Device for the treatment of a solid feedstock, comprising recycling of the solid feedstock
Patent Information
- Application Number
- EP2024715644
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2023-04-21
- Filing Date
- 2024-04-08
- Publication Date
- 2026-02-25
Smart Images
Figure EP2024059442_24102024_PF_FP_ABST
Abstract
Description
[0001] DEVICE FOR PROCESSING A SOLID LOAD COMPRISING THE
[0002] SOLID CHARGE RECYCLING
[0003] Technical field
[0004] The invention relates to the field of charge treatment devices, such as furnaces, in particular multiple hearth furnaces, for bringing a solid into contact with a gas.
[0005] The devices covered by the invention are in particular drying or roasting ovens in order to reduce or eliminate the humidity of a load (drying operation) or in order to modify the physicochemical properties of the load (roasting operation).
[0006] Generally speaking, multiple hearth furnaces can be used in different types of processes, including but not limited to waste incineration, calcination for cement manufacturing for example, regeneration of activated carbon, or even pretreatment of biomass.
[0007] More specifically, in the field of biomass transformation processes, for example described in the applicant's patent application FR 2,997,414, the objective is to produce advanced biofuels (biodiesel and biokerosene) by thermochemical conversion of lignocellulosic biomass. The different stages of this process are (i) pretreatment, (ii) gasification, (iii) conditioning of the synthesis gas and (iv) Fisher-Tropsch synthesis.
[0008] The first stage of biomass pretreatment is carried out to prepare the biomass for its future injection into the gasifier. This stage consists of drying and gentle thermal degradation of the wood called torrefaction. This pretreatment requires a significant heat input, first to raise the temperature of the biomass to a level suitable for the drying phase, then to remove the water present in the biomass, and finally to raise and maintain the temperature of the dry biomass at a level suitable for the torrefaction operation. This heat input is generally achieved by contacting the biomass with a hot gas flow. This pretreatment stage is generally carried out using ovens, such as multi-hearth ovens, for the drying stage and / or for the torrefaction stage. The ovens can then serve as dryers and / or torrefiers.
[0009] Prior art
[0010] Figure 1 shows an example of a multiple-hearth furnace for bringing a solid material into contact with a gas according to the prior art, described as such in patent application US 2016 / 356 548 A. According to this embodiment, the furnace (10) consists of a closed cylinder (11), (12) and (13) comprising 8 trays (1) to (8). A central shaft (15) is rotated by a mechanism (17) around the vertical axis (16). The shaft makes it possible to rotate arms (18) comprising teeth (19) and arranged above the trays. When the shaft rotates, the teeth are set in motion and, depending on their orientation, move the solid either towards the inside or towards the outside of the tray.The solid is introduced at the top of the furnace through the insert (20) and circulates downwards, from tray to tray, either through the outer holes (222), (224), (226) and (228) or through the central holes (211), (213), (215) or (217), before leaving the reactor through the outlet orifice (24). The gas, bringing its heat to the solid, is introduced tangentially either at the bottom of the furnace (countercurrent movement of the solid via the orifices 27), or at the top of the furnace (co-current movement) and circulates through the same central or peripheral holes on each tray.
[0011] These ovens are generally satisfactory. However, sometimes the load leaving the oven does not meet the prescribed specifications, for example in terms of drying or roasting performance. Drying performance can notably be a target moisture content for the load while roasting performance can concern the roasting rate, also known as anhydrous weight loss (AWL). Anhydrous weight corresponds to the mass of a load that no longer contains moisture. Anhydrous weight loss corresponds to the degradation of the load during roasting. Patent application FR3015513 describes a drying and roasting process integrating a step of combustion of the roasting gases with recycling of the combustion fumes in the drying oven.This process is illustrated in Figure 2 including a continuous line drying loop represented by streams 104, 105 and 107 and a dotted line torrefaction loop represented by streams 108, 110, 111, 112 and 113. In the process of Figure 2, the wet biomass 101 enters the drying oven (dryer) A in order to reduce its water content to values below 10% by weight. The generated drying gases 105 are extracted and sent to a heat exchanger C in which they are reheated and then reintroduced into the drying unit through stream 107. The dried biomass 102 is then sent to the torrefaction oven (torrefier) B operating in countercurrent with the gas. Thermal degradation of the biomass produces torrefaction gases extracted from the unit by stream 108 and a torrefied solid residue exiting by stream 103.The roasting gases 108 are sent to a combustion chamber D where they are burned in the presence of oxygen with additional fuel 109 producing hot smoke with a temperature greater than 700°C. All of these smokes are reused in the process: • A first part feeds the heat exchanger C through the flow 111 in order to reheat the gases from the drying zone. The smokes thus cooled are reintroduced into the roasting oven by the flow 112.
[0012] • The other part of the fumes 113 is recycled and feeds the inlet gases of the dryer (flow 104), mixing with the reheated gases 107.
[0013] We also know of patent application US 2012 / 0117815 A1 which deals with the torrefaction of biomass and which describes methods for evaluating the torrefaction rate of the load at the outlet of the torrefaction furnace. However, this patent application only measures the torrefaction rate at the outlet and does not propose any solution for improving the torrefaction rate.
[0014] Summary of the invention
[0015] The object of the invention is to propose an improved treatment device, making it possible to obtain a load at the outlet of the device which meets the targeted performance (drying or roasting), thus limiting the rate of non-compliant product at the outlet (the product being the dried or roasted load).
[0016] To do this, the invention relates to a device for treating a load comprising solid particles, the treatment preferably being drying or roasting, the device comprising a furnace comprising an enclosure with a vertical longitudinal axis in the operating position, the enclosure comprising at least one inlet and one outlet for said load and at least one inlet and one outlet for a gas capable of coming into contact with the solid particles.In addition, the device comprises a system for recovering said charge, the charge recovery system comprising at least one recovery line connected to the outlet of the charge on the enclosure, the recovery line being in fluid connection with a sampling and / or analysis means for in situ or ex situ analysis of the charge in order to measure a parameter representative of the treatment (drying or roasting for example) of the charge, the recovery line comprising at least two lines in parallel downstream of the sampling and / or analysis means, in the direction of circulation of the charge, at least one of the lines being a discharge line, the discharge line preferably leading to a storage tank, and at least one other line being a recycling line leading to an orifice allowing the charge to be reintroduced into the furnace, each discharge or recycling line comprising a valve means.Advantageously, the recovery system comprises a control means for controlling the opening and closing of the valve means, the control means preferably being connected to said sampling and / or analysis means.
