Title of Invention	''PROCESS FOR CONTINUOUS PREPARATION OF A WATER-IN-OIL EMULSIFIED MONODISPESRSED FUEL AND APPRATUS FOR CARRYING OUT THE SAME''
Abstract	The invention relates to a process for continuous preparation of a water in-oil emulsified monodispersed fuel allowing additives, water and a hydrocarbon phase to be mixed by agitation, characterized in that in a first step, using a distribution device, at least one phase A constituted by additives necessary for stabilizing an emulsion, water and optionally any additive useful for implementing the emulsion are distributed in the hydrocarbon phase, these components being introduced alone or in a mixture, the droplet distribution of each phase A in the hydrocarbon phase corresponding to a homogeneous spatial distribution of water droplets of size less than 200 µm, in a second step, all phases A having been distributed in the hydrocarbon phase, droplet size is decreased by dispersion using an emulsifying device chosen from the group constituted by multi-stage or non-multistage rotors/stators, smooth or grooved tapered emulsifiers, this device having a dynamic peripheral velocity of at least 10 m/s, preferably greater than 25 m/s, and allowing a dwell time in an enclosure containing the emulsifying device varying from 1 second to 80 seconds, preferably from 2-30 seconds, and optionally a.llowing recirculation of the mixture obtained in a circulation loop.

Title of Invention

''PROCESS FOR CONTINUOUS PREPARATION OF A WATER-IN-OIL EMULSIFIED MONODISPESRSED FUEL AND APPRATUS FOR CARRYING OUT THE SAME''

Abstract

The invention relates to a process for continuous preparation of a water in-oil emulsified monodispersed fuel allowing additives, water and a hydrocarbon phase to be mixed by agitation, characterized in that in a first step, using a distribution device, at least one phase A constituted by additives necessary for stabilizing an emulsion, water and optionally any additive useful for implementing the emulsion are distributed in the hydrocarbon phase, these components being introduced alone or in a mixture, the droplet distribution of each phase A in the hydrocarbon phase corresponding to a homogeneous spatial distribution of water droplets of size less than 200 µm, in a second step, all phases A having been distributed in the hydrocarbon phase, droplet size is decreased by dispersion using an emulsifying device chosen from the group constituted by multi-stage or non-multistage rotors/stators, smooth or grooved tapered emulsifiers, this device having a dynamic peripheral velocity of at least 10 m/s, preferably greater than 25 m/s, and allowing a dwell time in an enclosure containing the emulsifying device varying from 1 second to 80 seconds, preferably from 2-30 seconds, and optionally a.llowing recirculation of the mixture obtained in a circulation loop.

