WO2020126310A1 - Radial tubular reactor - Google Patents

Abstract

The present invention relates to a tubular reactor (1) provided at one of its ends with an at least partially solid charge inlet (2) and at its opposite end with a charge outlet (3), characterized in that said reactor houses a fluid distributor (5), the external wall of which delimits a tubular or annular space (51) which is coaxial with respect to the longitudinal axis (X) of the reactor (1), - said tubular or annular space comprises a fluid inlet (6) at one of its ends, - said tubular or annular space comprises a plurality of lateral fluid outlets (7), said outlets having orifices passing through the outer wall of the distributor to emerge inside the reactor, - said fluid distributor (5) is surrounded in the reactor (1) over at least part of the length of said distributor by a filter (8) which confines the load in the space between the distributor and said filter.

Description

RADIAL TUBULAR REACTOR

Technical area

The invention relates to radial tubular reactors. Typically, these reactors can be provided with screws, these screws, by rotation of the worm type around the longitudinal axis of the reactors, bring an at least partially solid charge from the upstream end to the downstream end of the reactor, in order modify / process the charge in question. The modifications targeted can generally be of a physico-chemical order, for example to modify the quality of the filler by modifying its structure, certain of its properties, or to carry out a chemical conversion of the latter.

The targeted modifications can also be of the thermal type, by an exchange of calories with a liquid or gaseous fluid of a temperature higher or lower than the load: the objective is then to heat or cool the product.

The invention is particularly interested in, but not limited to, loads of the biomass type, in particular biomass of the lignocellulosic type.

It is thus known to treat biomass with a view to producing sugars, biofuels such as bioethanol, or bio-based molecules, this treatment comprising a step of impregnation in an acid medium then of enzymatic hydrolysis, as described in the WO 2018/015227.

It is also known to use a feedstock, a fraction of which contains biomass and another fraction contains a different feedstock, in order to produce synthetic hydrocarbons by the Fischer-Tropsch reaction, a process comprising at least one pretreatment step and one gasification step, as for example described in patent WO 2014/068253. The load must be roasted during pretreatment.

Prior art

There are also known methods of treatment by acid hydrolysis of lignocellulosic biomass, including that described in the aforementioned patent, the use of continuous steam explosion reactors. These tubular reactors have an endless conveyor screw and can process the biomass under pressure, thanks to a supply by a conveyor conveyor screw described above for example. In the treatment of biomass, the temperatures range from about 160 to 220 ° C, the residence times range from about 2 to 60 minutes. Acid impregnation facilitates hydrolysis, and is generally done beforehand. In general, only steam is injected to heat the reactor. The reactor auger turns in a cylindrical metallic enclosure, also called ferrule, in order to convey the biomass from the feeding zone to the explosive detent zone where the biomass undergoes a physical modification. This tool therefore allows a fairly effective physicochemical treatment of the biomass, with good control of the residence time. However, hemicellulose and cellulose do not convert at the same rate, and it remains difficult to maintain good reactivity of the cellulose to enzymatic hydrolysis without degrading the hemicellulose too much during the pretreatment. Furthermore, the impregnation is a step which generally takes place separately, and upstream, from the acid hydrolysis reactor. Acid cooking therefore takes place with a single acid liquor (used in impregnation), which limits the flexibility of the cooking operating conditions.

Reactors are also known, commonly called digesters, used for example in the paper industry. In these descending vertical reactors, the charge and the liquor, generally basic, are injected in the upper part and descend in a gravity manner. The reaction is carried out globally co-currently, with a number of intermediate liquid / solid separation zones.

