WO2012056073A1

WO2012056073A1 - Device and method for generating autothermal hydrothermal flames

Info

Publication number: WO2012056073A1
Application number: PCT/ES2011/070727
Authority: WO
Inventors: María Dolores BERMEJO RODA; Pablo CABEZA PÉREZ; Joao Paulo Silva Queiroz; Cristina JIMÉNEZ DE LA PARRA; María José COCERO ALONSO
Original assignee: Universidad De Valladolid
Priority date: 2010-10-29
Filing date: 2011-10-20
Publication date: 2012-05-03
Also published as: ES2381345A1; ES2381345B1

Abstract

Device and method for generating autothermal hydrothermal flames. This device uses an oxidization process of essentially organic fuels and/or residues in water above the critical point. The device includes a reaction chamber (1), a pressure casing (3), between which a pressurized cooling fluid (5) such as cold water or brine flows, and an injector (9). This fluid (5) enters through the lower part of the reaction chamber (6), re-dissolving the salts that have precipitated on the base (12) of the casing (3). Since the chamber (1) has an opening (15) in its base, they leave the reaction chamber (1) without causing any blockages.

Description

APPARATUS AND PROCEDURE FOR THE GENERATION OF AUTOTHERMAL HYDROTERMAL FLAMES OBJECT OF THE INVENTION

The present invention relates to an apparatus and a method for the generation of autothermal hydrothermal flames. This device makes use of a process of oxidation of fuels and / or wastes, essentially organic, in water, above the critical point. Under these conditions, water has physical properties that confer characteristics of organic solvent.

The apparatus may be used for the destruction of waste by oxidation in supercritical water, for the production of energy or for any other hydrothermal process that uses the hydrothermal flame as an energy source such as gasification produced in supercritical water or precipitation of materials on the hydrothermal flame.

BACKGROUND OF THE INVENTION

When oxidation of reagents occurs in supercritical water at temperatures above the reagent autoignition temperature, this oxidation occurs in the form of flames, known as hydrothermal flames. These flames were first described by Schilling and Franck in 1988. The high pressures allow the self-ignition temperatures of the compounds to be significantly reduced, in some cases up to 400 ° C, so this process takes place at temperatures lower than the Conventional combustion avoiding the formation of by-products such as NO _x or dioxins. When oxidation in supercritical water occurs in a hydrothermal flame regime, contaminants can be completely eliminated in times of milliseconds [Augustine and Tester, 2009]. The main application of oxidation in supercritical water both in flame and flameless regime is the destruction of waste, especially those that are not biodegradable, recalcitrant or xenobiotic. Hydrothermal flames have also been applied to the drilling of deep wells, as described in US Patents 5,771,984 and WO 2010072407.

Oxidation in supercritical water was patented by Modell in 1981, US 4,113,446, US 4,338,199 and US 4,543,190. These patents describe a complex system of oxidation of sludge and organic waste that operates at temperatures of 600 ° C in an oxidation chamber followed by a combustion ash separator and gas recirculation to the oxidation chamber.

The problems of this technology associated with the harsh operating conditions were soon revealed: corrosion, due to the oxidizing atmosphere and deposition of inorganic salts due to the low solubility they present in supercritical water. Most of the patents that followed were aimed at solving these problems.

Regarding the problem of separating inorganic salts precipitated in the effluent, US Patent 4,338,199 of the year 1982 of MODAR already proposes the separation of inorganic solids in a cyclone that receives the effluent from the reactor. In 1989 they patented a reactor, US 4,822,497, consisting of a large pressure vessel that provides a relatively stationary environment in which solid particles fall to the bottom of the vessel through which cold water is injected so that it remains below the supercritical temperature such that a small part of the water condenses and an accumulation of concentrated brine will be formed by dissolving the sedimented salts. The hot brine solution and Pressurized is removed through a valve at the bottom of the reactor vessel. A modification to this patent is the W09221621 of 1992, in which the cold water stream is introduced by sliding down the reactor wall and thus avoiding the deposition of the salts in the wall.

In 1997, Spanish patent ES2108627 de Cocero describes a reactor system consisting of a refrigerated housing containing a reaction chamber, which provides lower cost reactors because it is not necessary for its pressurized housing to support the oxidation environment and for being This housing at a lower temperature than the oxidation process. For this, said housing is cooled internally, thus requiring less thickness, by the system itself or by a fluid outside the process. Continuing with the idea of the refrigerated wall another way to perform oxidation in supercritical water is using agitation.

