Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL-COMBUSTION ENGINES
  • F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
  • F01N3/08—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous
  • F01N3/10—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust
  • F01N3/24—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for rendering innocuous by thermal or catalytic conversion of noxious components of exhaust characterised by constructional aspects of converting apparatus
  • F01N3/30—Arrangements for supply of additional air
  • F01N3/306—Preheating additional air
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
  • B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
  • B01J23/10—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of rare earths
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10L—FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G OR C10K; LIQUIFIED PETROLEUM GAS; USE OF ADDITIVES TO FUELS OR FIRES; FIRE-LIGHTERS
  • C10L1/00—Liquid carbonaceous fuels
  • C10L1/10—Liquid carbonaceous fuels containing additives
  • C10L1/12—Inorganic compounds
  • C10L1/1233—Inorganic compounds oxygen containing compounds, e.g. oxides, hydroxides, acids and salts thereof
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10L—FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G OR C10K; LIQUIFIED PETROLEUM GAS; USE OF ADDITIVES TO FUELS OR FIRES; FIRE-LIGHTERS
  • C10L1/00—Liquid carbonaceous fuels
  • C10L1/10—Liquid carbonaceous fuels containing additives
  • C10L1/14—Organic compounds
  • C10L1/18—Organic compounds containing oxygen
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10L—FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G OR C10K; LIQUIFIED PETROLEUM GAS; USE OF ADDITIVES TO FUELS OR FIRES; FIRE-LIGHTERS
  • C10L1/00—Liquid carbonaceous fuels
  • C10L1/10—Liquid carbonaceous fuels containing additives
  • C10L1/14—Organic compounds
  • C10L1/18—Organic compounds containing oxygen
  • C10L1/1814—Chelates
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10L—FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G OR C10K; LIQUIFIED PETROLEUM GAS; USE OF ADDITIVES TO FUELS OR FIRES; FIRE-LIGHTERS
  • C10L1/00—Liquid carbonaceous fuels
  • C10L1/10—Liquid carbonaceous fuels containing additives
  • C10L1/14—Organic compounds
  • C10L1/18—Organic compounds containing oxygen
  • C10L1/188—Carboxylic acids; metal salts thereof
  • C10L1/1881—Carboxylic acids; metal salts thereof carboxylic group attached to an aliphatic carbon atom
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10L—FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G OR C10K; LIQUIFIED PETROLEUM GAS; USE OF ADDITIVES TO FUELS OR FIRES; FIRE-LIGHTERS
  • C10L1/00—Liquid carbonaceous fuels
  • C10L1/10—Liquid carbonaceous fuels containing additives
  • C10L1/14—Organic compounds
  • C10L1/24—Organic compounds containing sulfur, selenium and/or tellurium
  • C10L1/2431—Organic compounds containing sulfur, selenium and/or tellurium sulfur bond to oxygen, e.g. sulfones, sulfoxides
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10L—FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G OR C10K; LIQUIFIED PETROLEUM GAS; USE OF ADDITIVES TO FUELS OR FIRES; FIRE-LIGHTERS
  • C10L1/00—Liquid carbonaceous fuels
  • C10L1/10—Liquid carbonaceous fuels containing additives
  • C10L1/14—Organic compounds
  • C10L1/24—Organic compounds containing sulfur, selenium and/or tellurium
  • C10L1/2431—Organic compounds containing sulfur, selenium and/or tellurium sulfur bond to oxygen, e.g. sulfones, sulfoxides
  • C10L1/2437—Sulfonic acids; Derivatives thereof, e.g. sulfonamides, sulfosuccinic acid esters
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10L—FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G OR C10K; LIQUIFIED PETROLEUM GAS; USE OF ADDITIVES TO FUELS OR FIRES; FIRE-LIGHTERS
  • C10L1/00—Liquid carbonaceous fuels
  • C10L1/10—Liquid carbonaceous fuels containing additives
  • C10L1/14—Organic compounds
  • C10L1/30—Organic compounds compounds not mentioned before (complexes)
  • C10L1/301—Organic compounds compounds not mentioned before (complexes) derived from metals
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10L—FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G OR C10K; LIQUIFIED PETROLEUM GAS; USE OF ADDITIVES TO FUELS OR FIRES; FIRE-LIGHTERS
  • C10L10/00—Use of additives to fuels or fires for particular purposes
  • C10L10/02—Use of additives to fuels or fires for particular purposes for reducing smoke development
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10L—FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G OR C10K; LIQUIFIED PETROLEUM GAS; USE OF ADDITIVES TO FUELS OR FIRES; FIRE-LIGHTERS
  • C10L10/00—Use of additives to fuels or fires for particular purposes
  • C10L10/06—Use of additives to fuels or fires for particular purposes for facilitating soot removal
