Salt separator comprising a deformable porous structure forming a support for salt precipitation and removal, associated biomass gasification plant.

Abstract

Salt separator comprising a deformable porous structure forming a support for salt precipitation and removal, associated biomass gasification plant. The invention relates to a salt separator for a solution subjected to supercritical conditions to precipitate the salts within a deformable porous structure. The open porosity of the structure's pores defines a very large surface area for salt deposition / precipitation. The solution is injected into the separator chamber through a tube that can reach the interior of the chamber and penetrate the deformable structure, even in its most deformed state. The porous structure is heated via the chamber's side wall to a temperature between 300°C and 1000°C. The inorganic salts contained in the solution are trapped / precipitated upon contact with the heated porous structure in its deformed state.The flow of the salt-depleted solution is discharged through the dedicated outlet. Figure for the abbreviation: fig. 3.

Description

Title of the invention: Salt separator comprising a deformable porous structure forming a support for salt precipitation and evacuation, associated biomass gasification plant. technical field

[0001] The present invention relates generally to salt separators and more particularly to those intended to be used in a thermochemical conversion plant of a carbonaceous material feed, in particular under supercritical fluid, for the production of a gaseous mixture.

[0002] By "carbonaceous material charge", we mean here and within the framework of the invention any material containing a quantity of carbon, in particular any carbonaceous material from residues.

[0003] It can therefore be biomass, that is to say any inhomogeneous material of plant origin containing carbon, such as lignocellulosic biomass, forest or agricultural residues (straw), which can be almost dry or soaked with water like household waste or waste resulting from the treatment of water such as sewage sludge.

[0004] It can also be a fossil fuel, such as coal.

[0005] It may also be combustible waste of industrial origin, in particular of The agri-food industry, containing carbon, such as plastics or used tires, used oils, organic solvents

[0006] It can also be a combination of biomass and fossil fuel.

[0007] For the purposes of this invention, "supercritical fluid" means in its usual sense, namely, a pressure and temperature above which the fluid is in a supercritical state. Its behavior becomes intermediate between the liquid and gaseous states: its density is that of a liquid, but its low viscosity is similar to that of a gas.

[0008] Thus, by "supercritical water" is understood in the usual sense, that is to say, water at temperatures above 374°C under a pressure above 22.1 MPa.

[0009] Although described with reference to a preferred application of gasification of a carbonaceous material feed under supercritical water, a salt separator according to the invention can be implemented in numerous applications, and particularly in the industrial fields of food processing, chemicals, energy, including the oil sector and the transport sector, ... for which separation salts from an aqueous fluid mixture are required.

[0010] In general, a salt separator according to the invention is suitable for separating salts initially present in aqueous solutions with or without organic matter.

[0011] More specifically, a salt separator according to the invention is advantageously implemented in a thermochemical conversion plant of wet carbon resources, such as supercritical water gasification. Previous technique

[0012] Many existing processes allow for the thermochemical conversion of a carbon feedstock into liquid fuels (biofuels, biochar), solid fuels (granules), and gaseous fuels (biogas, methane, syngas, hydrogen).

[0013] Among these, the gasification of biomass and coal has been known for a long time. Generally speaking, it can be defined as a thermochemical transformation of biomass or coal by the action of heat in the presence of gasifying agents. The aim is to generate, at the end of the gasification process, a mixture of gases.

[0014] Thus, the processes of gasification of ligno-cellulosic biomass make it possible to generate a gas rich in methane or hydrogen.

[0015] More specifically, hydrothermal gasification, also called supercritical water gasification, is a thermochemical process for producing renewable gas from wet organic matter with a dry matter content typically between 5 and 20% by mass, for example, agri-food industry waste, industrial effluents such as black liquor, non-spreadable digestate from methanization, and sewage sludge. By operating at high temperature and pressure, the process generates a high-energy synthesis gas composed of a mixture rich in methane, hydrogen, carbon dioxide (syngas), and other light hydrocarbons.