In the patent ES 2219567 of 2004 published by the Commissioner of Atomic Energy (France), it is described as the mixture of the water / oxidant fluid under pressure and hot, and the material to be treated in the inner tube, can be carried out by mechanical agitation. The flow would tend to be at a rate equivalent to that of a perfectly agitated reactor or the agitation could be confined to successive volumes in order to maintain an essentially quasi-piston evacuation regime of the hot fluid mixture of water / pressure oxidizer in the inner tube and of the treated material. The cooling of the fluid mixture / oxidized material in the inner tube is preferably carried out under strong stirring.

Another type of oxidation reactor is the breathable wall developed by McGuinness, US 5,384,051, in 1996. The reactor consists of a permeable sheath that surrounds the reaction chamber and is located within the pressurized chamber. The cover insulates the pressure chamber from the high temperatures and oxidizing conditions in the reaction zone, reducing the cost of the pressure vessel. The organic residue is introduced through the central part of the reaction chamber and the mixture of oxidant and hot and pressurized water is introduced into the reaction zone through the permeable sheath. In US Patent 5,558,783 of 1996, McGuiness proposes this same system to homogeneously distribute the oxidant in an oxidation with hydrothermal flame.

Another patent in which a breathable element is used is that of Aerojet, US 5,387,398, from 1995. Organic waste is oxidized in supercritical water in the reaction zone in a reactor tube formed by "platelet", that is a series of microperforated plates that form ducts in the wall and create preferential paths making the wall breathable. Supercritical water is injected into the annular section, both outside the annular section and through the central chamber, through the ducts of the wall, forming a protective film of supercritical water on the surface that defines the annular area of reaction that mitigates corrosion and salt deposition problems. The water in turn also heats the mixture of residue and oxidant to the reaction temperature.

Another patent that seeks to protect the walls of the hydrothermal chamber from the heat generated in the hydrothermal flame is that published as EP0612697, and US 5,437,798 to Sulzer in which a cooled injector is described in its external part to avoid flame contact with the walls of the reaction chamber in 1994. US Patents 5,804,066, EP0820423 (Al) and WO9729050 (Al) of Mueggenburg et al. published in 1997 and 1998 describe an injector for hydrothermal flames in which the Fuel, water, waste and oxidant are injected separately to prevent oxidation at too high temperatures.

To prevent preheating, in 1997 McBrayer patented a recirculation reactor where cold reagents were mixed with hot products by the effect of natural convection (W09746494, US 6001243 and US 6017460). Continuing with the same idea, in the same year patents US9705069 and WO 5,674,405 of MODAR show a reactor in which the organic aqueous residue and the oxidant are introduced in a small reaction chamber and allows mixing the feed with the products formed, allowing internal heat recycling. This back mixing allows to start the reaction of the feed that is entering while decreasing the amount of solids formed in the reactor.

References :

- C. Augustine, J. W. Tester, Hydrothermal flames: From phenomenological experimental demonstrations to quantitative understanding, J. Supercrit. Fluids 47 (2009) 415-430

- W. Schilling, E. U. Franck, Combustion and Diffusion Flames at High Pressures to 2000 bar, Ber. Bunsenges Phys. Chem. 92 (1988) 631-636

DESCRIPTION OF THE INVENTION

To achieve the objectives and avoid the drawbacks indicated above, the present invention consists of an apparatus capable of supporting stationary hydrothermal flames, comprising a tubular injector, a reaction chamber of a material capable of withstanding temperatures greater than 400 ° C opened by its lower part and contained in a pressure housing capable of withstanding high pressures, cooled by a flow of cold water or brine that is introduced through the upper part of the housing and enters the bottom of the reaction chamber. The invention also comprises the method that makes use of this apparatus for the generation of stationary hydrothermal flames.

Thus, the apparatus for generating hydrothermal flames is characterized in that it comprises,

• An injector, which will be introduced inside the device and through which the reagents and the oxidizer that will generate the hydrothermal flame will be injected. At the outlet of the injector there is a stationary hydrothermal flame that serves to preheat the cold reagents to the autoignition temperature.

• A reaction chamber open at the bottom for the entry of a cooling fluid. It will be constructed of a material resistant to reaction temperatures above 374 ° C and at pressures above 22.1 MPa. These are the temperature and pressure conditions at which the critical water point is reached.

• A pressure housing comprising at least one hole located at the bottom thereof, this bottom of the housing being preferably flat, for the effluent outlet generated inside the apparatus. The reaction chamber will be located inside the pressure housing with a space between them for the circulation of the cooling fluid. This housing will be constructed of a material resistant to pressures above 22.1 MPa.