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL-COMBUSTION ENGINES
  • F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
  • F01N3/02—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust
  • F01N3/021—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters
  • F01N3/023—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters using means for regenerating the filters, e.g. by burning trapped particles
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL-COMBUSTION ENGINES
  • F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
  • F01N3/02—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust
  • F01N3/021—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters
  • F01N3/023—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters using means for regenerating the filters, e.g. by burning trapped particles
  • F01N3/029—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for cooling, or for removing solid constituents of, exhaust by means of filters using means for regenerating the filters, e.g. by burning trapped particles by adding non-fuel substances to exhaust
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02D—CONTROLLING COMBUSTION ENGINES
  • F02D19/00—Controlling engines characterised by their use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures
  • F02D19/12—Controlling engines characterised by their use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures peculiar to engines working with non-fuel substances or with anti-knock agents, e.g. with anti-knock fuel
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10L—FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G OR C10K; LIQUIFIED PETROLEUM GAS; USE OF ADDITIVES TO FUELS OR FIRES; FIRE-LIGHTERS
  • C10L1/00—Liquid carbonaceous fuels
  • C10L1/10—Liquid carbonaceous fuels containing additives
  • C10L1/14—Organic compounds
  • C10L1/18—Organic compounds containing oxygen
  • C10L1/188—Carboxylic acids; metal salts thereof
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL-COMBUSTION ENGINES
  • F01N2430/00—Influencing exhaust purification, e.g. starting of catalytic reaction, filter regeneration, or the like, by controlling engine operating characteristics
  • F01N2430/04—Influencing exhaust purification, e.g. starting of catalytic reaction, filter regeneration, or the like, by controlling engine operating characteristics by adding non-fuel substances to combustion air or fuel, e.g. additives
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
  • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL-COMBUSTION ENGINES
  • F01N2610/00—Adding substances to exhaust gases
  • F01N2610/01—Adding substances to exhaust gases the substance being catalytic material in liquid form
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
  • Y02T10/00—Road transport of goods or passengers
  • Y02T10/10—Internal combustion engine [ICE] based vehicles
  • Y02T10/12—Improving ICE efficiencies

Definitions

• the subject of the present invention is a process for the filtration and combustion of carbonaceous materials from internal combustion engines.
• the invention relates more particularly to the regulation of the pressure drop caused in the filters by the accumulation of soot in the filters.
• the most effective technique seems to be the adaptation to the exhaust of a filter capable of stopping all or at least most of the soot formed by the combustion of the various fuels.
• the problem to be solved resides in the accumulation of this soot in the filters which firstly causes an increase in pressure drop and, secondly, a start of blockage which leads to a loss of efficiency of the combustion engine. internal.
• the temperature of ignition of the soot remains relatively high (of the order of 500 ° C.) and on the other hand intermittent and violent combustions are likely to cause significant deterioration of the filter and of its capacities. filtration, either by cracking due to thermal shock, or even by fusion. This alteration of the filters can take the form of a loss of capacity to retain a high percentage of soot, while the initial percentage is sometimes considered insufficient.
• one of the aims of the present invention is to provide a process for burning the soot which is as continuous as possible.
• Another object of the present invention is to provide a method of burning soot which does not result in sudden, violent and sudden ignitions leading to damage to the filter. To achieve such a result, it should be avoided that during the ignition phase, at no point in the filter does the temperature reach 1000 ° C., advantageously 900 ° C., preferably 700 ° C.
• Another object of the present invention is to provide a method of filtration and combustion of soot, which makes it possible to improve the proportion of soot retained on the filters and then subsequently burned.
