JP5219035B2 - Dehydrator - Google Patents

Description

  The present invention relates to a method for dehydrating a biodiesel fuel at the final stage in the production of a biodiesel fuel produced by transesterification of a raw oil such as vegetable oil, animal oil, and waste edible oil with alcohol.

  In recent years, production of biodiesel fuel (BDF), a higher fatty acid ester, from raw oils and fats such as vegetable oil (rapeseed oil, soybean oil, etc.), animal oil, waste oil (waste edible oil, etc.) has become active worldwide. It has been broken.

  A plurality of methods are known as conventional methods for producing BDF. However, a comparison between about 50 ° C. and about 65 ° C. under atmospheric pressure is possible in that the reaction rate is high and the handling of the reaction apparatus is relatively simple. The phase-homogeneous alkali method, in which a catalyst alkali is added under a mild reaction condition to cause a transesterification reaction with an alcohol, is most widely used as a de facto world standard.

  In manufacturing such BDF, it is necessary to dehydrate until a predetermined standard is reached in the final process. With regard to this predetermined standard, no clear standard is currently established in Japan, but the EU has established that the moisture content should be suppressed to 500 ppm or less. It is thought that it is necessary to suppress the concentration.

  Regarding the dehydration method in the final stage, as conventional technology, solid adsorbent (silica gel, zeolite, activated clay, molecular sieve, alumina, activated alumina, sodium sulfate, magnesium sulfate, calcium chloride, alcohol adsorption resin, water absorption resin, etc.) The method used is described in Patent Document 1.

However, in the dehydration method that adsorbs and removes moisture using a solid adsorbent, the solid adsorbent after adsorption removal must be discarded, and operation and cost for that purpose are required, and the adsorbent itself must be used. Costs are also required, and such costs increase as the manufacturing scale increases.
JP 2007-99882 A

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a method capable of efficiently dehydrating biodiesel fuel without using a solid adsorbent.

  In order to solve the above-mentioned problems, the present invention is a method for dehydrating a biodiesel fuel, wherein the water-containing biodiesel fuel is sprayed under a reduced pressure condition of 0.04 MPa or less at a temperature of 85 ° C. or higher. It is characterized in that the degree of dehydration is improved by causing particles of biodiesel fuel to collide during the flight.

  In the above method, in order for the sprayed hydrous biodiesel fuel particles to collide during the flight, the hydrous biodiesel fuel is sprayed from a plurality of directions so that the hydrous biodiesel fuels collide with each other from a plurality of directions. It is preferable to do. Alternatively, the water-containing biodiesel fuel may be sprayed from two opposing directions. Alternatively, a baffle plate for collision of biodiesel fuel particles may be provided in the direction in which the hydrated biodiesel fuel is sprayed, thereby dehydrating the biodiesel fuel.

  In the method for dehydrating a biodiesel fuel according to the present invention, the water-containing biodiesel fuel is sprayed under a reduced pressure condition of 0.04 MPa or less at a temperature of 85 ° C. or higher, and the sprayed water-containing biodiesel fuel particles are in the flight. Since the degree of dehydration is improved by causing the collision, the biodiesel fuel can be easily dehydrated without using a solid adsorbent. The effect of the dehydration of the present invention is considered to be due to the fact that the particles of biodiesel fuel collide with each other to further subdivide the particles and increase the surface area.

  Furthermore, by using the method of the present invention, it is possible to dehydrate various water-containing substances in addition to biodiesel fuel, and it is possible to facilitate the treatment and reuse of waste, the use as biomass, and the like.

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

(Embodiment)
FIG. 1 is a flow sheet for explaining the dehydration method of the present invention.

  Biodiesel fuel (BDF) produced by transesterification contains water (moisture content of 2 to 3%). After being divided into two routes, a vacuum dehydrator (1 ) Is sprayed in. The upper and lower spray firing positions of the vacuum dehydrator (1) are 300 to 400 mm long and are spaced apart from each other.

  If the temperature of the vacuum dehydrator (1) when spraying the hydrous BDF is 80 ° C. or higher, a dehydration effect can be obtained, but if it is 85 ° C. or higher, the EU standard 500 ppm or less requirement is satisfied. Can do. On the other hand, it is clear that the dehydration rate improves as the temperature increases, but if the temperature is 100 ° C., it is clear that the requirement of 500 ppm or less of the EU standard is satisfied. From the viewpoint, it is sufficient that the maximum temperature is 100 ° C.

  If the pressure of the vacuum dehydrator (1) is 0.06 MPa or less by the vacuum pump (3), a dehydrating effect can be obtained, but if it is 0.04 MPa or less, the EU standard requirement of 500 ppm or less is satisfied. Can be satisfied.

