JP2006182890A - Method for producing emulsion fuel and apparatus for producing the same and apparatus for modifying fuel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and apparatus for producing a quality emulsion fuel, a miniaturized cluster fuel in low cost and in compact system with a low energy consumption, and to provide fuel modifying apparatus. <P>SOLUTION: The emulsification is carried out by adding water from a water tank 3 to a fuel oil 2 circulating by a circulating pump 4 using a tubular SPG membrane with an outer diameter of 10mm, an inner diameter of 8.5mm and 125mm of a length. The fuel liquid molecule cluster is miniaturized by passing through contiguous pore of three dimensional net work of porous glass fabricated in arbitrary shape. The Shirasu (white sandy sediment found in Kagoshima) porous glass (SPG) is most suitable for the invention which has many pin holes penetrating membrane and excellent in homogeneity of pin holes with high porosity. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  In recent years, due to the enforcement of the Kyoto Protocol and the pollution conditions of the Tokyo Metropolitan Government, there has been a growing interest in preserving the global environment. In particular, in the current automobile society, the criticism of diesel engines used for heavy trucks is the largest. In order to preserve the environment, simultaneous reduction of NOX (nitrogen oxides), black smoke, and PM (particulate matter) discharged from diesel engines is being studied. The present invention provides a high quality emulsion fuel generation method and fuel reforming method capable of preventing pollution and making effective use of limited fossil fuels as environmental problems become more serious. The present invention also relates to a simple and compact emulsion fuel generator and fuel reformer.

  Conventionally, in order to reduce NOx, black smoke, and PM in engine exhaust gas, a water-in-oil emulsion fuel obtained by mixing and emulsifying fuel oil and water or fuel oil and an aqueous solution has been used. Emulsion fuel mixes with air by lowering the high-temperature combustion temperature at which water droplet particles in the emulsion are instantaneously generated in the engine, suppressing NOX generation, and by causing water droplet particles in the emulsion to slightly explode in the engine. It is said that PM is promoted and it leads to reduction of PM by approaching ideal combustion. As a method for producing an emulsion fuel that is a mixed liquid of fuel oil and water having such characteristics, for example, as described in Patent Document 1 and Patent Document 2, fuel oil, water, and surfactant are mixed at high speed. A method of mixing with a mixer, and several partition walls are provided in the liquid feed line, and small holes are formed in each partition wall, and a small hole is formed by pumping a mixture of fuel oil and water with a booster pump. And a method of obtaining a fine water emulsion fuel while jetting at high pressure and high speed, and a fuel reforming method described in Patent Document 3.

Japanese Patent Application Laid-Open No. 07-024284 JP 2002-159832 A JP 2001-348581 A

  However, among the conventional emulsion fuel generation methods, it is difficult to ensure reliability and reproducibility in the uniformity of the size of the water-in-oil droplet particles in the emulsion with the stirring method. Then, stable combustion cannot be obtained. In addition, in order to obtain fine water droplet particles by passing through a small hole having a diameter of about 0.5 mm to 2 mm of each partition provided in the liquid feeding line, the pressure feeding pressure of the pressure pump is 5 MPa to 15 MPa. In terms of the structural safety of the device, the risk is very high. Liquid fuel reforming methods include liquid agitation and jetting onto the collision wall to break up the liquid to make the liquid cluster finer, and in conjunction with this, the liquid cluster is applied by magnetic field, electric field or ultrasonic vibration. It is said that can be refined. The present invention has been made in view of these problems, and in the fuel oil while allowing water to permeate through the infinite number of ultrafine pores having a uniform three-dimensional network pore size of the porous body in the fuel oil. The W / O emulsion, which is water-in-oil droplets, can be produced as uniform water droplet particles with low-pressure energy, and the fuel oil can be made uniform in a three-dimensional network-like continuous pore size of the porous body. Liquid clusters can be easily miniaturized with low energy and low cost by allowing them to permeate through a myriad of ultrafine holes. Thus, an object of the present invention is to provide an emulsion fuel generation apparatus or a fuel reformer capable of generating high-quality emulsion fuel, cluster refined fuel with low cost, compactness and low energy. The same applies to the O / W emulsion fuel in the present invention.