• the partial oxygen pressure be at least equal to 6.10 3 Pascals, preferably 8 kilo Pascals.
• the contact between the oxygen-containing gas and the soot be maintained for a period of time sufficient to burn at least 90% of the soot.
• rare earths and in particular rare earth oxides especially those due to cerium catalyze the oxidation of carbonaceous materials at temperatures as low as 100 ° C.
• This phenomenon only occurs when the oxygen content of the gas is sufficiently high.
• the threshold from which soot oxidation occurs depends to some extent on the value of the other parameters. It increases when the rare earth content of the soot decreases and / or when the temperature approaches the low values of the ranges mentioned above.
• the method according to the invention can be used in many ways to reduce the emissions of solid carbonaceous rejection from all sooty combustions and in particular from internal combustion engines.
• the partial pressure of oxygen and temperature be maintained for a sufficiently long period to oxidize all of the soot. produced in order to prevent them from accumulating or being rejected. So on average or statistically or continuously, it is appropriate that, for a defined duration, the sum of the periods of time when the conditions of the present invention are met is sufficient for the soot produced during said defined duration to oxidize in their entirety. From this defined duration depends the constraint imposed on the soot producing and purifying system.
• the residence time is large or even infinite with regard to their life expectancy, it is possible to provide said long defined durations. Said defined duration can then reach ten minutes or even 1/2 hour.
• a defined long period is paid for by periods during which the pressure drop caused by the filter can be relatively high.
• the accumulation of particles in the filters improves the quality of filtration. So there is a compromise to be found.
• the present invention makes it possible to envisage the use of systems which are less restrictive than the particle filter.
• It can in particular be enriched by injecting air into the flow of exhaust gases.
• This air can advantageously be heated by contacting different heat sources and in particular with hot parts of the engine directly or through a heat exchanger.
• thermal flywheels which would be heated during the period of non-regeneration of the filter by the exhaust gases and would restore the heat stored in the air in charge of enriching the exhaust gases with oxygen during the periods of use of the method according to the present invention.
• the simple mixing of the outside air with the exhaust gases makes it possible to obtain a temperature and an oxygen content sufficient to be placed in the zone where the catalytic oxidation takes place in good conditions.
• the preferred rare earths are cerium, neodymium and lanthanum.
• these metals are preferably in the form of their oxide IV in the case of cerium (and for the good rule for praseodymium, but it is not very economical), bivalent oxide in the other cases.
• cerium and / or lanthanum are the majority.
• rare earths of the preceding type doped with non-rare earth elements (cf. part on doping lanthanum, which part is transposable for any rare earth or mixture of rare earth).
• Rare earths can be introduced into soot by the introduction into the fuel of a derivative such as their salts or their soils.
• the introduction of compounds based on rare earth (s) can be carried out in particular by the introduction of compounds based on rare earth (s) in the fuel intended to be introduced into the engine.
• Another possibility is to introduce the rare earth (s) in various forms through the air, and in particular air when it is mixed with engine exhaust gases. , when a fraction of the exhaust gases is recycled in the engine. In this case, the rare earth compounds incorporated in the recycled soot are introduced into the engine.
• the quantity of rare earths introduced into the engine is determined so that the content of rare earth (s) (by mass of metal contained) in the soot reaches a level of between 1000 ppm and 30%, advantageously at least 5000 ppm preferably at least 5% and advantageously at most 25%, preferably at most 10%.
• a satisfactory value is of the order of 5 to 10%.
• cerium oxide plays the role of paradigm (in the same way as the verb "to love” is the paradigm of the first French conjugation or that "dominus” is the paradigm of the second Latin declination) of rare earth oxides.
• the cerium oxide thus formed has a particle size such that the d ⁇ o (diameter of the mesh allowing 80% by mass of the product to pass) is at most equal to 10,000 ⁇ (1,000 nanometers), preferably 5,000 ⁇ ( 500 nanometers). It is also preferable that the ⁇ 0 is greater than 200 ⁇ (20 nanometers) and preferably 500 ⁇ (50 nanometers).