[0016] By exploiting the properties of water under supercritical conditions, i.e. at a temperature above 374°C and at a pressure above 221 bar, the medium becomes very reactive, which allows hydrothermal gasification to achieve excellent conversion rates of biomass carbon into gas, around 70-90%, while separating inorganic elements (salts), potentially allowing their valorization as nutrients, in particular the elements nitrogen, phosphorus, and potassium.

[0017] In general, the separation and recovery of inorganic constituents present in the feed stream of reactors implementing thermochemical processes are crucial, as these constituents can lead to plant blockage, fouling, and poisoning of the gasification catalyst. Furthermore, salt recovery offers the possibility of producing a fertilizer as a valuable by-product (nutrients), as explained above.

[0018] This problem of salt separation is even more pronounced in the case of supercritical water gasification: the evolution of the dielectric constant and the ionic product of water in the supercritical state leads to the precipitation of salts contained in the resource. Indeed, near the critical point, the properties of water change, with a significant decrease in density and dielectric constant, among other things. Under these conditions, the atoms of inorganic components that could be dissolved / transported in the water below the critical point are no longer so. Some of these salts can modify the physical properties of the water and form a dense phase that flows to the bottom of the reactor, but most precipitate and then agglomerate on the hot surfaces, causing reactor blockages and inducing intermittent shutdowns of the associated installation.Managing precipitation and its location is a key element for the development of hydrothermal gasification.

[0019] Numerous articles in the literature show that salt separation in a thermochemical conversion process is of major importance for the actual efficiency of the overall process and for the service life of the associated equipment. However, the drawback of salt separators known to date is that salt separation is still not satisfactory or, even when satisfactory, requires excessively high thermal or mechanical energy inputs, or the salts are associated with a significant proportion of organic matter. Furthermore, fouling and deposits are a major problem in such salt separators.

[0020] More particularly, various scientific articles are interested in the dynamics of salt precipitation under supercritical hydrogenation conditions, which makes it possible to separate salts initially present from an aqueous solution containing organic matter.

[0021] Figure 1 reproduces a salt separator as disclosed in publication 1, as envisaged for the gasification of biomass with supercritical water. This separator 1 comprises, as a biomass injection device, a cylindrical tube 10 with an injection orifice 11 through which the biomass is injected, and an outlet orifice 12 through which the biomass is discharged into an inner chamber C delimited by a double-walled enclosure 2 20, 21, the outer wall 21 of which is thermally insulated and incorporates heating elements 22 which thus heat the chamber C and the injection tube 10.

[0022] When the wet biomass is introduced into the tube 10, it is gradually brought to a temperature of approximately 450°C: precipitation occurs almost instantaneously as soon as the temperature reached causes a decrease in the solubility of the salts, leading to the separation of the wet biomass into various phases, in particular solids in a separation zone S within chamber C.

[0023] In the configuration installed vertically above the separator, the biomass / water / salts and other solids mixture is separated by gravity in this separation zone S into a brine highly concentrated in salts and a solution depleted in salts. A resolubilization zone R, immediately below the separation zone S, allows the resolubilization of the salts, which are then discharged by gravity as brine through the outlet 23 drilled in the bottom 24 of the separator, without mixing with the portion of the effluent that rises into chamber C to be discharged through the outlet 25 to a gasification reactor, not shown.

[0024] Such gravity separators are also described in publications [2] and [3]: they are used for inorganic fluids and salt deposits for hydrothermal gasification. Cyclonic separators also exist for the same application.

[0025] Overall, a gravity separator works satisfactorily when the phases involved are denser than the carrier medium and according to a grain size distribution allowing gravity separation and brine-type behavior, salts which are described as type I in this case.

[0026] However, in some cases, the salts precipitate in particles so small (micro or nanoparticles) that they do not settle.