  The present invention relates to a low-energy and easy-to-produce emulsion fuel having fine particles, and to a low-cost and compact emulsion fuel production apparatus, which is a three-dimensional network of molded porous bodies. It is characterized by being dispersed in fuel oil while allowing water to permeate through ultra-fine pores of uniform uniform pore size, and to produce a W / O emulsion having uniform water droplet particles that are water droplets in oil at low pressure energy. it can.

In addition, as a method for reforming the fuel oil, it is possible to easily create a cluster of molecules constituting the fuel oil by permeating through an infinite number of three-dimensional network-like continuous ultra-fine pores of the molded porous body. It can be miniaturized. The porous Shirasu porous glass membrane (hereinafter referred to as SPG) most suitable for the present invention has innumerable ultrafine pores penetrating the membrane, has extremely high porosity, and pore uniformity. It is a known porous glass membrane that is very good. The shape of the SPG to be molded is not particularly limited, but it can be formed into a shape according to the purpose of use, such as a flat plate shape or a cylindrical shape. SPG is a glass filter, and a tubular filter can withstand about 30 kgf / cm ² against external pressure. The porosity constituting the porous SPG has about 50% to 60% regardless of the pore diameter. No high pressure is required to permeate the liquid through the SPG, and it can be permeated with very low energy.

The emulsion fuel produced according to the present invention uniformly reduces the high-temperature combustion temperature generated instantaneously by spraying and diffusing the water droplet particles in the emulsion having a uniform particle size into the engine, thereby reducing the generation of NOX. Because the emulsion produced by the present invention has a uniform water droplet size, the monodisperse emulsion fuel has a density proportional to the water content, which is greater than that of light oil, and is the same in the engine due to the mass effect. When only light oil is injected under pressure, it is possible to encounter a lot of air by diffusing and blasting more widely, so that it can approach ideal combustion and lead to a reduction in PM. Moreover, combustion can be improved and fuel consumption can be improved. Further, SPG is higher pore diameter decreases SPG surface area surface area widens pore diameter 10μm to about 0.2 m ² / g, the surface area at pore size 0.2μm also about ^8m 2 / g. This means that there is a very high probability that the permeating liquid will contact the SPG surface and be modified. As described above, the emulsion fuel generation method and the fuel reforming method using the porous body of the present invention can be generated more easily than the conventional emulsion fuel generation method, and are lightweight and can be widely processed into a porous body shape. Therefore, it can be easily incorporated into an emulsion fuel generation device for use in automobiles and an emulsion fuel generation device for internal combustion engines such as in-house power generation.

  Hereinafter, the present invention will be described in detail based on examples shown below. Examples of the porous body in the present invention include a metallic porous body, a glassy porous body, and a wooden porous body. In this example, emulsion fuel generation was performed using the most suitable SPG for the porous body of the present invention. Tap oil was used as light oil and water with surfactant added to fuel oil.

  As the mixing method, in the SPG membrane emulsification according to the present embodiment, the SPG shape dimensions are a cylindrical shape having an outer diameter of 10 mm, an inner diameter of 8.5 mm, and a length of 125 mm, and the fuel oil 2 circulated by the circulation pump 4 Emulsify while injecting water from the water tank 3. In this way, water is permeated through the three-dimensional network-like continuous pores of the SPG film (porous glass), thereby reducing the water molecule cluster and modifying the water. The shirasu porous glass most suitable for the present invention has a large number of pores penetrating the membrane and is excellent in the uniformity of pores having a high porosity. The shape of the SPG is not particularly limited, but it can also be formed into a filter in which a flat plate, a cylinder, or a hollow fiber membrane SPG is bundled. As a comparison object, an in-pipe mixer that mixes while slitting fuel oil and water by providing several slits in a liquid feeding pipe line, and an ultrasonic mixing method were performed. FIG. 1 shows an outline of emulsion fuel production produced by the SPG membrane emulsification method. It emulsifies while injecting water from the water tank 3 into the fuel oil 2 circulated by the circulation pump 4. Light oil added with 3% surfactant and tap water were mixed and emulsified by SPG membrane emulsification method, pipe mixer and ultrasonic emulsification method to produce W / O emulsions, and the emulsion particle sizes were compared. The results are shown in Table 1 and the graphs of FIGS.

