Fuel additive for removing soot continuously, and method for continuously removing soot to improve fuel consumption

Abstract

To provide a method for continuously oxidizing soot though catalyst action and removing soot, to reduce an amount of soot deposited on a DPF (diesel particulate filter), thereby improving fuel consumption, in the DPF, a combustion chamber and an exhaust system, in a diesel engine of an automobile or the like.SOLUTION: Provided are: a fuel additive for continuously removing soot through catalytic action in an engine combustion chamber, an exhaust system, and a DPF, which is composed of a catalyst with a particle size of 20 nm or less, and a solvent containing a substance with an adhesive function that acts to bind and accumulate catalyst particles with a particle size of 20 nm or less, where the adhesive solvent with an adhesive function has a function that increases a mass while maintaining a surface area as a complex bond, increases kinetic energy, causes a reactant to come into contact in a collision or near collision state, thereby activating a catalytic reaction and continuously removing soot; and a method for removing soot to improve fuel consumption using the fuel additive.SELECTED DRAWING: Figure 11

Description

[Technical field]

[0001] The present invention relates to a cerium-based fuel additive that is composed of cerium oxide having an oxygen storage effect that reduces the generation of soot in the combustion chamber of the engine, and a solvent that has the function of effectively accumulating and dispersing this cerium oxide, in order to continuously regenerate the DPF installed in a diesel engine by having cerium oxide effectively perform two functions: an oxygen storage effect that reduces the generation of soot in the combustion chamber of the engine, and an oxidative removal effect that removes soot trapped in a DPF (diesel particulate filter) installed in the exhaust pipe. [Background technology]

[0002] In order to continuously reduce the PM generated during the combustion process in diesel engines, three methods are mainly used: 1. A method of oxidizing and removing PM using a catalyst supported on DOC (diesel oxidation catalyst) and DPF (diesel particulate filter), which is used for PM emitted from diesel engines installed in automobiles, etc. (1) First, in the DOC, at a temperature range of 200 to 450°C, SOF (soluble organic matter), a PM component contained in exhaust gas, is oxidized and removed, and NO (nitric oxide) generated in the engine's combustion chamber is oxidized and converted to NO2 (nitrogen dioxide). CO generated by incomplete combustion of fuel is also oxidized and converted to CO2. Next, C (carbon, soot), a PM component captured in the DPF, is oxidized (converted to CO2, a carbon compound) at a temperature of 400°C or less by the action of catalysts such as CeO2 (cerium oxide) and Pt (platinum) supported on the DPF and O2 (oxygen) and NO2 in the exhaust gas, thereby removing it (hereinafter, this is referred to as DPF regeneration). (2) In order to achieve this effect in PM reduction devices consisting of a DOC and a DPF, a temperature of approximately 200°C or higher is required for the DOC and approximately 300°C or higher for the DPF, but these temperatures are tending to fall due to the development of high-performance catalysts (which are activated at lower temperatures). This temperature can be achieved using only the exhaust gas from the engine itself during steady-state operation (normal driving) because the exhaust gas temperature is high, but it is difficult to achieve the temperature required for DPF regeneration during low-load operation, including immediately after the engine is started, because the exhaust gas temperature is low. (3) For this purpose, various methods are used to obtain the desired temperature, such as injecting fuel from a fuel injection device installed in the exhaust system and oxidizing this fuel in the DOC to raise the temperature of the exhaust gas to obtain the desired temperature, installing an electric heater midway in the exhaust pipe leading from the engine to the DOC to raise the temperature of the exhaust gas to obtain the desired temperature, and throttling the intake air and recirculating the exhaust gas to the intake side.

[0003] 2. A method in which fuel is injected into the exhaust pipe (post-injection) to generate high-temperature combustion gases and burn the soot. (1) Fuel is injected into the exhaust pipe, and the DOC (diesel oxidation catalyst) installed just before the DPF This function raises the exhaust gas temperature to over 500°C, burning the soot that has accumulated in the DPF. This is a method of removing the (2) This method increases the exhaust gas temperature to oxidize and remove soot inside the piping. This requires more fuel (deteriorating fuel efficiency), and the vehicle must be driven for 20 to 30 minutes while this is being done. Not only is it impossible to operate the DPF (reducing operating efficiency), but the high-temperature gas also causes soot to build up in the DPF. If the fuel burns rapidly, the DPF itself may burn and be damaged. the law of nature).

[0004] 3. Method of reducing soot by mixing additives into fuel Patent Document 1 states that in order to effectively utilize the oxygen storage and release properties of cerium oxide, when added to a fuel as an additive, the particles must be small enough to maintain stable dispersion in the fuel, for example less than 1 micron in size, and since the catalytic effect is surface area dependent, the particles should preferably be 1 to 300 nm in size. Patent Document 2 describes that by adding 20 to 30 ppm of ferrocene to fuel, carbon-containing deposits in the combustion chamber are removed and fuel consumption per driving distance is reduced by 5%, but since ferrocene is generally solid, considerable stirring power and time are required to dissolve it, and in order to improve this, ferrocene and / or a ferrocene derivative are used in combination with lecithin, which enhances the effects of combustion promotion, soot reduction, and NOx reduction. Patent Document 3 describes that the use of a dispersion containing an organic phase, at least one soot-amyloid substance, and a solid mainly composed of small-sized crystallized particles of an iron compound as a fuel additive contributes to lowering the self-ignition temperature of soot. Patent Document 4 describes how, by circulating only diesel fuel in a contact fluidized state for 60 to 300 minutes through a mixture of ceramics made by powder sintering using granite and Maifan stone, a porous natural rock, and applying a magnetic field of 100 to 5,000 gauss using a magnetic generator during the circulation, and adding 0.5 mL to 2 mL of a combustion promoter per liter of diesel fuel, the SO2 and NOx concentrations are reduced and PM is also reduced. However, although previous literature, including these documents, states that mixing additives into fuel can contribute to reducing air pollutants such as PM and CO2, a greenhouse gas, emitted from engines, they do not describe the specific properties of the additives or the physical and chemical mechanisms (physical and chemical bases) by which they exert their effects, and they do not present the results of academic experiments in laboratories using the additives or field experiments using actual vehicles. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Special table 2006-516996 [Patent Document 2] Patent No. 4131748 [Patent Document 3] Special table 2014-503649 [Patent Document 4] Patent No. 5700383 Summary of the Invention [Problem to be solved by the invention]