[0017] Preferably, the charge recovery system comprises several recycling lines each leading to a different orifice in the enclosure, the different orifices of the different lines being located at different altitudes on the enclosure.
[0018] According to a variant of the invention, at least one recycling line, preferably each recycling line, comprises an intermediate tank located between the valve means of the recycling line and the orifice for reintroducing the charge into the furnace.
[0019] According to one configuration of the invention, the representative parameter is the measurement of the moisture content of the load and either the sampling and / or analysis means comprises a sampling means, an oven and a mass measurement system for measuring the mass before and after the load passes through the oven, the difference in mass being representative of the moisture content of the load, or the sampling and / or analysis means comprises an online analyzer, preferably infrared or microwave, for measuring the moisture content of the load in situ.
[0020] According to another configuration of the invention, the representative parameter is the roasting rate of the load and either the sampling and / or analysis means comprises a means for sampling the load and a device for measuring the higher calorific value and / or the lower calorific value, the higher calorific value and / or the lower calorific value being directly linked to the roasting rate of the load, or the sampling and / or analysis means comprises a system for characterizing the color of the load online, the color of the load being directly linked to the roasting rate.
[0021] According to a preferred embodiment of the invention, the furnace is a multiple-hearth furnace, the enclosure comprising:
[0022] - a plurality of trays distributed along the longitudinal axis in the operating position, each tray comprising an upper surface capable of receiving solid particles and at least one passage opening allowing the solid particles and the gas to pass through said tray,
[0023] - at least one stirring arm associated with each tray, each stirring arm comprising stirring teeth extending from the stirring arm towards the upper surface of the tray associated with the stirring arm,
[0024] - means for driving the stirring arms in rotation around the longitudinal axis of the enclosure, the orifice of each recycling line being located above one of said trays for the introduction of the load at the level of said tray, preferably each recycling line allowing the introduction of the load at the level of a different tray.
[0025] The invention also relates to a method for drying or roasting a load comprising solid particles (and possible fluids contained in the solid particles such as water) from a device as described above, in which at least the following steps are carried out:
[0026] - The said charge composed of solid particles and a gas is introduced into the furnace;
[0027] - The dried or roasted load is recovered at the outlet of the oven;
[0028] - A parameter representative of the drying or roasting of the load is measured from the dried or roasted load leaving the oven;
[0029] Depending on said measured representative parameter, said load (dried or roasted) is sent to a discharge line where the load can be stored, for example, in the storage tank, and / or the load (dried or roasted) is sent to at least one recycling line to reintroduce it into the furnace.
[0030] Preferably, depending on said representative parameter, the dried or roasted charge is introduced into a recycling line which leads to an orifice defined according to its altitude in the furnace.
[0031] Advantageously, the measurement of the representative parameter is carried out online by an analyzer.
[0032] Alternatively, the measurement of the representative parameter is carried out by taking a sample of the dried or roasted load by the sampling and / or analysis means, the measurement being carried out offline on the sample.
[0033] According to a configuration of the invention, the representative parameter is a humidity level of the load and the mass of the sample taken is measured, then the sample taken is placed in an oven to eliminate the humidity it contains and the mass of the sample taken and ovened is measured, the humidity level being defined as the ratio between the difference in the masses of the sample taken and the sample taken and ovened to the mass of the sample taken.
[0034] According to another configuration of the invention, the representative parameter is a roasting rate of the load and the higher calorific value and / or the lower calorific value of the sample taken is measured, the higher calorific value and / or the lower calorific value being directly linked to the roasting rate.
[0035] The invention also relates to an installation for the production of liquid hydrocarbons from a feed containing at least one fraction of biomass and optionally at least one fraction of another feed comprising: - at least one feed pretreatment unit, comprising a drying unit, a roasting unit, optionally a granulation unit, and a grinding unit;
[0036] - possibly a combination unit comprising a pipe allowing the effluents from the different pre-treatment units to be combined;
[0037] - a pre-treated effluent gasification unit comprising at least one entrained flow reactor;
[0038] - a synthesis gas conditioning unit comprising:
[0039] - a water washing and gas flow fractionation unit enabling the synthesis gas flow to be divided into at least two effluents;
[0040] - at least one guard bed allowing the elimination of halogenated compounds on one of said two effluents located upstream of a unit for converting carbon monoxide to steam;
[0041] - a catalytic hydrolysis unit;
[0042] - a unit for recombination of effluents from the steam carbon monoxide conversion unit and the catalytic hydrolysis unit respectively;
[0043] - a water washing unit for the effluent from the synthesis gas conditioning unit;
[0044] - a unit for eliminating acid gases contained in the washed effluent;
[0045] - a final purification unit for the washed and deacidified effluent comprising at least one guard bed;
[0046] - a Fischer-Tropsch catalytic synthesis reaction unit.
[0047] In addition, the drying unit and / or the roasting unit comprises a device as described above.
[0048] Preferably, the installation further comprises at least one hydrotreatment and / or isomerization unit for the hydrocarbon cuts from the Fischer-Tropsch catalytic synthesis reaction unit.
[0049] List of figures
[0050] Other characteristics and advantages of the device, method and installation according to the invention will appear on reading the following description of non-limiting examples of embodiments, with reference to the figures appended and described below.
[0051] Figure 1 shows a multiple hearth furnace.
[0052] Figure 2 illustrates a method for drying and roasting biomass according to the prior art. Figure 3 illustrates a drying or roasting device according to the invention.
[0053] Description of the embodiments
[0054] The terms "upper", "lower", "top", "middle", "bottom", are understood relative to the vertical axis with the multi-hearth furnace in the operating position (also called service position).
[0055] The terms "vertical", "horizontal", "level" or "altitude" are understood to mean in operating position.
[0056] The terms “upstream” and “downstream” refer to the direction of flow of the charge in the device.
[0057] The terms "first", "second", "third", "previous" and "next" are understood in the direction in which the load passes through the enclosure, preferably vertically from top to bottom.
