JP2009280755A - Method and apparatus for producing petroleum-alternative fuel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and an apparatus for producing petroleum-alternative fuel having high purity while dispensing with a cleaning step. <P>SOLUTION: The method for producing petroleum-alternative fuel comprises: an ester interchange step of subjecting oils and fats to an ester interchange reaction in the coexistence of alcohol and an alkali catalyst to produce a mixture of the petroleum-alternative fuel with glycerol being a by-product; and a distillation step of distilling the produced mixture under reduced pressure of ≤5 mmHg at 150-300°C liquid temperature in order to separate the petroleum-alternative fuel from the glycerol while agitating the mixture together with a solvent used at the ester interchange step to distill/extract the petroleum-alternative fuel. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method and an apparatus for producing an alternative petroleum fuel, and more particularly, to a method and an apparatus for producing an alternative petroleum fuel for producing biodiesel fuel and the like using fats and oils such as waste cooking oil.

Conventionally, petroleum-based fossil fuels such as gasoline, heavy oil, and light oil have been frequently used as fuel. However, since these fossil fuels emit harmful substances such as sulfur oxides when burned, they are a serious social problem as a cause of air pollution.
In addition, vegetable oils such as rapeseed oil and palm oil, and animal oils such as lard and butter are frequently used in daily life, but used waste cooking oil can cause environmental pollution if discarded as it is, The disposal method is a problem.

For this reason, as shown in the following patent document 1 or 2, a method for producing biodiesel fuel (BDF), which is a petroleum substitute fuel, from waste cooking oil has been proposed.
In this method, waste edible oil is transesterified with methanol in the presence of an alkali catalyst to recover a fatty acid ester that can be used as a diesel fuel and its by-products.
Japanese Patent Laid-Open No. 10-182518 JP 2006-8758 A

  Specifically, the reactor is charged with 100 parts of waste cooking oil, 18 parts of methanol, and 1 part of caustic soda as a catalyst and stirred at an internal temperature of 40 to 65 ° C. for 1 hour. Then, saponification (2) and neutralization of free fatty acids (3) occur as transesterification (1) and side reactions as follows, and glycerin and higher fatty acid methyl esters and soap as by-products are produced.

(1) C ₃ H ₅ (OCOR) ₃ + 3CH ₃ OH → 3CH ₃ OOCR + C ₃ H ₅ (OH) ₃
(2) C ₃ H ₅ (OCOR) ₃ +3 NaOH → C ₃ H ₅ (OH) ₃ + 3RCOONA (soap)
(3) RCOOH + NaOH → RCONa (soap) + H ₂ O
Stop stirring and let stand for 30 minutes to separate the higher fatty acid methyl ester soap and glycerin into two layers due to the difference in specific gravity, withdraw the glycerin layer with higher specific gravity from the bottom, and the higher fatty acid methyl ester remaining in the reaction kettle and this Add about 10% by volume of water (about 40 ° C) to a small amount of alkali-dissolved methanol and soap contained in the mixture, stir, transfer the remaining alkali-dissolved methanol and the generated soap to water, and let stand. The two layers are separated, and the lower layer washing water is extracted and further washed with water several times in the same manner. Finally, the product is dehydrated and dried by vacuum heating to obtain a higher fatty acid methyl ester having a high purity.

  In Patent Document 2, a transesterification process in which fats and oils coexist with an alcohol and an alkali catalyst to perform transesterification, a by-product discharge process 6 in which glycerin as a by-product is removed, and an acid and water are added and mixed. In a method for producing an alternative petroleum fuel comprising a washing step for summing and washing and a washing water discharging step 10 for discharging washing water, it is disclosed that heat dehydration is performed at normal pressure at least after the washing water discharging step. ing.

  Thus, in the conventional method for producing an alternative fuel for petroleum, a cleaning process is indispensable, and the treatment of the cleaning water discharged by the cleaning process has been an important problem.