Full Text	The present relates to a process for continuous preparation of a water in-oil emulsified mono-dispersed fuel allowing additives, water and a hydrocarbon phase to be mixed by agitation. The present invention relates to a continuous process for preparing an emulsified fuel, in other words an emulsified mixture of water and at least one organic compound with a view to distributing it like other internal combustion engine fuels or domestic heating oils. In such fuels, the organic phase is a petroleum cut, vegetable or animal oil, or any other fuel employed in motorized vehicles and domestic boilers, and more generally for supplying internal and other combustion engines, and for supplying energy generation apparatus. This invention also relates to the apparatus or unit for carrying out this process continuously on an industrial scale. Numerous researchers have investigated processes for preparing emulsified fuels, but have rapidly been confronted with the difficulties of implementing them, principally arising through a lack of stability of the emulsions obtained. Storage stability of such emulsions is covered by a definition from the French Industry Ministry Department responsible for hydrocarbons. According to this Government Department, water in gas oil, i.e. a hydrocarbon, emulsion is considered as stable in storage when, kept at ambient temperature, in other words 10 to 20 C, for at least four months, no splitting of the emulsion into two or more phases is observed. To overcome a lack of stability of emulsions, German patents DE 19,704,874 and DD 216863, United States Patent 5,445,656 and international application WO 95/33023 have disclosed processes and devices for emulsifying fuels intended to be carried on board terrestrial vehicles, notably diesel engine vehicles. The emulsions described are emulsions of an external, frequently aqueous, phase, this emulsions being able to be subsequently reversed by subsequent dilution in a combustible organic phase, like in German Patent DE 19,704,874. The emulsion disclosed in international application WO 95/33023 contains less than 20% water, the latter constituting the external phase of the emulsion. In international application WO 92/11927, a concentrated emulsion containing from 40 to 80% by volume water is prepared, this process consisting in preparing separately a fuel/de-emulsifying additive and a water/alcohol mixture, introducing these two mixtures into two separate places in a circulation loop comprising a pump fulfilling the dual function of emulsifying and circulating the mixture within the loop. The emulsion thus obtained is recovered at another end, on the loop. In international application WO 95/27021, an emulsified fuel is claimed comprising 20 to 80% by volume of water, the latter constituting the external phase of the emulsion, 2-20% by volume of. alcohol, the remainder being constituted by hydrocarbons and at least one non-ionic emulsifying additive. The hydrocarbons introduced into this emulsion are gasolines, kerosene, gas oils, synthetic fuels or derivatives of vegetable or animal oils. The claimed process is a process for preparing a bulk emulsion that is stable over at least three months, and consisting in mixing a water/alcohol solution with a liquid compiosed of hydrocarbons and a de-emulsifying additive. None of these patent applications discloses a method for industrial preparation of a stable emulsified fuel in which the external phase is constituted by an organic phase. Now, for obvious reasons of compatibility of the fuel with an automobile fuel system running from the tank to the system for introducing it into the engine, it is preferable to use a fuel the external phase of which is identical to that of the fuel for which the fuel system has been dimensioned. In the case of a fuel the external phase of which is aqueous, there are increased risks of corroding metal surfaces arid/or premature wear of elastomer materials. This is the reason why the applicant developed a first discontinuous production process for water in oil emulsions cis disclosed in French patent application serial number 98/15625 of 8ch December, 1998. Such emulsions proposed by the cipplicant in international application WO 97/34969 have the advantage, when compared to oil in water emulsions, of improving combustion by sudden vaporization of water droplets dispersed in the oil the effect of which is to disperse the hydrocarbons in the combustion chamber (SAE 89 0449 and SAE 92 0464 in the name of Mr. Tsukhara et al, SAE 92 0198 in the name of N. Sewa et al). The present invention sets out to prepare such water-in-oil emulsions, i.e. having an organic external phase, which are stable over a period greater than four months, but this time by a continuous process with a view to preparing either emulsions able to be used directly as internal combustion engine fuels or combustible fuels, which are readily distributed by a pump, or precursors thereof allowing industrial production costs and the storage volumes and/or distribution costs to depots to be limited. Precursors of such fuels should here be taken to mean a concentrated internal combustion engine or combustible fuel which it is sufficient to dilute with a hydrocarbon phase in order to obtain the corresponding fuel. The present invention consequently provides a process for continuous preparation of a water-in-oil emulsified fuel allowing additives, water and a hydrocarbon phase to be mixed by agitation and optionally allowing recirculation of the mixture obtained in a circulation loop, characterized in that, in a first step, using a distribution device, at least one phase A constituted by additives necessary for stabilizing an emulsion, water and optionally any additive useful for implementing the emulsion are distributed in the hydrocarbon phase, these components being introduced alone or in a mixture, the droplet distribution of each phase A in the hydrocarbon phase corresponding to a homogeneous spatial distribution of water droplets of size less than 200 µm and, in a second step, all phases A having been distributed in the hydrocarbon phase, droplet size is decreased by dispersion using an emulsifying device with a dynamic peripheral velocity of at least 10 m/s, preferably greater than 25 m/s, and allowing a dwell time in an enclosure containing the emulsifying device varying from 1 second to 80 seconds, preferably from 2-30 seconds. In the framework of this invention, it has been noted that the dispersion of water is droplet formed in hydrocarbons is favoured by the combined effect of emulsion-stabilizing additives and the dual-step emulsifying method, the first step consisting in consecutively distributing one or several phases A in the hydrocarbon phase and the second step consisting in putting the water/additive/hydrocarbon phase mixture into stable emulsion form, the devices for distribution and putting into emulsion form being suitably chosen. Additionally, for the continuous process according to the invention, the additives for stabilizing the emulsion are introduced into the hydrocarbon and/or aqueous phase. Thus in the first step of the invention at least a first phase A is completely or partially constituted by the additives needed to stabilize the emulsion. Thus, we can imagine there will be as many phases A as there are emulsifying additives or alternatively, one single phase A for the mixture of additives or the mixture of additives and water, intermediate cases not being excluded. At this stage, the specific additives required in every fuel notably in the case of diesel oils, can be added, typically for withstanding low temperatures, combustion additives, anti-oxidizing agents, detergents, etc. In phase A, constituted by water, the specific additives for maintaining physical and chemical characteristics of this water such as for example antibacterial additives, fungicides, anti-freeze