[0058] "Solid particles" are defined as agglomerates of different sizes of solids, which may contain a compound in a liquid state, in particular water in varying proportions. Solid particles may correspond to a biomass feedstock. The biomass feedstock may advantageously vary depending on its origin. It may be wood or wood by-products, such as waste produced by logging (forest residues), sawmills, wood processing industries. It may also come from industrial by-products such as sludge or agri-food waste. Biomass may also come from traditional agriculture and consist of residues such as straw, coppice, bagasse, as well as crops dedicated to energy production (miscanthus, short-rotation coppice, etc.).Finally, it may correspond to organic waste, such as urban waste including sewage sludge, household waste may also constitute the feedstock. Preferably, the biomass feedstock may be lignocellulosic biomass or cellulose, and more preferably lignocellulosic biomass. The biomass feedstock may also come from algae. The feedstock may be composed of solid particles. In particular when the solid according to the invention corresponds to a biomass feedstock, it may contain a certain content of compound in the liquid state and in particular water (it includes a moisture content).
[0059] Solid particles can be obtained in particular by prior mechanical treatment such as grinding.
[0060] The invention relates to a device for the treatment, in particular for drying or roasting, of a load composed of solid particles (a load composed of solid particles and possibly fluids contained in these solid particles, in particular water). The load is in particular a hydrocarbon load where the solid particles may be particles derived from biomass, for example crushed wood and / or plant residues. The device comprises a furnace comprising an enclosure with a vertical longitudinal axis in the operating position and the enclosure comprises at least one inlet and one outlet for the load composed of solid particles and at least one inlet and one outlet for a gas capable of coming into contact with the solid particles.Thus, in the oven, the hot gas can exchange heat with the load and thus treat it (dry it or roast it for example), depending on the temperatures used and the time the load spends in the oven. For drying, the oven temperature is generally between 90 and 110°C, and for roasting, it is generally between 200 and 350°C.
[0061] In addition, the device comprises a load recovery system, the load recovery system comprising at least one recovery line connected to the outlet of the treated load (partially or totally) on the enclosure, the recovery line being in fluid connection with a sampling and / or analysis means for measuring a parameter representative of the treatment (drying or roasting for example) of the load in situ or ex situ.
[0062] The sampling and / or analysis means may comprise a load sampling means for taking a sample in order to carry out the analysis ex situ, in the laboratory for example, and / or it may comprise an analysis means for carrying out the measurement directly with or without sampling the load. In other words, the analysis means may be integrated into the recovery system or be independent, for example when the analysis of the sample taken is carried out ex situ.
[0063] The recovery line comprises at least two lines in parallel downstream of the sampling and / or analysis means, in the direction of circulation of the load, at least one of the lines being a discharge line for the load (fully treated) and at least one other line being a recycling line leading to an orifice allowing the load (partially treated) to be reintroduced into the furnace. Preferably, the discharge line may lead to a storage tank. Alternatively, the discharge line may lead directly to a unit which uses the treated load (dried or roasted in particular) or may lead to trucks for transporting the load.
[0064] Thus, thanks to the sampling and / or analysis means, it is possible to characterize the load at the outlet of the oven by the representative parameter, to know its level of treatment (drying or roasting level). Depending on this representative parameter, one can: - Either choose to send the load (fully treated) to a storage tank or to a unit for example using the evacuation line, the load then respecting predefined treatment criteria (drying or roasting for example);
[0065] - Either choose to recycle the load (partially treated) if it is insufficiently treated (dried or roasted for example), by reintroducing it into the furnace, via the recycling line.
[0066] Thanks to the device of the invention, it is thus possible to limit the quantity of insufficiently treated charge and thus improve treatment performance.
[0067] The gas according to the invention may be, depending on the intended application, air but also recycled combustion gases, carbon dioxide, water vapor, or an inert gas such as helium or nitrogen.
[0068] According to a preferred implementation of the invention according to which the system is implemented within the framework of a process for drying and / or torrefaction of a biomass, the gas can be an inert gas such as helium, nitrogen, or a mixture of these gases with recycled gases from a previous drying and / or torrefaction step. According to an implementation of the invention according to which the system is implemented within the framework of a process for torrefaction of a biomass, the gas can also be water vapor.
[0069] According to the invention, each recycling and / or discharge line comprises a valve means (a valve for example) to allow or prevent the circulation of the charge in said line, in particular in the discharge or recycling line. Indeed, if the representative parameter meets the predefined criteria (a predefined range with a minimum value and a maximum value for example or possibly only a threshold), the charge can be directly introduced into the discharge line to go for example into the storage tank. It is then possible to open the valve means of the discharge line and close the valve means of the recycling line to send the charge to the storage tank for example and prevent its reintroduction into the furnace, which could lead to unwanted over-treatment (over-drying or over-torrefaction for example).
[0070] For example, for drying, the predefined representative criteria may include a humidity level of between 1 and 35%, preferably between 2 and 20% and more preferably between 3 and 10%.
[0071] For example, for roasting, the predefined representative criteria may include a roasting rate (anhydrous mass loss rate) of between 5 and 60%, preferably between 15 and 45% and more preferably between 20 and 30%. For this, the residence time in the oven of the load may be between 10 and 100 minutes, preferably between 15 and 60 minutes and more preferably between 25 and 40 minutes.
[0072] When the recovery system comprises several recycling lines, the circulation in each recycling line may depend on the value of the measured representative parameter. In other words, each recycling line is configured to allow the circulation of the feedstock according to the measured representative parameter, and the further the measured representative parameter is from the predefined criteria, the more the recycling line in which the feedstock can circulate ends at an orifice at a high height (altitude) (if the furnace is crossed by the feedstock vertically from top to bottom) in the furnace to ensure sufficient residence time in the furnace to obtain the treatment rate, in particular drying or roasting, targeted (within the predefined criteria). Therefore, it is possible to choose to introduce the feedstock more or less upstream, in the direction of the feedstock crossing, into the reactor.Furthermore, the charge can also be reintroduced through several orifices at a given height, for example to better distribute the reintroduced charge around the circumference of the reactor.
[0073] Advantageously, the recovery system may comprise at least three recycling lines, one leading to an orifice located in the upper part of the furnace, one leading to an orifice located in the lower part of the furnace and the last of the three recycling lines leading to the middle of the furnace (i.e. at an altitude located between the orifice located in the upper part of the furnace and that located in the lower part of the furnace).
[0074] According to a preferred configuration of the invention, the furnace may be a multiple hearth furnace with a succession of trays from top to bottom in the enclosure, the trays of the succession being alternately configured to move the charge from the inside to the outside then from the outside to the inside or vice versa.