[0006] In order to effectively oxidize and remove PM trapped in DPFs installed in diesel engines of automobiles, etc., by the action of a catalyst, it is necessary to raise the exhaust temperature above the temperature at which the catalyst is activated. In automobiles, etc., this temperature is not reached during idling or low load, so methods such as installing a fuel injection device in the exhaust system to inject fuel and installing an electric heater in the middle of the exhaust pipe to heat the exhaust gas are used. However, from the perspective of preventing global warming and saving energy, it is necessary to reduce fuel consumption and power consumption as much as possible and to effectively remove PM trapped in DPFs while maintaining engine performance. In addition, it is necessary to develop DPFs carrying catalysts that are activated at lower temperatures than before, and to respond to technology that can be activated at low temperatures by adding this catalyst to fuel, and it is also necessary to continue to develop regeneration systems and regeneration methods for diesel particulate filters that correspond to these technological innovations.

[0007] The method developed by Johnson Matthey (JM) uses a catalyst to generate some kind of gas component that has a stronger oxidizing power than O2 (oxygen), and this oxidizing component travels through the gas phase and reaches the PM surface, promoting the oxidation of soot. Many of the current practical and improved DPF systems use this method. Diesel exhaust gas contains soot, O2, and NO (nitric oxide), so by oxidizing this on a catalyst to nitrogen dioxide (NO2), which has a stronger oxidizing power than O2, it is possible to continuously oxidize and remove soot in the combustion chamber and exhaust system, and also promote the oxidation of PM trapped in the DPF. In this type of reaction, the catalyst itself does not need to come into direct contact with PM. The reaction of oxidizing and removing soot with NO2 begins above the activation temperature of the catalyst, so it is possible to continuously remove PM accumulated in the DPF even under normal engine exhaust gas temperature conditions.

[0008] By mixing a fuel additive consisting of a catalyst and a solvent that dissolves the catalyst into the fuel, it is possible to oxidize and remove soot continuously in the combustion chamber, exhaust system, and DPF. The particle size of the catalyst that makes up the catalytic fuel additive generally needs to be 20 nm or less in order to maximize the contact area with reactants such as O2 and NO. In contrast, the oxidation reaction of soot is not a normal solid-state contact, but a reaction between a solid and a gas, such as solid (catalyst) - gas (O2 or NO) or gas (O2 or NO) - solid (soot). In the engine combustion chamber, exhaust system, and DPF, the fuel gas and exhaust gas (gas) are subject to vigorous flow, so if the mass of the solid (catalyst) is small, it will flow while suspended in the combustion gas or exhaust gas, making it difficult to achieve a state of "collision or near-contact, which is a condition for effective reaction between cerium oxide, a heterogeneous (solid) catalyst, and the reactants O2 and NO," making it difficult for the solid to function as a catalyst.