and/or any additive needed for the use of the said emulsion can be added. For distributing each phase A in the hydrocarbon phase, the distribution device is chosen from the group comprising orifice injection systems, sintered materials, impacting jet mixtures, mixing heads, static mixers, sonic mixers and mechanically aigitated turbines. For forming the emulsion, the emulsifying device is chosen from the group constituted by multi-stage or non-multistage rotors/stators smooth or grooved tapered emulsifiers and in-line turbine systems. In a preferred embodiment, the process can comprise a third additional step in which the emulsion formed is recycled totally or in part into the inlet conduit of the hydrocarbon phase, upstream of the distribution devices for phase A, recirculation throughput varying from one to three times the recovered emulsion throughput. In a particular embodiment, the emulsified mixture is diluted in a second hydrocarbon phase injected by means of a dilution device selected from the group comprising orifice injection systems, sintered materials, impacting jet mixers, mixing heads, static mixers, sonic mixers and mechanically agitated turbines. This dilution device can be arranged on the production line or at the place of storage or yet again, prior to the emulsified fuel distributor. In this case, it is possible to transport the fuel precursor to the place of distribution which represents non-negligible transport cost economies for these emulsified fuels, there being less volume to transport. The present invention also provides an emulsion obtained by the continuous process of the invention, containing from 5 to 20% by weight water in the hydrocarbon phase. This emulsion can be a concentrated emulsion, also called a water-in-oil emulsion precursor, containing more than 20% by weight water in a first hydrocarbon phase which is subsequently diluted, in a second hydrocarbon phase, these two phases being able to be of the same or different natures. The invention also provides an emulsion precursor obtained by the process of the invention, comprising from 20-90% by weight water, preferably between 40 and 70% by weight water. The invention also provides an apparatus for carrying out the process according to the invention comprising: i) an inlet conduit for a hydrocarbon phase at which there arrives at least one inlet conduit provided with a distribution device for at least one phase A, preferably two conduits for at least two phases A, a first conduit for emulsion stabilizing additives and a second conduit for water, ii) an emulsifying device arranged on said conduit downstream of said inlet conduits for phase A, having a dynamic peripheral velocity of at least 10 m/s, preferably greater than 25 m/s, and allowing a dwell time for the emulsion varying from one second to 80 seconds, preferably from 2-30 seconds, iii) storage means on an outlet conduit from the emulsifying device, iv) and, optionally, a conduit for tapping a portion of emulsified mixture and for bringing said portion into the inlet conduit for the hydrocarbon phase upstream of said distribution devices. Alternatively, the device can further comprise, on the outlet conduit from the emulsifying device or storage means a distribution device comprising a distributor and storage means for diluted emulsion. Intermediate emulsifying and storage means can consequently be provided. The invention also covers the application of the continuous process according to the invention to the preparation of combustible emulsions, namely water-petroleum, water-gas oil and water/fuel emulsions or their emulsion precursor for an external hydrocarbon phase. Statement of Invention Accordingly, the present invention relates to a process for continuous preparation of a water in-oil emulsified monodispersed fuel allowing additives, water and a hydrocarbon phase to be mixed by agitation, characterized in that in a first step, using a distribution device, at least one phase A constituted by additives necessary for stabilizing an emulsion, water and optionally any additive useful for implementing the emulsion are distributed in the hydrocarbon phase, these components being introduced alone or in a mixture, the droplet distribution of each phase A in the hydrocarbon phase corresponding to a homogeneous spatial distribution of water droplets of size less than 200 µm, in a second step, all phases A having been distributed in the hydrocarbon phase, droplet size is decreased by dispersion using an emulsifying device chosen from the group constituted by multi-stage or non-multistage rotors/stators, smooth or grooved tapered emulsifiers, this device having a dynamic peripheral velocity of at least 10 m/s, preferably greater than 25 m/s, and allowing a dwell time in an enclosure containing the emulsifying device varying from 1 second to 80 seconds, preferably from 2-30 seconds, and optionally allowing recirculation of the mixture obtained in a circulation loop. FIGS. 1-4 illustrate the invention. FIG. 1 shows apparatus for carrying out the process of the invention, allowing the emulsion comprising at the most 20% water or an emulsion precursor comprising from 40 to 70% by weight water to be obtained directly. FIG. 2 shows apparatus for diluting the emulsion precursor, this apparatus being able to be arranged on the emulsion precursor production line or at a distribution and/or storage site for the latter, before use. FIG. 3 is a diagram representing the volume % of the droplets versus the diameter of the particles, with a high peripheral velocity. FIG. 4 is a diagram representing the volume % of the droplets versus the diameter of the particles, with a low peripheral velocity. The hydrocarbon phase, i.e. internal combustion engine or combustible fuel, arrives on the line 1 in the emulsifying device. A first conduit 2 introduces one or several additives arriving on the lines 2i and/or water into the mixture, via a first distribution device 3, this device being able to be one of the devices mentioned above. Optionally, a second conduit 4 introduces water and soluble additives originating from lines 4i via a distribution device 5, into the conduit in which the hydrocarbon phase and the previously introduced additives are circulating. Conduit 1 then discharges into emulsifying device 6, outlet conduit 10 leading the emulsified phase into a storage vessel 7 that includes a discharge outlet 8. By means of conduit 9, all or part of the emulsified phase can be re-circulated upstream of emulsifying device 6, either prior to introducing phases A, or just ahead of the apparatus itself. In FIG. 2, the fuel precursor is supplied from a storage vessel, or by tanker, into a conduit 20 in which a hydrocarbon phase is introduced through conduit 21 and distribution device 22, the product obtained being delivered to a storage vessel or distribution pump 23, comprising a. discharge outlet 24. The distribution device is similar to the one already used in FIG. 1. The examples given below illustrate the implementation of the invention and its essential characteristics without however limiting the scope thereof. EXAMPLE - I This example consists in describing the effectiveness of the process implemented in the present invention, in particular the influence of the choice of distributor and emulsifying device on emulsion stability. The tests were carried out on a pilot plant of semi-industrial scale such as described in FIG. 1. However, ahead of conduit 1, a storage tank for gas oil to be emulsified was provided and, ahead of conduit 2, storage means were provided for the eidditive composition needed for stabilizing the emulsion. Distribution devices 3 and 5 are mixing valves. The waiter/water-soluble additive mixture was introduced from a tank arranged upstream of conduit 4. Two types of emulsifying device 6 were tested: these are multi-stage rotors/stators which shear