  As is apparent from the graphs shown in Table 1 and FIGS. 3 to 5, the emulsion generally generated by SPG membrane emulsification produces an emulsion having a particle size of about 3 to 4 times the SPG membrane pore diameter to be used. Also, the emulsion produced has a uniform pore size and is very monodispersed. For emulsions produced by other emulsification methods, the emulsion produced by the in-pipe mixer is fine with an average of about 2 μm, but the standard deviation is 10% D to 90% D compared to the emulsion obtained by SPG membrane emulsification. Wide distribution range. The emulsion produced by ultrasonic waves has a very wide emulsion particle size of about 1.7 μm with the largest relative particle amount, but the entire emulsion particle size distribution range is very wide. When an emulsion generated by an in-pipe mixer and ultrasonic waves was observed under a microscope, double-type emulsions such as O / W / O were found in some places. This is considered to cause a variation in combustion within the engine along with the wide distribution width of the emulsion. As described above, the emulsion fuel obtained by SPG membrane emulsification can ensure stable combustion in the engine because the emulsion particle size is very monodispersed as compared with other emulsion fuel generation methods.

  The emulsion fuel obtained by the SPG membrane emulsification of the present embodiment is a method for producing an emulsion fuel, and it is very easy to control the emulsion particle size by the SPG pore size. This example shows that the particle size of the emulsion fuel can be controlled by the difference in the pore size of the SPG membrane used in the SPG membrane emulsification. The emulsion particle size distribution at this time is shown in FIGS.

Using the emulsion fuel produced by SPG membrane emulsification in a water-cooled single cylinder direct injection diesel engine, a partial load test was performed at a constant engine speed of 1000 rpm, and the overall performance and exhaust gas analysis were compared. Emulsifier 3% was added to fuel oil JIS No. 2 gas oil, and tap water was dispersed in the gas oil circulating like the emulsification system shown in FIG. 1 through an SPG membrane to produce an emulsion fuel. Using an SPG membrane having a pore diameter of 1 μm, the volume ratio of water (W) to light oil (O) was generated as W / O = 30%, 40%, and 50%. A comparison of engine performance and exhaust gas characteristics with this emulsion fuel is shown in FIG.
(1) Net nitrogen oxide (BSNOX) shows a maximum reduction of 55 to 99% in the full load range. This is thought to be due to the fact that water in the emulsion fuel absorbs combustion heat and the maximum combustion temperature is lowered, thereby reducing NOx. In addition, a part of the water gas reaction occurs in which water reacts with free carbon generated from hydrocarbons during combustion, which promotes combustion promotion, contributes to endothermic action, and further reduces combustion temperature to suppress NOX. Expected to be involved.
(2) Black smoke was reduced by a maximum of 49% to 69% in almost all load ranges. Monodisperse emulsion fuel has a density higher than that of light oil in proportion to the water content, and the kinetic energy of the droplets after injection becomes larger, spreads more widely when injected at the same pressure, and encounters more air It is thought that the combustion was improved and the black smoke was reduced. The reduction in PM is also expected due to the decrease in black smoke.
(3) Net fuel consumption rate (BSFC) showed a decrease rate of up to 17% to 19% with increasing water content. Although similar to the reason for the reduction of black smoke, monodisperse emulsion fuels are more dense than light oil in proportion to the water content and diffuse more widely when injected at the same pressure due to mass effects. As a result, it was considered that more air could be encountered, combustion was improved, and fuel consumption was improved.
(4) The increase in noise was 2 to 5, 0 to 8, 1 to 8 dB · A, respectively. This is presumed that the heat delay increases due to the mixing of water, so that the ignition delay period becomes longer and the pressure increase rate increases.

  The present invention is simple, light weight, low cost, and low energy, which is not possible with conventional emulsion fuel generation systems, and is porous as shown in the schematic diagram of an example of an emulsion fuel generation system for automobiles shown in FIG. An emulsion fuel supply path 16 obtained by a porous membrane emulsification system surrounded by a broken line of a loop connecting the body 1 and the fuel oil 2-2, and a pure fuel supply path 17 are provided in consideration of engine operation stability. It is sufficiently possible to configure an engine system equipped with an emulsion fuel generation apparatus to which a switching system is added such that the route 17 is used only when the operation is started and stopped, and the route 16 is used during operation. Further, it is possible to operate while adjusting the emulsion fuel concentration while gradually injecting into the pure fuel supply path 17 by the switching system 15 from the emulsion fuel tank having a constant water concentration while using the pure fuel. The uniform particle size emulsion fuel obtained from the porous body having a uniform pore size of the present invention is a revolutionary environment-friendly emulsion fuel generation system capable of simultaneously reducing NOX and PM.