[0075] The trays (or at least their median plane) may preferably be, in the operating position of the multi-hearth furnace, substantially horizontal.
[0076] By "inside to outside" is meant from the reactor axis to the outer wall of the reactor; by "outside to inside" is meant from the outer wall of the reactor to the reactor axis. For example, if the first (topmost) tray moves the feed from inside to outside, the second tray (the one directly following the first tray) then moves the feed in the opposite direction, from outside to inside and the third tray (the one directly following the second tray) then moves the feed from inside to outside and so on. In this preferred configuration, there may be as many recycle lines as there are trays configured to circulate the feed from outside to inside and the ports of each recycle line may each terminate just above one of these trays configured to circulate the feed from outside to inside.Thus, each recycling line can deliver the load to a separate tray capable of circulating the load from the outside to the inside.
[0077] Furthermore, the valve means can allow the flow rate of the charge from each recycling line to be controlled for reintroduction into the furnace.
[0078] Advantageously, the recovery system can be configured so that the circulation of the load in one line (discharge or recycling) makes it impossible for the load to circulate in the other lines. Thus, each recycling or discharge line is dedicated to a predetermined range of the measured representative parameter. In other words, if the valve means (valve) of one line (discharge or recycling) is open, the other valve means (valve) of the other lines can advantageously be closed.
[0079] Preferably, the recovery system may comprise a control means (or a servo means) for controlling (servo-controlling) the opening and closing of the valve means, the control means preferably being connected to said sampling and / or analysis means. Thus, depending on the representative parameter measured, it is possible to control the opening and closing of the different valve means of the different lines to drive the charge towards the storage tank, for example via the discharge line or towards the desired orifice for reintroduction of the charge into the furnace.
[0080] According to an advantageous implementation of the invention, the charge recovery system may comprise several recycling lines, each leading to a different orifice in the enclosure, the different orifices of the different lines being located at different altitudes on the enclosure.
[0081] Of course, the higher the load is introduced into the oven, the more time it spends in the oven, and the more it is processed (dried or roasted for example).
[0082] By distributing the orifices of the different lines at different altitudes (or heights) in the furnace, it is possible to refine the treatment parameter (drying or roasting in particular) that can be obtained at the recycling outlet according to the representative parameter measured before recycling. For example, if the load is poorly treated (dried or roasted for example), it can advantageously be reintroduced into the upper part of the furnace so that it has a passage time in the furnace allowing a treatment rate (drying or roasting in particular) to be obtained within the predefined criteria at the recycling outlet.On the contrary, if the load has a treatment rate (drying or roasting for example) slightly below the minimum value of the targeted criteria, it can advantageously be reintroduced into the lower part of the oven so that it has a fairly short passage time in the oven to obtain a treatment rate (drying or roasting for example) within the predefined criteria at the recycling outlet and avoiding unwanted over-treatment (over-drying or over-roasting in particular) (outside the maximum value of the predefined criteria).
[0083] Furthermore, by distributing several orifices at different altitudes in the furnace, it is possible to choose the altitude necessary to avoid over-treatment (over-drying or over-roasting in particular) (beyond the maximum value of the predefined criteria), this over-treatment (this over-drying or this over-roasting in particular) then leading to the elimination (rejection) of the charge which can then no longer be used for the intended application. By elimination (rejection) of the charge, it is meant that the over-treated charge (over-dried or over-roasted for example), will not be used for the intended application. This embodiment therefore makes it possible to limit the charge produced which will be lost without being used.
[0084] This embodiment is also advantageous at the time of calibration because it is advantageous to reintroduce the load at the lowest level to see how the load reacts to this minimal recycling and then, depending on the results, recycle it little by little higher and higher so as to establish methodologies allowing the treatment rate (drying or roasting in particular) to be chosen at the recycling outlet depending on this rate before recycling and depending on the load reintroduction orifice. This calibration makes it easier to use the device and to limit the number of recycles necessary to obtain representative parameters within the predefined criteria.
[0085] Preferably, the orifices of the different lines can be distributed regularly along the vertical axis on the oven, so as to further refine the treatment rate (drying or roasting for example) targeted according to the treatment rate (drying or roasting for example) before recycling.
[0086] Advantageously, at least one recycling line, preferably each recycling line, may comprise an intermediate reservoir located between the valve means of the recycling line and the orifice for reintroducing the charge into the furnace. Thus, a buffer stock can be built up and the charge can be stored in this buffer stock for later reintroduction without having to stop the device.
[0087] Preferably, for this embodiment, a second valve means can then be positioned on the recycling line between the intermediate tank and the orifice of the line, so as to control the introduction of the charge from the intermediate tank into the furnace. This second valve means (a valve in particular) can be identical to the valve means located upstream of the intermediate tank. It can also be connected to the control means (servo means).
[0088] According to a first variant of the invention, the representative parameter may be the measurement of the moisture content of the load, in particular when the device is a drying device. Indeed, the moisture content (ratio between the mass of water contained in the load and the total mass of the load) is directly linked to the drying performance.
[0089] In this first variant, the sampling and / or analysis means may comprise a means for sampling the load, such as a sampler, to take a sample of the load at the outlet of the oven. The mass of this sample taken may then be measured in a mass measuring means, such as a balance, then the sample may be placed in an oven to be heated so as to eliminate all the water it contains. The mass of the sample taken and ovened is then measured in a mass measuring means (identical or different from the previous measuring means before ovening). The difference in mass of the sample between the inlet and the outlet of the oven corresponds to the humidity which was present in the sample taken and which has disappeared in the oven. Thus, the humidity level of the sample taken can be deduced.The device may comprise the mass measuring means(s) and the oven and they may be connected (or linked) to the sampling means, so that the sample taken is conveyed to the mass measuring means then to the oven and either back to the mass measuring means or to another mass measuring means. The mass measuring means(s) thus forms a mass measuring system for measuring the mass of the load (of the sample of the load) before and after passing through the oven.
[0090] Alternatively, these mass measurement and sample drying operations can be carried out outside the device by an operator who then recovers the sample in the sampling and / or analysis means. The sample analysis is then carried out ex situ. This first variant allows good precision of the representative drying parameter but does not allow immediate results to be obtained, and therefore does not allow online measurement. Indeed, it takes approximately 24 hours to obtain the moisture content of the load.