[0009] Therefore, the present invention aims to provide a cerium-based fuel additive that reduces soot generation in the combustion chamber and oxidizes and removes soot captured in the DPF, characterized in that the additive contains a high-boiling point component in the solvent that constitutes the combustion additive, and this component acts as an adhesive that bonds catalyst particles together at or above the activation temperature of the catalyst, forming a bond on the catalyst that can be described as a bunch of grapes or a chain, thereby increasing the kinetic energy (inertia force), and in the catalytic reaction with the reactants, the reactants are brought into contact with each other in a collision or similar state, activating the catalytic reaction and continuously removing soot. The additive has the following physical and chemical functions: (1) By mixing cerium oxide with a particle size of 20 nm or less into the fuel, it repeatedly collides with soot particles with a particle size of 20 nm to 100 nm in the combustion chamber, reducing the generation of soot due to the "oxygen storage effect" of cerium oxide, and oxidizing and removing the generated soot due to the catalytic effect of cerium oxide. (2) Most of the solvents that are injected with the fuel and contain components with boiling points in the range of 300°C to 600°C are vaporized during the fuel combustion process in the combustion chamber where the combustion temperature exceeds 1000°C, but during the expansion stroke of the combustion, the temperature of the fuel gas drops to below 1000°C, and by the time the exhaust valve opens, it drops to below 600°C, and the temperature drops further in the exhaust pipe. In this state, the components in the additive with boiling points in the range of 300°C to 600°C condense around cerium oxide particles of 20 nm or less, and serve to accumulate and bond the individual cerium oxide particles into complex shapes that can be described as bunches of grapes or chains. (3) The additive’s solvent contains components with boiling points in the range of 300°C to 600°C that condense to form complex shapes resembling grape bunches or chains. The cerium oxide accumulates and bonds in these complex shapes, and passes through the DOC (oxidation catalyst) to reach the DPF. (4) The diameter of the exhaust gas flow passage in the DPF is 10 to 30 μm. However, the soot particles with a particle size of 20 nm to 100 nm generated in the combustion chamber subsequently agglomerate to fill the spaces between the carbon microspheres in the combustion chamber and exhaust pipe, growing to nearly 1 μm in size (secondary particles), and are deposited in the complex exhaust gas flow passage of the DPF. (5) The surface of the DPF exhaust gas flow passage is supported with catalysts such as CeO2 (cerium oxide) and Pt (platinum). When the exhaust gas temperature is below the activation temperature of the catalyst, the “secondary soot particles” aggregate and grow to nearly 1 μm in size. If this covers the surface of the catalyst, the “secondary soot particles” cannot come into contact with NO2, the reducing agent necessary to oxidize and remove the “soot particles.” As a result, the “secondary soot particles” continue to accumulate in the DPF flow passage, eventually causing the flow passage itself to become clogged. (6) On the other hand, cerium oxide with a particle size of 20 nm or less that is injected into the combustion chamber along with the fuel reduces the generation of soot in the combustion chamber through its “oxygen storage effect” and contributes to the oxidative removal of the generated soot through its “catalytic effect”. After that, the cerium oxide accumulates and bonds in the exhaust pipe in complex shapes that can be described as bunches of grapes or chains. As its mass increases, its kinetic energy (inertial force) increases, and it collides with the “secondary soot particles” that have accumulated in the DPF flow passages, which have complex flow passages, thereby effectively functioning as a catalyst and oxidizing and removing them. (7) In contrast, cerium oxide that is not accumulated or bonded, or that does not have sufficient kinetic energy due to a small number of accumulated or bonded particles, flows along the DPF flow path together with the exhaust gas and is discharged into the atmosphere without colliding with the “secondary soot particles” that have accumulated in the DPF flow path, which has a complex flow path. (8) By setting the boiling point of the solvent that makes up the cerium-based catalyst below the temperature at which soot accumulated in the DPF is burned off, the solvent that acts as an adhesive to bind the cerium oxide particles together when the soot accumulated in the DPF is burned off vaporizes and turns the cerium oxide back into tiny particles. As a result, the cerium oxide that remained in the DPF is discharged out of the DPF along with the combustion gas. [Means for solving the problem]

[0010] The fuel additive for continuously removing soot of the present invention comprises cerium oxide having a particle size smaller than the particle size of soot generated in the combustion chamber of an engine, which is 20 to 100 nm, thereby effectively storing oxygen on its surface and efficiently functioning as a catalyst by effectively coming into contact with soot particles, in order to continuously regenerate a DPF (diesel particulate filter) installed in a diesel engine by having cerium oxide effectively perform two functions: an oxygen storage function to reduce soot generation in the combustion chamber of an engine, and an oxidative removal function to remove soot trapped in a DPF installed in an exhaust pipe. This solvent contains a substance whose temperature is lower than that of the soot accumulated in the DPF when it is burned off, and as a result, several to several hundred or more cerium oxide particles are linked together in the exhaust pipe to form a complex structure that can be described as a bunch of grapes or a chain, increasing in mass and resulting in increased kinetic energy (inertia force). This effectively contacts the soot accumulated in the DPF, and acts like an adhesive to effectively and efficiently oxidize and remove it, and when the soot accumulated in the DPF is burned off, it vaporizes and turns the cerium oxide back into tiny particles, which are then discharged outside the DPF along with the combustion gas.

[0011] The fuel additive for continuously removing soot of the present invention is characterized by being composed of cerium oxide having a particle size of 20 nm or less and a solvent having the function of effectively accumulating and dispersing the cerium oxide, in order to continuously regenerate diesel particulate filters installed in diesel engines.

[0012] The fuel additive for continuously removing soot of the present invention is characterized by being composed of cerium oxide having a particle size of 5 nm or less and a solvent having the function of effectively accumulating and dispersing the cerium oxide, in order to continuously regenerate diesel particulate filters installed in diesel engines.

[0013] The fuel additive for continuously removing soot of the present invention is characterized by being composed of cerium oxide having a particle size of 1 nm or less and a solvent having the function of effectively accumulating and dispersing this cerium oxide, in order to continuously regenerate diesel particulate filters installed in diesel engines.

[0014] The fuel additive for continuously removing soot of the present invention is characterized by being composed of cerium oxide having a particle size of 20 nm or less and a solvent containing a component having a boiling point in the range of 300°C to 600°C, in order to continuously regenerate diesel particulate filters installed in diesel engines.

[0015] The fuel additive for continuously removing soot of the present invention is characterized by being composed of cerium oxide having a particle size of 20 nm or less and a solvent containing a component having a boiling point in the range of 350°C to 550°C, in order to continuously regenerate diesel particulate filters installed in diesel engines.

[0016] The fuel additive for continuously removing soot of the present invention is characterized by being composed of cerium oxide having a particle size of 20 nm or less and a solvent having a boiling point of 300°C to 600°C, in order to continuously regenerate diesel particulate filters installed in diesel engines.

[0017] The fuel additive for continuously removing soot of the present invention is characterized by being composed of cerium oxide having a particle size of 20 nm or less and a solvent having a boiling point of 350°C to 550°C, in order to continuously regenerate diesel particulate filters installed in diesel engines.