the water droplets in a tangential velocity field, motor rotation speed determining the peripheral or tangential shearing speed of the droplets. The device was an Ika Works Dipax 3-6/6A (device Dl) able to be used for small volumes, and the VMI-Rayneri emulsifier/homogenizer (device D2) for semi-industrial scale volumes. Water/gas oil emulsions having 13% and 26% by weight water were prepared using device D2, and water/gas oil emulsions having 52% by weight water using device Dl in the presence of the combination of additives as disclosed in international application WO 97/34969. For these tests, the gas oil used was a gas oil meeting the specifications of the EN590 standard. The results obtciined with the two devices are given in Table 1. Table 1 (Table Removed) In this table, emulsion stability is quantified by the time measured between the date the emulsion was produced on and the date the emulsion broke, in other words the date on which free water at the bottom of the storage recipient for the emulsion appeared. It is noticed that the effectiveness of production varied depending on the size and geometry of the rotator/stator employed. With device Dl, peripheral velocity needs to be greater than 25 m/s for a dwell time of at least one second. Where this velocity is less than 25 m/s and/or dwell time is less than 1 second, the emulsion splits into two phases after the first or second month. With the device D2, of different geometry to Dl, for a peripheral velocity greater than 25 m/s, dwell time should exceed 14 seconds for an emulsion containing 13% by weight water. If peripheral velocity is less than 25 m/s and/or dwell time is less than 14 seconds the emulsion is unstable and rapidly separates. For a given device D2, the greater the water content, the move peripheral velocity and dwell time need to increase. EXAMPLE - II This example aims at demonstrating the importance of the peripheral tangential velocity of the device for the obtention of a monodispersed distribution of the droplets which favours the stability over time. A semi-industrial pilot plant was used as in Example I. A single device D2 was used with emulsions having 13% by weight water. The tangential velocity of the device was varied cind the size distribution of the droplets was measured as a function of the tangential velocity. The results are given below in Table 2. Table 2 (Table Removed) The results for Trials 1 and 2 are represented on FIG. 3 and 4, respectively. We Claim: A process for continuous preparation of a water in-oil emulsified monodispersed fuel allowing additives, water and a hydrocarbon phase to be mixed by agitation, characterized in that in a first step, using a distribution device, at. least one phase A constituted by additives necessary for stabilizing an emulsion, water and optionally any additive useful for implementing the emulsion are distributed in the hydrocarbon phase, these components being introduced alone or in a mixture, the droplet distribution of each phase A in the hydrocarbon phase corresponding to a homogeneous spatial distribution of water droplets of size less than 200 µm, in a second step, all phases A having been distributed in the hydrocarbon phase, droplet size is decreased by dispersion using an emulsifying device chosen from the group constituted by multi-stage or non-multistage rotors/stators, smooth or grooved tapered emulsifiers, this device having a dynamic peripheral velocity of at least 10 m/s, preferably greater than 25 m/s, and allowing a dwell time in an enclosure containing the emulsifying device varying from 1 second to 80 seconds, preferably from 2-30 seconds, and optionally allowing recirculation of the mixture obtained in a circulation loop. The process as claimed in claim 1, wherein at least a first phase A is constituted totally or in part by additives necessary for stabilizing the emulsion. The process as claimed in claims 1 and 2, wherein at least one second phase A is constituted by water, optionally comprising anti-bacterial additive and/or any additive needed for the use of said emulsion. The process as claimed in claims 1-3, wherein the distribution device is chosen from the group comprising orifice injection systems, sintered materials, impacting jet mixers, mixing heads, static mixers, sonic mixers and mechanically agitated turbines. The process as claimed in any one of claims 1-4, wherein in a third step, the emulsion formed is recycled totally or in part into the inlet conduit of the hydrocarbon phase, upstream of the distribution devices for phase A, recirculation throughput varying from one to three times the recovered emulsion throughput. The process as claimed in any one of claims 1-5, wherein the water in-oil emulsified monodispersed fuel is optionally diluted in a second hydrocarbon phase by means of a dilution device selected from the group comprising orifice injection systems, sintered materials, impacting jet mixers, mixing heads, static mixers, sonic mixtures and mechanically agitated turbines. The process as claimed in claim 6, wherein the first and the second hydrocarbon phases being of the same nature. The water in-oil emulsified monodispersed fuel obtained by the process as claimed in claims 1-7, wherein the same contains 5-90 % by weight water. The water in-oil emulsified monodispersed fuel as claimed in claim 8, wherein the same contains from 20-90 % by weight water, preferably between 40 and 70 % by weight water in the hydrocarbon phase. 10. A water in-oil emulsified monodispersed fuel as claimed in claim 8, wherein the same contains from 5 to 20 % by weight water in the hydrocarbon phase. 11. An apparatus for carrying our the process as claimed in any one of claims 1-6 and 8-9, said apparatus comprising: i) an inlet conduit (1) for a hydrocarbon phase at which there arrives at least one inlet conduit provided with a distribution device (3, 5) for at least one phase A, preferably two conduits for at least two phases A, a first conduit (2) for emulsion stabilizing additives and a second conduit (4) for water, ii) an emulsifying device (6) chosen from the group constituted by multistage or non-multistage rotors/stators, smooth or grooved tapered emulsifiers, this device being arranged on said conduit downstream of said inlet conduits for phases A, having a dynamic peripheral velocity of at least 10 m/s, preferably greater than 25 m/s, and allowing a dwell time for the emulsion varying from one second to 80 seconds, preferably from 2-30 seconds, iii) storage means (7) on an outlet conduit (10) from the emulsifying device, and iv) optionally, a conduit (9) for tapping a portion of the emulsified mixture and for bringing said portion into the inlet conduit (1) for the hydrocarbon phase upstream of said distribution devices (3,5) . 12. The apparatus as claimed in claim 11, wherein said apparatus comprises, on the outlet conduit from emulsifying device (6) or storage means (7) or (20) a distribution device (22) identical to the distribution devices (3) and (5) and storage means (23), the diluting hydrocarbon phase being introduced via a conduit (21) . 13. The apparatus as claimed in claims 11 and 12, wherein the distribution device is selected from the group comprising orifice injection systems, sintered materials, impacting jet mixers, mixing heads static mixers, sonic mixers and mechanically agitated turbines. 14. Application of the process as claimed in any of the preceding claims for the preparation of combustible water-petroleum, water-gas oil and water fuel monodispersed emulsions or their monodispersed emulsion precursor for an external hydrocarbon phase. 15. A process for continuous preparation of a water in- oil emulsified monodispersed fuel allowing additives substantially as herein described with reference to the accompanying drawings. 16. An apparatus substantially as herein described with reference to the accompanying drawings.