• A refrigeration system comprising a refrigerant fluid that circulates through the space between the pressure housing and the reaction chamber and enters in the reaction chamber by the bottom opening of said reaction chamber. In this way, the cooling fluid, which will have been heated to a temperature close to the critical temperature, will redissolve the salts generated inside the reaction chamber and that will have precipitated to the bottom of the pressure chamber and will drag them through the holes in the outlet located in said bottom of the pressure chamber outside the apparatus. This will prevent clogging of the outlets or the pipe that conducts this effluent and once it is out of the device. The cooling system fluid will be selected from cold water and brine.

The injector can be inserted either from the top of the device or from the bottom. In addition, the invention provides that the effluent gases generated inside the reaction chamber leave the apparatus either from the top or bottom of said apparatus.

In the case where the injector is introduced through the lower part of the apparatus and the effluent gases exit through the upper part of the apparatus, there are at least two holes in the bottom of the pressure housing one through which said injector is introduced and at least one other where the cooling fluid with the dissolved salts and / or a part of the effluent flows out, and also a hole in the upper part of the reaction chamber and the pressure housing for the effluent gas outlet that They are generated inside the device.

In the case where the injector is introduced through the lower part of the device and the effluent gases leave through the lower part of the device, there is a hole at the bottom of the pressure housing where the said injector is inserted into the chamber of reaction through the opening of the bottom of the chamber. For the exit of the effluent gases that are generated inside it is provided that they mix with the cooling fluid and exit through the holes in the bottom of the housing for the exit of the fluid.

In the case where the injector is introduced through the upper part of the apparatus and the effluent gases leave through the upper part of the apparatus, there is a hole in the upper part of the reaction chamber and a conduit in the pressure housing that connects the chamber with the outside and having the diameter of the hole through which the injector is introduced is greater than the diameter of the injector allowing the exit of the effluent gases generated inside the chamber through the gap between them of reaction. Optionally the apparatus comprises at least one hole and a conduit located in the upper part of the apparatus, as described above, independent of the one used for the introduction of the injector for the effluent gas outlet.

In the case where the injector is introduced through the upper part of the apparatus and the effluent gases leave through the lower part of the apparatus, there is a hole in the upper part of the pressure housing through which said injector is introduced. For the discharge of the effluent gases that are generated inside the apparatus it is provided that they are mixed with the cooling fluid and out through the holes in the bottom of the housing for the exit of the fluid.

Optionally, when the gases leave the reaction chamber at the top, the apparatus comprises a filter, resistant to temperatures above 374 ° C, between the injector outlet and the effluent gas outlet. It is also provided that the apparatus has the bottom of the conical pressure housing to facilitate the deposition of the salts that are generated inside the reaction chamber.

Optionally the injector may comprise fins or have a helical shape to increase the heat exchange surface between the reaction chamber and the injector. The injector may be tubular.

In addition, the apparatus may have elements that modify the dynamics of the flow, such as, for example, baffle plates that are located inside the reaction chamber transversely thereto.

On the other hand, the process of generating hydrothermal flames that uses the apparatus described above, comprises the following phases:

i) Generate the temperature and pressure conditions at which the ignition of organic matter, such as fuels and / or waste in supercritical water, is achieved inside the reaction chamber.

ii) Introduce reagents and a temperature oxidizer through the injector above the reagent self-ignition to generate the hydrothermal flame at the outlet of the injector. iii) Insert the pressurized refrigerant fluid through the gap between the pressure housing and the reaction chamber for cooling the pressure housing.

iv) Dissolve in the refrigerant fluid the salts that precipitate at the bottom of the reaction chamber and release this fluid to the outside with the dissolved salts through the holes in the bottom of the pressure housing. Optionally in phase ii) a fluid for gasification of said fluid is injected together with the reagents and oxidizer under conditions in which the oxidant is in a lower proportion than the stoichiometric one.

The procedure that makes use of the apparatus for processes of gasification of substances in supercritical water on the hydrothermal flame consists in introducing, together with the reagents and the oxidant, the material to be gasified, which could be the same reagents or other organic material. Preferably, it will be a material or fluid comprising organic substances. When the reagents, oxidant and material to be gasified are injected onto the flame, these are suddenly heated so that the reagents oxidize and generate heat but the material to be gasified is transformed into mostly hydrogen and carbon dioxide gases, and to a lesser extent other gases like methane, carbon monoxide or others. In this process of gasification on the hydrothermal flame it is important to work in an oxidant defect, so that part of the material and / or reagents is oxidized to generate the flame and the other part is gasified to provide combustible gases.