The article “Production of biokerosene and biodiesel by the thermochemical route” published on May 10, 2016 by Engineering Techniques (ref IN303V1, authors L. Bournay, JP Heraud, AC Pierron) describes the main principles of roasting , as well as the most commonly used reactor technologies. In particular, it describes a multi-stage oven, which consists of several trays superimposed in an enclosure of vertical cylindrical shape. The biomass is introduced into the upper part of the furnace, then flows from tray to tray by gravity. The biomass is set in motion by scrapers attached to a shaft rotating around the central axis of the enclosure. The scrapers are positioned and oriented so that the biomass particles are pushed towards the outer or inner circumference alternately from one tray to the other. The biomass particles then flow to the lower tray through openings positioned at the circumference of the tray. The oven temperature is regulated by a generation of remote hot gases and circulation ensured by fans. The hot gas passes through each section delimited by two soles, the contact with the product is therefore not dense (the gas does not pass through a charge bed).

The object of the invention is then to improve these different types of reactors, in particular in order to improve their performance and / or flexibility. Summary of the invention

The invention firstly relates to a tubular reactor provided at one of its ends with a charge inlet, in particular at least partially solid, and at its opposite end with a charge outlet, such that said reactor houses a fluid distributor whose external wall delimits a tubular or annular space which is coaxial with the longitudinal axis of the reactor,

- said tubular or annular space comprising a fluid inlet at one of its ends, and a fluid outlet (9) in particular at its other end,

- said tubular or annular space comprising a plurality of lateral fluid outlets, said outlets comprising orifices passing through the external wall of the distributor to open out inside the reactor,

- said fluid distributor being surrounded, in the reactor, over at least part of the length of said distributor, by a filter confining the charge in the space between the distributor and said filter.

Within the meaning of the invention, the term “filter” is to be understood generically as any means capable of containing the charge by filtering, in particular, at least partially the fluid medium (liquid or gaseous) in which it may be in suspension. .

For the purposes of the invention, a “partially solid” filler is understood to mean a solid filler which can also comprise a variable proportion of liquid, for example water.

Such a reactor radically modifies the implementation of the chemical reactions or of the heat exchanges taking place by contact on the one hand between the fluid injected by the axial distributor according to the invention, and on the other hand the load supplying the reactor, in particular the lignocellulosic biomass-type charge more particularly of interest to the present invention.

Indeed, the reactor according to the invention makes it possible to decouple the residence times of the fluid, injected via the distributor, from the residence times of the solid, that is to say of the charge. This makes it possible to improve the selectivity and / or the yield of a chemical reaction, in particular by limiting the degradation of the products of interest into soluble compounds in the fluid, when it is a fluid in liquid form, which are discharged with the fluid in question. This also makes it possible to maximize the efficiency of the heat exchanges, by removing the constraints associated, for example, with the pressure losses of a flow of fluid passing through a bed of solid, since the thickness of charge traversed by the fluid is here. small (it is limited to the radius of the annular space between the distributor and the filter).

The fluid thus has, according to the invention, a controlled residence time in the reactor, which can be different from the residence time of the feed (generally a shorter residence time), which can make it possible to limit the possible formation unwanted secondary products, secondary products which can create risks of fouling of the reactor and / or which reduce the yield of the desired transformation of the feedstock.

By thus opening the fluid from the axial distributor transversely to the general direction of flow of the charge in the reactor, there is a charge / fluid contact in cross flow (also called cross flow): this maximizes the surface area of exchange of material (and possibly heat) between the load and the fluid, which also makes it possible to limit the size of the equipment, and which generally also leads to a limitation of the energy consumption necessary compared to conventional reactors operating the same treatment.

If we take the application of this reactor to the pretreatment of lignocellulosic biomass by roasting, we see all the interest: the cross current makes it possible to increase the coefficient of exchange and therefore to reduce the size of the equipment.

If we take the application of this reactor to the pretreatment of lignocellulosic biomass by a given liquor, acid for example, we see all the interest: the liquor / feed cross-flow facilitates the reaction, and, by injecting the liquor to different levels of the reactor via this distributor, we will be able to maintain the performance of the action of the acid on the cellulose, while reducing the degradation of the hemicellulose.

More generally, we will also be able to reduce the residence times of the charge in the reactor, compact the installations and / or improve the charge treatment flow rates.