• soot containing the above aggregates may play a role in the present invention. It is therefore preferable that the particle size of the soot is such that the grain has a do equal to at least 100 ⁇ and / or a d ⁇ o at most equal to 1000 ⁇ and which contain at least 0.01%, advantageously at least 0.1 %, preferably at least 0.5% aggregate according to the present invention.
• the content of rare earth (s) (by mass of metal contained) in the soot reaches a level of between 1000 ppm and 30% advantageously at least 5000 ppm preferably at least 5% and advantageously at most 25 %, preferably at most 10%.
• the soot grains form clusters with a dso of between 2000 and 5000 ⁇ .
• the soot thus formed has a total cerium content of between 1 and 5% by weight, preferably from 1.5 to 2.5%.
• the aggregate of crystallites is formed during the combustion of the fuel, or of the fuel, the latter being added with at least one compound of cerium, preferably tetravalent in the form of solution or of soil.
• the d2o be greater than 200 ⁇ (20 nanometers) and preferably 500 ⁇ (50 nanometers).
• the elements promoting this low temperature combustion (or regeneration) are the oxygen content and the content of hydrocarbon compounds. With regard to the oxygen content (which has already been treated above), it is preferable that the oxygen content is at least equal to 3%, preferably approximately 5%.
• the volatility of the hydrocarbon compounds, their content in the gases and their temperature are such that, at the temperature where the soot is liable to be subjected upon combustion (for example accumulate in the particulate filter), the content (mass ratio) of volatile hydrocarbon compounds in the soot is at least equal to one tenth, preferably a quarter, more advantageously a half of the mass over dry.
• volatile is meant all the hydrocarbon compounds, in particular those which exist in the exhaust gases, which are in the form of gas at 600 ° C., advantageously at 400 ° C., preferably at 350 ° C.
• hydrocarbon compounds have a boiling point of between about 100 and 400 ° C.
• This regeneration generally occurs when the content of hydrocarbon compounds in the gases is greater than or equal to 10 ppm, preferably greater than 20 ppm.
• gas oils of which 95% by mass of the constituents distill under atmospheric pressure at a temperature at least equal to 160 ° C. advantageously at 180 ° C. and of which 95% by mass of the constituents are volatile under atmospheric pressure at 400 ° C preferably at 360 ° C.
• the process gives good results with gas oils with a high aromatic content, than with gas oils with a high aliphatic content, provided that the distillation constraints set out above are observed.
• the compositions are compounds of rare earth (s) liquid under the conditions of use (in particular ambient temperature with the engine), in the form of sol (s), or dissolved, in hydrocarbon diluents, in particular the fuels, including diesel.
• the present invention is particularly advantageous for two kinds of fuel, those whose aromatic content is very high [content of aromatic derivative (s) is at least equal to 1/5 advantageously to a third], because it allows to use these fuels which without this invention would lead to excessively disturbing deposits.
• paraffinic the paraffin content of which is at least equal to 30% that the effects are most marked.
• the aromatic content is at most equal to 1/5, advantageously 1/10, preferably 1/20.
• the invention is particularly well suited to particles emitted by fast diesel engines (as opposed to slow engines). These engines are mainly used in land transport, such as heavy goods vehicles (trucks, coaches, etc.), and light vehicles.
• fast diesel engine means engines whose maximum power is reached at rotational speeds at least equal to 1500 revolutions / minute; advantageously at least equal to 1800 revolutions / minute.
• a particularly advantageous implementation of the present invention consists in a process for filtering the gases of an internal combustion engine.
• This process which consists in: introducing into the combustion chamber at least one rare earth derivative or mixture of rare earths at a concentration of between 10 ppm and 500 ppm (by mass), preferably between 20 ppm and 200 ppm;
• the temperature of the gases entering the filter being chosen in the range 100 ° C-350 ° C (position zeros are not significant figures);
• soot to accumulate until reaching a regime where a significant fraction of the incoming soot is compensated by the combustion of soot in the soot cake on the filter and do not provide for any regeneration as long as the pressure drop caused by the soot n '' does not exceed a value chosen in advance and does not exceed 400 millibar.
• the above pressure drop does not incorporate the pressure drop caused by the filter not loaded with soot, pressure drop which is generally less than 100 millibar, and very often less than 50 millibar.
