rate of the above process is about 55%, and the recovery rate of N,N-dimethylcyclohexylamine is about 39%.

Comparative Example 2 (Extraction of wet algae using amphoteric secondary amines)

30 g of algae solution having a water content of 85% was added, and 52.08 g (about 60 mL) of N-methylcyclohexylamine was added thereto, and the mixture was extracted by magnetic stirring at room temperature for 1 hour, and then the algae was removed by filtration. The filtrate was collected and passed through a carbon dioxide gas to form N-methylcyclohexylamine to form an ammonium hydrogencarbonate layer to separate from the algal oil. Next, an ammonium hydrogencarbonate layer was taken, and nitrogen gas was introduced at 70 ° C to remove carbon dioxide from the ammonium hydrogencarbonate salt layer to form N-methylcyclohexylamine. The oil extraction rate of the above process is about 70%, but N-methylcyclohexylamine cannot be separated from the algae liquid, so it cannot be recovered.

Comparative example 3

1 g of the dried algal flour was added, and 12.75 g (about 10 mL) of the ionic liquid [C ₄ -mim][NTf ₂ ]) was added, and the mixture was extracted by magnetic stirring at room temperature, and then the algae were removed by filtration. The filtrate was collected and 3.85 g (1 equivalent) of 1,8-diazabicyclo[5.4.0]undec-7-ene (1,8-Diazabicyclo[5.4.0]undec-7-ene, DBU was added. ) Stir for 1 hour. Carbon dioxide is then passed to the above mixture to adjust the ionic liquid [C ₄ -mim][NTf ₂ ] to a highly polar ionic liquid. At this point the solution is layered, the upper layer is algae oil and the lower layer is a highly polar ionic liquid. After separating the algal oil, the lower layer of the highly polar ionic liquid is heated to 80 ° C and then passed through nitrogen to convert the highly polar ionic liquid back to the original ionic liquid [C ₄ -mim][NTf ₂ ]. The oil extraction rate of the above procedure was about 3%, and the recovery rate of [C ₄ -mim][NTf ₂ ] was about 90%.

While the invention has been described above in terms of several embodiments, it is not intended to limit the invention, and any one of ordinary skill in the art can make any changes and modifications without departing from the spirit and scope of the invention. Therefore, the scope of the invention is defined by the scope of the appended claims.

Claims (9)

A method for extracting oils and fats in algae, comprising: (a) mixing an algae with an amine, so that the amine dissolves the oil in the algae to form a first solution; (b) mixing a hydrophobic ionic liquid with the first After the solution is layered, an oil layer is formed and the hydrophobic ionic liquid layer is added to the amine; (c) separating the oil layer and the amine and adding the hydrophobic ionic liquid layer, then introducing carbon dioxide or sulfur dioxide into the amine and adding the hydrophobic ion a liquid layer which causes the amine to form an ammonium amide ammonium salt, an ammonium hydrogencarbonate salt, an ammonium sulfonate ammonium salt, or an ammonium hydrogen sulfate salt, and then stratifies the hydrophobic ionic liquid; and (d) separates the hydrophobic ionic liquid from the amine After ammonium carbamate or ammonium hydrogencarbonate, ammonium amidine sulfonate or ammonium hydrogen sulphate, air or inert gas is passed to ammonium amide or ammonium hydrogencarbonate or ammonium sulfonate. Or an ammonium hydrogen sulfate salt, which is converted back to the amine, wherein the amine is a primary amine, a secondary amine, or a tertiary amine, and wherein the hydrophobic ionic liquid comprises 1-butyl-3-methylimidazole Hexafluorophosphate, 1-butyl-3-methylimidazolium bistrifluoromethanesulfonimide salt, N-butyl -N- methylpiperidine-bis trifluoromethane sulfonate salt (PEI), or a combination of the above. The method for extracting fats and oils in algae according to claim 1, further comprising: using the amines in the step (d) for the step (a) to be mixed with another algae. A method for extracting oils and fats in algae as described in claim 1, wherein the algae contains water. The method for extracting oil from algae as described in claim 1 of the patent application scope The method wherein the weight ratio of the algae to the amine is between 1:20 and 1:1. The method for extracting fats and oils in algae according to claim 1, wherein the weight ratio of the algae to the hydrophobic ionic liquid is between 1:20 and 1:1. The method for extracting fats and oils in algae according to claim 1, wherein the amines have a log K _ow value of between 0.5 and 2.5. The method for extracting fats and oils in algae according to claim 1, wherein the amines include N-methylcyclohexylamine, N-isopropyl-cyclohexylamine, dipropylamine, cyclohexylamine, and third Amine, piperidine, N,N-dimethylcyclohexylamine, triethylamine, or a combination thereof. The method for extracting fats and oils in algae according to claim 1, wherein the inert gas of the step (d) comprises nitrogen, helium, or a combination thereof. The method for extracting fats and oils in algae according to claim 1, further comprising: in step (d), introducing air or an inert gas into ammonium ammonium amide, ammonium hydrogencarbonate, ammonium sulfonate, Or ammonium hydrogen sulfate, the ammonium amide ammonium salt, ammonium hydrogencarbonate salt, ammonium amine sulfonate, or ammonium hydrogen sulfate salt is heated to between 40 ° C and 90 ° C.