Preferably, the orifices of the dispenser fluid outlets are distributed regularly over its external wall, in particular on the circumference of the axial dispenser over at least a portion of the length of said dispenser. This ensures a radially homogeneous distribution of the fluid from the distributor in the direction of the zone between the distributor and the internal walls of the reactor where the charge moves. Preferably, the filter comprises a sintered component or a plate pierced with orifices or a grid, for example a Johnson grid, surrounding the distributor, preferably over the entire length of said distributor. This filter thus retains the charge, or at least its solid fraction, in the zone between distributor and filter, and makes it possible to drain the excess fluid and / or the liquid contained in the initial charge in the zone between the filter and the internal walls of the reactor. This draining can be useful with a view to their possible recycling, in the reactor, or upstream or downstream thereof, in the process for treating the charge incorporating such a reactor.

The filter and the distributor are preferably coaxial (and coaxial with the longitudinal axis of the reactor, which thus has a symmetry of revolution about this axis).

Preferably, the charge inlet is provided with an injection means and / or the charge outlet is provided with an extraction means, the injection and / or extraction means being chosen from among screws endless or vibrating injectors / extractors.

According to a variant of the invention, the dispenser can delimit an internal tubular space and at least one annular space coaxial and external to said internal tubular space, each space, tubular and annular, conveying its own fluid.

The fluids can be of different compositions and / or temperatures, and these spaces internal to the distributor can then be designed so that each fluid is brought into contact with the charge in different portions of the reactor, all along the axial distributor: the charge may undergo a first modification by contacting a first type of fluid on a first section of the distributor / reactor, then the modified charge may undergo another modification by contacting a second type of fluid on a following section.

They may be different reactions, or of the same nature, with the same type of fluid under different operating conditions (for example using the same fluid but at different temperatures, at different concentrations of active agent, or using two fluids with different active agents but with similar properties, such as two acid solutions with acids of different strength).

It is thus possible to “cut” the reactor into different successive reaction zones along the reactor, according to the general direction of flow of the charge in the reactor, for example two or three successive reaction zones, depending on the size of the equipment and the needs. One can for example "cut" the reactor into a reaction zone preceded and / or followed by a zone intended to heat or cool the feed. An embodiment of the reactor according to the invention can thus comprise, from upstream to downstream, a zone of heating by a first heat-transfer fluid, then a zone of reaction with another fluid containing a reagent, then finally a zone of cooling with another fluid, refrigerant this time.

If we take the application of this reactor to the pretreatment of lignocellulosic biomass by roasting, we see all the interest: it is possible to use gases of different nature and or temperatures according to the zones in order to minimize the costs of the drying and roasting stages (by optimizing the operating temperatures) and integrating a final drying zone, thus limiting the number of equipment: the dryer, the roaster and the cooling being integrated.

The fluids distributed by the distributor can therefore have a purely thermal role, by being chemically inert vis-à-vis the load: they can be heat transfer fluids or refrigerants. They can also have a chemical / physical role with respect to the filler by containing at least one reagent capable of modifying it chemically / physically.

It is of course also possible to provide fluids which contain one or more reagents and which, by their temperature different from that of the feed, will also play a thermal role, for example to facilitate the initiation of the reaction, or for monitor its evolution.

Each tubular and annular space can extend over all or part of the length of the dispenser.

According to one embodiment, one can have an internal tubular space which extends over the entire length of the distributor and which is provided with lateral fluid outlets than on a downstream portion of the distributor, and one can have the or at least one of the outer annular space (s) which extends only over an upstream portion of the distributor, distinct from said downstream portion.

If the tubular / annular space defined by the distributor is unique, it is preferable to choose a space which extends over the entire length of the distributor, which itself extends over the majority of the operating area of the reactor, to distribute the fluid over the entire length of the reactor.

If the distributor delimits several spaces each conveying their fluid, at least one of these spaces will preferably extend over a given portion of the distributor, and the fluid outlets of each of the spaces are distributed over the length of the distributor of such so that the charge is sequentially brought into contact, as it advances in the reactor, with a different fluid.