  The objective of this invention is providing the manufacturing method and manufacturing apparatus of a petroleum alternative fuel which solve the problem mentioned above, do not require a washing | cleaning process, and can manufacture a petroleum alternative fuel with high purity.

  In order to solve the above-mentioned problem, the invention according to claim 1 is a transesterification process in which fats and oils coexist with an alcohol and an alkali catalyst to perform transesterification, and a petroleum substitute fuel and a by-product generated by the transesterification process. Distillation step of distilling and extracting the petroleum alternative fuel by distilling under reduced pressure within a range of 150 to 300 ° C. under a pressure of 5 mmHg or less while stirring the solution subjected to the transesterification step in order to separate a certain glycerin. And a method for producing an alternative petroleum fuel.

  According to a second aspect of the present invention, in the method for producing a petroleum alternative fuel according to the first aspect, the liquid temperature management in the distillation step includes at least a heating means for measuring the temperature of the vaporized gas and heating the solution. It is characterized by controlling.

  The invention according to claim 3 is the method of producing petroleum substitute fuel according to claim 2, wherein the heating means is controlled so that the temperature of the gas is in the range of 100 to 250 ° C. during the distillation step. It is characterized by that.

  According to a fourth aspect of the present invention, there is provided a primary tank capable of storing a liquid, a recovery liquefying means for recovering and liquefying gas evaporating from the primary tank, and a secondary for storing the liquid liquefied by the recovered liquefaction means. A tank, heating means for heating the liquid in the primary tank, decompression means for reducing the pressure in the primary tank via the recovery liquefaction means, and stirring means for stirring the liquid in the primary tank; Gas temperature measuring means for measuring the temperature of the gas discharged from the primary tank, and transesterification is carried out by stirring and mixing oil, fat, alcohol and alkali catalyst using the stirring means in the primary tank. The pressure-reducing means is operated while stirring the transesterified solution to adjust the pressure in the primary tank to a predetermined atmospheric pressure, and the measured value of the gas temperature measuring means is predetermined. The heating hand so that the temperature of An apparatus for producing petroleum substitute fuel, wherein the petroleum substitute fuel is evaporated from the solution in the primary tank, and the evaporated petroleum substitute fuel is liquefied and accumulated in the secondary tank. is there.

  The invention according to claim 5 is the apparatus for producing petroleum alternative fuel according to claim 4, wherein the heating means uses a heater arranged at least inside and outside the primary tank.

  The invention according to claim 6 is the petroleum alternative fuel manufacturing apparatus according to claim 4 or 5, wherein the pressure formed by the pressure reducing means is 5 mmHg or less, and the measured value of the gas temperature measuring means is 100 to 250. The heating means is controlled to be in the range of ° C.

  According to the invention of claim 1, in order to separate the transesterification step in which fats and oils coexist with alcohol and an alkali catalyst to perform transesterification, and the petroleum substitute fuel produced by the transesterification step and glycerin as a by-product, The washing step is performed by stirring the solution subjected to the transesterification step while distilling under reduced pressure at a pressure of 5 mmHg or less and a liquid temperature of 150 to 300 ° C. and distilling and extracting the petroleum substitute fuel. It becomes unnecessary, and there is no discharge of washing water as in the conventional method for producing alternative fuel for petroleum. Moreover, since the petroleum alternative fuel is separated by distillation, it is difficult for impurities to be mixed in the petroleum alternative fuel, and it is possible to obtain an oil alternative fuel with high purity and transparency.

  According to the invention according to claim 2, the liquid temperature management in the distillation process measures at least the temperature of the gas to evaporate and controls the heating means for heating the solution. It becomes possible to judge, and it becomes possible to obtain a petroleum alternative fuel with higher purity and transparency.

  According to the invention of claim 3, since the heating means is controlled so that the temperature of the gas is in the range of 100 to 250 ° C. during the distillation step, only petroleum alternative fuel can be distilled and extracted. .