[0018] The invention described in claim 1 is a fuel additive characterized by comprising a catalyst having a particle size of 20 nm or less and a solvent containing a substance with an adhesive function that acts to bind and aggregate the catalyst particles having a particle size of 20 nm or less to each other, and the adhesive-like solvent forms a complex bond between the catalyst particles, which can be described as a bunch of grapes or a chain of several to several hundred or more particles, thereby increasing the kinetic energy (inertia force), and thereby activating the catalytic reaction by bringing the reactants into contact with each other in a collision or near-collision state in the catalytic reaction with the reactants, thereby effectively removing soot.

[0019] The invention described in claim 2 is a method for continuously removing soot and improving fuel efficiency, characterized in that it uses a fuel additive that is composed of a catalyst having a particle size of 20 nm or less and a solvent containing a substance with an adhesive function that serves to bind and accumulate the catalyst particles having a particle size of 20 nm or less, and the adhesive-like solvent forms a complex bond between the catalyst particles into a complex bond that can be described as a bunch of grapes or a chain of several to several hundred or more particles, thereby increasing the kinetic energy (inertia force) and activating the catalytic reaction by bringing the reactants into contact with each other in a collision or near-collision state in the catalytic reaction with the reactants, thereby effectively removing the soot.

[0020] The invention described in claim 3 is a fuel additive described in claim 1 that effectively oxidizes O2 (oxygen) and NO (nitric oxide), which coexist along with soot in the exhaust gas of a diesel engine, on a catalyst to continuously generate nitrogen dioxide (NO2), which has a greater oxidizing power, thereby oxidizing and continuously removing soot in the combustion chamber and exhaust system, as well as oxidizing and continuously removing soot trapped in the DPF.

[0021] The invention described in claim 4 is a method for continuously removing soot and improving fuel efficiency described in claim 2, characterized in that it uses a fuel additive that can effectively oxidize O2 (oxygen) and NO (nitric oxide), which coexist with soot in the exhaust gas of a diesel engine, on a catalyst to continuously generate nitrogen dioxide (NO2), which has a greater oxidizing power, thereby oxidizing and continuously removing soot in the combustion chamber and exhaust system, and that can oxidize and continuously remove soot trapped in the DPF.

[0022] The invention described in claim 5 is a fuel additive capable of continuously removing soot by the action of cerium oxide in the combustion chamber, exhaust system, and DPF of an engine as described in claim 1, characterized in that the fuel additive is composed of cerium oxide having a particle size of 20 nm or less and a solvent containing a substance with an adhesive function that serves to bind and accumulate the cerium oxide particles having a particle size of 20 nm or less, and the adhesive solvent forms a complex bond of several to several hundred or more cerium oxide particles linked together like a bunch of grapes or a chain, thereby increasing the kinetic energy (inertia force). In the combustion chamber, exhaust system, and DPF (diesel particulate filter), O2 (oxygen) and NO (nitric oxide) collide or come into contact with the cerium oxide in the complex shape of the bond, activating a reaction that produces NO2 and continuously removing soot.

[0023] The invention described in claim 6 is a method for continuously removing soot and improving fuel efficiency described in claim 2, characterized in that the fuel additive capable of continuously removing soot by the action of cerium oxide is used in the combustion chamber, exhaust system, and DPF of an engine, characterized in that the fuel additive is composed of cerium oxide having a particle size of 20 nm or less and a solvent containing a substance having an adhesive function that serves to bind and accumulate the cerium oxide particles having a particle size of 20 nm or less, and the adhesive solvent forms a complex bonded body of several to several hundred or more cerium oxide particles linked together, which can be described as a bunch of grapes or a chain, thereby increasing the kinetic energy (inertia force) and causing O2 (oxygen) and NO (nitric oxide) to collide or come into contact with the complexly shaped bonded body of cerium oxide in the combustion chamber, exhaust system, and DPF (diesel particulate filter), activating a reaction that generates NO2 and continuously removing soot.

[0024] The invention described in claim 7 is a fuel additive for continuously removing soot, comprising a catalyst having a particle size of 20 nm or less and a solvent that dissolves the catalyst, as described in claim 1, characterized in that the solvent contains a substance whose boiling point is higher than the activation temperature of the catalyst, and this component acts like an adhesive that bonds and accumulates catalyst particles having a particle size of 20 nm or less at temperatures above the activation temperature of the catalyst, and in the catalytic reaction with the reactants, the reactants are brought into contact with each other in a colliding or nearly colliding state, thereby activating the catalytic reaction and making it possible to continuously remove soot.

[0025] The invention described in claim 8 is a method for continuously removing soot and improving fuel efficiency described in claim 2, which uses a fuel additive for continuously removing soot, which is composed of a catalyst having a particle size of 20 nm or less and a solvent that dissolves the catalyst described in claim 1, characterized in that the solvent contains a substance whose boiling point is higher than the activation temperature of the catalyst, and this component acts like an adhesive that bonds and accumulates catalyst particles having a particle size of 20 nm or less at temperatures above the activation temperature of the catalyst, and in the catalytic reaction with the reactants, the reactants are brought into contact with each other in a colliding or nearly colliding state, thereby activating the catalytic reaction and making it possible to continuously remove soot.