The subject of the invention is also the method of implementing the reactor described above, in which one or more fluids are circulated in the space or spaces delimited by the distributor, with cross-current contact of the fluid or fluids with the load at the outlet of said spaces.

The process for implementing the reactor according to the invention preferably treats a feed comprising biomass, in particular of the lignocellulosic type.

Preferably, in one embodiment, the annular space between the distributor and the filter is the place of passage of a load comprising biomass, in particular of the lignocellulosic type. The characteristic size of this charge is generally less than 30 cm, preferably less than 15 cm and in particular less than 5 cm. To give an example, the load may consist of straw pellets 8 mm in diameter and 5 cm long, or forest chips of 3 to 5 cm per side. This charge may have been previously dried, ground, shaped (pelletizing, briquetting), impregnated, for example.

According to a first variant, a fluid is circulated in the dispenser in at least partially gaseous form, in particular poor in oxygen, preferably between 200 and 350 ° C, to ensure roasting of the charge.

According to a second variant of the process, a fluid is circulated in the dispenser in at least partially liquid form, in particular an acidic or basic aqueous solution, preferably between preferably between 80 and 250 ° C or even between 140 and 250 ° C, to ensure hydrolysis of the charge.

The charge can generally comprise between 1 and 95%, especially between 20 and 80% by weight of water.

In the first variant of the process, the gross load is preferably lignocellulosic biomass of all types: various straws, coniferous and deciduous woods, herbaceous plants (miscanthus, canes, etc.), etc. The dry matter content of this gross load at the start of the process is approximately 30% to 60% DM for wood chips and greater than 80% DM for straws. The bulk density is 50 to 100 kgMS / m ³ for loose straws and 125 to 200 kgMS / m ³ for wood chips. Before the reactor, the biomass often undergoes impregnation in a liquor, which modifies the dry matter content at the input of reactor. This gives a dry matter content of 15 - 30% DM at the end of the impregnation. The dry matter content can go up to 35 - 45% in the event of mechanical recompression of the load, using a "plug screw" type screw for example.

In the second variant of the process, the dry matter content at the reactor inlet is generally much lower, with rates greater than 30% DM, preferably 50% or even 70%, or even 90%. Furthermore, this variant also makes it possible to work with shaped biomasses which have a much greater density of approximately 1000 kgMS / m ³ .

Throughout this text, the acronym "MS" designates the dry matter content which is measured according to standard ASTM E1756 - 08 (2015) "Standard Test Method for Determination of Total Solids in Biomass". (The humidity of a material is calculated as follows: it is the ratio between dry matter and the sum of dry matter and water.)

Advantageously, the fluid collected by the filter in the space between the filter and the walls of the reactor can be recycled, at least partially, into the fluid inlet of a space delimited by the distributor. Recycling can include an intermediate stage of cleaning, regeneration, temperature adjustment, adjustment in concentration of active agent, etc., when necessary. (For example when the collected liquid fluid is added to the water contained in the biomass injected into the reactor, or when it has changed due to the reaction with the charge.)

Advantageously, the reactor is arranged in a substantially vertical orientation, with the charge inlet at the top, this is the preferred configuration when the charge is solid and the fluid is gaseous. This orientation promotes a good distribution of the load between the axial distributor and the filter in the reactor, it uses gravity to facilitate the transport of the load in the reactor, which has two advantages: on the one hand, the density in the reactor can be larger, so the equipment can be of limited size, on the other hand the fluid injected from the screw can be distributed more evenly across the charge. When the charge is solid and the fluid rather liquid, the preferred configuration is rather a reactor oriented substantially vertically and a charge inlet at the bottom this time, the charge tending to rise in the reactor by suspension in the liquid.

Optionally, if necessary, the load can be saturated with water (aqueous solvent) prior to its treatment with the fluid or fluids conveyed in the tubular or annular space or spaces of the distributor, in particular so that the load reaches a dry matter content of not more than 20%. List of Figures

FIG. 1 represents a view in longitudinal section of a reactor according to the invention according to a first example of a first embodiment.

