KR101458573B1 - Method for Preparing Biodiesel Using Simultaneous Lipid Extraction and Transesterification of Microalgae - Google Patents

Abstract

The present invention relates to a method for producing biodiesel using simultaneous lipid extraction and transesterification of microalgae, and more particularly, to a method for producing bioalgae using microalgae, which are not subjected to a drying process, using a solvent, an alcohol and a catalyst, A method of obtaining diesel is provided. The present invention is useful in terms of cost by merging extraction and conversion into one process.

Description

TECHNICAL FIELD The present invention relates to a method for preparing a biodiesel by simultaneous lipid extraction and transesterification of microalgae,

More particularly, the present invention relates to a method for preparing biodiesel using simultaneous lipid extraction and transesterification of microalgae, and more particularly, to a method for producing biodiesel by adding a solvent, an alcohol and an acid catalyst to wet microalgae, And a method for producing biodiesel with high conversion efficiency by simultaneously performing an exchange reaction.

Recently, attention has been focused on biofuels due to increased depletion rate of fossil fuels and global climate change due to greenhouse gas emissions (JY Lee et al., Bioresource Technol . , 101, S75-S77, 2010). It has been shown that microalgae can produce bio-diesel replacing petroleum diesel without using soil, starting with the first-generation biofuels using wheat and corn as raw materials, and it is attracting attention as the most promising third-generation biofuel material (N Nagle et al., Appl Biochem Biotechnol . , 24/25, 355-361, 1990; X. Miao et al., Bioresource Technol . , 97, 841-846, 2006). Generally, biodiesel can be produced from lipid extracted from cultured microalgae through a conversion process (JV Gerpen, Fuel Processing Technol . , ≪ / RTI > 86, 1097-1107, 2005). However, biodiesel productivity is very low if the microalgae are cultured in a wet microalgae state after they are extracted and converted (EA Ehimen et al., Fuel , 89, 677-684, 2010; BD Wahlen et al. al., Bioresource Technol . , 102, 2724-2730, 2011).

For this reason, in order to increase the extraction efficiency, the drying process is performed before lipid extraction in most processes. This drying process is high enough that the required energy accounts for more than 50% of the total energy consumption, but is inevitably driven by the problem of extraction efficiency (L. Xu et al., Bioresource Technol . , 102, 5113-5122, 2011). In the case of using wet microalgae (moisture content in the total microalgae weight: 50-80%), additional microwaves (BD Wahlen et al., Bioresource Technol . (PD Patil et al., Fuel , 97, 822-831, 2012), or high temperature or pressure (175 C, 22 bars) (YA Tsigie et al., Chem . Eng. using J., 213, 104-108, 2012) was performed a lipid extraction and conversion processes. Despite this additional energy use, their extraction and conversion yields are up to 84%.

Therefore, it is one of the most important researches to secure the economical efficiency of biodiesel production by directly using wet microalgae to increase the lipid extraction and biodiesel conversion rate and to develop a single process without supplying additional energy. Korean Patent Laid-Open Publication No. 10-2013-0014091 discloses a method for extracting raw oil for biodiesel from microalgae and a method for producing biodiesel using the same, and Korean Patent Publication No. 10-1134294 discloses a method for extracting oil from microalgae And a biodiesel conversion method. However, all of the above-mentioned inventions have a problem in that extraction and conversion yields are considerably low.

The present inventors have made intensive efforts to solve the above problems. As a result, the inventors have found that, when organic solvents, alcohols, and catalysts are added to microalgae and heated to perform lipid extraction and transesterification by transesterification, And that the biodiesel can be produced at a high yield, thereby completing the present invention.

It is an object of the present invention to provide a method for producing biodiesel having high extraction and conversion efficiency by simultaneously carrying out lipid extraction and conversion by adding organic solvent, alcohol and catalyst to microalgae and heating them.

In order to achieve the above object, the present invention provides a method for producing biodiesel which comprises adding an organic solvent, an alcohol and a catalyst to a microalgae, and heating the same to effect conversion by lipid extraction and transesterification.

The present invention is useful for obtaining biodiesel with high conversion efficiency using a solvent, methanol and an acid catalyst in microalgae without a drying process. The present invention can also benefit from the additional reduction of the process cost by merging the extraction and conversion into one process.

1 is a schematic diagram showing an experimental procedure of the present invention.
FIG. 2A is a graph showing the yield of biodiesel per solvent, and FIG. 2B is a photograph of biodiesel of Examples 1 and 3. FIG.
3 is a graph showing the yield of biodiesel according to the change in mass of microalgae of Experimental Example 1. FIG.
FIG. 4 is a graph showing the yield of biodiesel according to the reaction time of Experimental Example 2. FIG.
FIG. 5 is a graph showing the yield of biodiesel according to the change in sulfuric acid volume, which is the acid catalyst of Experimental Example 3. FIG.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In general, the nomenclature used herein is well known and commonly used in the art.