Full Text

The present relates to a process for continuous preparation of a water in-oil emulsified mono-dispersed fuel allowing additives, water and a hydrocarbon phase to be mixed by agitation. The present invention relates to a continuous process for preparing an emulsified fuel, in other words an emulsified mixture of water and at least one organic compound with a view to distributing it like other internal combustion engine fuels or domestic heating oils. In such fuels, the organic phase is a petroleum cut, vegetable or animal oil, or any other fuel employed in motorized vehicles and domestic boilers, and more generally for supplying internal and other combustion engines, and for supplying energy generation apparatus. This invention also relates to the apparatus or unit for carrying out this process continuously on an industrial scale.
Numerous researchers have investigated processes for preparing emulsified fuels, but have rapidly been confronted with the difficulties of implementing them, principally arising through a lack of stability of the emulsions obtained. Storage stability of such emulsions is covered by a definition from the French Industry Ministry Department responsible for hydrocarbons. According to this Government Department, water in gas oil, i.e. a hydrocarbon, emulsion is considered as stable in storage when, kept at ambient temperature, in other words 10 to 20 C, for at least four months, no splitting of the emulsion into two or more phases is observed.
To overcome a lack of stability of emulsions, German patents DE 19,704,874 and DD 216863, United States Patent 5,445,656 and international application WO 95/33023 have disclosed processes and devices for emulsifying fuels intended to be carried on board terrestrial vehicles, notably diesel engine vehicles. The emulsions described

are emulsions of an external, frequently aqueous, phase, this emulsions being able to be subsequently reversed by subsequent dilution in a combustible organic phase, like in German Patent DE 19,704,874. The emulsion disclosed in international application WO 95/33023 contains less than 20% water, the latter constituting the external phase of the emulsion.
In international application WO 92/11927, a concentrated emulsion containing from 40 to 80% by volume water is prepared, this process consisting in preparing separately a fuel/de-emulsifying additive and a water/alcohol mixture, introducing these two mixtures into two separate places in a circulation loop comprising a pump fulfilling the dual function of emulsifying and circulating the mixture within the loop. The emulsion thus obtained is recovered at another end, on the loop.
In international application WO 95/27021, an emulsified fuel is claimed comprising 20 to 80% by volume of water, the latter constituting the external phase of the emulsion, 2-20% by volume of. alcohol, the remainder being constituted by hydrocarbons and at least one non-ionic emulsifying additive. The hydrocarbons introduced into this emulsion are gasolines, kerosene, gas oils, synthetic fuels or derivatives of vegetable or animal oils. The claimed process is a process for preparing a bulk emulsion that is stable over at least three months, and consisting in mixing a water/alcohol solution with a liquid compiosed of hydrocarbons and a de-emulsifying additive.
None of these patent applications discloses a method for industrial preparation of a stable emulsified fuel in which the external phase is constituted by an organic phase. Now, for obvious reasons of compatibility of the fuel with an automobile fuel system running from the tank to the system for introducing it into the engine, it is

preferable to use a fuel the external phase of which is identical to that of the fuel for which the fuel system has been dimensioned. In the case of a fuel the external phase of which is aqueous, there are increased risks of corroding metal surfaces arid/or premature wear of elastomer materials.
This is the reason why the applicant developed a first discontinuous production process for water in oil emulsions cis disclosed in French patent application serial number 98/15625 of 8ch December, 1998. Such emulsions proposed by the cipplicant in international application WO 97/34969 have the advantage, when compared to oil in water emulsions, of improving combustion by sudden vaporization of water droplets dispersed in the oil the effect of which is to disperse the hydrocarbons in the combustion chamber (SAE 89 0449 and SAE 92 0464 in the name of Mr. Tsukhara et al, SAE 92 0198 in the name of N. Sewa et al).
The present invention sets out to prepare such water-in-oil emulsions, i.e. having an organic external phase, which are stable over a period greater than four months, but this time by a continuous process with a view to preparing either emulsions able to be used directly as internal combustion engine fuels or combustible fuels, which are readily distributed by a pump, or precursors thereof allowing industrial production costs and the storage volumes and/or distribution costs to depots to be limited.
Precursors of such fuels should here be taken to mean a concentrated internal combustion engine or combustible fuel which it is sufficient to dilute with a hydrocarbon phase in order to obtain the corresponding fuel.
The present invention consequently provides a process for continuous preparation of a water-in-oil

emulsified fuel allowing additives, water and a hydrocarbon phase to be mixed by agitation and optionally allowing recirculation of the mixture obtained in a circulation loop, characterized in that, in a first step, using a distribution device, at least one phase A constituted by additives necessary for stabilizing an emulsion, water and optionally any additive useful for implementing the emulsion are distributed in the hydrocarbon phase, these components being introduced alone or in a mixture, the droplet distribution of each phase A in the hydrocarbon phase corresponding to a homogeneous spatial distribution of water droplets of size less than 200 µm and, in a second step, all phases A having been distributed in the hydrocarbon phase, droplet size is decreased by dispersion using an emulsifying device with a dynamic peripheral velocity of at least 10 m/s, preferably greater than 25 m/s, and allowing a dwell time in an enclosure containing the emulsifying device varying from 1 second to 80 seconds, preferably from 2-30 seconds.
In the framework of this invention, it has been noted that the dispersion of water is droplet formed in hydrocarbons is favoured by the combined effect of emulsion-stabilizing additives and the dual-step emulsifying method, the first step consisting in consecutively distributing one or several phases A in the hydrocarbon phase and the second step consisting in putting the water/additive/hydrocarbon phase mixture into stable emulsion form, the devices for distribution and putting into emulsion form being suitably chosen.
Additionally, for the continuous process according to the invention, the additives for stabilizing the emulsion are introduced into the hydrocarbon and/or aqueous phase.