FIG. 2 represents a view in longitudinal section of a reactor according to the invention according to a second example of a first embodiment.

FIG. 3 represents a view in longitudinal section of a reactor according to the invention according to a third example of a first embodiment

FIG. 4 represents a view in longitudinal section of a first example of a dispenser according to the invention according to the second embodiment of the invention.

FIG. 5 represents a view in longitudinal section of a second example of a reactor with another type of distributor according to the invention according to the second embodiment of the invention.

Description of the embodiments

The set of figures is very schematic, the different components are not necessarily to scale, and keep the same reference from one figure to another. The terms “upstream” and “downstream” used in the present text refer to the general direction of flow of the charge in the reactor, along its longitudinal axis X, from top to bottom or from bottom to top according to the examples which will be described.

The first embodiment, which relates to Figures 1 to 3, corresponds to a reactor with a type of distributor according to the invention which is capable of distributing a single type of fluid, with a preferred vertical orientation.

The second embodiment, which relates to Figures 4 and 5, corresponds to a reactor with other types of distributors according to the invention, which are capable of distributing several different fluids. The orientation of the reactor can also be vertical, or it can also be horizontal.

FIG. 1 represents a reactor 1 of the invention according to a first example of the first embodiment.

The reactor 1 is tubular, cylindrical and has a substantially vertical longitudinal axis X. It is provided at its upstream end, in the upper part, with a load inlet 2, the load supply being made by an injection screw 21. It is provided at its downstream end, in the lower part, with a load outlet 3, the load outlet being effected by an extraction screw 31 which makes it possible to control the output speed of the load treated. The extraction screw 31 and / or the injection screw 21 can be supplemented or replaced by any other extraction / injection means, such as a vibrating extractor for example for the extraction screw 31.

The extraction speed is such that the charge (at least partially solid) advances at a speed preferably between 0.1 and 20 m / h, a speed which is compatible with the required residence time of the charge in the reactor to carry out the desired chemical reactions. Using a mechanical extractor makes it possible to control the residence time of the charge in the reactor, and therefore to have good homogeneity in the treatment of the solid charge.

The reactor 1 houses an axial distributor 5, coaxial with the longitudinal axis X of the reactor, of the tube type. It also houses a grid 8, which makes it possible to contain the solid part of the load in the annular space which is located between the grid 8 and distributor 5, the grid and the distributor being coaxial). This grid 8 therefore fulfills the filter function, and the dimensioning of its mesh is chosen as a function of the size of the components of the load.

The distributor 5 is a tube which defines a central tubular / cylindrical space 51 over the entire length of the distributor. This tubular space 51 is supplied with fluid F by an inlet 6, itself connected to a source of the fluid, not shown. The inlet 6 is located in the upstream part of the reactor, here in the upper part therefore, near the screw 21 for injecting the charge. The dispenser is provided with outlets of the fluid F through perforations / orifices 7 opening out of the tubular space into the space between the dispenser 5 and the grid 8, and allowing the fluid to leave the out of the dispenser and come into contact with load. These perforations 7 are dimensioned so as to have a good distribution of the fluid through the charge bed. Figure 1 shows only a few, to simplify the figure, but there are some over the entire height of the dispenser, distributed around its circumference (which is also the case for the following figures). The pressure drop across these orifices 7 is preferably at least 1 bar, in order to limit the influence of the heterogeneity of the load, at least partially solid, in the annular space between the distributor 5 and the grid 8. Preferably, orifices are provided regularly distributed both over the circumference of the external wall of the dispenser and over its entire length. The fluid F is then extracted from the reactor by an outlet 9 at the downstream part, low here, of the reactor.

Here, the internal space 51 in which the fluid is intended to circulate is tubular and the center of the distributor core is therefore empty. Alternatively, provision can be made for this internal space to be annular, with a center of the distributor which would therefore be full, or at least which would not be intended to circulate the fluid. In operation, the at least partially solid load is therefore transported axially from the inlet 2 to the outlet 3, and, throughout its path, is brought into contact with the fluid leaving the orifices 7, by a contact called " particularly effective to maximize the reaction / conversion / modification of the charge by the fluid.