In the present invention, the solvent, the alcohol and the catalyst are added to the microalgae without heating and heated to simultaneously perform lipid extraction and conversion. As a result, it was confirmed that biodiesel having a remarkably high lipid extraction and conversion efficiency can be produced.

In one embodiment of the present invention, hexane and methanol, which are organic solvents, were added to microalgae, and then sulfuric acid was added as a catalyst and heated at 95 ° C to obtain biodiesel having a lipid extraction and conversion efficiency of about 33.65% (± 1.65) Can be produced.

In another embodiment of the present invention, toluene and methanol, which are organic solvents, were added to microalgae, and then sulfuric acid was added as a catalyst. The mixture was heated at 95 ° C to obtain biodiesel having a lipid extraction and conversion efficiency of about 50.36% Can be produced.

In another embodiment of the present invention, chloroform and methanol, which are organic solvents, are added to microalgae, and then sulfuric acid is added as a catalyst, and the mixture is heated at 95 ° C. It was confirmed that diesel can be produced.

In one aspect, the present invention relates to a method for producing biodiesel which comprises adding an organic solvent, alcohol and a catalyst to microalgae, and heating the same to effect conversion through lipid extraction and transesterification.

In the present invention, the microalgae may be selected from the group consisting of chlorella, chlamydomonas, nannochloropsis, chroococcus, chaetoceros, achnanthes, (Amphora). Any strains containing lipids in cells can be used without limitation.

In the present invention, the moisture content of the microalgae is at least 85% at a minimum of 0% (dry microalgae).

In the present invention, the organic solvent is preferably hexane, toluene, chloroform, acetone, heptane, dichloromethane, carbon tetrachloride or benzene. However, the present invention is not limited to this, and any organic solvent generally used can be used.

In the present invention, the amount of the organic solvent is 50 to 4000 parts by weight based on 100 parts by weight of the total microalgae.

In the present invention, the alcohol is methanol, ethanol, propanol or butanol. However, the present invention is not limited to this and an alcohol of C1-C10 may be used.

In the present invention, the amount of the alcohol is 100 to 2000 parts by weight based on 100 parts by weight of the total microalgae.

In the present invention, the catalyst is a solid catalyst such as an acid catalyst such as sulfuric acid, hydrochloric acid, nitric acid or acetyl chloride, or an amberlyst catalyst.

In the present invention, the amount of the acid catalyst is 50 to 1,500 parts by weight based on 100 parts by weight of the total microalgae.

In the present invention, heating is performed at 80 to 120 ° C. However, it may be heated at room temperature up to 400 ° C.

[Example]

Hereinafter, the present invention will be described in more detail with reference to Examples. It is to be understood by those skilled in the art that these embodiments are only for illustrating the present invention and that the scope of the present invention is not construed as being limited by these embodiments. It is therefore intended that the scope of the invention be defined by the claims appended hereto and their equivalents.

Example  1: Extraction and conversion of microalgae by solvent

1-1: hexane (n-hexane)  Extraction and conversion of microalgae as solvent

In this experiment, microalgae, n annochloropsis I used oceanica . The lipid content convertible to biodiesel was 19.17% of the dry microalgae mass and the experiment was carried out with moisture content of 65% of the total microalgae weight. 0.2 ml of wet micro-algae was placed in a test tube (using a Teflon-sealed screw-capped tube). After adding 2 ml of hexane and 1 ml of methanol, 0.3 ml of sulfuric acid was added and the mixture was incubated for 2 hours in a constant- And conversion were carried out simultaneously, and then the amount of fatty acid methyl ester was measured (Fig. 1). The yield is calculated as follows.

The amount of converted fatty acid methyl ester (FAME), measured in the experiment, is the maximum amount of fatty acid methyl ester (FAME) that can be extracted and converted at 100% efficiency through dry microalgae (Amount of maximum FAME). When this process was followed, the yield was about 33.65% (+/- 1.65). In the analysis of the amount of fatty acid methyl ester, the solution in which the transesterification reaction proceeded was neutralized, and the standard substance was added and the organic phase was analyzed.

1-2: Toluene ( toluene Extraction and conversion of microalgae as a solvent

The same procedure as in Example 1-1 was carried out using toluene instead of hexane as a solvent. In this case, the yield was 50.36% (+/- 7.4).