[0027] In other cases, gravity separation is not easy, as specified in publication [3]. Thus, the transition of wet carbonaceous material under subcritical to supercritical conditions can be accompanied by the appearance of very sticky solid phases, in the form of salts that are described as type II. These type II salts can accumulate on the internal walls of the inner chamber of the separator and, if necessary, clog the injection tube 10 of the separator as shown in [Fig. 1].

[0028] To avoid such a harmful accumulation of salt II, one could consider applying known solutions implemented in scraped-surface heat exchangers. Such exchangers are notably used in fouling processes, that is, when the exchanger walls can be subject to fouling phenomena involving the heat transfers, i.e., with the deposition of undesirable materials.

[0029] By way of example, the scrapers used may be rotary, for example of the worm gear or paddle type, or oscillating of the piston type, for example with annular or non-annular plates. The actuation of the rotary or oscillating piston-type scraper is generally operated by an electric motor.

[0030] Scrapers for heat exchangers have in particular been considered for supercritical oxidation reactors, as described in US patents 5,100,560A, US6,054,057 A and US5,461,648 A.

[0031] US patent application US2012 / 214977 describes a scraper for ultrafiltration applications. Specific scrapers have also been considered for viscous fluids: https: / / www.hrsasia.co.in / heat-exchanger-specialists / scraped-surface-heat-exchanger / .

[0032] In the field of organic fluids, other descaling solutions have already been considered, among which we can mention:

[0033] - the vibration of parts by pressure pulsation, as described in the US application US2008 / 0073063A1

[0034] - chemical treatments, such as that of patent application CA 2119056.

[0035] None of these solutions are suitable for the problem of salt accumulation. type II on the walls, which may also occur on the scrapers themselves.

[0036] There is therefore a need to find a solution which allows better control of the removal of salts, in particular of type II, present in a solution, in particular a solution intended to undergo a thermochemical conversion treatment such as wet biomass intended to be gasified.

[0037] The aim of the invention is to meet at least part of this need. Description of the invention

[0038] To this end, the invention relates to a salt separator for separating salts from a carbonaceous material containing them, the salt separator comprising:

[0039] - a tube comprising an injection orifice through which a solution containing a or salts are intended to be injected, and an outlet is provided through which the solution is intended to be discharged;

[0040] - an enclosure delimiting an inner chamber and comprising:

[0041] • a cover to which the tube is attached or entirely formed,

[0042] • at least one side wall pierced with a second injection orifice, through which a draining fluid is intended to be injected, at least part of the height of the side wall being adapted to be heated to a temperature greater than or equal to the precipitation temperature of the salts, the side wall and / or the cover being pierced with at least one first outlet orifice through which the effluents of carbonaceous matter devoid of precipitated salts are intended to be discharged,

[0043] • a base, the side wall and / or the lid and / or the base being pierced with less an outlet through which the precipitated salts are intended to be discharged in the form of brine or in solid form by being drained by the draining fluid;

[0044] - a grid arranged in the inner chamber of the enclosure;

[0045] - a deformable porous structure, arranged in chamber (C) of the enclosure at- above the grid so that the tube's outlet opens into it when it is in its undeformed state;

[0046] - at least one deformation means, arranged in the chamber of the enclosure at- above the grid, the deformation means being actuated to reversibly deform, at least once, the structure from an undeformed state, in which, when the solution is injected into the tube, the salts contained in the solution precipitate onto its surface, to at least one deformed state in which, in the absence of injected solution, the precipitated salts present on the surface of the latter detach.

[0047] According to a first advantageous embodiment, the deformable structure is a compressible structure, the deformation means being a compression means for compressing the compressible structure in the inner chamber from an uncompressed state to at least one compressed state.

[0048] According to this first embodiment and an advantageous variant, the compressible structure consists of at least one open-pore compressible foam, coated or not with a catalytic coating, or at least one compression spring, preferably a plurality of compression springs arranged concentrically. A metallic or ceramic foam advantageously has essentially open porosity, which makes it accessible and allows for a high capacity to retain precipitated salts.