The reaction chamber is intended to work at temperatures up to 800 ° C inside the reaction chamber. Preferably, the apparatus is intended to work at temperatures above 374 ° C and at pressures above 22.1 MPa. It can also work at temperatures above 374 ° C and at pressures below 22.1 MPa. In addition, the pressure housing is expected to support pressures that will preferably be up to 30 MPa. The device is intended for the housing to withstand the pressure conditions that are generated due to the extreme conditions of the reactions that occur inside the reaction chamber. The reagents with the oxidizer that are injected in phase ii) may be at temperatures between 20 and 500 ° C and preferably at pressures greater than 22.1 MPa. They can also be injected at pressures below 22.1 MPa. Optionally, the reagents and the oxidizer used in phase ii) are made of a combustible material as a reagent and hydrogen peroxide or oxygen as a oxidizer, the oxygen being able to be mixed with nitrogen in any proportion.

The refrigerant fluid used in phase iii) is selected from cold water and brine.

The following operating characteristics stand out:

• It presents the possibility of injecting reagents at room temperature over the flame, avoiding preheating, and it is also possible to inject feeds with a high content of mineral salts, without clogging the equipment and without these salts accumulating inside of the device

• Produces an effluent at high temperature, so that there is an efficient and clean energy generation system from fuels or high-calorie aqueous waste based on the formation of hydrothermal flames.

The main advantage of this design is that the same cooling fluid, water or brine, once the reaction chamber has cooled and at an elevated temperature close to the critical water enters through the bottom of the reaction chamber forming a liquid water reservoir in which the salts precipitated in the flame are redissolved and can leave the reaction chamber without causing plugging problems. The design of the device minimizes the cost of construction materials using the concept of a reaction chamber with a refrigerated wall pressure housing. This design will allow operating at high temperature in the reaction chamber, and using a refrigerated pressure housing to withstand the operating pressure, being able to build lower cost equipment.

Regarding the operating conditions, reagents with the oxidizer can be injected at temperatures between 20 ° C and 500 ° C and preferably at pressures greater than 22.1 MPa. Optionally they can also be injected at pressures below 22.1 MPa. The device can work with maximum temperatures of up to 800 ° C inside the reaction chamber.

Regarding the applicability of the apparatus, this apparatus will allow the realization of processes that have as a source of energy a hydrothermal flame, such as oxidation in supercritical water of sewage and sludge, processes of gasification in supercritical water, precipitation of particles by sudden heating of an aqueous stream in the hydrothermal flame, as well as any other process to generate high pressure steam or any other hydrothermal process that uses the flame as an energy source.

BRIEF DESCRIPTION OF THE FIGURES

Figure 1.- Shows an embodiment of the configuration of the apparatus with the injector inserted through the lower part of the apparatus and the effluent gas outlet through the upper part thereof.

Figure 2.- Shows an embodiment of the configuration of the apparatus with the injector inserted through the lower part of the apparatus and the effluent gas outlet through the lower part thereof. Figure 3.- It shows an embodiment of the configuration of the apparatus with the injector inserted through the upper part of the apparatus and the effluent gas outlet through the upper part thereof.

Figure 4.- It shows an embodiment of the configuration of the apparatus with the injector inserted through the upper part of the apparatus and the effluent gas outlet through the lower part thereof.

Figure 5.- Shows the scheme of the installation in which the tests of the device are carried out.

Figure 6.- Shows the experimental data obtained in an experience in which the injection temperature was reduced to 30 ° C.

Figure 7.- It shows the experimental data obtained in an experience in which the cooling flow was modified to observe the temperature variation in the bottom of the housing.

Figure 8.- Shows the temperature contour diagram in Kelvin degrees resulting from the simulation of the operation of the device with the configuration corresponding to the scheme in Figure 1.

Figure 9.- Shows the representation of the flow lines resulting from the operation simulation of the apparatus with the configuration corresponding to the scheme of Figure 1.

Figure 10.- Shows the diagram of contours of mass water fraction resulting from the simulation of operation of the apparatus with the configuration corresponding to the scheme of Figure 1, with different flow distributions between the outputs (7 and 11 in Figure 1) .

DESCRIPTION OF VARIOUS EXAMPLES OF REALIZATION OF THE

INVENTION

Then, a description of several examples of embodiment of the invention, referring to the numbering adopted in the figures.

The elements that are common to all embodiments of the present invention are mentioned below. The apparatus comprises a reaction chamber (1) limited by a wall or inner housing (2) of a material resistant to high temperatures and corrosion which in turn is contained in a pressure housing (3). Between the walls (4) of the pressure housing (3) and the reaction chamber (1) a flow of a pressurized refrigerant fluid (5) such as cold water or brine will circulate, which will keep the pressure housing (3) refrigerated. This fluid (5) enters the lower part of the reaction chamber (6), redisolving the salts that may have precipitated in the hydrothermal flame, and thus leaving the reaction chamber (1) without causing blockages. These salts precipitate directly inside the reaction chamber (1) and fall to the bottom (12) of the housing (3), since the chamber (1) has an opening (15) at its bottom, communicating said chamber ( 1) with said housing (3). To inject the feed (17), that is to say the reagents and the oxidizer, an injector (9) is used inside the reaction chamber (1).