[0026] The invention described in claim 9 is a fuel additive for continuously removing soot, comprising cerium oxide having a particle size of 20 nm or less and a solvent that dissolves the catalyst described in claim 1, characterized in that the solvent contains a substance whose boiling point is higher than the activation temperature of cerium oxide, and this component acts like an adhesive that binds and accumulates oxidation catalyst particles having a particle size of 20 nm or less at temperatures above the activation temperature of cerium oxide, and in the reaction with O2 or NO in the combustion chamber, exhaust system, or DPF, the O2 or NO is brought into contact with the complex-shaped bound cerium oxide in a collision or similar state, activating the reaction and making it possible to continuously remove soot.

[0027] The invention described in claim 10 is a method for continuously removing soot and improving fuel efficiency described in claim 2, which uses a fuel additive for continuously removing soot, comprising cerium oxide having a particle size of 20 nm or less and a solvent that dissolves the catalyst described in claim 1, characterized in that the solvent contains a substance whose boiling point is higher than the activation temperature of cerium oxide, and this component acts like an adhesive that binds and accumulates oxidation catalyst particles having a particle size of 20 nm or less at temperatures above the activation temperature of cerium oxide, and in the reaction with O2 or NO in the combustion chamber, exhaust system, or DPF, the O2 or NO is brought into contact with the cerium oxide that has become a complex-shaped bonded body in a collision or similar state, thereby activating the reaction and making it possible to continuously remove soot. Effect of the Invention

[0028] By using the present invention, it is possible to continuously regenerate DPFs (diesel particulate filters) installed in diesel engines of automobiles, etc., using a cerium-based fuel additive consisting of a solvent that has the function of effectively accumulating and dispersing cerium oxide and an oxygen storage function that reduces the generation of soot generated in the combustion chamber. [Brief description of the drawings]

[0029] [Figure 1] This shows the role and challenges of the DPF installed in the exhaust pipe. [Diagram 2] This shows the deterioration of fuel efficiency due to an increase in exhaust pipe pressure. [Diagram 3] This demonstrates a technology in which fuel is injected into the exhaust to generate high-temperature combustion gases and burn the soot. [Figure 4] This shows the basic control of the DPF forced regeneration system. [Diagram 5] This shows the function of cerium-based catalysts. [Figure 6] This shows the function of the high boiling point solvent contained in the fuel additive of the present invention. [Figure 7]1 shows the boiling point distribution of a solvent contained in the fuel additive of the present invention. [Figure 8] 1 is a diagram showing a model of how the catalyst contained in the fuel additive of the present invention repeatedly removes soot in a DPF. [Figure 9] 1 shows the effect of the fuel additive of the present invention in reducing soot accumulation in the DPF. [Figure 10] This shows the function of the fuel additive of the present invention to oxidize and remove soot that has accumulated in the DPF. [Figure 11] 1 shows an outline of the "method for improving fuel economy by continuously removing soot" according to the present invention. [Figure 12] This shows the effect of reducing soot in the combustion chamber by the "method of continuously removing soot to improve fuel economy" of the present invention. [Figure 13] 1 shows a vehicle used in an actual vehicle test of the "method of continuously removing soot to improve fuel economy" according to the present invention. [Figure 14] This shows the fuel economy improving effect of the "method of improving fuel economy by continuously removing soot" according to the present invention. [Figure 15] This shows the change in post-injection interval (DPF regeneration interval) [km]. - Figure 11 DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0030] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Figure 1 shows the role and challenges of the DPF installed in the exhaust pipe. Soot (black carbon) is produced by the combustion of fuel in an engine. Regulations require that soot be captured in a DPF, but if left unattended, the DPF will become clogged and engine performance will decline, so the clogged soot must be removed periodically.

[0031] Figure 2 shows the deterioration of fuel efficiency due to an increase in exhaust pipe pressure. When the exhaust pipe pressure reaches about 20 kPa, fuel efficiency worsens by about 8%. (1) When soot accumulates in the DPF, the exhaust gas flow path is narrowed, reducing the exhaust gas flow rate. (2) When the exhaust gas flow rate decreases, the performance of the turbocharger decreases and the amount of air required for combustion becomes insufficient. (3) If the amount of air required for combustion is insufficient, incomplete combustion occurs in the combustion chamber, resulting in poor fuel economy and increased soot production. (4) It is believed that repeated cycles of this process cause the DPF to become clogged at an accelerated rate, resulting in a deterioration in fuel efficiency.

[0032] Figure 3 shows a technology in which fuel is injected into the exhaust to generate hot combustion gases to burn the soot. The technologies that have been implemented to prevent soot from accumulating in the DPF, which impairs the exhaust flow and reduces engine performance and fuel economy, can be broadly categorized as follows: (1) Technology to reduce soot by mixing additives into fuel (2) As shown in Figure 3, this technology injects fuel into the exhaust (post-injection) to generate high-temperature combustion gas and burn soot. (3) Removing the DPF, cleaning it at a repair shop, and then reinstalling it There is.

[0033] However, when the conventional technology is implemented, the following problems (problems) arise. (1) Fuel additives are effective in improving fuel ignition, combustion, and fuel system cleaning. Most of the additives that claim to be effective in reducing soot have no clear explanation of their specific reduction effect and the reason for their effectiveness. The reason is not given. (2) “Post-injection technology” requires extra fuel (reducing fuel efficiency) and is prone to high-temperature gases. If the soot stuck in the DPF burns too quickly, the DPF itself may burn and be damaged. Yes (there have been reports of problems). (3) If the DPF is removed, cleaned at a repair shop, and then reinstalled, the DPF The cost of removing the filter, transporting it to the factory, cleaning the DPF, transporting it from the factory, and installing the DPF (daily) Not only will this increase the number of DPFs and the associated costs, but it will also mean having to install a replacement DPF or suspend operations during that time. It is necessary to do so.