• pressure drop which is generally less than 100 millibar, and very often less than 50 millibar.
• metal filters give particularly good results, or more precisely, particularly frequent regenerations.
• the filters give better results after 3, preferably 5 regeneration cycles.
• the point overheating can be carried out by any means known to those skilled in the art, such as micro-resistance (s) distributed over the surface of the filter, metal particles heated by eddy current, mini-arc or the like.
• s micro-resistance
• the filtration mode according to the invention generally works only during part of the engine speed, since some of the modes generate gases with a temperature of at least 500 ° C (two significant figures) which ipso facto performs a gradual and often complete regeneration of the filter. It should be noted that the temperature of the gases entering the filter can vary widely within the 100-400 ° C temperature range. These variations, which can be deliberately caused, promote regeneration and maintain a low value pressure drop. It is advantageously possible to choose the position of the filter so that the temperature of the filter is for most of the time possible at a temperature included in the above ranges.
• the preferred rare earths are cerium, lanthanum and mixtures containing cerium and lanthanum.
• the most common content of the rare earth (metal) fuel contained is between 50 and 150 ppm.
• the rare earth content of the fuel can be chosen so as to adjust the pressure drop to a value chosen in advance.
• This value chosen in advance is preferably between 100 and 400 millibar, preferably between 150 and 300 millibar.
• the rare earths present in the soot have a concentration between 500 ppm and 10%, preferably between at least 1000 ppm (mass of metal contained relative to the total mass of soot, including including the compounds they have adsorbed) and at most 5% on average.
• the rare earth, or the mixture of rare earths with its procession of impurity (s) and adjuvant (s), with a content of between 10 and 1000 ppm in the fuel. These values are expressed in contained metal.
• contents of 20 to 200 ppm are used, preferably from 50 to 150 ppm.
• the form in which the rare earth, or the mixture of rare earths is introduced induces the formation of aggregates of crystallites of rare earth oxide, or mixture of rare earths, where the largest dimension of said aggregate is between 20 angstroms and 10,000 angstroms, preferably between 100 and 5,000 angstroms, for which the size of the crystallites is between 20 and 250 angstroms, preferably between 50 and 200 angstroms.
• the introduction of compounds based on rare earths, alone or in mixture can be carried out in particular by the introduction of compounds based on rare earths, alone or in mixture, in the fuel intended to be introduced into the engine.
• Another possibility is to introduce the rare earths, alone or as a mixture, in various forms by means of air, and in particular air when it is mixed with engine exhaust gases, when a gas fraction exhaust is recycled to the engine.
• the rare earth compounds, alone or as a mixture, incorporated into the recycled soot are introduced into the engine.
• One of the most practical means of introducing rare earths, alone or as a mixture, into the engine circuit consists in introducing it into the fuel either in the form of salt or in the form of soil.
• These compounds, salts or soils advantageously contain products which are not harmful to combustion or to the environment.
• the salts or the soils are prepared from hydrocarbon compounds such as the carbon acid salts, whether they are of the carboxylic type or of the type with mobile hydrogen compounds such as, for example, acetylacetonates.
• the carboxylic acid salts from C2 to C20. preferably from C4 to C15 are among the best suited for this use.
• cerium derivatives of cerium IV are preferred because of their stability and their ability to make few particles.
• the rare earth oxides or mixtures of rare earth oxides are stable in the fuel.
• Cerium is the preferred rare earth, alone; or in combination.
• cerium can be introduced either in the form of soils or in the form of various salts provided that the latter are sufficiently stable in the medium. Mention may in particular be made of the salts which are the subject of the European patent application filed under the number 93 / 304760.7 and published under the number 0575189.
• the behavior in the presence of additives based on rare earth elements allows more flexible management of the pressure drop phenomena; in fact, in the case of additives based on elements of the transition metals (in particular copper and iron), the regenerations are random, violent and brutal, the pressure drops change very suddenly. This causes variations in engine power and affects driving safety and comfort as well as the proper functioning of the engine; on the other hand, in the case of additives based on rare earth elements, the regenerations are of low amplitude which reduces the effects on the pressure drop and the thermal effects.