FIG. 2 is another example of the same first embodiment: all other things being equal, only the differences from the example of FIG. 1 will be described here. The fluid F is injected not at the top, but in the lower part of the reactor, via the inlet 6 'which is in the vicinity of the outlet 3 of the charge, and the fluid leaves the reactor via an outlet 9' in the upper part of the reactor 1 ': the charge flows from top to bottom in the reactor, while the fluid F will “rise” from bottom to top in the distributor 5. The charge / fluid contact leaving the orifices 7 on the height of the distributor remains a cross-current contact.

FIG. 3 is another example of the same first embodiment: all other things being equal, only the differences from the example of FIG. 2 will be described here. Here, the charge is injected not at the top, but in the lower part of the 1 ”reactor, through the inlet 2 'via the injection screw 21', which is in the vicinity of the inlet 6 'of fluid F of the charge: the charge flows from bottom to top in the reactor, like the fluid F which also "rises" from bottom to top in the distributor 5. The charge / fluid contact leaving the orifices 7 on the height of the distributor remains a cross-current contact.

FIG. 4 presents a first example of the second embodiment: here the distributor 5 ′ is provided with several internal coaxial spaces making it possible to inject fluids F1, F2, F3, F4 of different natures and / or temperatures in defined zones of the annular space between the distributor 5 'and the grid 8. For example, the fluid F1 can be at 20 ° C, the fluid F2 can be at 280 ° C, the fluid F3 can be at 300 ° C and the fluid F4 at 140 ° C. As in the first variant, there is an internal tubular space 51 of diameter d1 which is supplied with a fluid F1, and an annular space 52 around this tubular space 51, which is supplied with a fluid F2, an annular space 52 around of space 51 supplied with a fluid F3 and an annular space 53 around the space 52 supplied with fluid F4. The different spaces 51, 52, 53, 54 are supplied by their respective fluids at the inlet of the reactor, in its downstream part. By their configuration and their holes by orifices 7 (some only shown), each of these spaces 51 to 53 will successively supply with their respective fluids each of the four zones Z4 to Z1 of the reactor aligned along the longitudinal axis X of the reactor (which is also that of the 5 'distributor):

- The tubular space 51 extends to the entrance of zone Z4, which it supplies with fluid F1 by orifices 7 located only in this zone, passing from a given diameter to a much larger diameter d2, which is the diameter of the cylindrical external wall of the distributor

the annular space 52 extends up to the entrance of the zone Z3 where it widens, zone which it supplies with fluid F2 through orifices 7 located only in this zone,

- the annular space 53 extends to the entrance of the zone Z2 where it widens, zone which it supplies with fluid F3 through orifices located only in this zone, and finally

- the annular space 54 stops at the exit from zone Z1, which it supplies via orifices located in this zone.

It can be seen that all of the orifices 7 through which the fluid concerned leaves the distributor are arranged on the external cylindrical wall of the distributor 5 ’. In order for the fluids to be correctly distributed, a sufficient pressure drop is provided to compensate, at least with regard to the fluids F1, F2 and F3, the increase in external diameter of the tubular / annular spaces when they open in their zones of distribution.

Each of the zones Z1 to Z4 is also provided, at its downstream end, with an outlet for the fluid which feeds it (symbolized by an arrow F1 to F4). These fluids can be recovered and possibly treated according to their quality to be recycled.

The charge which advances along the X axis is therefore successively in contact with the fluid F4, then F3, then F2, then F1.