[0049] Advantageously, the compressible structure is arranged to scrape the wall of the inner chamber when it passes from its uncompressed state to its compressed state. By scraping the inner wall of the enclosure in this way, its cleaning is ensured by removing any precipitated particles and / or salt.

[0050] According to an advantageous embodiment, the compression means consists of a piston mounted to slide in the inner chamber and actuated by a motor arranged outside the enclosure.

[0051] According to an advantageous configuration, the outlet orifice of the salts precipitated in solid form by being drained by the draining fluid is the first outlet orifice through which the effluents of the carbonaceous matter devoid of the precipitated salts are intended to be evacuated.

[0052] According to a second advantageous embodiment, the deformable structure is a bed of balls, the deformation means being an agitation means for agitating the bed of balls in the inner chamber from a static state to at least one agitated state.

[0053] According to this second mode and an advantageous embodiment, the stirring means is a mechanical agitator, in particular with blades, mounted in rotation in the inner chamber and driven by a motor arranged outside the enclosure.

[0054] According to an advantageous configuration, the outlet for the salts precipitated in the form of brine is a second outlet arranged below the second injection outlet, so that the brine can be discharged by gravity drainage.

[0055] The enclosure is advantageously made of a metallic material suitable for the operating conditions of temperature and pressure: it can be made of Inconel®, stainless steel or other materials.

[0056] For the means of heating the side wall of the enclosure, several alternatives can be considered, which can be combined with each other:

[0057] - external heating means arranged around the side wall of the enclosure to heat the solution to a temperature greater than or equal to the critical temperature of water and precipitation of salts; - heating elements, in the form of cartridges, intended to be powered by an external power source and integrated into the thickness of the side wall of the enclosure to heat the solution to a temperature greater than or equal to the critical temperature of water and precipitation of salts; - a heat transfer fluid circuit made in the thickness of the side wall of the enclosure to heat the solution to a temperature greater than or equal to the critical temperature of water and precipitation of salts.

[0058] Preferably, the operating pressure of the enclosure is between 222 bars and 1000 bars.

[0059] Preferably, the temperature of the inner chamber is between 300°C and 1000°C.

[0060] The invention also relates to a method for operating a salt separator as described above, comprising the following successive steps:

[0061] i / injection of a solution through the first injection orifice and heating of the enclosure so that the solution is at a temperature greater than or equal to the critical temperature of water and precipitation of salts, the deformable porous structure being in the undeformed state;

[0062] ii / stopping the injection of solution then actuation of the deformation means to change the deformable porous structure from its undeformed state to at least one deformed state;

[0063] iii / stopping the actuation of the deformation means to return the deformable porous structure to its undeformed state then injection of a draining fluid to drain towards the outlet orifice the precipitated salts detached from the structure in the form of brine or in solid form.

[0064] Advantageously, steps i / to iii / are repeated continuously or with a waiting period between step iii / and the successive step i / .

[0065] The invention also relates to a biomass gasification plant comprising:

[0066] - a salt separator as described above;

[0067] - a gasification reactor connected to the enclosure of the salt separator to be fueled by salt-free biomass.

[0068] Advantageously, the operating temperature of the reactor is about 600°C and the operating pressure of the reactor is about 300 bars.

[0069] Thus, the invention essentially consists of making a separator of salts contained in a solution, preferably to be converted thermochemically, which is brought into supercritical conditions to precipitate the salts it contains within a deformable porous structure.

[0070] The open porosity of the pores of the structure defines a very large surface area for the deposition / precipitation of salts.

[0071] The solution is injected into the separator enclosure by means of a tube, such as an injection lance, advantageously adjustable in height, which can reach the interior of the chamber and penetrate into the deformable structure, even in its most deformed state.

[0072] The porous structure is heated through the side wall of the enclosure to a temperature between 300°C and 1000°C, for example 400°C. The inorganic salts contained in the solution are trapped / precipitated upon contact with the heated porous structure, which is in its deformed state. The flow of the salt-depleted solution is discharged through the dedicated outlet.