The fuel oil molecule clusters are refined through the SPG membrane and used in a water-cooled single-cylinder direct-injection diesel engine. A partial load test is performed at a constant engine speed of 1000 rpm, and overall performance and exhaust gas analysis are compared. did. As fuel oil, JIS No. 2 diesel oil was permeated through an SPG membrane having a pore diameter of 1 μm at a pressure of about 0.1 MPa as in the membrane permeation fuel reforming system shown in FIG. 2 to produce a fuel in which molecular clusters were refined. A comparison of engine performance and exhaust gas characteristics of this reformed fuel is shown in FIG.
(1) Net nitrogen oxide (BSNOX) showed a decrease of 9% at maximum in the atomized diesel oil from the low load region to the medium load region.
(2) The black smoke concentration shows a reduction of 47% at maximum in the atomized light oil between 200 (kPa) and 700 (kPa). This is thought to be due to the fact that the cluster structure of light oil molecules is reduced by allowing light oil to permeate through the SPG membrane, so that it easily encounters the air inside the cylinder and leads to a reduction in the black smoke concentration.
(3) The net fuel consumption rate (BSFC) is 0 to 19 (g / kW · h) reduction in atomized diesel oil, and the reduction rate is 0 to 4%, indicating that the combustion state is better than that of diesel oil. It was. Similar to the decrease in the black smoke concentration, the permeation of light oil through the SPG membrane reduces the cluster structure of light oil molecules, making it easier to encounter the air inside the cylinder, leading to improved fuel economy.
(4) Noise (Noise) was less than that of atomized diesel oil in the entire load range. This is also considered to be an effect of miniaturization of the fuel molecular structure. It is considered that combustion was performed quickly because the combustion state was good, and the ignition delay period was shortened.

  As described above, the refined diesel oil obtained by allowing the diesel oil to permeate the SPG membrane was able to reduce the BSNOX and black smoke concentrations by 9% and 47%, respectively, as compared with the diesel oil before the penetration. This is thought to be because the SPG membrane permeation for atomizing the fuel led to an emission reduction effect. In this embodiment, a pore diameter of 1 μm was used, but there is a possibility that the emission reduction effect will be remarkably exhibited by permeating the fuel into a smaller pore diameter and atomizing. In this way, it is possible to easily refine the molecular clusters constituting the fuel oil with low energy by permeating through an infinite number of three-dimensional mesh-like continuous ultrafine holes with uniform pore diameters. .

It is the schematic of the emulsion fuel production | generation direct film | membrane emulsification system using a SPG film | membrane. 1 is a schematic view of a membrane permeation fuel reforming system using an SPG membrane. It is a graph which shows the emulsion fuel W / O particle size distribution obtained using SPG pore diameter 0.6 micrometer. It is a graph which shows the emulsion fuel W / O particle size distribution obtained by the in-pipe mixer. It is a graph which shows the emulsion fuel W / O particle size distribution obtained by ultrasonic emulsification. It is a graph which shows the emulsion fuel W / O particle size distribution obtained using SPG pore diameter 0.4 micrometer. It is a graph which shows the emulsion fuel W / O particle size distribution obtained using SPG pore diameter of 0.9 micrometer. It is a graph which shows a combustion experiment result. It is the schematic which shows the example of the porous body emulsification emulsion fuel production | generation system for motor vehicles mounting. It is a graph which shows a combustion experiment result.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Porous body 2 Fuel oil tank 2A Fuel molecule cluster before porous body permeation 2B Fuel molecule cluster after permeation of porous body 3 Water tank 4 Circulation pump 5 Fuel supply destination 12 Fuel oil supply 13 Water supply 14 Emulsifier supply 15 Fuel Supply switching system 16 Emulsion fuel supply path 17 Pure fuel supply path

Claims (4)

W having uniform water droplet particles that become water droplets in oil by dispersing water in fuel oil while allowing water to permeate through ultra-fine pores having a uniform and uniform pore size in a three-dimensional network shape of the molded porous body. / O emulsion is produced | generated, The production | generation method of the emulsion fuel characterized by the above-mentioned. A fuel oil reforming method characterized by refining molecular clusters constituting the fuel oil by allowing the fuel oil to permeate through a porous body. A generator or a fuel reformer for producing an emulsion fuel using the porous body according to claim 1. A generator for producing an emulsion fuel for automobile mounting or private power generation using the porous body according to claim 1 or 2.

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