1-3: Chloroform ( chloroform Extraction and conversion of microalgae as a solvent

The same procedure as in Example 1-1 was carried out using chloroform instead of hexane as a solvent. In this case, the yield was 90.6% (± 2.6), which was significantly higher than that of the two solvents.

The yield of biodiesel according to the solvent is as shown in Fig.

Example  2: Extraction and conversion according to moisture content of microalgae

In order to examine the extraction yield and conversion yield of biodiesel according to the moisture content of microalgae, the same method as in Example 1-3 was performed using microalgae having a moisture content of 75%. In this case, the yield was 70%. Therefore, it can be seen that the moisture content of microalgae can be used up to 80 ~ 85%.

Experimental Example  1: Analysis of yield of biodiesel according to change of microalga mass

Since the highest yield was obtained when chloroform was used as a solvent, experiments were conducted to optimize reaction conditions for chloroform. The yields were calculated by fixing the solvent volume and increasing the mass of the microalgae. Other variables, except for the microalgae mass, are the same as in Example 1. When the microalgae were 0.1 g and 0.2 g, the yield was almost the same, but when the amount was 0.4 g, the yield decreased sharply (FIG. 3).

Experimental Example  2: Analysis of yield of biodiesel according to reaction time

The experiment was carried out at 30 minutes, 60 minutes, 90 minutes and 120 minutes except for the reaction time, and the yield was greatly increased between 30 minutes and 60 minutes, but the yield was not changed from 90 minutes As a result, it was found that it was most efficient to react for 90 minutes (FIG. 4).

Experimental Example  3: Yield analysis of biodiesel according to sulfuric acid volume change as an acid catalyst

There are various catalysts such as an acid catalyst and a solid catalyst which can carry out the transesterification reaction. Sulfuric acid was used in this experiment. As a result of changing the volume of sulfuric acid without changing the volume of methanol and chloroform, the yields were almost the same at 0.3 ml and 0.4 ml of sulfuric acid volume, and the yield was slightly decreased at 0.2 ml of sulfuric acid volume (FIG. 5). Therefore, it was found that the most effective value exists in 0.2 to 0.3 ml of sulfuric acid volume.

While the present invention has been particularly shown and described with reference to specific embodiments thereof, those skilled in the art will readily appreciate that many modifications are possible in the exemplary embodiments without materially departing from the novel teachings and advantages of this invention. something to do. Accordingly, the actual scope of the present invention will be defined by the appended claims and their equivalents.

Claims (13)

A method for producing biodiesel using simultaneous lipid extraction and transesterification, which comprises adding an organic solvent, an alcohol and a catalyst to a microalgae and then heating the microalgae.
The method of claim 1, wherein the microalgae are selected from the group consisting of chlorella, chlamydomonas, nannochloropsis, chroococcus, chaetoceros, achnanthes, Wherein the biodiesel is selected from the group consisting of ammonia and ammonia.
The method of claim 1, wherein the moisture content of the microalgae is 0 to 85% (w / w).
The method according to claim 1, wherein the organic solvent is any one selected from the group consisting of hexane, toluene, chloroform, acetone, heptane, dichloromethane, carbon tetrachloride, and benzene.
5. The method for producing biodiesel according to claim 4, wherein the amount of the organic solvent is 50 to 4000 parts by weight based on 100 parts by weight of the total microalgae.
The method according to claim 1, wherein the alcohol is any one selected from the group consisting of C1 to C10 alcohols.

Claim 7 has been abandoned due to the setting registration fee. 7. The method of claim 6, wherein the alcohol is any one selected from the group consisting of methanol, ethanol, propanol, and butanol.
The method for producing biodiesel according to claim 7, wherein the amount of alcohol is 100 to 2000 parts by weight based on 100 parts by weight of the total microalgae.
The method for producing biodiesel according to claim 1, wherein the catalyst is an acid catalyst.
10. The method according to claim 9, wherein the acid catalyst is any one selected from the group consisting of sulfuric acid, hydrochloric acid, nitric acid, acetyl chloride, and amberlyst.
11. The method for producing biodiesel according to claim 10, wherein the amount of the acid catalyst is 50 to 1500 parts by weight based on 100 parts by weight of the total microalgae.
The method for producing biodiesel according to claim 1, wherein the biodiesel is heated at 80 to 400 캜.
Characterized in that 50 to 4000 parts by weight of chloroform, 100 to 2000 parts by weight of methanol and 50 to 1500 parts by weight of sulfuric acid are added to 100 parts by weight of microalgae containing lipids and then heated at 80 to 120 캜. Process for the preparation of biodiesel using ester exchange reaction.

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