Figure 5 presents a second example of the second embodiment: as in the example in Figure 4, it involves treating a load with several different fluids, here also 4 in number, but the design of the distributor 5 ” is different: the reactor is always divided into four zones Z1 to Z4 along its longitudinal axis X, but the 5 ”distributor, to supply them with fluids F1 to F4, is divided into four tubular zones 51 ', 52,' 53 'and 54', each of the same diameter and provided in its upstream end with an inlet for the fluid concerned and in its downstream end with an outlet for the fluid concerned. As in the case of FIG. 4, all of the orifices 7 through which the fluids exit from the distributor 5 ”are on the cylindrical external envelope of the distributor. Means are provided for securing these 4 portions of cylinders to each other, in particular mechanical means. This distributor design is simpler than that shown in FIG. 4. It also has the advantage of limiting any possible heat exchange between the different fluids before they are injected into their dedicated zone in the reactor. For the distributors according to the invention intended to distribute more than one fluid, such as those of FIGS. 4 and 5 previously described, it should be noted that the relative size of the different zones Z1 to Z4 can be adjusted: in conjunction with the flow rate / the concentration of any active agent in the fluids, it is thus possible to adjust the necessary contact times as well as possible, depending on the quantity of filler to be treated.

The number of zones can also be adjusted as a function of the number of reaction steps / modifications of the desired charge, for example between 2 and 5. It is also possible to use the same reactor, with four zones for example, and adapt it in terms of size. '' supply with the same fluid in at least two of its zones, when only 1, 2 or 3 reactions are desired, and not 4.

Note also that the outer casing of the dispenser of the invention is not necessarily cylindrical (its section can be oval for example), nor necessarily absolutely straight, even if this configuration is the simplest.

Examples

Below are examples of implementation of the reactors according to the second embodiment described above with the aid of FIGS. 4 or 5.

The process is a drying and roasting process which has two inputs: a raw solid charge, in the form of straw pellets whose length varying between 5 mm and 20 mm, and of diameter 6 mm, and a hot gas inlet. This gas is composed of smoke from an external combustion chamber, not described here, which burns natural gas in mixture with the roasting gases from the tubular reactor of the invention. The load input dry matter content is 35% by mass. The charge is initially at room temperature.

The charge rate is 10t / h.

Example 1 according to the invention:

Here the reactor 1 makes it possible to roast a charge injected at the top via the injection screw 21. The charge follows a descending trajectory according to a piston flow. The residence time of the product is very well controlled, which brings an advantage of homogeneity of heat treatment. According to this example, the operating conditions of which are reported in Table 1 below, the product leaves cooled (42 ° C. on average), it is not necessary to add a specific device downstream (unlike the example 2 comparative described below).

The reactor according to the invention has 4 gas injection zones Z1 to Z4. The first zone Z1 is a drying zone, the second zone Z2 is a heating zone, the third zone Z3 is a roasting zone, the last zone Z4 is a cooling zone. Equipment characteristic:

Exemple comparatif 2 selon l’art antérieur :

Comparative example 2 according to the prior art:

Here the equipment is a multiple hearth oven. The fresh charge is injected at the top of the equipment on the first floor. Rotating arms provided with plowshares make it possible to advance the product in a spiral on this sole until reaching an orifice making it possible to reach the second sole, and so on. The equipment has two zones: a drying zone and a roasting zone. The product leaves hot equipment. A cooling device (for example water cooler fitted with conveyor screws) must be provided downstream. The distribution of the residence time of the product in the equipment is fairly dispersed, the homogeneity of the heat treatment is therefore lower than in the case of Example 1. The operating conditions and the tools used are described in table 2 below.

Au-delà de l’homogénéité plus faible du traitement thermique, cet exemple conduit à une densité de traitement 5 fois plus faible que dans le cas de l’exemple 1 (ratio capacité/volume), donc des installations 5 fois plus volumineuses pour une même quantité de charge à traiter. L’exemple de l’invention propose une solution compacte, où l’ensemble des réactions/échanges thermiques nécessaire peut être réalisé au sein d’un seul réacteur.

Beyond the lower homogeneity of the heat treatment, this example leads to a treatment density 5 times lower than in the case of Example 1 (capacity / volume ratio), therefore installations 5 times larger for a same amount of filler to be treated. The example of the invention proposes a compact solution, where all the necessary reactions / heat exchanges can be carried out within a single reactor.