[0091] Alternatively, in this first variant, the sampling and / or analysis means may comprise an online analyzer to carry out the measurement in situ. In particular, infrared or microwave online analyzers may be used to measure the moisture content of the load. This solution is particularly advantageous because it allows both precise measurement and immediate results. According to a second variant of the invention, the representative parameter may be the roasting rate of the load, i.e. the loss of anhydrous mass of the load, in particular when the device is a roasting device. This parameter is important for units that may be located downstream of the roasting device, in particular if it is a granulation, grinding or pneumatic conveying unit. Indeed, for transport, roasting makes the roasted powder more homogeneous in size and shape, which thus facilitates transport.
[0092] In this second variant, the sampling and / or analysis means may comprise a means for sampling the charge, such as a sampler, for taking a sample of the charge at the outlet of the furnace. The higher calorific value and / or the lower calorific value of the sample can then be measured.
[0093] The term "higher calorific value" refers to the quantity of energy released by the complete combustion of a unit of the load, the water vapor being assumed to be condensed and the heat recovered.
[0094] The term "lower calorific value" refers to the amount of energy released by the complete combustion of a unit of the load, without taking into account the heat from the condensation of water, unlike the higher calorific value.
[0095] Using the higher and lower calorific values, the roasting rate can be quantified.
[0096] The gross and net calorific values can be measured using a calorimeter, which measures the mass, the amount of heat released during combustion under oxygen (often via the temperature increase caused by combustion), and also the initial moisture content of the sample. The result is expressed in J / kg.
[0097] The gross and net calorific values are physicochemical properties of the solid that can be directly related to the anhydrous mass loss. In other words, from the measured gross and net calorific values, the anhydrous mass loss, and therefore the roasting rate, can be directly determined. A preliminary calibration step is generally used to relate the gross or net calorific value to the anhydrous mass loss. To do this, the device may include a device for measuring the gross and / or net calorific value, for example, a calorimeter. In this case, a sample may be taken, for example, via an operator and the sample may be analyzed in the calorimeter.
[0098] Alternatively, these operations of measuring the higher or lower calorific value can be carried out outside the device by an operator who then recovers the sample in the sampling and / or analysis means. In this case, the analysis is carried out ex situ. This second variant allows good precision of the representative roasting parameter but does not allow an immediate result to be obtained, and therefore does not allow an online measurement, given the need to obtain complete combustion in the combustion chamber.
[0099] Alternatively, in this second variant, the sampling and / or analysis means may comprise an online load color characterization system, the load color being able to be directly linked to the roasting rate and thus allowing the roasting rate to be determined by the identified color of the load alone. The color characterization system may be an optical system (a camera for example) which allows the color to be determined automatically and which may possibly be linked to the control means to adapt the opening and closing of the various valve means instantly according to the determination of the color of the load in order to achieve control.
[0100] The color characterization system may also include a transparent window. In this case, it is the operator who determines the color of the load and who can open or close the various valve means according to this color or who can control the control means to command these openings and closings of the various valve means.
[0101] Alternatively, a camera and software can be used to continuously analyze the color of photos. In this case, the color characterization system includes a camera and color analysis software.
[0102] Infrared color analysis can also be used. Continuous infrared spectroscopy of the solid can also be considered, or RAMAN measurement can be considered. Other types of continuous analysis of the solid can be considered without departing from the scope of the invention.
[0103] Preferably, the oven may be a multiple-stove oven and the enclosure may then comprise:
[0104] - a plurality of trays distributed along the vertical longitudinal axis in the operating position, each tray comprising an upper surface capable of receiving solid particles and at least one passage orifice allowing the solid particles and the fluid to pass through said tray,
[0105] - at least one stirring arm associated with each tray, each stirring arm comprising stirring teeth extending from the stirring arm towards the upper surface of the tray associated with the stirring arm,
[0106] - means for driving the stirring arms in rotation around the longitudinal axis of the enclosure. In addition, the orifice of each recycling line can advantageously be located above one of the trays for the introduction of the load at the level of the tray.
[0107] The use of a multi-deck oven allows for efficient drying and torrefaction of the load. Indeed, the multiplication of trays combined with the rotation of the arms allows for good homogeneity of treatment of the load in this type of oven. In addition, this allows for a robust and flexible process that can process any type of biomass with a fairly high throughput.
[0108] Preferably, each recycling line may result in the introduction of the feedstock at a different tray. In other words, the orifice of each recycling line ends at a different tray. Thus, the drying or roasting rate of the recycled feedstock can be fine-tuned based on this same rate before recycling.
[0109] The invention also relates to a method for drying or roasting a feedstock composed of solid particles, preferably a hydrocarbon feedstock or biomass, using a device as described above, in which at least the following steps are carried out:
[0110] - The charge composed of solid particles (and any fluids contained in the solid particles, such as water) and a gas are introduced into the furnace, preferably into a multiple-hearth furnace;
[0111] - The dried or roasted load is recovered at the outlet of the oven;
[0112] - A parameter representative of the drying or roasting of the load is measured from the dried or roasted load leaving the oven, the representative parameter preferably being the drying rate (or humidity rate of the load) or the roasting rate;
[0113] Depending on the representative parameter, the said charge is sent to a discharge line where the charge is, for example, stored in the storage tank, or the charge is sent to a recycling line to reintroduce it into the furnace.
[0114] The method according to the invention makes it possible to increase the quantity of charge in accordance with predefined criteria thanks to the possibility of recycling when the drying or roasting rate is insufficient. It thus makes it possible to improve the performance of drying or roasting.
[0115] According to an advantageous implementation of the invention, depending on said representative parameter, the charge can be introduced into a recycling line which leads to an orifice defined according to its altitude in the furnace. Indeed, if the representative parameter is quite far from the minimum value of the predefined criteria, the charge can be reintroduced into the upper part of the furnace whereas if the representative parameter is lower but close to this minimum value, the charge can be reintroduced into the lower part of the furnace to avoid over-drying or over-torrefaction of the charge. To do this, a recovery system can be used which has several recycling lines which each lead to an orifice located at a different altitude on the furnace.
[0116] Preferably, the measurement of the representative parameter can be carried out online by an online analyzer. For example, the online analyzer can be an infrared or microwave analyzer to determine the moisture content of the load. The online analyzer can also be a color characterization system as described above, and the representative parameter is then the color of the load which allows the roasting rate to be directly determined.