With the apparatus of the present invention, whose main parts are described in the previous paragraph and are common for all the different dispositions thereof, if the arrangement of the inputs and outputs is varied, different embodiments of the apparatus can be obtained. The embodiments are described below.

Example 1

Figure 1 shows a first preferred embodiment of the invention. In this configuration the injection of the reagents and oxidizer (8) will be produced by a tubular injector (9) inserted through a hole (13) made at the bottom (12) of the pressure housing (3), which conducts the reagents, through the opening (15) of the lower part of the reaction chamber (1), to the upper or middle part of the reaction chamber (1) of the apparatus.

The salts dissolved in the reagents and the oxidizer that generate the hydrothermal flame when entering the reaction chamber (1), precipitate due to the supercritical conditions of the water and are collected by the water that cools the outer wall (5) and that it accumulates at the bottom (12) of the pressure housing (3) leaving the holes (7) at the bottom (12), thus preventing the formation of plugs in the outlet pipe of the apparatus.

The effluent gases generated will leave the device through the hole in its upper part (11) of the chamber (1), which communicates with a conduit (14) of the housing (3), without mixing with the cooling water (5 ). This allows the gases to leave the appliance at a higher temperature (600-700 ° C) and free of salts, which could be expanded in a turbine for the generation of electricity or used to produce steam.

The apparatus can be used to generate energy and for waste disposal in addition to other associated hydrothermal processes such as gasification or partial oxidation.

Example 2

Figure 2 shows another preferred embodiment of the invention identical to that of Figure 1 with the exception that the reaction chamber (1) is not open at its top, so there is no hole (11) for the exit of the effluent gases. Similarly there is no conduit (14) in the pressure housing (3) that communicates with the hole in the chamber (1) through which the gases exit. Due to this, the effluent gases will flow through the holes (7) in the bottom (12) of the housing pressure (3) mixing with the cooling fluid (5) in the lower area of the apparatus (6).

Example 3

Figure 3 shows another preferred embodiment. In this embodiment the injection of the reagents and the oxidizer (8) is carried out by means of an injector (9) inserted from the top through a hole

(11) located in the upper part of the apparatus made for this purpose, in this case leading the reagents to the lower and middle part of the reaction chamber

(one) . In this embodiment, the effluent gases will exit through the hole (11) of the chamber (1), which communicates with the conduit (14) of the housing, located at the top of the apparatus, since the diameter of the orifice (11 ) and the duct (14) is provided to be larger than the diameter of the injector (9) and said injector (9) is located concentrically with respect to the hole (11) and the duct (14). In this way the effluent gases will not be mixed with the cooling water (5), but nevertheless the salts as in the first example would dissolve in the water accumulated at the bottom (12) of the pressure housing (3 ) so the gases would be free of salts.

Example 4

Figure 4 shows another preferred embodiment of the invention identical to that of Figure 3 with the exception that the injection of the reagents and the oxidizer (8) is carried out by means of an injector (9) inserted from the top through a hole (11), which communicates with a conduit (14) of the housing (3), located in the upper part of the apparatus made for this purpose, in this case leading the reagents to the lower and middle part of the reaction chamber . After the reaction occurs, the effluent gases will flow out of the holes (7) at the bottom (12) of the pressure housing (3) mixing with the cooling water (5) in the lower area of the device (6).

Example 5

In another preferred embodiment of the invention, the installation of a filter of a high temperature resistant material is provided for the configuration of Figure 1 between the outlet of the injector (9) and the outlet orifice of the effluent gases (11) .

Example 6

In another preferred embodiment of the invention, the modification of the bottom of the pressure housing (3) is provided so that it is conical, thus facilitating the deposition of salts.

Example 7

In other embodiments, variations in the design of the injector are provided such as: fins or a helical shape of the injector to increase the heat exchange surface between the reaction chamber (1) and the injector (9).

Example 8

Tests have been carried out with a prototype of the apparatus in a pilot plant with a design equivalent to that of Figure 5 for the oxidation of organic matter under supercritical conditions, at an operating pressure of up to 300 bars and with operating flows of up to 25 kg / h. The apparatus has operated satisfactorily, and by way of example the results corresponding to an experiment are presented in Table 1 and Figure 6.