  According to the invention of claim 4, a primary tank capable of storing liquid, a recovery liquefying means for recovering and liquefying gas evaporating from the primary tank, and a secondary for storing liquid liquefied by the recovered liquefaction means A tank, heating means for heating the liquid in the primary tank, decompression means for reducing the pressure in the primary tank via the recovery liquefaction means, and stirring means for stirring the liquid in the primary tank; Gas temperature measuring means for measuring the temperature of the gas discharged from the primary tank, and transesterification is carried out by stirring and mixing oil, fat, alcohol and alkali catalyst using the stirring means in the primary tank. The pressure-reducing means is operated while stirring the transesterified solution to adjust the pressure in the primary tank to a predetermined atmospheric pressure, and the measured value of the gas temperature measuring means is predetermined. So that the temperature of A petroleum substitute fuel production apparatus characterized by evaporating petroleum substitute fuel from the solution in the primary tank by controlling the means, liquefying the evaporated petroleum substitute fuel and accumulating it in the secondary tank Therefore, since only two tanks are used, it is possible to efficiently obtain an oil substitute fuel with high purity and transparency while having a simple structure. In addition, since the temperature of the liquid is controlled by the gas temperature measuring means, it is possible to accurately determine the start and end of the generation of petroleum substitute fuel, and it is possible to obtain a petroleum substitute fuel with higher purity and transparency. Become.

  According to the invention according to claim 5, in the apparatus for producing petroleum alternative fuel, the heating means uses a heater disposed at least outside the primary tank, so even when the liquid in the primary tank is reduced during the distillation process. The liquid can always be maintained at a constant temperature, and a petroleum substitute fuel can be stably obtained.

  According to the sixth aspect of the present invention, in the apparatus for producing petroleum alternative fuel, the heating means is provided so that the pressure formed by the pressure reducing means is 5 mmHg or less, and the measured value of the gas temperature measuring means is in the range of 100 to 250 ° C. Since it is controlled, it is possible to stably obtain an alternative fuel for oil.

Hereinafter, the present invention will be described in detail using preferred examples.
The method for producing a petroleum substitute fuel according to the present invention is performed in the following processing flow.
(1) Transesterification step The fats and oils coexist with alcohol and an alkali catalyst to carry out the transesterification.
(2) Distillation Step In order to separate the petroleum alternative fuel produced by the transesterification step and glycerin as a by-product, the atmospheric pressure is 5 mmHg or less and the liquid temperature is 150 while stirring the solution subjected to the transesterification step. Distilled under reduced pressure within a range of ˜300 ° C., the petroleum substitute fuel was distilled and extracted.

  The oils and fats that are the raw materials used in the method for producing petroleum alternative fuels of the present invention are vegetable oils such as rapeseed oil, palm oil, safflower oil, and soybean oil used in factories and households, and waste edible oils that are animal oils such as lard and butter. Etc. are available.

  In the transesterification step, the temperature of the oil and fat is heated to about 60 ° C., an alcohol such as methanol or ethanol and an alkali catalyst such as sodium hydroxide are added, and the solution is stirred at 60 ° C. for about 1 hour. Perform transesterification.

In the distillation step, petroleum substitute fuel (biodiesel fuel) such as methyl ester produced in the transesterification step is separated from the liquid. Under atmospheric pressure, the methyl ester does not vaporize unless heated to a high temperature of about 400 to 450 ° C. However, by reducing the pressure to 5 mmHg or less, more preferably 1 mmHg or less as in the present invention, the liquid temperature is about 150 to 220. Evaporates easily at ° C.
On the other hand, the boiling point of glycerin as a by-product is higher than 300 ° C. even under reduced pressure as described above. For this reason, it becomes possible to distill only petroleum substitute fuels, such as methyl ester, by keeping liquid temperature at 150-300 ° C.