[0034] Figure 4 shows the basic control of the DPF forced regeneration system. The amount of soot trapped in the DPF is estimated, and forced regeneration is performed when the amount of trapped soot reaches a specified amount or more. At this time, if the exhaust temperature is below a specified value (the activation temperature of the oxidation catalyst), the exhaust temperature is raised by after-injection, and when the exhaust temperature reaches or exceeds the specified value, post-injection is performed, sending unburned fuel into the exhaust pipe, where it is oxidized by the oxidation catalyst, raising the exhaust temperature flowing to the DPF and forcibly regenerating the DPF. If the exhaust temperature is above the specified value, the DPF is forcibly regenerated by post-injection alone. The DPF inlet temperature during forced regeneration generally needs to be controlled to around 600°C to enable soot combustion and prevent DPF melting and catalyst deterioration due to high temperatures. In this system, the amount of post-injection is controlled to keep the exhaust temperature at an optimum level while checking the exhaust temperature with an exhaust temperature sensor.

[0035] Figure 5 shows the function of cerium-based catalysts. Figure 5 (a) shows the soot reduction effect of the fuel additive of the present invention in the combustion chamber. CeO2 (cerium oxide) contained in the cerium-based additive absorbs oxygen in areas of high oxygen concentration and supplies it to soot in areas of oxygen deficiency where soot is generated, thereby suppressing soot generation. Figure 5 (b) shows a model of NO2 generation, which has the function of promoting the oxidation of soot and removing it. (1) CEO 2 (Cerium oxide) absorbs O2 (oxygen) (2) When the catalyst reaches its active temperature (the temperature at which it can function), NO (nitric oxide) reacts with O2. NO2 (nitrogen dioxide) is released by colliding or coming into contact with the absorbed CeO2. Generate (3) NO2 promotes the oxidation of C (soot) in the combustion chamber, exhaust system, and DPF, and removes it.

[0036] FIG. 6 shows the function of the high boiling point solvent contained in the fuel additive of the present invention. The fuel additive of the present invention is composed of a catalyst and a solvent that dissolves the catalyst, and the catalyst particle size is 10 nm or less. Therefore, in a separated state (single), the catalyst flows with the flow of combustion gas and exhaust gas, and it is difficult for the catalyst to function as a catalyst by colliding with O2 or NO or coming into contact with it in a similar manner. To address this issue, the solvent of the fuel additive of the present invention contains a high-boiling point component that acts like an adhesive to bind the catalyst particles together above the catalyst's activation temperature, causing the catalyst to form bonds that can be described as bunches of grapes or chains, making it easier for O2 and NO to collide.

[0037] FIG. 7 shows the boiling point distribution of the solvent contained in the fuel additive of the present invention. In the range of about 350°C or higher, which is the activation temperature of the catalyst contained in the fuel additive of the present invention, the high boiling point solvent contained in the solvent that dissolves the catalyst acts as an adhesive, forming catalyst particles with a particle size of 10 nm or less into a bond that can be described as a bunch of grapes or a chain, increasing the volume and mass, so that they can come into contact with O2 and NO contained in the combustion gas or exhaust gas in a state of collision or close to collision. This improves the function of the catalyst and promotes the production of NO2.

[0038] FIG. 8 shows a model diagram of how the catalyst contained in the fuel additive of the present invention repeatedly removes soot in the DPF. When fuel is burned in the engine shown in Figure 8, soot is generated mainly due to a lack of oxygen. When the temperature in the combustion chamber reaches approximately 600°C or higher, the generated soot combines with oxygen to become CO2 (carbon dioxide) (removal of soot through combustion), but if the temperature in the combustion chamber is lower than that or if there is not enough oxygen supplied for combustion, the soot travels through the exhaust pipe together with O2 (oxygen) and NO (nitric oxide) contained in the exhaust gas to reach the DOC (oxidation catalyst). As shown in Figure 8(a), the NO and O2 that reach the DOC are converted to NO2 by the action of the catalyst supported on the DOC (2NO + O2 → 2NO), and after the soot accumulated in the DPF is removed by oxidation (2NO2 + C → 2NO + CO2), the NO2 is discharged from the DPF. Normally, NO2 is released from the DPF as NO after removing soot accumulated in the DPF through oxidation (2NO2+C→2NO+CO2), but as shown in Figure 8(b), when a fuel additive is mixed into the fuel, NO becomes NO2 inside the DPF due to the action of "CeO2 (cerium oxide) that has become a bond described as a bunch of grapes or a chain and is in a state where O2 and NO can easily collide" contained in the exhaust gas as shown in Figure 6, and the soot is oxidized and removed to become NO, but NO2 is generated again by the action of CeO2 contained in the exhaust gas. By repeating this reaction, the soot accumulated in the DPF is continuously removed by oxidation.