• the pressure drop due to the filter stabilizes and can be managed without penalizing safety and driving pleasure.
• the lanthanum derivatives can be used to practice the present invention. This led to the development of lanthanum derivatives as well as other doped rare earths.
• the lanthanum is added to the fuel in the form of a salt or a stable soil.
• rare earths as combustion aids has been described for a long time in the state of the prior art, but lanthanum has never been cited except incidentally, or rather accidentally, as a member of this family. More recently, in an exhaustive study carried out at the French Petroleum Institute on different rare earths and on their ability to catalyze the oxidation of soot, M. DESOETE showed that lanthanum had no catalysis property on carbonaceous particles .
• soot formed by the introduction of lanthanum-based compounds into the circuits of internal combustion engines, and in particular diesel engines, have the property of being significantly more flammable, that is to say with a lower ignition temperature than soot prepared without additives.
• the introduction of lanthanum-based compounds can be carried out in particular by the introduction of lanthanum-based compounds into the fuel intended to be introduced into the engine.
• Another possibility is to introduce lanthanum in various forms through the air, and in particular air when it is mixed with engine exhaust gases, when a fraction of the exhaust gases is recycled in the engine.
• the lanthanum compounds incorporated in the recycled soot are introduced into the engine.
• One of the most practical ways to introduce lanthanum into the engine circuit is to introduce it into the fuel either in the form of salt or soil form.
• the salts or the soils are prepared from hydrocarbon compounds such as the carbon acid salts, whether they are of the carboxylic type or of the type with mobile hydrogen compounds such as, for example, acetylacetonates.
• carboxylic acid salts from C2 to C20 are among the best suited for this use.
• this concentration is advantageously between 500 ppm and 10%, preferably between at least 1000 ppm (mass of metal contained relative to the total mass of soot, including the compounds which they have adsorbed) and at most 5% by average.
• Some internal combustion engines such as gasoline engines and some diesel engines under test and development, produce or should produce less soot. Insofar as only the regeneration effect of the filter is sought (and not the general improvement of combustion), this makes it possible to reduce the quantities of lanthanum to be introduced; in fuel, when this mode of introduction has been favored; and more generally in the combustion chamber. This reduction is made in proportion to the production of soot to maintain the lanthanum content in said soot.
• the form in which the lanthanum is introduced induces the formation of aggregates of lanthanum oxide crystallites where the largest dimension of the aggregate is between 20 angstroms and 10,000 angstroms (2 and 1000 nm), preferably between 100 and 5000 angstroms (10 and 500 nm), for which the size of the crystallites is between 20 and 250 angstroms (2 and 25 nm), preferably between 50 and 200 angstroms (5 and 20 nm).
• lanthanum is an element capable of potentiating, or of being potentiated by, other elements in particular capable of catalyzing the oxidation of carbonaceous products and those inducing defects in the crystal lattice of lanthanum oxide.
• transition elements that is to say metals of which one of the sublayers d is being filled, gave marked synergistic effects with lanthanum.
• This synergistic effect is also demonstrated with the other elements of the layers f being filled, and in particular with the other rare earths including yttrium.
• the most marked results are those due to lanthanum associated with manganese, copper, cobalt and / or iron.
• other rare earths including yttrium, alone or in admixture.
• the lanthanum content relative to the sum of the metallic elements contained in the adjuvant is generally between 5% and 95%. Advantageously, it is at least equal to 50%, preferably to 80%.
• the elements potentiating, or potentiated by, lanthanum are introduced as this element can be.
• Another object of the present invention is to provide a process which allows regeneration which can be described as low temperature of the particulate filters.
• This object is achieved by means of a process using the lanthanum-based compounds mentioned above.
• This process consists of:
• a lanthanum derivative as specified above at a concentration between 10 ppm and 500 ppm (by mass), preferably between 20 ppm and 200 ppm (in metal content);
• the engine used is an atmospheric diesel engine, with four cylinders, with indirect injection, of 1.696 liters of displacement and developing 50 kilowatts at 4400 rpm. This engine is sold under the Volkswagen brand.
