KR100490115B1 - Refinement method of substitution fuel using chitosan - Google Patents

Abstract

The present invention relates to a method for purifying alternative fuel using chitosan that can effectively remove free fatty acids from alternative fuels obtained by regenerating waste oil such as waste cooking oil or animal fats and oils. An acid solution preparation step of preparing an acid solution by adjusting to 3.5 to 5.5; (2) a mixing step of mixing the acid aqueous solution with alternative fuel such as diesel engine obtained from waste oil such as waste cooking oil or fat or oil through a conventional esterification reaction at a ratio of 1: 0.5 to 1.5 volume ratio; (3) a chitosan contacting step of bringing the mixed solution mixed in the mixing step into contact with chitosan, while contacting chitosan in an amount of 0.1 to 1% by weight per liter of the alternative fuel in the mixed solution; (4) after the chitosan contacting step, separating the mixed solution into an aqueous layer and an oil layer; And (5) a post-treatment step of removing the remaining moisture by drying the oil layer.

Description

Purification of alternative fuel using chitosan {Refinement method of substitution fuel using chitosan}

The present invention relates to a method for purifying alternative fuel using chitosan. More specifically, the present invention relates to a method for purifying alternative fuel using chitosan that can effectively remove free fatty acids in alternative fuels obtained by regenerating waste oil such as waste cooking oil or animal fats and oils.

In the present invention, the alternative fuel means an alternative fuel obtained by regenerating waste oil such as waste cooking oil or animal fats and oils, wherein the waste oil is not an industrial waste oil generally used, but is used in households, restaurants, food processing companies, etc. Compared to industrial oils containing mineral oil as a main component such as waste cooking oil or animal fats discharged, it refers to organic oils, not mineral oils.

In recent years, as the eating habits are westernized, the consumption of fried foods (potato chips, french fries, fried chichen, etc.) is increasing, and the generation of waste cooking oil used to cook them is also increasing. The waste cooking oil (waste oil generated by plants, oils, fats, etc.) has a biological oxygen demand (BOD) of about 1,000,000ppm significantly higher than 35,000ppm of doenjang stew, and 200,000 times higher than the 5ppm that can survive fish, sewage Release of pollutants causes serious pollution of rivers.

Therefore, in order to prevent contamination by natural waste, a method of regenerating waste oil and regenerating it as a fuel for a diesel engine or a boiler has been proposed.

In the conventional method of regeneration of the waste cooking oil into fuel, in the "automatic fuel supply device using waste cooking oil and its fuel manufacturing method" of Republic of Korea Patent Publication No. 99-16815 (published date, March 15, 1999), The fuel production method comprises the steps of dissolving the waste cooking oil refined by a filter in an organic solvent, and adding an alcohol containing water to perform esterification, and leaving the solution obtained by the esterification for a predetermined time to leave the upper and water layers of the organic layer. Separating the lower part by separating the lower part, and injecting water into the upper part, which is the organic layer, dissolving the remaining water-soluble substance in water, separating the lower layer as the aqueous layer after several marching, and removing the lower layer. The organic layer is placed in an oil refiner and the nucleic acid is removed by boiling point difference to obtain a monoester that can be used as an automobile fuel. All. By removing the water-soluble substances by the esterification method of the waste oil of the high viscosity component to improve the properties of the fuel to a state close to diesel, to prevent contamination while reducing the cost of disposal of waste oil, using raw materials obtained from waste oil It is known to provide the effect of import substitution and to reduce the harmful components such as soot to prevent environmental pollution. However, in the conventional fuel regeneration method using waste cooking oil, excessive wastewater is generated by injecting a large amount of water to dissolve the water-soluble substance remaining in the organic layer of the upper layer in the solution obtained by esterification in water. Of course, there are disadvantages of increased water cost and separate purification facilities. In addition, when the water-soluble substance remaining in the organic layer is separated again through the injection of water, and the organic layer from which the water layer is removed is directly used as a fuel, since the equipment is corroded by the remaining organic solvent and water, the collected organic layer is refined. The process and apparatus for obtaining monoesters that can be used as automobile fuels by separating nucleic acids by boiling point difference and boiling point must be complicated and expensive facilities have to be installed.

In addition, the Republic of Korea Patent Publication No. 99-70659 (published date, September 15, 1999) "recycling method and regeneration device of the waste oil" and the ions formed by the functional ceramic installed with the magnet to the molecules of the waste oil The present invention relates to a method and apparatus for regenerating a diesel fuel by raising a negative potential of a molecule by acting and activating it, which merely lowers the viscosity of waste oil suitable for a diesel engine. In addition, since the waste oil having a low viscosity is filtered by a conventional filter, there is a risk of damaging the engine and environmental pollution due to incomplete combustion.