  Further, a water recovery tank (1) is provided between the vacuum dehydrator (1) and the vacuum pump (3) so that the water distilled under reduced pressure by the vacuum dehydrator (1) does not reach the vacuum pump (3). 2) is provided.

  The water-containing BDF is sprayed with a particle size of 150 to 250 μm by spraying from above and below.

  In FIG. 1, the spraying is performed so as to be opposed to each other from the upper and lower directions, but as shown in FIG. 2, the same effect can be obtained by spraying from the two left and right directions. The spray direction need not be 180 °, which is a completely opposed relationship.

  Moreover, as shown in FIG. 3, the position which sprays water-containing BDF may be three or more places in any case of up and down or horizontal.

  Furthermore, since the above dehydration effect is considered to be obtained by causing a collision during the flight, as shown in FIG. 4, a baffle plate for colliding the particles of hydrous biodiesel fuel during the flight May be provided.

  Hereinafter, since the reaction mixture after the transesterification was actually separated by the method of the present invention, this will be described in the following examples.

Example 1
In the dehydration process shown in FIG. 1, a vacuum dehydrator (1) having a height of 1500 mm, an inner diameter of 320 mm, and upper and lower spray positions separated by about 400 mm was used. The water content of the water-containing BDF is 2%, and after heating it to 85 ° C., the flow rate is 1500 mL / min, and after being divided into two paths, the vacuum dehydrator (1 ) Sprayed inside.

  The pressure was reduced by the vacuum pump (3) so that the inside of the vacuum dehydrator (1) was 0.04 MPa.

(Example 2)
The operation was performed in the same manner as in Example 1 except that the temperature of the hydrous BDF was 90 ° C.

(Example 3)
The operation was performed in the same manner as in Example 1 except that the temperature of the hydrous BDF was 95 ° C.

(Comparative Example 1)
The operation was performed in the same manner as in Example 1 except that the vacuum pump had a reduced pressure of 0.05 MPa.

(Comparative Example 2)
The operation was performed in the same manner as in Example 1 except that the temperature of the hydrous BDF was 80 ° C.

(Comparative Example 3)
The operation was performed in the same manner as in Example 1 except that the temperature of the hydrous BDF was 95 ° C. and the vacuum pump was reduced to 0.06 MPa.

(Comparative Example 4)
The operation was performed in the same manner as in Example 1 except that the water-containing BDF was sprayed only from the upper side.

(Comparative Example 5)
The operation was performed in the same manner as in Example 1 except that the water-containing BDF was sprayed only from the lower side and the temperature of the water-containing BDF was 90 ° C.

(Comparative Example 6)
The operation was performed in the same manner as in Example 1 except that the water-containing BDF was sprayed from one place in the lateral direction and the temperature of the water-containing BDF was 95 ° C.

(Comparative Example 7)
The operation was performed in the same manner as in Comparative Example 4 except that the temperature of the hydrous BDF was 80 ° C.

  The results (water content) of Examples 1 to 3 and Comparative Examples 1 to 7 are shown in Table 1.

  As is clear from Table 1, the dehydration rate is over 500 ppm in the comparative example that is not sprayed from two opposing directions or that does not satisfy the temperature condition of 85 ° C. or more and the pressure condition of 0.04 MPa or less. There is a clear difference from Examples 1 to 3 in which the dehydration rate can be suppressed to 500 ppm or less.

It is a flow sheet explaining the dehydration method of this invention. It is a figure which shows spraying facing from two right and left directions. It is a figure which shows spraying from three places. It is a figure which shows the case where the baffle plate for the particle | grains of a hydrous biodiesel fuel to collide in the middle of flight is provided.

Explanation of symbols

1 Vacuum dehydrator 2 Moisture recovery tank 3 Vacuum pump

Claims (4)

  A method for dehydrating a biodiesel fuel, wherein the hydrous biodiesel fuel is sprayed at a temperature of 85 ° C. or higher under a reduced pressure of 0.04 MPa or less, and the sprayed hydrous biodiesel fuel particles collide during the flight. A method characterized in that the degree of dehydration is improved by causing hydration.   The method of claim 1, wherein the water-containing biodiesel fuel is sprayed from a plurality of directions such that the hydrated biodiesel fuels collide with each other from a plurality of directions.   The method according to claim 1, wherein the hydrous biodiesel fuel is sprayed from two opposite directions. Wherein in a direction moisture biodiesel fuel is sprayed, it is provided baffle plate for particle biodiesel collide, by spraying so as to collide the particles of biodiesel baffles, thereby biodiesel The method according to claim 1, wherein dehydration of the is accelerated.

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