Thus in the first step of the invention at least a first phase A is completely or partially constituted by the additives needed to stabilize the emulsion. Thus, we can imagine there will be as many phases A as there are emulsifying additives or alternatively, one single phase A for the mixture of additives or the mixture of additives and water, intermediate cases not being excluded. At this stage, the specific additives required in every fuel notably in the case of diesel oils, can be added, typically for withstanding low temperatures, combustion additives, anti-oxidizing agents, detergents, etc.
In phase A, constituted by water, the specific additives for maintaining physical and chemical characteristics of this water such as for example antibacterial additives, fungicides, anti-freeze and/or any additive needed for the use of the said emulsion can be added.
For distributing each phase A in the hydrocarbon phase, the distribution device is chosen from the group comprising orifice injection systems, sintered materials, impacting jet mixtures, mixing heads, static mixers, sonic mixers and mechanically aigitated turbines.
For forming the emulsion, the emulsifying device is chosen from the group constituted by multi-stage or non-multistage rotors/stators smooth or grooved tapered emulsifiers and in-line turbine systems.
In a preferred embodiment, the process can comprise a third additional step in which the emulsion formed is recycled totally or in part into the inlet conduit of the hydrocarbon phase, upstream of the distribution devices for phase A, recirculation throughput varying from one to three times the recovered emulsion throughput.
In a particular embodiment, the emulsified mixture is diluted in a second hydrocarbon phase injected by

means of a dilution device selected from the group comprising orifice injection systems, sintered materials, impacting jet mixers, mixing heads, static mixers, sonic mixers and mechanically agitated turbines. This dilution device can be arranged on the production line or at the place of storage or yet again, prior to the emulsified fuel distributor. In this case, it is possible to transport the fuel precursor to the place of distribution which represents non-negligible transport cost economies for these emulsified fuels, there being less volume to transport.
The present invention also provides an emulsion obtained by the continuous process of the invention, containing from 5 to 20% by weight water in the hydrocarbon phase.
This emulsion can be a concentrated emulsion, also called a water-in-oil emulsion precursor, containing more than 20% by weight water in a first hydrocarbon phase which is subsequently diluted, in a second hydrocarbon phase, these two phases being able to be of the same or different natures.
The invention also provides an emulsion precursor obtained by the process of the invention, comprising from 20-90% by weight water, preferably between 40 and 70% by weight water.
The invention also provides an apparatus for carrying out the process according to the invention comprising:
i) an inlet conduit for a hydrocarbon phase at which there arrives at least one inlet conduit provided with a distribution device for at least one phase A, preferably two conduits for at least two phases A, a first conduit for emulsion stabilizing additives and a second conduit for water,

ii) an emulsifying device arranged on said conduit downstream of said inlet conduits for phase A, having a dynamic peripheral velocity of at least 10 m/s, preferably greater than 25 m/s, and allowing a dwell time for the emulsion varying from one second to 80 seconds, preferably from 2-30 seconds,
iii) storage means on an outlet conduit from the emulsifying device,
iv) and, optionally, a conduit for tapping a portion of emulsified mixture and for bringing said portion into the inlet conduit for the hydrocarbon phase upstream of said distribution devices.
Alternatively, the device can further comprise, on the outlet conduit from the emulsifying device or storage means a distribution device comprising a distributor and storage means for diluted emulsion. Intermediate emulsifying and storage means can consequently be provided.
The invention also covers the application of the continuous process according to the invention to the preparation of combustible emulsions, namely water-petroleum, water-gas oil and water/fuel emulsions or their emulsion precursor for an external hydrocarbon phase. Statement of Invention
Accordingly, the present invention relates to a process for continuous preparation of a water in-oil emulsified monodispersed fuel allowing additives, water and a hydrocarbon phase to be mixed by agitation, characterized in that in a first step, using a distribution device, at least one phase A constituted by additives necessary for stabilizing an emulsion, water and optionally any additive useful for implementing the emulsion are distributed in the hydrocarbon phase, these components being introduced alone or in a mixture, the

droplet distribution of each phase A in the hydrocarbon phase corresponding to a homogeneous spatial distribution of water droplets of size less than 200 µm, in a second step, all phases A having been distributed in the hydrocarbon phase, droplet size is decreased by dispersion using an emulsifying device chosen from the group constituted by multi-stage or non-multistage rotors/stators, smooth or grooved tapered emulsifiers, this device having a dynamic peripheral velocity of at least 10 m/s, preferably greater than 25 m/s, and allowing a dwell time in an enclosure containing the emulsifying device varying from 1 second to 80 seconds, preferably from 2-30 seconds, and optionally allowing recirculation of the mixture obtained in a circulation loop.
FIGS. 1-4 illustrate the invention.
FIG. 1 shows apparatus for carrying out the process of the invention, allowing the emulsion comprising at the most 20% water or an emulsion precursor comprising from 40 to 70% by weight water to be obtained directly.
FIG. 2 shows apparatus for diluting the emulsion precursor, this apparatus being able to be arranged on the emulsion precursor production line or at a distribution and/or storage site for the latter, before use.
FIG. 3 is a diagram representing the volume % of the droplets versus the diameter of the particles, with a high peripheral velocity.
FIG. 4 is a diagram representing the volume % of the droplets versus the diameter of the particles, with a low peripheral velocity.
The hydrocarbon phase, i.e. internal combustion engine or combustible fuel, arrives on the line 1 in the emulsifying device. A first conduit 2 introduces one or several additives arriving on the lines 2i and/or water