  As one of the features of the present invention, the liquid temperature management in the distillation process measures at least the temperature of the vaporized gas and controls the heating means for heating the solution. Although it is possible to directly measure the temperature of the liquid, the liquid level changes as a part of the liquid evaporates, so only the direct temperature measurement method allows the position of the thermometer to be adjusted to the change in the liquid level. It is feared that the structure of the manufacturing apparatus will become complicated, such as changing. Further, as will be described later, it is difficult to specify the start and end of distillation of petroleum alternative fuel only by changing the temperature of the liquid, and in order to obtain high-purity petroleum alternative fuel, the temperature of the evaporated gas as in the present invention is set. It is preferable to use a measuring method in combination.

When the temperature of the liquid is gradually raised in the distillation process, the temperature of the evaporated gas shows a graph as shown in FIG.
In the period up to the point A in the graph, alcohol and moisture such as methanol remaining unreacted in the liquid are evaporated as an initial flow. The temperature at point A is about 130 ° C.
When there are no components that evaporate at a relatively low temperature, such as alcohol and moisture, the temperature of the steam increases rapidly and depends on the reduced pressure, but for example, about 1 mmHg, about 160 ° C. The temperature reaches a steady state (see point B). This means that the evaporation of petroleum alternative fuels in the liquid has begun. The liquid heating means is energized and controlled so that the vapor temperature is in a range of about 160 ° C. ± 5 ° C., for example, in order to maintain the evaporation state of the petroleum alternative fuel.

When the evaporation of the petroleum substitute fuel is completed, the steam temperature starts to decrease and reaches the point C in the graph. When the evaporation of the petroleum substitute fuel is completed, the driving of the heating means is stopped. If the heating means is driven and the vapor temperature is maintained at, for example, 160 ° C. even after the point C has elapsed, the liquid is heated to the temperature at which the next evaporation starts in the liquid. Evaporation of glycerin, which is an impurity, starts. Naturally, when the evaporation of such impurities starts, as shown by the dotted line in FIG. 2, the vapor temperature starts to rise again even after passing the C point.
Therefore, in the present invention, in order to obtain a high-purity petroleum alternative fuel, the petroleum alternative fuel is distilled in a section between points B and C in the graph of FIG.

  After distillation of the petroleum substitute fuel is completed, by-products such as glycerin and soap remain in the liquid. The treatment of these liquids is not particularly limited in the present invention, but if necessary, an acid such as acetic acid and hydrochloric acid and water are added to dissolve soap and the like, and a washing treatment for separating from glycerin is performed, or washing is performed. Necessary treatments such as dehydration treatment by heating the moisture remaining in the liquid during the treatment can be added as appropriate.

Next, the petroleum substitute fuel manufacturing apparatus according to the present invention will be described.
The apparatus for producing petroleum alternative fuel includes a primary tank 1 capable of storing a liquid 7, a recovery liquefying means 8 for recovering and liquefying gas evaporated from the primary tank, and a liquid 20 liquefied by the recovered liquefying means. Secondary tank 18 to be accumulated, heating means (3, 4) for heating the liquid in the primary tank, decompression means 17 for reducing the pressure in the primary tank via the recovery liquefaction means, and the primary A stirring means 2 for stirring the liquid in the tank and a gas temperature measuring means 9 for measuring the temperature of the gas discharged from the primary tank are provided.

  The manufacturing apparatus stirs and mixes fat, alcohol, and alkali catalyst in the primary tank 1 using the stirring means 2 to perform transesterification, and while stirring the transesterified solution 7, The pressure reducing means 17 is operated to adjust the pressure in the primary tank to a predetermined atmospheric pressure, and the heating means (3, 3) so that the measured value of the gas temperature measuring means 9 becomes a predetermined temperature. By controlling 4), the petroleum substitute fuel is evaporated from the solution in the primary tank 1, and the evaporated petroleum substitute fuel is liquefied and accumulated in the secondary tank 18.