In addition, Korean Patent Application Publication No. 99-79052 (published date, November 5, 1999), "Method and Apparatus for Recycling Waste Oil," adds an alkaline substance as methanol and a catalyst after removing impurities using a filter. After esterification, free alkali and debris are removed by natural precipitation, and water is mixed to separate methyl ester and glycerin. And finally, by heating to a predetermined temperature to evaporate the water, and through the purification process to make a fuel. However, high-viscosity waste cooking oil is filtered through a conventional filter, and impurities are still present, and depending on natural phenomena such as esterification, separation of methyl ester and glycerin, and purification process, the processing time becomes longer and productivity is lowered. There is a problem.

As described above, a technique for recycling waste oil and using it as an alternative fuel for diesel engines has been generally developed, but impurities in the resulting alternative fuel are a problem, and removal thereof is difficult, and a removal process If used as a fuel without a lot of problems in the engine corrosion or environmental pollution.

Therefore, in order to more widely utilize alternative fuels, such as those for diesel engines, obtained by recycling waste oil, a purification method for removing free fatty acids contained in alternative fuels obtained by esterification is required.

It is an object of the present invention to provide a method for purifying alternative fuel using chitosan that can efficiently remove free fatty acids in alternative fuels such as for diesel engines using chitosan.

Purification method of alternative fuel using chitosan according to the present invention, (1) an acid aqueous solution manufacturing step of preparing an acid solution by adding acid to water to adjust the pH to 3.5 to 5.5; (2) a mixing step of mixing the acid aqueous solution with alternative fuel such as diesel engine obtained from waste oil such as waste cooking oil or fat or oil through a conventional esterification reaction at a ratio of 1: 0.5 to 1.5 volume ratio; (3) a chitosan contacting step of bringing the mixed solution mixed in the mixing step into contact with chitosan, while contacting chitosan in an amount of 0.1 to 1% by weight per liter of the alternative fuel in the mixed solution; (4) after the chitosan contacting step, separating the mixed solution into an aqueous layer and an oil layer; And (5) a post-treatment step of removing the remaining moisture by drying the oil layer.

In the acid aqueous solution production step, the pH may be preferably 4 to 5.

The acid for adjusting the pH in the acid aqueous solution production step may be selected from the group consisting of acetic acid, phosphoric acid, nitric acid, sulfuric acid or a mixture of two or more thereof.

In the chitosan contacting step, the chitosan may be powdery chitosan or granular chitosan.

When the chitosan is in powder form, the chitosan contacting step may be in contact with alternative fuel in the mixed solution by dissolving chitosan in the acid aqueous solution.

When the chitosan is in powder form, the chitosan contacting step may be in contact with alternative fuel in the mixed solution by dissolving chitosan in the mixed solution.

When the chitosan is granular, the chitosan contacting step may be brought into contact with alternative fuel in the mixed solution by passing the mixed solution through a filtration layer made of the granular chitosan.

In the case of the granular chitosan, it can be used repeatedly by washing with methanol.

Hereinafter, the present invention will be described in detail with reference to specific examples.

Purification method of alternative fuel using chitosan according to the present invention, (1) an acid aqueous solution manufacturing step of preparing an acid solution by adding acid to water to adjust the pH to 3.5 to 5.5; (2) a mixing step of mixing the acid aqueous solution with alternative fuel such as diesel engine obtained from waste oil such as waste cooking oil or fat or oil through a conventional esterification reaction at a ratio of 1: 0.5 to 1.5 volume ratio; (3) a chitosan contacting step of bringing the mixed solution mixed in the mixing step into contact with chitosan, while contacting chitosan in an amount of 0.1 to 1% by weight per liter of the alternative fuel in the mixed solution; (4) after the chitosan contacting step, separating the mixed solution into an aqueous layer and an oil layer; And (5) a post-treatment step of removing the remaining moisture by drying the oil layer.

The acid aqueous solution manufacturing step of (1) is a step of preparing an acid solution by adding acid to water to adjust its pH to 3.5 to 5.5, the acid solution is mixed with alternative fuel to adjust the pH of the alternative fuel to replace the fuel Free fatty acid to be removed is a function to adjust to be in a state that can be removed by adsorption well to chitosan. In addition, the water in the acid aqueous solution functions as a medium to accommodate the chitosan, especially when the chitosan is used in a powder state, and replaces the chitosan adsorbed free fatty acid in the alternative fuel by separation of the aqueous and oil layers by standing still. It can be easily separated from fuel. The pH in the range of 3.5 to 5.5 is a value experimentally obtained as a range suitable for the chitosan to adsorb free fatty acids in the alternative fuel, and in the case of exceeding the lower limit or the upper limit when the chitosan exceeds this range, There may be a problem that the removal efficiency of free fatty acids by adsorption is reduced.