[0039] FIG. 9 shows the effect of the fuel additive of the present invention in reducing soot accumulation in the DPF. In FIG. (a) When the DPF inlet temperature (exhaust gas temperature) is below the catalyst activation temperature, as shown in Figure 5 It performs the function of "producing NO2 from O2 and NO contained in exhaust gas through the action of a catalyst." As a result, the DPF inlet pressure continues to rise, and soot enters the DPF, as shown in Figure 9(a). The soot continues to accumulate on the surface of the supported catalyst. If this condition continues, the soot will eventually Covering up (b) When soot covers the surface of the catalyst, the DPF inlet temperature exceeds the catalyst activation temperature. However, the O2 and NO contained in the exhaust gas cannot come into contact with the catalyst, and the catalyst function is impaired. In order to deal with this, The soot that has accumulated in the DPF must be burned and removed by post-injection. (c) In response to this, a fuel additive is mixed into the fuel, which increases the temperature at the DPF inlet to the activation temperature of the catalyst. Above this temperature, soot is repeatedly oxidized and removed in the combustion chamber, exhaust system, and DPF. Therefore, the DPF pressure stops increasing and starts to decrease (as the soot accumulated in the DPF is continuously removed). (It will be in a state where it can be used.)

[0040] FIG. 10 shows the function of the fuel additive of the present invention to oxidize and remove soot accumulated in the DPF. As shown in Figure 10, even when soot has accumulated on the DPF and covered the surface of the catalyst, the fuel can still be added to the fuel. By mixing the additive, the soot that has accumulated in the DPF can be continuously oxidized and removed.

[0041] FIG. 11 shows an outline of the "method of improving fuel economy by continuously removing soot" according to the present invention. Until now, after soot had accumulated in the DPF and reduced fuel efficiency, the soot was removed by burning it at a high temperature of about 600°C through "post-injection." However, with this technology, the catalyst "repeatedly generates NO2 (nitrogen dioxide), which promotes the oxidation of soot, making it possible to continuously oxidize and remove soot at a relatively low temperature of about 350°C.

[0042] FIG. 12 shows the effect of reducing soot in the combustion chamber by the "method of continuously removing soot to improve fuel economy" of the present invention. This technology removes soot by generating NO2, which promotes the oxidation of soot, from O2 (oxygen) and NO (nitric oxide), which are present in large quantities in combustion gas and exhaust gas. This makes it possible to continuously remove soot through oxidation in the combustion chamber, exhaust system, and DPF.

[0043] FIG. 13 shows a vehicle used in an actual vehicle test of the "method of improving fuel economy by continuously removing soot" according to the present invention. The actual vehicle tests were carried out as follows using a truck with a maximum load capacity of 15 tons and a maximum output of 279 kW. (1) Test Dates: December 1, 2021 - April 14, 2021 (2) Test location: Regular commute from Kitakyushu City, Fukuoka Prefecture to Tagawa City, Fukuoka Prefecture, and Isahaya City, Nagasaki Prefecture (3) Purpose: To demonstrate the fuel efficiency improvement effect of fuel additives using a truck of the same class as a dump truck. (4) Test method: Mix the additive into the fuel and measure fuel efficiency (km / L) every 5,000 km. (5) Test results: Average fuel efficiency improvement of approximately 7%

[0044] FIG. 14 shows the fuel economy improvement effect of the "method of improving fuel economy by continuously removing soot" according to the present invention. From the results shown in FIG. 14, it is possible to improve fuel economy by 7% within the experimental range by using the "method for improving fuel economy by continuously removing soot" of the present invention to continuously oxidize and remove soot through the action of catalysts in the combustion chamber, exhaust system, and DPF.

[0045] FIG. 15 shows the change in post-injection interval (DPF regeneration interval) [km]. As shown in FIG. 15, by using the "method of improving fuel economy by continuously removing soot" of the present invention, the post-injection (forced regeneration interval) of the DPF is also improved from about 600 hours to 1200 hours. [Industrial Applicability]

[0046] The present invention is applicable to diesel engines of automobiles, etc., in which soot is continuously oxidized and removed through the action of a catalyst in the combustion chamber, exhaust system, and DPF (diesel particulate filter), thereby reducing the amount of soot accumulated in the DPF and improving fuel efficiency.

Claims

1. It is composed of a catalyst with a particle size of 20 nm or less and a solvent containing an adhesive substance that acts to bind and accumulate the catalyst particles with a particle size of 20 nm or less. The adhesive solvent forms a complex bond between several to several hundred catalyst particles or more, resembling a bunch of grapes or a chain, while maintaining the total surface area of ​​the catalyst, thereby increasing its mass and increasing its kinetic energy (inertia force). This causes the catalyst to move in a different way from O2 (oxygen) and NO (nitric oxide), which coexist with soot in the combustion gas and exhaust gas of diesel engines, causing the O2 and NO to collide or come into contact with each other in a state similar to collision, and oxidize them on the catalyst to produce nitrogen dioxide (NO2), which has a greater oxidizing power than O2. This fuel additive improves fuel efficiency by continuously oxidizing and removing soot through the action of the catalyst in the combustion chamber, exhaust system, and DPF (diesel particulate filter) of diesel engines in automobiles, etc., thereby reducing the amount of soot that accumulates in the DPF.

2. A method for continuously removing soot and improving fuel economy, comprising a catalyst having a particle size of 20 nm or less and a solvent containing an adhesive substance that functions to bind and accumulate the catalyst particles having a particle size of 20 nm or less, the adhesive solvent forming a complex bond of several to several hundred or more catalyst particles linked together like a bunch of grapes or a chain, thereby increasing the mass while maintaining the total surface area of ​​the catalyst and increasing the kinetic energy (inertia force), and causing the catalyst to move differently from O2 (oxygen) and NO (nitric oxide) that coexist with soot in the combustion gas and exhaust gas of a diesel engine, thereby causing O2 and NO to come into contact with each other or in a state close to collision, and oxidize them on the catalyst to produce nitrogen dioxide (NO2), which has a greater oxidizing power than O2. The method is characterized by using a fuel additive for continuously removing soot in the combustion chamber, exhaust system, and DPF (diesel particulate filter) of a diesel engine of an automobile, etc., to reduce the amount of soot that accumulates in the DPF and improve fuel economy by continuously oxidizing and removing the soot through the action of a catalyst.