  Thus, since the petroleum substitute fuel manufacturing apparatus of the present invention uses only two tanks, it is possible to efficiently obtain a petroleum substitute fuel with high purity and transparency while having a simple structure. . Moreover, since the temperature of the liquid is controlled by the gas temperature measuring means 9, it is possible to accurately determine the start and end of the generation of the petroleum substitute fuel as described above, and the petroleum substitute fuel with higher purity and transparency can be obtained. Can be obtained.

  The primary tank is provided with heating means 3 installed internally such as an internal sheathed heater and heating means 4 installed outside the tank such as an external rubber heater as heating means. For heating the liquid, the internally installed heating means is efficient. However, if the liquid level decreases and the heater is exposed, it becomes difficult to heat the liquid. In this case, the externally installed heating means 4 is indispensable. Become.

  In the primary tank 1, a stirring means 2 is disposed and is rotationally driven by a driving means (not shown). For example, the liquid 7 is stirred so that the whole liquid reacts homogeneously during the transesterification process, or during the distillation process, In order to keep the temperature of the liquid uniform and suppress bumping due to a local temperature rise, the liquid 7 is used for stirring.

  Further, the primary tank 1 is provided with a thermometer 6 for measuring the temperature of the liquid, and the liquid level is sufficiently higher than the position of the thermometer in the temperature control in the transesterification process and the distillation process. Then, it is used to measure and control the temperature of the liquid.

Under the primary tank, a drain pipe 5 for discharging the liquid in the tank is provided together with an opening / closing valve. For example, it is used to discharge residual liquid such as glycerin after the distillation process is completed.
In addition, FIG. 1 does not show an inlet for supplying raw materials necessary for transesterification such as fats and oils, alcohol, and alcohol catalyst into the primary tank, but it can be opened and closed as appropriate on the upper side of the primary tank. It is possible to provide a simple lid or pipe. However, in the present invention, since the inside of the primary tank is depressurized to 5 mmHg or less, it is necessary to adopt a structure that enhances the air tightness so that external gas does not flow in through the lid or the piping under the depressurization.

  On the upper part of the primary tank, a pipe 8 and a cooling means 10 are provided as a recovery liquefaction means for recovering and liquefying the vapor in the primary tank. The cooling means 10 can employ any mechanism of air cooling or water cooling. The pipe 8 is connected to a secondary tank 18 that stores petroleum substitute fuel. In addition to that, the pipe 12 that fractionates the initial flow generated in the early stage of the distillation process and the inside of the primary tank are decompressed. It is also connected to a pipe 15 connected to a decompression means for maintaining.

  A thermometer for measuring the temperature of the steam is installed as a gas temperature measuring means 9 in the vicinity of the connection portion between the primary tank and the pipe 8. The feature of the present invention is that the gas temperature measuring means is used to measure the temperature change of the gas and accurately specify the start and end of evaporation of the petroleum substitute fuel as described above.

  The pipe 12 for fractionating the initial flow is provided with an opening / closing valve 11 between the pipe 8 and the valve 11 is opened at the initial stage of the distillation process, and it is determined that the initial flow is completed. At the point B in the graph of FIG. 2, the valve 11 is closed and set so that the distilled petroleum alternative fuel does not flow into the pipe 12. Of course, in order to increase the purity of the petroleum alternative fuel, it is also possible to open the valve 11 for a while even when the point B is exceeded and to allow impurities remaining in the pipe 8 to flow into the pipe 12.

  A container 13 for accumulating the initial flow 14 is connected to the end of the pipe 12. When the capacity of the initial flow is small, the pipe 12 can also serve as the container 13. The initial flow 14 accumulated in the container 13 is discharged from a discharge port (not shown) provided in the container 13.

  A pressure reducing means 17 such as a high viscosity gear pump is connected to the pipe 15 as means for reducing the pressure in the primary tank. The decompression means 17 is always connected to a portion after the steam in the pipe 8 is liquefied so that the decompression means 17 does not exhaust the steam inside the pipe 8. The pipe 15 is provided with pressure measuring means 16 such as a vacuum meter.