[0073] After a certain period of time, the injection of the solution is stopped. The deformation of the structure, either by compression on a grid and, if necessary, decompression, or by agitation (bead bed) according to a cycle, allows the salts precipitated within the structure to be detached / dislodged.

[0074] Next, a flow of draining fluid, which may be water, a solvent, or a carrier gas, is injected through the dedicated orifice. The draining fluid is advantageously injected at a temperature between 300°C and 1000°C, for example 300°C, and at a pressure between 222 bar and 1000 bar, for example 250 bar.

[0075] When the structure is compressible, the draining fluid flows through the structure, which has been returned to its uncompressed state, and removes / drains the salt particles that have been detached from the porous structure. The draining fluid exits through the upper part of the separator, carrying these particles outwards. Advantageously, they can be discharged through the outlet dedicated to the discharge of the salt-depleted solution stream. The salt particles can then be advantageously separated from the draining fluid for recovery and valorization of the inorganic components.

[0076] When the structure is a deformable structure by agitation (bed of balls), the draining fluid sweeps the bottom of the separator and thus becomes loaded with dissolved salts to be extracted in the form of a brine evacuated by preferably gravity drainage through a grid.

[0077] Other advantages and features will become clearer upon reading the detailed description, given by way of illustration and not limitation, with reference to the following figures. Brief description of the drawings

[0078] [Fig-1] [Fig.1] is a schematic longitudinal cross-sectional view of a separator of salts according to the state of the art.

[0079] [Fig.2A][Fig.2B][Fig.2C] Figures 2A, 2B, 2C are longitudinal cross-sectional views illustrating the different stages of operation of a salt separator according to a first embodiment of the invention.

[0080] [Fig.3] [Fig.3] illustrates in longitudinal section view a first variant of a salt separator according to the first embodiment of the invention.

[0081] [Fig.4] Fig.4 illustrates in longitudinal section view a second variant of a salt separator according to the first embodiment of the invention.

[0082] [Fig. 5] [Fig. 5] illustrates in longitudinal section view a salt separator according to a second embodiment according to the invention.

[0083] [Fig.6] [Fig.6] is a synoptic view of a gasification plant wet biomass incorporating a salt separator according to the second mode of the invention. Detailed description

[0084] For the sake of clarity, the same elements are designated by the same numerical references according to the state of the art and according to the invention.

[0085] It is specified that throughout the application, the terms "inlet", "outlet", "upstream", "downstream" are to be understood in relation to the direction of circulation of the fluid considered within a salt separator and a gasification installation according to the invention.

[0086] Similarly, the terms "upper", "lower", "above", "below" are to be understood in reference to a salt separator according to the invention arranged vertically in its operating configuration.

[0087] Figure 1, relating to a salt separator according to the prior art, has already been discussed in the preamble. It will therefore not be discussed further below.

[0088] In [Fig. 2A], a salt separator 1 is shown according to a first embodiment of the invention. In the illustrated example, the salt separator 1 has an axisymmetric shape of revolution. In its installed configuration, it extends vertically.

[0089] This separator 1 includes first of all an injection port 11 through which the wet biomass containing salts is injected, and an outlet port 12 through which it is discharged.

[0090] The separator 1 also includes an enclosure 2 delimiting an inner chamber C.

[0091] The lid 26 of the enclosure is crossed by the injection tube 10 advantageously mounted adjustable in height so as to inject the biomass into a salt precipitation zone.

[0092] The lid is also pierced with at least one first outlet 25 through which the effluents of the biomass devoid of precipitated salts are intended to be evacuated.

[0093] The enclosure 2 can be single-walled metallic 20 or double-walled metallic 20, 21, pierced with a second injection orifice 23 through which water is intended to be injected.