[0117] Alternatively, the measurement of the representative parameter can be carried out by taking a sample of the dried or roasted load via a sampling means as described above, at the outlet of the furnace. The measurement can then be carried out offline (ex situ) on the sample.
[0118] According to a first configuration of the method of the invention, the representative parameter can be the moisture content of the load and the mass of the sample taken can be measured, then the sample taken can be placed in an oven to eliminate the moisture it contains and then the mass of the ovened sample can be measured, the moisture content being defined as the ratio between the difference in the masses of the sample taken and the ovened sample to the mass of the sample taken. Thus, the moisture content can be evaluated using simple and inexpensive means (i.e. without infrared or microwave means).
[0119] According to a second configuration of the method of the invention, the representative parameter can be the roasting rate of the load and the higher calorific value and / or the lower calorific value of the sample taken can be measured, the higher calorific value and / or the lower calorific value being directly linked to the roasting rate (via a possible prior calibration step). The higher and lower calorific values can be determined by measurement via a calorimeter for example.
[0120] The invention also relates to an installation for the production of liquid hydrocarbons from a feedstock containing at least one fraction of biomass and optionally at least one fraction of another feedstock comprising:
[0121] - at least one feed pretreatment unit, comprising a drying unit, a roasting unit, possibly a granulation unit, and a grinding unit; - possibly a combination unit comprising a pipe for combining the effluents from the different pretreatment units;
[0122] - a pre-treated effluent gasification unit comprising at least one entrained flow reactor;
[0123] - a synthesis gas conditioning unit comprising:
[0124] - a water washing and gas flow fractionation unit enabling the synthesis gas flow to be divided into at least two effluents;
[0125] - at least one guard bed allowing the elimination of halogenated compounds on one of said two effluents located upstream of a unit for converting carbon monoxide to steam;
[0126] - a catalytic hydrolysis unit;
[0127] - a unit for recombination of effluents from the steam carbon monoxide conversion unit and the catalytic hydrolysis unit respectively;
[0128] - a water washing unit for the effluent from the synthesis gas conditioning unit;
[0129] - a unit for eliminating acid gases contained in the washed effluent;
[0130] - a final purification unit for the washed and deacidified effluent comprising at least one guard bed;
[0131] - a Fischer-Tropsch catalytic synthesis reaction unit.
[0132] As a result, the installation can allow the implementation of the process described in the applicant's patent application FR 2,997,414.
[0133] In addition, the drying unit and / or the roasting unit comprises a device as described above. Thanks to this device, the processing performance of the load and therefore of the installation can be improved.
[0134] Furthermore, the drying unit and / or the roasting unit advantageously comprises a multiple deck oven.
[0135] Preferably, the installation further comprises at least one hydrotreatment and / or isomerization unit for the hydrocarbon cuts from the Fischer-Tropsch catalytic synthesis reaction unit.
[0136] The facility thus makes it possible to enhance hydrocarbon fractions through the production of liquid hydrocarbons, in particular liquid biofuels, namely bio-naphtha, bio-gasoline, bio-kerosene, bio-diesel and very high-quality bio-lubricating bases.
[0137] Figure 3 illustrates, in a schematic and non-limiting manner, an example of a drying or roasting device according to the invention. This drying or roasting device (which may be a treatment device in a broader sense) comprises a furnace 301, such as a multi-hearth furnace, with an enclosure with a vertical longitudinal axis. A load, preferably biomass, may be introduced at the top of the furnace 301 through the inlet 316, the treated load leaving the furnace 301 through one or more outlets 304 (here two outlets 304) positioned at the bottom of the furnace, so that the load moves by gravity in the furnace. One or more gas inlets 317 are also positioned on the furnace 301, as well as one or more gas outlets 318.Thus, the load, preferably solid such as biomass, can be brought into contact with a gas, preferably hot, in the oven, in order either to dry the load (to reduce its humidity level), or to torrefy it.
[0138] The gas can flow co-currently or counter-currently with the load in the furnace 301.
[0139] The furnace 301 may comprise one or more horizontal trays 302 to promote the exchange of heat between the gases and the load and promote their contact.
[0140] When the furnace 301 is a multi-hearth furnace, it comprises a central axis capable of rotating, and driving stirring arms with teeth fixed on the stirring arms and directed towards the trays 302 of the furnace 301. The stirring arms extend radially from the central axis. The stirring arms and the teeth then make it possible to improve the mixing of the charge and the gases and to convey the charge from a charge inlet on each tray to a charge outlet of each tray to reach the tray below. The drying or roasting device comprises a recovery system 306 with a recovery line 305 fixed to at least one outlet 304 (preferably to all the outlets 304) of the treated charge. The recovery line 305 comprises a sampling and / or analysis means 319 (which may be a means for taking a sample of the charge, or an online analyzer for example).
[0141] The recovery line 305 comprises, downstream of the sampling and / or analysis means 319, a branch 311 with several parallel lines, of which at least one line is an evacuation line 310 and at least one line is a recycling line 312 (here three recycling lines 312).
[0142] The discharge line 310 leads to a storage tank 308 and the recycling lines 312 each lead to an orifice 303 in the furnace 301. Each recycling line 312 advantageously leads to an orifice 303 located at a different altitude in the furnace 301, so as to allow the recycling of the charge with a more or less long residence time (recycling time) in the furnace 301.
[0143] As shown, the oven may be a multi-hearth oven with six trays 302 and the orifices 303 of each recycling line 312 lead to a tray capable of circulating the load from the outside to the inside. When the treated load leaves the oven through the outlet 304 (or through the outlets 304), it is conveyed through the recovery line 305 of the recovery system 306. The treated load is then analyzed via the sampling and / or analysis means 319. For example, an analysis can be carried out online, via an infrared or microwave analyzer to determine the moisture content of the load continuously and online. The roasting rate can also be characterized by the color of the load (via the user or via an optical color determination system).Alternatively, a sampling means may also be provided for taking a sample, the sampling means then acting as a sampling and / or analysis means 319. The sample taken may then be analyzed via a measurement of the higher calorific value and / or the lower calorific value to determine the roasting rate or by placing it in an oven and measuring its mass before and after passing through the oven so as to determine its moisture content. Depending on the moisture content or the roasting rate, the treated load may then either be sent to the storage tank 308 via the discharge line 310 if the measured rate meets predefined criteria (the load is then completely treated), or the load may be sent to a recycling line 312 in order to increase the drying rate (to reduce the moisture content) or roasting rate.If the measured rate is far from the predefined minimum criterion, the partially treated load can be reintroduced into the upper part via the highest orifice 303. On the contrary, if the measured rate is close to but below the predefined minimum criterion, the partially treated load can be reintroduced into the lower part via the lowest orifice 303. In other words, the introduction orifice 303 (and therefore the recycling line 312 associated with this orifice 303) is chosen according to the humidity or roasting rate measured by the sampling and / or analysis means 319 and according to the predefined criteria for the drying and roasting rate.