In the acid aqueous solution production step, the pH may be preferably 4 to 5, and the removal efficiency of the free fatty acid in the alternative fuel is the highest at this pH.

The acid for adjusting the pH in the acid aqueous solution production step may be selected from the group consisting of acetic acid, phosphoric acid, nitric acid, sulfuric acid or a mixture of two or more thereof. The acid for adjusting the pH may preferably be acetic acid or phosphoric acid.

In the mixing step of (2), the acid aqueous solution obtained in the acid aqueous solution preparation step is replaced with alternative fuel, such as diesel engine, obtained from waste oil such as waste cooking oil or fat or oil by a general esterification reaction, and the volume ratio is 1: 0.5 to 1.5. The mixing is carried out by mixing at a ratio of, so that the free fatty acid in the alternative fuel is brought to an optimal pH state which can be easily removed by chitosan. When the mixing ratio of the alternative fuel is less than 0.5 volume ratio in the mixing ratio, it is difficult to separate the chitosan adsorbed free fatty acid in the case of the chitosan powder in the subsequent separation step or the pH of the mixed solution is lowered to remove the free fatty acid itself There may be a problem that the efficiency is lowered, on the contrary, if the volume ratio exceeds 1.5, the pH of the mixed solution may also be too high, thereby reducing the removal efficiency of the free fatty acid itself.

Subsequently, in the chitosan contacting step of (3), the mixed solution mixed in the mixing step is substantially contacted with chitosan, and the chitosan in an amount of 0.1 to 1% by weight per 1 liter of the alternative fuel in the mixed solution is contacted. It consists of If the amount of chitosan is less than 0.1% by weight per 1 L of the alternative fuel, there may be a problem that the removal of free fatty acids in the alternative fuel by chitosan is not sufficient, if the amount exceeds 1% by weight, waste of chitosan is severe There may be a problem that the efficiency of chitosan is lowered.

In the chitosan contacting step, the chitosan is treated with alkaline water to remove shellfish such as crab or shrimp shell such as red crab, and removes protein. The pure chitin can be obtained simply by removing with an oxidizing agent, and chitosan is obtained from the chitin, and is widely known so that it can be purchased and used commercially by leading domestic and foreign manufacturers. The chitosan may be powdery chitosan or granular chitosan. These properties of chitosan are properties supplied by prominent manufacturers at home and abroad, and are well known to those skilled in the art so that any powder or granule can be purchased and used commercially. When the chitosan is in powder form, the chitosan contacting step may be in contact with alternative fuel in the mixed solution by dissolving chitosan in the acid aqueous solution. The powdered chitosan is dissolved or dispersed in water, whereby by mixing with the alternative fuel it is possible to effectively contact and remove the free fatty acid contained in the alternative fuel, the chitosan adsorbed the free fatty acid is then separated In the step of separating into the water and oil layers, it is contained in the water layer and is separated from the alternative fuel constituting the oil layer. When the chitosan is in powder form, the chitosan contacting step may also be in contact with alternative fuel in the mixed solution by dissolving chitosan in the mixed solution.

When the chitosan is granular, the chitosan contacting step may be brought into contact with alternative fuel in the mixed solution by passing the mixed solution through a filtration layer made of the granular chitosan. In the case of the granular chitosan, it can be reused by washing with a countercurrent of methanol, and thus can be used repeatedly, thereby making it possible to reduce the amount of chitosan used as a raw material, thereby reducing raw materials and preventing waste of resources. And lower production costs can be expected.

Thereafter, in the separation step (4), after the chitosan contacting step, the mixed solution is left to separate into an aqueous layer and an oil layer, and natural separation is possible due to the immiscibility of the aqueous layer and the oil layer by simple standing. It can be easily understood by those skilled in the art that this can be easily accomplished by the use of means for distinguishing the aqueous and oil layers such as a separatory funnel.

The post-treatment step (5) is a step through a conventional post-treatment such as drying the oil layer to remove residual water, and can be easily understood by those skilled in the art.

Hereinafter, preferred embodiments and comparative examples of the present invention will be described.

The following examples are intended to illustrate the invention and should not be understood as limiting the scope of the invention.

Example 1

0.5 g of acetic acid was dissolved in water to make 1 L, and an acid aqueous solution having a pH of 4.5 was prepared, and alternative fuels such as diesel engines obtained from waste oil such as waste cooking oil or fat or oil, and 1: After mixing at the ratio of 1 volume ratio, it was left to stand and separated into an aqueous layer and an oil layer, and the obtained oil layer was fractionated and distilled to obtain a purified alternative fuel.

Before purification, 0.5% of various free fatty acids were present in the alternative fuel as a raw material, but after purification, it was confirmed that the purification efficiency was about 99.9% at 0.004% by weight.