• the filters used are cordierite filters produced by the Corning Company, of the EX 4-7 type (5.66 inches in diameter, 6 inches in length, with a cell density of 100 cpi / 17 mil). Each additive has been tested on a new filter. We continuously measure during the tests:
• the tests are carried out at 2000 rpm, keeping the temperature of the gas entering the filter constant over time.
• the trials conducted at a temperature of 250 ° C are reported below but similar results have been obtained at other temperatures.
• the copper content in the fuel oil is 20 ppm;
• the molar contents or more exactly atomic contents, are substantially of the same order for all the additives, namely:
• iron 0.36 moles / 1000 kg of fuel oil
• copper 0.32 moles / 1000 kg of fuel oil
• cerium 0.36 moles / 1000 kg of fuel oil.
• FIG. 1 This figure gives on the one hand the evolution of the pressure drop as a function of time as well as the carbon monoxide content in the gas leaving the filter, as well as the evolution of the temperature of the gas leaving the filter as a function of time. It is noted that the accumulation periods can reach a duration of 35,000 seconds. The pressure drop easily reaches 300 millibar. During the regenerations which correspond to the sudden decrease in the back pressure, there is a sharp increase in the carbon monoxide content for the gases leaving the filter.
• the iron-based additive is ferrocene.
• Example 2 case of the copper-based additive
• the copper used is a cupric carboxylate.
• the results are shown in FIG. 2. This figure gives on the one hand the evolution of the back pressure as a function of time as well as the carbon monoxide content in the gas leaving the filter, and the evolution of the temperature of the gas leaving the filter as a function of time.
• the accumulation periods can reach 54,000 seconds, or almost 20 hours.
• back pressure of up to 350 millibar.
• the regenerations which correspond to the sudden decrease in the pressure drop, there is a sharp increase in the carbon monoxide content in the gases leaving the filter.
• there is a very sudden increase in the temperature of the gases leaving the filter with temperatures which can reach more than 800 ° C., while the temperature of the gases entering the filter is only 250 ° C.
• the variation in back pressure is very abrupt. You can lose 300 millibar very quickly during these regeneration phases.
• the duration of the accumulation zones as well as the amplitude of the variations in back pressure seem to vary randomly. These graphs highlight the random and brutal behavior of these regenerations, which suggests that the engine will be affected by these sudden downstream variations in back pressure.
• Example No. 3 Case of a cerium-based additive (compound described in the European patent application filed under number 93 / 304760.7 and published under number 0575189)
• FIG. 3 This figure gives on the one hand the evolution of the back pressure as a function of time as well as the CO content in the gas leaving the filter, and the evolution of the temperature of the gas leaving the filter as a function of time.
• the regenerations which correspond to very small decreases in the back pressure (less than 50 millibar), variations in the carbon monoxide content in the gases leaving the filter are observed. These variations testify constant regeneration activity over time.
• Example n ° 4 example of an additive based on cerium sol.
• FIG. 4 This figure gives on the one hand the evolution of the back pressure as a function of time as well as the carbon monoxide content in the gas leaving the filter, and the evolution of the temperature of the gas leaving the filter as a function of time.
• the regenerations which correspond to very small reductions in the back pressure (less than 50 millibar), variations in the carbon monoxide content in the gases leaving the filter are observed. These variations bear witness to a constant regeneration activity over time.
• Tests have been carried out on a new F8Q 706 type engine of 1870 cm 3 , and the particle filter used is an EBERSPACHER particle filter number 2626000415. This filter is equipped with two thermocouples, one upstream, the other in downstream. The tests were carried out on particulate filters which have undergone several loads and several regenerations. Indeed, the first effects are relatively erratic.
• a new particle filter (F.A.P.) is used.
• the particulate filter must be initially stabilized, that is to say it must undergo a minimum of 3 cycles: fouling and regeneration.
• the self-regeneration test is carried out as follows: - Initial conditions:
• the particle filter is cold (room temperature)
• the tests below are tests on stabilized particle filters (FAP).
• the tests are carried out in isoregime, the speed being expressed in number of revolutions per minute.
• the filters are previously charged with particles under conditions where they accumulate even in the presence of rare earths, these conditions are: 1500 revolutions / minute; 3/4 of the full load; richness of the mixture between 0.8 and 0.9; • oxygen content of gases: between 2 and 4%; the particulate filters are loaded with 70 g of soot per filter.