3. A fuel additive as described in claim 1, which effectively oxidizes O2 (oxygen) and NO (nitric oxide) that coexist with soot in the exhaust gas of a diesel engine on a catalyst, thereby continuously generating nitrogen dioxide (NO2), which has a stronger oxidizing power than O2, thereby oxidizing and continuously removing soot in the combustion chamber and exhaust system, and oxidizing and continuously removing soot trapped in the DPF.

4. A method for continuously removing soot and improving fuel efficiency as described in claim 2, characterized by using the fuel additive described in claim 1, which effectively oxidizes O2 (oxygen) and NO (nitric oxide) that coexist with soot in the exhaust gas of a diesel engine on a catalyst to continuously generate nitrogen dioxide (NO2), which has a stronger oxidizing power than O2, thereby oxidizing and continuously removing soot in the combustion chamber and exhaust system, and oxidizing and continuously removing soot trapped in the DPF.

5. 2. A fuel additive capable of continuously removing soot by the action of cerium oxide in an engine combustion chamber, exhaust system, or DPF as described in claim 1, characterized in that the fuel additive is composed of cerium oxide having a particle size of 20 nm or less and a solvent containing a substance with an adhesive function that serves to bind and accumulate the cerium oxide particles having a particle size of 20 nm or less, and the adhesive solvent forms a complex bond of several to several hundred or more cerium oxide particles linked together like a bunch of grapes or a chain, increasing the kinetic energy (inertia force) of the cerium oxide particles. This causes O2 (oxygen) and NO (nitric oxide) to collide or come into contact with the complexly shaped bonded cerium oxide in the combustion chamber, exhaust system, or DPF (diesel particulate filter), activating a reaction that produces NO2 and continuously removing soot.

6. 3. A method for continuously removing soot and improving fuel economy as described in claim 2, characterized in that the fuel additive is used in an engine combustion chamber, exhaust system, or DPF (diesel particulate filter) capable of continuously removing soot by the action of cerium oxide, characterized in that the fuel additive is composed of cerium oxide having a particle size of 20 nm or less and a solvent containing a substance having an adhesive function that serves to bind and accumulate the cerium oxide particles having a particle size of 20 nm or less, and the adhesive solvent forms a complex bond of several to several hundred or more cerium oxide particles linked together, which can be described as a bunch of grapes or a chain, thereby increasing the kinetic energy (inertia force) of the cerium oxide particles, thereby causing O2 (oxygen) and NO (nitric oxide) to collide or come into contact with the complex bond of cerium oxide in the combustion chamber, exhaust system, or DPF (diesel particulate filter), activating a reaction that produces NO2 and continuously removing soot.

7. A fuel additive for continuously removing soot, comprising a catalyst having a particle size of 20 nm or less and a solvent that dissolves the catalyst, as described in claim 1, characterized in that by including in the solvent a substance having a boiling point higher than the activation temperature of the catalyst, this component acts as an adhesive that binds and aggregates catalyst particles having a particle size of 20 nm or less together at temperatures above the activation temperature of the catalyst, and in a catalytic reaction with a reactant, the reactants are brought into contact with each other in a collision or similar state, thereby activating the catalytic reaction and making it possible to continuously remove soot.

8. A method for continuously removing soot and improving fuel efficiency as described in claim 2, which uses a fuel additive for continuously removing soot, which is composed of a catalyst having a particle size of 20 nm or less and a solvent that dissolves the catalyst as described in claim 1, characterized in that by making the solvent contain a substance having a boiling point higher than the activation temperature of the catalyst, this component plays a role of an adhesive that binds and accumulates catalyst particles having a particle size of 20 nm or less at temperatures above the activation temperature of the catalyst, and in a catalytic reaction with a reactant, by contacting the reactants in a collision or similar state, the catalytic reaction is activated and soot can be continuously removed.

9. A fuel additive for continuously removing soot, comprising cerium oxide having a particle size of 20 nm or less and a solvent that dissolves the catalyst, as described in claim 1, characterized in that by including in the solvent a substance having a boiling point higher than the activation temperature of cerium oxide, this component acts as an adhesive that binds and accumulates oxidation catalyst particles having a particle size of 20 nm or less at temperatures above the activation temperature of cerium oxide, and by bringing O2 or NO into contact with the complex-shaped bound cerium oxide in a collision or similar state in a reaction with O2 or NO in the combustion chamber, exhaust system, or DPF, the reaction is activated and soot can be continuously removed.

10. A method for continuously removing soot and improving fuel efficiency as described in claim 2, which uses a fuel additive for continuously removing soot, comprising cerium oxide having a particle size of 20 nm or less and a solvent that dissolves the catalyst as described in claim 1, characterized in that by including a substance having a boiling point higher than the activation temperature of cerium oxide in the solvent, this component acts as an adhesive that binds and accumulates oxidation catalyst particles having a particle size of 20 nm or less at temperatures above the activation temperature of cerium oxide, and by bringing O2 or NO into contact with the cerium oxide that has become a complex-shaped bond in a collision or similar state in a reaction with O2 or NO in the combustion chamber, exhaust system, or DPF, the reaction is activated and soot can be continuously removed.

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