into the mixture, via a first distribution device 3, this device being able to be one of the devices mentioned above. Optionally, a second conduit 4 introduces water and soluble additives originating from lines 4i via a distribution device 5, into the conduit in which the hydrocarbon phase and the previously introduced additives are circulating. Conduit 1 then discharges into emulsifying device 6, outlet conduit 10 leading the emulsified phase into a storage vessel 7 that includes a discharge outlet 8. By means of conduit 9, all or part of the emulsified phase can be re-circulated upstream of emulsifying device 6, either prior to introducing phases A, or just ahead of the apparatus itself.
In FIG. 2, the fuel precursor is supplied from a storage vessel, or by tanker, into a conduit 20 in which a hydrocarbon phase is introduced through conduit 21 and distribution device 22, the product obtained being delivered to a storage vessel or distribution pump 23, comprising a. discharge outlet 24. The distribution device is similar to the one already used in FIG. 1.
The examples given below illustrate the implementation of the invention and its essential characteristics without however limiting the scope thereof.
EXAMPLE - I
This example consists in describing the effectiveness of the process implemented in the present invention, in particular the influence of the choice of distributor and emulsifying device on emulsion stability.
The tests were carried out on a pilot plant of semi-industrial scale such as described in FIG. 1. However, ahead of conduit 1, a storage tank for gas oil to be emulsified was provided and, ahead of conduit 2, storage means were provided for the eidditive composition needed for stabilizing the emulsion. Distribution devices 3 and

5 are mixing valves. The waiter/water-soluble additive mixture was introduced from a tank arranged upstream of conduit 4.
Two types of emulsifying device 6 were tested: these are multi-stage rotors/stators which shear the water droplets in a tangential velocity field, motor rotation speed determining the peripheral or tangential shearing speed of the droplets. The device was an Ika Works Dipax 3-6/6A (device Dl) able to be used for small volumes, and the VMI-Rayneri emulsifier/homogenizer (device D2) for semi-industrial scale volumes.
Water/gas oil emulsions having 13% and 26% by weight water were prepared using device D2, and water/gas oil emulsions having 52% by weight water using device Dl in the presence of the combination of additives as disclosed in international application WO 97/34969.
For these tests, the gas oil used was a gas oil meeting the specifications of the EN590 standard. The results obtciined with the two devices are given in Table 1.
Table 1
(Table Removed)
In this table, emulsion stability is quantified by the time measured between the date the emulsion was produced on and the date the emulsion broke, in other words the date on which free water at the bottom of the storage recipient for the emulsion appeared.
It is noticed that the effectiveness of production varied depending on the size and geometry of the rotator/stator employed. With device Dl, peripheral velocity needs to be greater than 25 m/s for a dwell time of at least one second. Where this velocity is less than 25 m/s and/or dwell time is less than 1 second, the emulsion splits into two phases after the first or second month.
With the device D2, of different geometry to Dl, for a peripheral velocity greater than 25 m/s, dwell time should exceed 14 seconds for an emulsion containing 13% by weight water. If peripheral velocity is less than 25 m/s and/or dwell time is less than 14 seconds the emulsion is unstable and rapidly separates.
For a given device D2, the greater the water content, the move peripheral velocity and dwell time need to increase.
EXAMPLE - II
This example aims at demonstrating the importance of the peripheral tangential velocity of the device for the obtention of a monodispersed distribution of the droplets which favours the stability over time.
A semi-industrial pilot plant was used as in Example I. A single device D2 was used with emulsions having 13% by weight water. The tangential velocity of the device was varied cind the size distribution of the droplets was measured as a function of the tangential velocity. The results are given below in Table 2.
Table 2
(Table Removed)

The results for Trials 1 and 2 are represented on FIG. 3 and 4, respectively.

We Claim:
A process for continuous preparation of a water in-oil emulsified monodispersed fuel allowing additives, water and a hydrocarbon phase to be mixed by agitation, characterized in that
in a first step, using a distribution device, at. least one phase A constituted by additives necessary for stabilizing an emulsion, water and optionally any additive useful for implementing the emulsion are distributed in the hydrocarbon phase, these components being introduced alone or in a mixture, the droplet distribution of each phase A in the hydrocarbon phase corresponding to a homogeneous spatial distribution of water droplets of size less than 200 µm,
in a second step, all phases A having been distributed in the hydrocarbon phase, droplet size is decreased by dispersion using an emulsifying device chosen from the group constituted by multi-stage or non-multistage rotors/stators, smooth or grooved tapered emulsifiers, this device having a dynamic peripheral velocity of at least 10 m/s, preferably greater than 25 m/s, and allowing a dwell time in an enclosure containing the emulsifying device varying from 1 second to 80 seconds, preferably from 2-30 seconds, and optionally allowing recirculation of the mixture obtained in a circulation loop. The process as claimed in claim 1, wherein at least a first phase A is constituted totally or in part by additives necessary for stabilizing the emulsion. The process as claimed in claims 1 and 2, wherein at least one second phase A is constituted by water,