• the self-regeneration tests are carried out on three isoregimes in the order: 2500 -
• the test is carried out by increasing the load every ten minutes according to predefined stages (PME: 0; 1; 2; 3; 4; 4,5; 5; 5,5; 6,5; 7; 7,5 bar ).
• Average effective pressure (PME) is given from the couple by the PME relation
• the engine is stalled on a certain speed and as specified above, the load is gradually increased in steps of 10 minutes (increment of the order of 9 Nm per step) until reaching the value of around 100 Nm once the regeneration has been obtained, the values of the various variables are determined just before the trigger.
• the engine is run empty at the desired speed.
• the soot is obtained by pyrolysis of fuel oil containing the additive.
• a tube called a "reactor tube” is traversed by a gas flow consisting of a mixture of nitrogen and oxygen 98/2 (by volume).
• the reactor tube is heated by an oven and the gas flow is thus brought to 1200 ° C.
• Upstream of the oven the fuel oil, with or without additive, is sprayed very finely.
• the oil droplets are transported by the gas flow and are also brought to 1220 ° C.
• soot is then collected downstream from the pyrolysis oven by filtration of the gas flow. If the fuel oil contains a metallic additive, the metal is found in the form of an oxide intimately mixed with the soot.
• the fuel injection rate upstream of the pyrolysis oven is adjusted to 10 ml / h. Under these conditions, the average diameter of the elementary particles of the soot produced by pyrolysis is identical to that of the soot produced by a diesel engine.
• the metal additives are used at a concentration in the diesel fuel such that the metal concentration in the diesel is between 0 and 200 ppm.
• the metal concentrations in the soot produced by an engine supplied with an additive diesel fuel are between 0 and 4%.
• the final catalyst concentration in the soot is one of the important parameters which condition the ignition temperature, it was necessary to find out what metal concentration in the fuel oil it was necessary to have in order to obtain the same metal concentration in the soot obtained by pyrolysis. It has been shown that it is necessary for the metal concentration in the fuel oil to be multiplied by 20 with respect to the additive concentration in the diesel fuel. The interval is thus of the order of 0 to 4000 ppm by mass. In conclusion, for the soot obtained by pyrolysis to be representative of the motor soot, the concentration of additive in the fuel oil must be multiplied by 20.
• the soot produced by the pyrolysis oven can be recovered in ATG.
• ATG records the remaining mass of soot as a function of time.
• the ignition temperature as the abscissa of the point defined as the intersection of the baseline at the origin with the tangent to the curve where the combustion speed is maximum (i.e. at inflection point of the so-called "S" curve).
• Copper and cobalt are two metals which are known for their ability to lower the ignition temperature, are known to be toxic and cause dangerous thermal shock to the filter.
• One of the objects of the present study was to show the synergy that exists between a metal like copper or cobalt with respect to lanthanum.
• the soot was all produced by the method described above and its ability to burn was measured by ATG.
• the metal concentrations in the fuel oil are certainly very high, but they give indications on an implementation on an engine test bench with concentrations in the diesel oil used as fuel corresponding to approximately i / 20 ⁇ m ⁇ of the concentrations in the fuel oil.
• Ignition temperature as a function of the lanthanum concentration acting alone in the fuel oil

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• 1994
  • 1994-12-30 BR BR9408456A patent/BR9408456A/pt not_active Application Discontinuation
  • 1994-12-30 US US08/505,251 patent/US5813223A/en not_active Expired - Fee Related
  • 1994-12-30 HU HU9601778A patent/HU9601778D0/hu unknown
  • 1994-12-30 EP EP95905693A patent/EP0737236A1/de not_active Withdrawn
  • 1994-12-30 CA CA002180181A patent/CA2180181A1/fr not_active Abandoned
  • 1994-12-30 CN CN94194732A patent/CN1139951A/zh active Pending
  • 1994-12-30 WO PCT/FR1994/001560 patent/WO1995018198A1/fr not_active Ceased
  • 1994-12-30 JP JP7517833A patent/JPH09507278A/ja active Pending
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