Example 2

Except for setting the pH of the acid aqueous solution to 3.2 was carried out in the same manner as in Example 1, as a result it was confirmed that the purification efficiency for the free fatty acid represented 99.1%.

Example 3

Except that the pH of the acid aqueous solution to 5.3 was carried out in the same manner as in Example 1, as a result it was confirmed that the purification efficiency for the free fatty acid represented 98.9%.

Example 4

Except for adjusting the pH using phosphoric acid was carried out in the same manner as in Example 1, as a result it was confirmed that the purification efficiency for the free fatty acid represented 99.3%.

Example 5

In order to purify the alternative fuel of 40 tons per day, 300 kg of granular chitosan was charged into the filtration tank, and 40 tons of acidic aqueous solution of pH 4.5 and 40 tons of alternative fuel were passed through to remove the free fatty acids. Measured. As a result, it was confirmed that the purification efficiency for free fatty acid was about 99.5%.

Example 6

After one purification in Example 5, 5 tons of methanol was flowed back to the filter tank to wash granular chitosan in the filter tank, and then 40 tons of acidic aqueous solution of pH 4.5 and 40 tons of alternative fuel were passed through the mixture. The removal efficiency of free fatty acids was measured. As a result, the purification efficiency for free fatty acid was found to be about 98.1%.

Example 7

After one reuse in Example 6, 5 tons of methanol was flowed back into the filter tank to wash the granular chitosan in the filter tank, and then mixed with 40 tons of an acid solution of pH 4.5 and 40 tons of alternative fuel therethrough. The removal efficiency of free fatty acids was measured. As a result, it was confirmed that the purification efficiency for free fatty acid was about 97.6%.

As a result of the synthesis of the above embodiments, it was confirmed that according to the present invention, free fatty acids in the alternative fuel can be removed and purified at a high efficiency of at least 97.5% by contact with chitosan after adjusting the pH. In addition, in the case of the tablet by the method of passing through the granular chitosan, it was confirmed that the free fatty acid can be repeatedly removed with high efficiency even after reuse after washing the granular chitosan with methanol.

Therefore, according to the present invention, there is an effect of providing a method for purifying alternative fuel using chitosan that can efficiently remove free fatty acids in alternative fuels such as diesel engines by utilizing chitosan, and also using granular chitosan, After washing it with methanol, it is also possible to reuse it repeatedly, which has the effect of providing a purification method to remove free fatty acids in alternative fuels very efficiently and economically.

Although the present invention has been described in detail only with respect to the described embodiments, it will be apparent to those skilled in the art that various modifications and variations are possible within the technical scope of the present invention, and such modifications and modifications are within the scope of the appended claims.

Claims (8)

(1) an acid solution preparation step of preparing an acid solution by adding acid to water and adjusting its pH to 3.5 to 5.5; (2) a mixing step of mixing the acid aqueous solution with alternative fuel such as diesel engine obtained from waste oil such as waste cooking oil or fat or oil through a conventional esterification reaction at a ratio of 1: 0.5 to 1.5 volume ratio; (3) a chitosan contacting step of bringing the mixed solution mixed in the mixing step into contact with chitosan, while contacting chitosan in an amount of 0.1 to 1% by weight per liter of the alternative fuel in the mixed solution; (4) after the chitosan contacting step, separating the mixed solution into an aqueous layer and an oil layer; And (5) post-treatment steps such as drying the oil layer to remove residual water; Method of purifying alternative fuel using chitosan, characterized in that consisting of. The method of claim 1, Purifying alternative fuel using the chitosan, characterized in that the pH of the acid aqueous solution production step 4 to 5. The method of claim 1, In the acid aqueous solution production step, the acid for controlling pH is purified from alternative fuels using chitosan, characterized in that selected from the group consisting of acetic acid, phosphoric acid, nitric acid, sulfuric acid or a mixture of two or more thereof. The method of claim 1, In the chitosan contacting step, the chitosan is a powdery chitosan or granular chitosan, characterized in that the purification of alternative fuel using the chitosan. The method of claim 4, wherein When the chitosan is in powder form, the chitosan contacting step is performed by dissolving chitosan in the acid aqueous solution and contacting the alternative fuel in the mixed solution. The method of claim 4, wherein When the chitosan is in powder form, the chitosan contacting step is performed by dissolving chitosan in the mixed solution and contacting the alternative fuel in the mixed solution. The method of claim 4, wherein When the chitosan is granular, the chitosan contacting step of the alternative fuel using the chitosan characterized in that the contact with the alternative fuel in the mixed solution by passing the mixed solution through a filtration layer consisting of the granular chitosan. Purification method. The method of claim 7, wherein In the case of the granular chitosan, alternative fuel purification method using the chitosan, characterized in that it is repeatedly used by washing with methanol.