Claims

Claims 1. Tubular reactor (1) provided at one of its ends with a charge inlet (2), in particular at least partially solid, and at its opposite end with a charge outlet (3), characterized in that said reactor houses a fluid distributor (5) whose outer wall defines a tubular or annular space (51) which is coaxial with the longitudinal axis (X) of the reactor (1), - said tubular or annular space comprises a fluid inlet (6) at one of its ends, and a fluid outlet (9) in particular at its other end, - said tubular or annular space comprises a plurality of lateral outlets (7) for fluid, said outlets comprising orifices passing through the external wall of the distributor to open out inside the reactor, - said fluid distributor (5, 5 ', 5 ”) is surrounded, in the reactor (1), over at least part of the length of said distributor, by a filter (8) confining the charge in the space between the dispenser and said filter. 2. Reactor (1) according to the preceding claim, characterized in that the orifices (7) of the fluid outlets of the distributor (5) are distributed regularly over its external wall. 3. Reactor (1) according to one of the preceding claims, characterized in that the filter comprises a sintered component or a plate pierced with orifices or a grid (8) surrounding the distributor (5), preferably over the entire length said distributor. 4. Reactor (1) according to one of the preceding claims, characterized in that the charge inlet (2) is provided with an injection means (21) and / or in that the charge outlet (3 ) is provided with an extraction means, the injection and / or extraction means being chosen from worms or vibrating injectors / extractors. 5. Reactor (1 ') according to one of the preceding claims, characterized in that the distributor (5') delimits an internal tubular space (51) and at least one coaxial annular space (52) and external to said internal tubular space ( 51), each space, tubular and annular, conveying its own fluid. 6. Reactor (1 ') according to the preceding claim, characterized in that each tubular and annular space (51, 52) extends over all or part of the length of the distributor (5'). 7. Reactor (1 ') according to the preceding claim, characterized in that the internal tubular space (51) extends over the entire length of the distributor (5', 5 ”) and is provided with lateral outlets (7) of fluid only on a downstream portion of the distributor (5 ′, 5 ”), and in that the or at least one of the outer annular space (s) (52,53,54) extends only on an upstream portion of the distributor separate from said downstream portion. 8. Reactor according to one of the preceding claims 1 to 4, characterized in that the distributor delimits a succession of compartmentalized tubular spaces (51 ', 52', 53 ', 54') along the longitudinal axis (X) of the reactor. 9. Method for implementing the reactor (1, 1 ') according to one of the preceding claims, characterized in that one or more fluids is circulated in the space or spaces (51, 52,53,54) defined by the distributor (5), with cross-current contact of the fluid or fluids with the load leaving said spaces. 10. Process for implementing the reactor (1, 1 ’) according to the preceding claim, characterized in that it treats a feed comprising biomass, in particular of the lignocellulosic type. 1 1. Method according to one of claims 9 or 10, characterized in that circulates in the space or one of the spaces defined by the distributor (5) a fluid in at least partially liquid form, in particular an aqueous solution acidic or basic, preferably between 80 and 250 ° C, to ensure hydrolysis of the charge. 12. Method according to one of claims 9 or 10, characterized in that circulates in the space or one of the spaces delimited by the distributor (5) a fluid in at least partially gaseous form, in particular poor in oxygen, preferably between 200 and 350 ° C, to ensure roasting of the load. 13. Method according to one of claims 9 to 12, characterized in that the fluid collected by the filter (8) in the space between the filter and the walls of the reactor (1, 1 ') is recycled, at least partially , at the fluid inlet of a space delimited by the distributor (5). 14. Method according to one of claims 9 to 13, characterized in that the reactor (1, 1 ') is arranged in a substantially vertical orientation, with the feed inlet (2) in the upper part or in the lower part. 15. Method according to one of claims 9 to 14, characterized in that one operates a saturation of the load with water prior to its treatment by the fluid or fluids conveyed in the tubular and / or annular space or spaces (51, 52) of the distributor (5), in particular so that the load reaches a dry matter content MS of at most 20%.