optionally comprising anti-bacterial additive and/or any additive needed for the use of said emulsion. The process as claimed in claims 1-3, wherein the distribution device is chosen from the group comprising orifice injection systems, sintered materials, impacting jet mixers, mixing heads, static mixers, sonic mixers and mechanically agitated turbines.
The process as claimed in any one of claims 1-4, wherein in a third step, the emulsion formed is recycled totally or in part into the inlet conduit of the hydrocarbon phase, upstream of the distribution devices for phase A, recirculation throughput varying from one to three times the recovered emulsion throughput.
The process as claimed in any one of claims 1-5, wherein the water in-oil emulsified monodispersed fuel is optionally diluted in a second hydrocarbon phase by means of a dilution device selected from the group comprising orifice injection systems, sintered materials, impacting jet mixers, mixing heads, static mixers, sonic mixtures and mechanically agitated turbines.
The process as claimed in claim 6, wherein the first and the second hydrocarbon phases being of the same nature.
The water in-oil emulsified monodispersed fuel obtained by the process as claimed in claims 1-7, wherein the same contains 5-90 % by weight water. The water in-oil emulsified monodispersed fuel as claimed in claim 8, wherein the same contains from 20-90 % by weight water, preferably between 40 and 70 % by weight water in the hydrocarbon phase.

10. A water in-oil emulsified monodispersed fuel as
claimed in claim 8, wherein the same contains from 5
to 20 % by weight water in the hydrocarbon phase.
11. An apparatus for carrying our the process as claimed
in any one of claims 1-6 and 8-9, said apparatus
comprising:
i) an inlet conduit (1) for a hydrocarbon phase at which there arrives at least one inlet conduit provided with a distribution device (3, 5) for at least one phase A, preferably two conduits for at least two phases A, a first conduit (2) for emulsion stabilizing additives and a second conduit (4) for water,
ii) an emulsifying device (6) chosen from the group constituted by multistage or non-multistage rotors/stators, smooth or grooved tapered emulsifiers, this device being arranged on said conduit downstream of said inlet conduits for phases A, having a dynamic peripheral velocity of at least 10 m/s, preferably greater than 25 m/s, and allowing a dwell time for the emulsion varying from one second to 80 seconds, preferably from 2-30 seconds,
iii) storage means (7) on an outlet conduit (10) from the emulsifying device, and
iv) optionally, a conduit (9) for tapping a
portion of the emulsified mixture and for
bringing said portion into the inlet conduit
(1) for the hydrocarbon phase upstream of
said distribution devices (3,5) .
12. The apparatus as claimed in claim 11, wherein said
apparatus comprises, on the outlet conduit from
emulsifying device (6) or storage means (7) or (20)
a distribution device (22) identical to the

distribution devices (3) and (5) and storage means (23), the diluting hydrocarbon phase being introduced via a conduit (21) .
13. The apparatus as claimed in claims 11 and 12,
wherein the distribution device is selected from the
group comprising orifice injection systems, sintered
materials, impacting jet mixers, mixing heads static
mixers, sonic mixers and mechanically agitated
turbines.
14. Application of the process as claimed in any of the
preceding claims for the preparation of combustible
water-petroleum, water-gas oil and water fuel
monodispersed emulsions or their monodispersed
emulsion precursor for an external hydrocarbon
phase.
15. A process for continuous preparation of a water in-
oil emulsified monodispersed fuel allowing additives
substantially as herein described with reference to
the accompanying drawings.
16. An apparatus substantially as herein described with
reference to the accompanying drawings.

Documents:

in-pct-2002-00469-del-abstract.pdf

in-pct-2002-00469-del-claims.pdf

in-pct-2002-00469-del-correspondence-others.pdf

in-pct-2002-00469-del-correspondence-po.pdf

in-pct-2002-00469-del-description (complete).pdf

in-pct-2002-00469-del-drawings.pdf

in-pct-2002-00469-del-form-1.pdf

in-pct-2002-00469-del-form-19.pdf

in-pct-2002-00469-del-form-2.pdf

in-pct-2002-00469-del-form-26.pdf

in-pct-2002-00469-del-form-3.pdf

in-pct-2002-00469-del-pct-304.pdf

in-pct-2002-00469-del-pct-409.pdf

in-pct-2002-00469-del-petition-137.pdf

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Patent Number

217349

Indian Patent Application Number

IN/PCT/2002/00469/DEL

PG Journal Number

15/2008

Publication Date

11-Apr-2008

Grant Date

26-Mar-2008

Date of Filing

06-May-2002

Name of Patentee

ELF ANTAR FRANCE

Applicant Address

24 COURS MICHELET, 92800 PUTEAUZ , FRANCE

Inventors:

#	Inventor's Name	Inventor's Address
1	TANGUY	5500-311 DE JUMONVILLE, MONTREAL, QUEBEC HIM 3L8, CANADA;
2	BROCART	3233 AVENUE VAN HORNE APARTMENT 3, MONTREAL, QUEBEC H3S IR3,
3	MAGNIN	28, DOMAINE DE SOURZY, F-69700 MOTAGNY FRANCE
4	SCHULZ	15 AVENUE DU 11 NOVEMBER 1918, F-69110 SAINTE FOY LES LYON,

PCT International Classification Number

A61K 31/192

PCT International Application Number

PCT/FR00/03162

PCT International Filing date

2000-11-13

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	99/14269	1999-11-15	France