[0094] At least part of the height of the side wall 20 is adapted to be heated. For this heating, heating elements, in the form of cartridges, intended to be powered by an external power supply, can advantageously be integrated into the thickness of the single 20 or double-walled metal 20, 21. These can be cylindrical cartridges of small diameter, typically 3.15 mm, such as those marketed by the company Omega: https: / / www.omega.fr / subsection / cartouches-chauffantes.html.

[0095] A grid 13 is arranged in the inner chamber C of the enclosure 2 preferably above the first outlet orifice 23.

[0096] A deformable porous foam 14 is arranged in chamber C of the enclosure above the grid 13 such that the outlet orifice 12 of the tube opens into it when in its uncompressed state. The porous foam 14 may be a high-temperature resistant metallic foam.

[0097] Finally, a compression means 15 is arranged in chamber C of the enclosure above the grid 13 to compress the porous foam 14.

[0098] The operation of the separator 1 will now be described with reference to figures 2A to 2C.

[0099] Step i / : The enclosure 2 is heated and wet biomass is injected through the tube 10 into the metal foam 14 which is in its uncompressed state, typically at a temperature of 300°C, and at a pressure above the critical pressure beyond 222 bars ([Fig.2A]).

[0100] The salts contained in the biomass then precipitate onto the surface of the metallic foam 14.

[0101] Salt-free biomass effluents are discharged from the enclosure through outlet 25.

[0102] Step ii: Biomass injection is stopped. The compression means 15 is actuated to bring the deformable porous structure from its uncompressed state to at least one compressed state (Fig. 2B). Several compressions / decompressions can be carried out. These mechanical stresses on the metallic foam 14 cause the detachment or in other words the detachment / dislocation of the salts previously precipitated in the metallic foam 14.

[0103] Step iii / : The compression deformation of the metallic foam 14 is stopped to return it to its uncompressed state. Water is then injected as a draining fluid through the injection port 23 to drain the precipitated salts detached from the foam 14 in solid form towards the outlet port 25 ([Fig.2C]).

[0104] Fig. 3 shows a first variant of the compression means 15 in the form of a piston mounted to slide in the inner chamber C and actuated by a motor 16 arranged outside the enclosure.

[0105] The compression piston here consists of a compression plate 150 moved in translation by a screw 151. The screw 151 is mounted for rotation about a central axis X inside the inner chamber C of the enclosure 2, and the compression plate 150 is screwed and fixed around the screw 151. Guide shafts 152 ensure the translational guidance of the plate 150 inside the enclosure 2; that is, they prevent the rotation of the compression plate 150 and thus only ensure its translation when the screw 151 is actuated by rotation by the motor 16. The compression plate 150 is further pierced with a through hole 153 to allow the injection tube 10 to pass through.

[0106] Figure 4 shows another embodiment of the deformable structure by a plurality of concentrically arranged compression springs 17. The compression piston here consists of a rod 154 connected to, or integrally formed with, the compression plate 150, which can be actuated by a reciprocating motion by the motor 16. The injection tube 10 can act as a sliding guide for the compression plate 150.

[0107] Whatever the variant of the compression-deformable structure (metal foam 15, concentric springs 17), it is dimensioned so that it also scrapes the wall of chamber C. Thus, the cleaning of the latter is guaranteed somewhere by removing any inorganic particles that may have been deposited on this surface.

[0108] Fig. 5 illustrates another embodiment of the invention in which, instead of a porous structure deformable by compression, a bed of balls 18 deformable by mechanical agitation is implanted within the enclosure 2.

[0109] To achieve mechanical agitation, a paddle-type agitator 19, which can be driven by a motor 16, is arranged inside chamber C.

[0110] The aforementioned step ii / is thus carried out by rotating the mechanical agitator 19, which will cause the beads 18 to be agitated and thereby dislodge the salts that have precipitated beforehand on their surface. These dislodged salts will settle in the lower part of the separator 1, i.e. below and / or above the grid 13.

[0111] Thus, step iii / is carried out by injecting water through the injection port 23 and the dislocated salts are evacuated by gravity drainage in the form of brine through an outlet port 27 made in the lower part, i.e. either in the side wall 20 or in the bottom 24 of the enclosure.