For all the experiments carried out, and which are set out below, water mixed with isopropanol has been used as feed (17) and air as oxidizer (18). For the specific cases of figures 6 and 7, the apparatus arranged with the configuration described in figure 2 has been used. Note that the feed also includes the reagents, water. The same reference (17) has been used herein for the reagents as for the feed although whenever it is spoken of feed it will be understood that it refers to the mixture of said reactants with the water.

For the specific case of the experiment whose results are shown in Figure 6 and Table 1, the effluent gas outlet must be mixed with the water (5) that cools the wall keeping it at a constant flow. The water (5) that enters pressurized to cool the appliance is supplied by a pump (14). The power supply (17) is supplied by a pump (20) that passes said power supply (17) through a heat exchanger (19) before introducing it into the apparatus. The oxidizer (18), note that the terms oxidant and oxidizer are equivalent, is supplied by a compressor (21) that passes it through a heat exchanger (19) as a prior step to introducing it into the apparatus. Since at the outlet (7) there is an effluent comprising gases, liquids and solid residues, a separator is used

(22) to obtain effluent gases on the one hand and liquids and solids on the other. As a previous step to the separator

(22), the effluent passes through a heat exchanger (19).

Table 1 shows the values corresponding to the operation variables and the most relevant results of the test performed.

Table 1

Flow Flow

T injection pressure

Sample air inlet

(Bar) (° C)

(kg / h) (kg / h)

Sample 1 13.29 213, 67 14, 93 29, 25 Sample 2 13.29 213, 15 15, 00 28.84

Sample 3 13, 13 215, 08 14, 63 29.09

Sample 4 13, 13 210.44 15, 13 29, 10

Sample 5 13, 13 213, 19 15.31 29, 61

Sample 6 13, 13 212, 59 15, 37 29.71

Note that the table has been divided into two parts by its size, so the data represented corresponds to the same 6 samples.

It is observed that it is possible to keep the apparatus running with injection temperatures of up to 30 ° C, achieving a total elimination of the organic matter present in the feed (17).

Figure 6 shows the temporal evolution of temperatures, pressure and elimination of organic carbon Total, TOC Elimination, obtained in an oxidation process where Tin is the feed temperature

(17) at the inlet of the apparatus (8) and TI and T2 are the reaction temperatures of the reagents (17) with the oxidant (18) inside the reaction chamber (1), where TI is temperature measured at the injector outlet (9) and T2 taken in the reaction zone (10). P effluent is the pressure to which the effluent is subjected.

Figure 7 shows the temporal evolution of the main operating variables in another experiment in which the cooling flow (F REF) is modified so that the bottom temperature is reduced

(T BACKGROUND) of the apparatus but maintaining the hydrothermal flame in the reaction zone (10), temperatures of 600-700 ° C inside the apparatus, demonstrating that it is possible to dispose within the apparatus a certain height of liquid at a temperature by below the critical temperature of the water so that the salts dissolve in it while the hydrothermal flame is generated in the upper part of the reaction chamber (1).

Table 2 shows the most relevant results of the experience reflected in Figure 7.

Table 2

T

Flow Flow of

Flow T bottom feed cooler Pressure

air Injection of the tion (Bar)

(kg / h) (° C) device (kg / h) (kg / h)

(° C)

23.7 3, 8 219, 6 23, 8 214, 8 458.5

23, 6 3, 8 219, 5 23, 8 215.4 457, 1

23, 6 7.5 226, 3 23, 8 213.4 419, 7

23, 6 7.5 225.7 23, 8 213.3 419, 0 3, 6 12, 0 226, 0 23, 9 209, 6 392, 0 3, 6 12, 0 226, 5 23, 9 209, 4 391, 0 3, 6 16, 5 229, 7 23, 9 207, 0 373, 7 3, 6 16, 5 230, 6 24.0 207.2 373, 4 3, 6 21.0 228.4 23, 8 206, 7 361, 9 3, 6 21.0 228.4 23 , 7 207, 1 361, 4 3, 6 25.3 233, 7 206, 2 348, 5

23, 6

3, 6 25.3 234, 5 23, 8 206, 0 349, 2 3, 6 29, 9 222.5 24.4 205, 0 338, 3 3, 6 29, 9 222.4 24.5 204, 9 338, 6 3, 1 34, 4 236, 6 24, 1 202, 1 321, 7 3, 1 34, 4 236, 4 24.3 203.4 319, 9

TOC flow AlimenTOC Conversion feed time tación Output TOC residence (kg / h) (ppm) (ppm) (%) (s)

23.7 54000 4.2 99, 99 16, 7

23, 6 54000 3.2 99, 99 16, 7

23, 6 54000 4.4 99, 99 16, 8

23, 6 54000 4.2 99, 99 16, 9

23, 6 54000 5.2 99, 99 16, 9

23, 6 54000 6, 8 99, 98 17.0

23, 6 54000 7.4 99, 98 17.0

23, 6 54000 9, 0 99, 98 17.2

23, 6 54000 8.7 99, 98 17.2 23, 6 54000 11.3 99, 98

17.3

23, 6 54000 11.4 99, 98 17.3

23, 6 54000 26, 1 99, 96 17.5

23, 6 54000 29, 0 99, 95 17.4

23, 1 54000 26, 3 99, 95 17, 9

23, 1 54000 27.3 99, 95 17, 9

Note that the table has been divided into two parts by its size, so the data represented correspond to the same cooling flows.