[0144] Each discharge line 310 or recycling line 312 comprises at least one valve 309 or
[0145] 313 (or any other means of sluicing) which allows the treated load to circulate in the line concerned or, on the contrary, prevents this circulation.
[0146] The valve 309 of the discharge line 310 is upstream of the storage tank 308 and the discharge line 310 may also comprise another valve means 307, downstream of the storage tank 308 to empty the storage tank (for example in a vehicle) or to prevent, on the contrary, the leakage of the charge stored in the storage tank 308.
[0147] 312 recycling lines may also include intermediate tanks
[0148] 314 to make a buffer stock of charge, before reintroducing the charge into the furnace 301 through the orifice 303 of the relevant recycling line 312. In this case, the valve 313 is then upstream of the intermediate tank 314 to prevent the storage of an unwanted charge in the intermediate tank 314 of the line and the recycling line 312 may also comprise another valve means 315, downstream of the intermediate tank 314, so as to control the introduction of the charge from the intermediate tank 314 into the furnace 301.
[0149] For example, each intermediate tank 314 may be dedicated to storing a load with a humidity or roasting rate within a predetermined range.
[0150] For example, the reservoir of the recycling line 312 which ends at the highest orifice 303 in the furnace corresponds to a drying rate between a first value and a second value; the reservoir of the recycling line 312 which ends at the orifice at the intermediate altitude in the furnace 301 corresponds to a drying rate between the second value and a third value; the reservoir of the recycling line 312 which ends at the orifice at the lowest altitude in the furnace 301 corresponds to a drying rate between the third value and the minimum value of the predefined criterion. Thus, depending on the measured humidity or roasting rate, it is known in which recycling or storage line the load must be circulated (and possibly in which storage tank or intermediate tank it must be stored).It is even possible to make this circulation fully automated depending on the value obtained by the sampling and / or analysis means 319.
[0151] Of course, the recovery system can include more than three recycling lines or less than three recycling lines, the position of the different orifices can thus be adapted in relation to the altitude on the oven and the circulation in each of these lines can depend on the measured humidity or roasting rate.
[0152] The valves or valve means 307, 309, 313 and / or 315 may be guillotine or pendulum valves or rotary locks feeding endless screws.
[0153] Depending on the flow rate of the recycled charge, the flow rate of the charge entering the furnace through inlet 316 can be adapted.
[0154] Advantageously, the injection means (of the charge via the inlet 316 and / or of the gas via the inlets 317) can guarantee the absence of oxygen in the furnace 301.
[0155] For example, a torrefaction device such as a torrefier containing six trays as shown in Figure 3 can be produced, with a dry biomass feed rate of 5 t / h (5000 kg / h) at the inlet 316 of the furnace and a targeted torrefaction rate (AWL) corresponding to 25% anhydrous mass loss. The torrefaction process can then consider the following different recycling processes:
[0156] • Roasting rates greater than 25% are considered to comply with the predefined criteria (the predefined criteria are then between 25% and 100%) and the load is then fed to the storage tank 308 via the discharge line 310 (and the opening of the valve means 309), for example for use of the roasted load in another downstream unit (in particular a grinding, pneumatic transport or thermochemical conversion unit).
[0157] • With a torrefaction rate of between 10 and 25%, the load can be directed to the intermediate tank 314 of the recycling line leading to the lowest orifice 303 on the furnace 301. The biomass is torrefied but still requires a slight additional heat treatment.
[0158] • With a roasting rate of between 5 and 15%, the charge can be led to the intermediate tank 314 of the recycling line leading to the orifice located in the middle of the furnace 301, to reinject the roasted charge into the center of the furnace. Thus, an additional heat treatment is carried out.
[0159] • With a torrefaction rate of less than 10%, the charge can be led to the intermediate tank 314 of the recycling line leading to the highest orifice on the furnace 301. Consequently, this insufficiently torrefied biomass undergoes complete thermal degradation in the furnace.
[0160] According to another example, a drying device such as a dryer can be produced, containing six trays in accordance with Figure 3, with a dry biomass feed at a flow rate of 5 t / h (5000 kg / h) at the inlet 316 of the furnace and a target humidity level of 10%. The drying process can then consider the following different recycling processes:
[0161] • A humidity level of less than 10% is considered to comply with the predefined criteria (the predefined criteria are then between 0% and 10%) and the load is then fed to the storage tank 308 via the discharge line 310 (and the opening of the valve means 309), for example for use of the dried load in another downstream unit (a roaster for example).
[0162] • With a humidity level between 10 and 20%, the load can be directed to the intermediate tank 314 of the recycling line leading to the lowest orifice 303 on the furnace 301. The biomass is dried but still requires a slight additional heat treatment.
[0163] • With a humidity level between 15 and 25%, the charge can be led to the intermediate tank 314 of the recycling line leading to the orifice located in the middle of the furnace 301, to reinject the partially dried charge into the center of the furnace. Thus, an additional heat treatment is carried out.
[0164] • With a moisture content above 25%, the feedstock can be directed to the intermediate tank 314 of the recycling line leading to the highest orifice on the furnace 301. Consequently, this insufficiently dried biomass then undergoes a complete drying step in the furnace. By recycling the feedstock, it is possible to improve the amount of feedstock that meets the predefined moisture content or torrefaction criteria and thus improve the drying or torrefaction performance.
[0165] In addition, differentiated recycling can be carried out depending on the deviation from the reference, which prevents overheating and optimizes the residence time of the recycled load in the enclosure.
[0166] The invention then makes it possible to reduce the quantity of treated load produced (dried or roasted) which does not meet the predefined criteria.