[0112] [Fig.6] illustrates a wet biomass gasification installation 3 which incorporates a salt separator 1 according to the embodiment of [Fig.5].

[0113] On this [Fig.4], the different symbols relating to temperatures are as follows:

[0114] T: heating temperature of the biomass to be converted before its entry into the separator 1, typically around 300°C.

[0115] Tg: biomass gasification temperature, typically around 600°C.

[0116] This installation 3 comprises, from upstream to downstream in the direction of the flow of biomass to be gasified:

[0117] - a heat exchanger 4, which may be standard in viscous fluid handling non-sticky and optimized for heat recovery between ambient temperature and a maximum temperature T,

[0118] - a salt separator 1, connected downstream to the heat exchanger 4, which allows to evacuate biomass effluents without salts while separating the salts in the form of brine,

[0119] - a high-pressure separator 5, connected downstream to the separator 1, for separating the salts precipitated in solid form from the discharged brine water;

[0120] - a gasification reactor 6, connected downstream to the salt separator 1 for gasifying the salt-free biomass at temperature Tg.

[0121] The gasification reactor 6 is typically a shell-and-tube reactor and operates at 600°C under a pressure of 300 bar.

[0122] On this [Fig.6], the solid lines symbolize the material flows before gasification, respectively at a cold (ambient) temperature at the inlet of the exchanger 4, at a temperature close to T at the outlet of the exchanger 4, and then at the required gasification temperature Tg from the outlet of the separator 1.

[0123] The dotted lines represent the post-gasification material flows which exit at temperature Tg from reactor 6 and return to heat exchanger 4 to be cooled.

[0124] As specified in this [Fig.6], once cooled, the effluents converted by gasification (syngas) are evacuated from the installation 3 to a storage or direct exploitation process.

[0125] Other variants and improvements may be envisaged without departing from the scope of the invention. List of cited references

[0126] [1]: “A novel sait separator for the supercritical water gasification of biomass”, J Reimer, G. Peng, S. Viereck, E. De Boni, J. Breinl, F. Vogel, J. of Supercritical Fluids 117 (2016)113-121.

[0127] [2]: "Continuons sait précipitation and séparation from supercritical water. Part 1: Type 1 salts”, Martin Schubert, Johann W. Regler, Frédéric Vogel, J. of Supercritical Fluids 52 (2010) 99-112.

[0128] [3]: “Continuons sait précipitation and séparation from supercritical water. Part 2. Type 2 salts and mixtures oftwo salts”, Martin Schubert, Johann W. Regler, Frédéric Voge, J. of Supercritical Fluids 52 (2010) 113-124.

Claims

Claims

1. A salt separator (1) for separating salts from a carbonaceous material containing them, the salt separator comprising: - a tube (10) comprising an injection orifice (11) through which a solution containing one or more salts is intended to be injected, and an outlet orifice (12) through which the solution is intended to be evacuated; - an enclosure (2) delimiting an interior chamber (C) and comprising: • a cover (26) to which the tube is fixed or made entirely, • at least one side wall (20, 21) pierced with a second injection orifice (23), through which a draining fluid is intended to be injected, at least part of the height of the side wall being adapted to be heated to a temperature greater than or equal to the precipitation temperature of the salts, the side wall and / or the cover being pierced with at least one first outlet orifice (25) through which the effluents of the carbonaceous material devoid of the precipitated salts are intended to be evacuated, • a bottom (24), the side wall and / or the cover and / or the bottom being pierced with at least one outlet orifice (25, 27) through which the precipitated salts are intended to be evacuated in the form of brine or in the solid form by being drained by the draining fluid; - a grid (13) arranged in the inner chamber of the enclosure; - a deformable porous structure (14, 17, 18), arranged in the chamber (C) of the enclosure above the grid so that the outlet orifice of the tube opens into it when it is in its undeformed state; - at least one deformation means (15; 150, 151, 152; 150, 154; 19), arranged in the chamber of the enclosure above the grid, the deformation means being actuated to reversibly deforming, at least once, the structure from an undeformed state, in which, when the solution is injected into the tube, the salts contained in the solution precipitate on its surface, to at least one deformed state in which, in the absence of injected solution, the precipitated salts present on the surface of the latter detach.