In another embodiment, for the configuration corresponding to Figure 1, numerical simulations have been carried out to study the possible behavior of the apparatus under different operating conditions. The results of these simulations are shown in Figures 8 to 10. The feed (15), which comprises the mixture of the oxidizer (18) with the reagents (17), considered in the simulation is a current of 22 kg / h of isopropanol in water, at a concentration of 8% by weight, which enters the reaction chamber (1) at a temperature of 360 ° C and a pressure of 23 MPa. The oxidant (16) is stoichiometric air and the cooling water flow (5) is also 22 kg / h.

Figure 8 shows the temperature contours inside the reaction chamber (1) under these conditions. The simulation indicates a temperature increase in the flow of the injector (9) due to heat transfer from the reaction chamber (1) and due to the heat itself released in the oxidation. A part of the effluent left by the injector (9) is cooled as it travels through the reaction chamber (1), while the cooling water (5) is heated, and finally mixed in the lower zone of the reaction chamber (6) leaving the reaction chamber (1) at a subcritical temperature (360 ° C, in this example) through the holes (7) located at the bottom (12) of the pressure housing ( 3) . Another part of the effluent, specifically the gases, exits at 500 ° C through the hole in the upper part (11) of the device, allowing its energy use.

The flow lines within the reaction chamber (1) are shown in Figure 9. These lines point to areas of turbulence, especially in the reagent exit zone by the injector (9), which are beneficial because they contribute to the "in situ" preheating of the reagents when their injection is made at subcritical temperatures, stabilizing the Hydrothermal flame region (10).

Figure 10 shows the concentration contours (mass fraction) of cooling fluid, specifically water for this case, for different flow distributions between the upper and lower outlets (7 and 11) of the apparatus. In the diagrams, the dark areas correspond to low concentrations of water, while the light areas indicate pure water. The level of liquid water accumulated in the lower part (6) of the reaction chamber (1) can be observed depending on the relationship between the gas flow in the upper outlet (11) and the lower outlet (7) . Figure 10a corresponds to a configuration in which the effluent gases leave the lower part of the apparatus, maintaining a low level of water in the lower area of the apparatus (6) for dissolving salts. Figures 10b, 10c and 10 correspond, respectively, to conditions in which a fraction of 50, 65 and 90% of the gas flow leaves the apparatus at the top (11). It is observed that the level of liquid water at the bottom of the reaction chamber increases to as the effluent flow leaving the chamber (1) through the upper outlet (11) increases. This increase in water level improves the dissolution of precipitated salts, however it reduces the temperature in the reaction chamber (1), being a parameter to be taken into account when deciding the outflow of gaseous effluents.

Claims

1- Apparatus for generating hydrothermal flames, characterized in that it comprises,

• an injector (9);

• a reaction chamber (1) comprising an opening

(15) at the bottom thereof for the entry of a cooling fluid (5), said opening (15) communicating the chamber (1) with a pressure housing (3) surrounding it;

• a pressure housing (3) comprising at least one hole located at the bottom of the housing for the discharge of an effluent (7), the reaction chamber (1) being located inside the pressure housing ( 3) and having a space (4) between them for the circulation of a refrigerant fluid (5); Y,

• a cooling system comprising a refrigerant fluid (5) that circulates through the space (4) between the pressure housing (3) and the reaction chamber (1) and that enters the reaction chamber (1) through the opening (15) communicating with the bottom (12) of the reaction chamber (1).

2. - Apparatus for generating hydrothermal flames, according to claim 1, characterized in that it comprises a hole (13) at the bottom of the reaction chamber (1) and the pressure housing (3) for the introduction of the injector ( 9).

3. - Apparatus for generating hydrothermal flames, according to claim 2, characterized in that the reaction chamber (1) and the reaction housing (3) have a hole (11) at the top for the exit of gases from the effluent that are generated inside.

4. - Apparatus for generating hydrothermal flames, according to claim 1, characterized in that it comprises a hole (13) in the upper part of the reaction chamber (1) and a conduit in the pressure housing (3) that communicates with said hole (13) where the injector (9) is inserted.