Claims
Claims 1. Device for treating a load comprising solid particles, the treatment preferably being drying or roasting, the device comprising a furnace (301) comprising an enclosure with a vertical longitudinal axis in the operating position, the enclosure comprising at least one inlet (316) and one outlet (304) for said load and at least one inlet (317) and one outlet (318) for a gas capable of coming into contact with the solid particles, characterized in that the device comprises a recovery system (306) for said load, the recovery system (306) of the load comprising at least one recovery line (305) connected to the outlet (304) of the load on the enclosure, the recovery line (305) being in fluid connection with a sampling and / or analysis means (319) for in situ or ex situ analysis of the load in order to measure a parameter representative of the treatment of the load,the recovery line (305) comprising at least two lines in parallel downstream of the sampling and / or analysis means (319), in the direction of circulation of the charge, at least one of the lines being an evacuation line (310), the evacuation line preferably leading to a storage tank (308), and at least one other line being a recycling line (312) leading to an orifice (303) allowing the charge to be reintroduced into the furnace (301), each evacuation or recycling line comprising a valve means (309, 313)., 2. Device according to claim 1, wherein the recovery system (306) comprises control means for controlling the opening and closing of the valve means (309, 313), the control means preferably being connected to said sampling and / or analysis means (319).
3. Device according to one of the preceding claims, in which the charge recovery system (306) comprises several recycling lines (312) each leading to a different orifice (303) in the enclosure, the different orifices (303) of the different lines being located at different altitudes on the enclosure.
4. Device according to one of the preceding claims, in which at least one recycling line (312), preferably each recycling line (312), comprises an intermediate tank (314) located between the valve means (309, 313) of the recycling line (312) and the orifice (303) for reintroducing the charge into the furnace (301).
5. Device according to one of the preceding claims, in which the representative parameter is the measurement of the humidity level of the load and either the sampling and / or analysis means comprises a sampling means, an oven and a mass measuring system for measuring the mass before and after the load passes through the oven, the difference in mass being representative of the humidity level moisture content of the load, or the sampling and / or analysis means comprises an online analyzer, preferably infrared or microwave, to measure the moisture content of the load in situ.
6. Device according to one of claims 1 to 4, in which the representative parameter is the roasting rate of the load and either the sampling and / or analysis means comprises a means for sampling the load and a device for measuring the higher calorific value and / or the lower calorific value, the higher calorific value and / or the lower calorific value being directly linked to the roasting rate of the load, or the sampling and / or analysis means comprises a system for characterizing the color of the load online, the color of the load being directly linked to the roasting rate.
7. Device according to one of the preceding claims, in which the oven (301) is a multiple-hearth oven, the enclosure comprising: - a plurality of trays (302) distributed along the longitudinal axis in the operating position, each tray (302) comprising an upper surface capable of receiving solid particles and at least one passage opening allowing the solid particles and the gas to pass through said tray (302), - at least one stirring arm associated with each tray (302), each stirring arm comprising stirring teeth extending from the stirring arm towards the upper surface of the tray (302) associated with the stirring arm, - means for driving the stirring arms in rotation around the longitudinal axis of the enclosure, the orifice (303) of each recycling line (312) being located above one of said trays (302) for the introduction of the load at the level of said tray (302), preferably each recycling line (312) allowing the introduction of the load at the level of a different tray (302).
8. Method for drying or roasting a load composed of solid particles from a device according to one of the preceding claims, in which at least the following steps are carried out: - Said charge comprising solid particles and a gas is introduced into the furnace (301); - The dried or roasted load is recovered at the outlet of the oven (301); - A parameter representative of the drying or roasting of the load is measured from the dried or roasted load leaving the oven (301); Depending on said measured representative parameter, said dried or roasted load is sent to a discharge line (310), and / or the load is sent dried or roasted to at least one recycling line (312) to reintroduce it into the oven (301).
9. Method according to claim 8, in which, depending on said representative parameter, the dried or roasted load is introduced into a recycling line (312) which leads to an orifice (303) defined depending on its altitude in the furnace (301).
10. Method according to one of claims 8 or 9, in which the measurement of the representative parameter is carried out online by an analyzer.
11. Method according to one of claims 8 or 9, in which the measurement of the representative parameter is carried out by taking a sample of the dried or roasted load by the sampling and / or analysis means, the measurement being carried out offline on the sample.
12. Method according to one of claims 8 to 11, in which the representative parameter is a humidity level of the load and for which the mass of the sample taken is measured, then the sample taken is placed in an oven to eliminate the humidity it contains and the mass of the sample taken and ovened is measured, the humidity level being defined as the ratio between the difference in the masses of the sample taken and the sample taken and ovened to the mass of the sample taken.
13. Method according to one of claims 8 to 11, in which the representative parameter is a roasting rate of the load and in which the higher calorific value and / or the lower calorific value of the sample taken is measured, the higher calorific value and / or the lower calorific value being directly linked to the roasting rate.
14. Installation for the production of liquid hydrocarbons from a feedstock containing at least one fraction of biomass and possibly at least one fraction of another feedstock comprising: - at least one feed pretreatment unit, comprising a drying unit, a roasting unit, possibly a granulation unit, and a grinding unit; - possibly a combination unit comprising a pipe allowing the effluents from the different pre-treatment units to be combined; - a pre-treated effluent gasification unit comprising at least one entrained flow reactor; - a synthesis gas conditioning unit comprising: - a water washing and gas flow fractionation unit enabling the synthesis gas flow to be divided into at least two effluents; - at least one guard bed allowing the elimination of halogenated compounds on one of said two effluents located upstream of a unit for converting carbon monoxide to steam; - a catalytic hydrolysis unit; - a unit for recombination of the effluents from the carbon monoxide to steam conversion unit and the catalytic hydrolysis unit respectively; - a water washing unit for the effluent from the synthesis gas conditioning unit; - a unit for eliminating acid gases contained in the washed effluent; - a unit for final purification of the washed and deacidified effluent comprising at least one guard bed; - a Fischer-Tropsch catalytic synthesis reaction unit, characterized in that the drying unit and / or the roasting unit comprises a device according to one of claims 1 to 7.
15. Installation according to claim 14 further comprising at least one hydrotreatment and / or isomerization unit for the hydrocarbon cuts resulting from the Fischer-Tropsch catalytic synthesis reaction unit.