2. A salt separator according to claim 1, the deformable structure being a compressible structure (14, 17), the deforming means being a compression means (15; 150, 151, 152; 150, 154) for compressing in the interior chamber the compressible structure from an uncompressed state to at least a compressed state.

3. Salt separator according to claim 2, the compressible structure consisting of at least one compressible open-pore foam, coated or not with a catalytic coating, or at least one compression spring, preferably a plurality of compression springs arranged concentrically.

4. A salt separator according to claim 2 or 3, the compressible structure being arranged to scrape the wall of the inner chamber as it passes from its uncompressed state to its compressed state.

5. Salt separator according to one of claims 2 to 4, the compression means being constituted by a piston (150, 151, 152; 150, 154) slidably mounted in the interior chamber and actuated by a motor arranged outside the enclosure.

6. Salt separator according to one of claims 2 to 5, the outlet orifice for the precipitated salts in solid form being drained by the draining fluid being the first outlet orifice (25) through which the effluents of the carbonaceous material devoid of the precipitated salts are intended to be evacuated.

7. A salt separator according to claim 1, the deformable structure being a bed of beads (18), the deforming means being an agitation means (19) for agitating in the interior chamber the bed of beads from a static state to at least an agitated state.

8. Salt separator according to claim 7, the stirring means being a mechanical stirrer, in particular with blades, mounted in rotation in the inner chamber and actuated by a motor arranged outside the enclosure.

9. A salt separator according to claim 7 or 8, the outlet for the precipitated salts in the form of brine being a second outlet (27) arranged below the second injection port (23) so that the brine can be discharged by gravity drainage.

10. Salt separator according to one of the preceding claims, comprising external heating means arranged around the side wall of the enclosure to heat the solution to the temperature greater than or equal to the critical temperature of water and precipitation of salts.

11. Salt separator according to one of the preceding claims, comprising heating resistors, in the form of cartridges, intended to be powered by an external electrical power source and integrated into the thickness of the side wall of the enclosure to heat the solution to the temperature greater than or equal to the critical temperature of the water and precipitation of the salts.

12. Salt separator according to one of the preceding claims, comprising a heat transfer fluid circuit produced in the thickness of the side wall of the enclosure to heat the solution to a temperature greater than or equal to the critical temperature of water and precipitation of salts.

13. Salt separator according to one of the preceding claims, the operating pressure of the enclosure being between 222 bars and 1000 bars.

14. Salt separator according to one of the preceding claims, the temperature of the inner chamber being between 300°C and 1000°C.

15. Method of operating a salt separator according to one of the preceding claims, comprising the following successive steps: i / injecting a solution through the first injection orifice and heating the enclosure so that the solution is at a temperature greater than or equal to the critical temperature of water and precipitation of the salts, the deformable porous structure being in the undeformed state; ii / stopping the injection of solution then actuating the deformation means to cause the deformable porous structure to pass from its undeformed state to at least one deformed state; iii / stopping the actuation of the deformation means to return the deformable porous structure to its undeformed state then injecting a draining fluid to drain the precipitated salts detached from the structure towards the outlet orifice in the form of brine or in the form solid.

16. Operating method according to claim 15, steps i / to iii / being repeated continuously or with a waiting period between step iii / and the successive step i / .

17. Biomass gasification installation (3) comprising: - a salt separator (1) according to one of claims 1 to 14; - a gasification reactor (6) connected to the enclosure of the salt separator (1) to be supplied with biomass devoid of salts.

18. Installation according to claim 17, the operating temperature of the reactor being approximately 600°C and the operating pressure of the reactor being approximately 300 bars.

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