5. - Apparatus for generating hydrothermal flames, according to claim 4, characterized in that the diameter of the hole (13) through which the injector is inserted is greater than the diameter of the injector (9) allowing the exit through the gap between both, of effluent gases that are generated inside the reaction chamber (1).

6. - Apparatus for generating hydrothermal flames, according to claim 4, characterized in that it comprises at least one hole in the reaction chamber (1) and a conduit in the housing (3) independent of the orifice (13) and the conduit of the injector for effluent gas outlet.

7. Apparatus for generating hydrothermal flames, according to any one of claims 4, 5 and 6, characterized in that it comprises a filter, resistant to temperatures above 374 ° C, between the injector outlet (10) and the outlet of the effluent gases (11).

8. - Apparatus for generating hydrothermal flames, according to claim 1, characterized in that the bottom of the pressure housing (12) is conical to facilitate the deposition of salts that are generated inside the reaction chamber (1 ).

9. - Apparatus for generating hydrothermal flames, according to claim 1, characterized in that the injector (9) comprises fins.

10. - Apparatus for generating hydrothermal flames, according to claim 1, characterized in that the injector (9) has a helical shape to increase the heat exchange surface between the reaction chamber (1) and the injector (9).

11. - Apparatus for generating hydrothermal flames, according to claim 1, characterized in that it comprises elements that modify the flow dynamics.

12. Apparatus for generating hydrothermal flames, according to claim 11, characterized in that they are deflector plates located transversely to the reaction chamber (1) to modify the flow dynamics.

13. Apparatus for generating hydrothermal flames, according to claim 1, characterized in that the injector (9) is of the tubular type.

14. Method of generating hydrothermal flames, by means of the apparatus defined in any one of claims 1 to 13, characterized in that it comprises the following phases:

i) generate the temperature and pressure conditions at which the ignition of the organic matter is reached inside the reaction chamber (1);

ii) introduce reagents (17) and a oxidizer (18) through the injector (9) at a temperature above the reagent self-ignition (17), for the generation of the hydrothermal flame at the outlet of the injector (10) );

iii) insert the pressurized refrigerant fluid (5) through the gap (4) between the pressure housing (3) and the reaction chamber (1) for cooling the pressure housing (3); Y, iv) dissolve in the refrigerant fluid (5) the salts that precipitate to the bottom (12) of the reaction chamber (3) and send said fluid (5) to the outside with the dissolved salts through the holes (7) from the bottom (12) of the pressure housing (3).

15. Method for generating hydrothermal flames, according to claim 13, characterized in that the apparatus works at temperatures up to 800 ° C inside the reaction chamber (1).

16. Method for generating hydrothermal flames, according to claim 14, characterized in that the reaction chamber (1) works at temperatures above 374 ° C and at pressures above 22.1 MPa.

17. Method for generating hydrothermal flames, according to claim 14, characterized in that the reaction chamber (1) works at temperatures above 374 ° C and at pressures below 22.1 MPa.

18. - Hydrothermal flame generation method, according to claim 14, characterized in that the reagents (17) and the oxidizer (18) injected in phase ii) are at temperatures between 20 and 500 ° C and at pressures greater than 22.1 MPa.

19. - Method of generating hydrothermal flames, according to claim 13, characterized in that the cooling fluid (5) used in phase i) is selected from cold water and brine.

20. - Hydrothermal flame generation process, according to claim 14, characterized in that the reagents and the oxidizer used in phase ii) are a combustible material as a reagent (17) and as a oxidizer (18) a fluid selected from hydrogen peroxide and oxygen mixed in any proportion with nitrogen.

21. - Hydrothermal flame generation method according to claim 14, characterized in that the pressure housing (3) withstands pressures of up to 30 MPa.

22. - Method of generating hydrothermal flames, according to claim 14, characterized in that in phase ii) a material for gasification of said material onto the hydrothermal flame under conditions is injected together with reagents (17) and oxidizer (18) in which the oxidizer (18) is in a lower proportion than the stoichiometric one.

23. - Method of generating hydrothermal flames, according to claim 22, characterized in that the material for gasification comprises organic substances.

24. - Use of the apparatus, defined in any one of claims 1 to 13, for the destruction of waste in supercritical water.

25. - Use of the gases produced in supercritical water inside the apparatus, defined in any one of claims 1 to 13, for the production of energy.

26. - Use of the apparatus, defined in any one of claims 1 to 13, for the precipitation of particles by sudden heating of an aqueous stream in the hydrothermal flame.

27. - Use of the apparatus, defined in any one of claims 1 to 13, for the gasification of substances on the hydrothermal flame.