  The secondary tank 18 connected to the pipe 8 accumulates petroleum alternative fuel 20, and a drain pipe 19 for discharging the liquid in the tank is provided along with an opening / closing valve at the lower part of the tank.

  The petroleum substitute fuel manufacturing apparatus of the present invention can be controlled by an electronic computer such as a microcomputer as disclosed in Japanese Patent Application Laid-Open No. H10-228707. At that time, a control program according to the manufacturing method of the present invention is stored in the memory, and the stirring means 2, the heating means (3, 4), the cooling means 10 and the decompression unit of the manufacturing apparatus of the present invention are sequentially called up. The means 17, the valve 11, etc. are sequentially controlled. It is also possible to use various display devices to instruct the operator on the operation procedure. Furthermore, the raw material charging process can be completely automated by connecting the container storing the raw material and the manufacturing apparatus with piping or a supply valve and controlling the supply valve.

  As described above, according to the present invention, it is possible to provide a method and an apparatus for producing an alternative petroleum fuel that does not require a washing step and that can produce an alternative petroleum fuel with high purity. Become.

It is the schematic of the manufacturing apparatus of the petroleum alternative fuel which concerns on this invention. It is a graph which shows the change of the steam temperature from a primary tank.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Primary tank 2 Stirring means 3 Internal sheath heater 4 External rubber heaters 5, 19 Discharge port 6, 9 Thermometer 7, 14, 20 Liquid 8, 12, 15 Pipe 10 Cooling means 11 Valve 16 Vacuum meter 17 Depressurization means 18 2 Next tank

Claims (6)

  A transesterification process in which fats and oils coexist with an alcohol and an alkali catalyst to perform transesterification, and a solution in which the transesterification process is performed in order to separate petroleum substitute fuel generated by the transesterification process and glycerin as a by-product. And a distillation step of distilling and extracting the petroleum substitute fuel by distillation under reduced pressure within a range of 150 to 300 ° C. under a pressure of 5 mmHg or less while stirring the oil.   2. The method for producing a petroleum alternative fuel according to claim 1, wherein the liquid temperature management in the distillation step measures at least a temperature of a gas to be evaporated and controls a heating means for heating the solution. Alternative fuel manufacturing method.   3. The method for producing a petroleum substitute fuel according to claim 2, wherein the heating means is controlled so that the temperature of the gas is within a range of 100 to 250 ° C. during the distillation step. Manufacturing method. A primary tank capable of containing liquid;
Recovery liquefaction means for recovering and liquefying gas evaporating from the primary tank;
A secondary tank for storing the liquid liquefied by the recovered liquefying means;
Heating means for heating the liquid in the primary tank;
Decompression means for decompressing the inside of the primary tank via the recovered liquefaction means;
Stirring means for stirring the liquid in the primary tank;
Gas temperature measuring means for measuring the temperature of the gas discharged from the primary tank,
The fats and oils, the alcohol and the alkali catalyst are stirred and mixed in the primary tank using the stirring means to perform transesterification, and the decompression means is operated while stirring the solution subjected to the transesterification, By adjusting the pressure in the primary tank to a predetermined pressure and controlling the heating means so that the measured value of the gas temperature measuring means becomes a predetermined temperature, the solution in the primary tank An apparatus for producing petroleum substitute fuel, wherein the petroleum substitute fuel is evaporated from the fuel, and the evaporated petroleum substitute fuel is liquefied and accumulated in the secondary tank.   5. The petroleum substitute fuel manufacturing apparatus according to claim 4, wherein the heating means uses a heater disposed at least outside the primary tank.   6. The petroleum substitute fuel production apparatus according to claim 4 or 5, wherein the pressure formed by the pressure reducing means is 5 mmHg or less, and the measured value of the gas temperature measuring means is in the range of 100 to 250 ° C. An apparatus for producing an alternative petroleum fuel, wherein the heating means is controlled.

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