FR2974108A1 - BIOMASS HYDROCONVERSION PROCESS INCORPORATING A BOILING BED TECHNOLOGY AND A SLURRY TECHNOLOGY - Google Patents

Abstract

The invention relates to a method for hydroconversion of biomass comprising a step of hydroconversion of the feedstock in at least one reactor containing a catalyst supported in bubbling bed and a hydroconversion step in at least one reactor containing a dispersed catalyst.

Description

The invention relates to a method for hydroconversion of biomass for producing fuel bases and / or chemicals. More particularly, the invention relates to a hydroconversion process with bubbling bed technology and slurry technology.

In recent years, there has been a renewed interest in incorporating products of renewable origin into the fuel and chemical sectors, in addition to or in substitution for products of fossil origin. One possible route is the conversion of lignocellulosic biomass or algae to fuels. Biomass has an elemental composition rich in carbon and oxygen but relatively low in hydrogen. To produce fuel bases from biomass, therefore, it is generally necessary to lower the oxygen content and increase the hydrogen content and / or reduce the carbon content. Biomass also contains other heteroatoms (sulfur, nitrogen, etc.) and inorganic compounds of various natures (alkali, transition metals, halogen, etc.). There are different methods of biomass conversion. A method of transforming biomass is gasification followed by the manufacture of a fuel from the synthesis gas. Another method of transformation is liquefaction such as, for example, rapid pyrolysis or hydrothermal conversion, with or without a catalyst, but without the addition of hydrogen. However, these processes lead to bio-oils still very rich in oxygen, which are thermally little or not stable and which have physico-chemical properties still far removed from those required for the final products and therefore require subsequent treatments. In addition, these purely thermal processes, in essence, have a very poor selectivity and these reactions can be accompanied by a large production of gas and solids. Another potentially attractive solution is the hydroconversion of the biomass using a catalytic process in the presence of hydrogen and a solvent, preferably a hydrogen donor solvent. This route allows a significant direct incorporation of hydrogen and produces an organic liquid having a reduced oxygen content and a molar ratio H / C close to that of hydrocarbons. The hydroconversion is all the easier as the water content of the biomass is low and in the form of divided particles, hence the interest of the pretreatment operations. During the hydroconversion of the biomass, the reactions in the reactor (s) are deoxygenation reactions which decompose in reaction of decarbonylation (-CO), decarboxylation (-CO2) and hydrodeoxygenation (-H2O), reactions hydrodesulfurization (HDS), hydrodenitrogenation reactions (HDN), hydrogenation reactions of unsaturations and / or aromatic rings (HDoI, HDA), more generally all hydrotreatment reactions (HDT), reaction reactions hydrocracking (HCK) which leads to naphthenic ring opening or fractionation of paraffins into several smaller molecular weight fragments, thermal cracking reactions and polycondensation (coke formation) although these are not desired, water gas shift reactions: CO + H2O - * CO2 + H2, and methanation reactions: CO + 3 H2 - * CH4 + H2O.

All reactions using hydrogen can be based on molecular hydrogen as on hydrogen transfer reactions between the hydrogen donor solvent or the conversion products (since the donor solvent can come from certain families of recycled conversion products) and reagents.

The hydroconversion of the biomass can be carried out according to a bubbling bed technology or according to a technology in trained bed (also called "slurry" technology according to the English terminology). Bubbling bed technologies use supported catalysts in the form of extrudates whose diameter is generally of the order of 1 mm or less than 1 mm. The catalysts remain inside the reactors and are not evacuated with the products. The temperature levels are high in order to obtain high conversions while minimizing the amounts of catalysts used. The process requires a low hydrogen coverage ratio (hydrogen / charge ratio). The catalytic activity can be kept constant by replacing the catalyst in line. It is therefore not necessary to stop the unit to change the spent catalyst, nor to increase the reaction temperatures along the cycle to compensate for the deactivation. In addition, operating at constant operating conditions provides consistent yields and product qualities along the cycle. Also, because the catalyst is kept agitated by a large recycling of liquid, the pressure drop on the reactor remains low and constant. The bubbling bed also allows an almost isothermal operation which represents an advantage for highly exothermic reactions such as hydodeoxygenation. Slurry hydroconversion technologies use a dispersed catalyst (also called slurry catalyst afterwards) in the form of very small particles, the size of which is a few tens of microns or less (usually 0.001 to 100 dam). The catalysts, or their precursors, are injected with the feed to be converted at the inlet of the reactors. The catalysts pass through the reactors with the feedstocks and the products being converted, and then are driven with the reaction products out of the reactors. They are found after separation in the heavy residual fraction. The dispersed catalysts are less subject to coking compared to supported catalysts which allows for higher thermal levels and higher conversion levels. The processes require a high hydrogen coverage rate. Slurry processes suffer from difficult operability and the conversion level, however, is not as high as desired. Biomass hydroconversion processes, whether by bubbling bed or slurry technology, are known in the prior art. Thus, application US2008 / 0076945 describes a process for hydroconversion of lignin and cellulosic waste into fuel products in a bubbling bed reactor. The unpublished application FR10 / 00097 of the applicant describes a biomass hydroconversion process comprising at least two ebullated bed hydroconversion steps. The application US2009 / 0326285 describes a hydroconversion process of a renewable filler in one or more slurry reactors. The challenge for the industrial development of hydroconversion of biomass is to obtain biofuels with a high yield and acceptable qualities vis-à-vis the final specifications and / or constraints related to the later stages of transformation.

The present invention relates to a method for hydroconversion of biomass selected from algae, lignocellulosic biomass and / or one or more lignocellulosic biomass constituents selected from the group formed by cellulose, hemicellulose and lignin to produce fuel bases comprising the following steps: a) a step of preparing a suspension of the biomass particles in a solvent, b) then a hydroconversion step in the presence of hydrogen in at least one reactor containing a bubbling bed supported catalyst and a step hydroconversion in the presence of hydrogen in at least one reactor containing a dispersed catalyst, and possibly a solid additive, c) then at least one step of separating the effluent from the two hydroconversion stages for separating the gases, a residual fraction containing at least a portion of the solid particles of the dispersed catalyst, and one or more liquid fractions s without naphtha solids, kerosene, diesel and vacuum gas oil. It has now been found that the method incorporating bubbling bed technology and slurry technology makes it possible to increase the conversion over the use of the two technologies separately, while maintaining an excellent deoxygenation rate. Operability, especially the cycle time, is significantly improved. The operability is improved thanks to the combination of these two technologies, which allows a flexibility of the operating conditions and the catalytic system on each of the technologies (thus hydroconversion on each technology) depending in particular on the load to be treated. Indeed, the catalysts used in the two technologies are different and therefore do not have the same ability to coke (which causes the deactivation of the catalyst), nor do they promote quite the same reactions of hydrotreatment, hydrocracking and hydroconversion, in contrast to each of these two methods used alone. According to a first embodiment, the bubbling bed hydroconversion step precedes that in slurry. According to a second embodiment, the hydroconversion step in slurry precedes that in bubbling bed.

According to the first embodiment with the hydroconversion sequence in a bubbling bed and then in slurry, it has been found that in the ebullated bed hydroconversion stage, coke formation and polymerization reactions are limited while promoting the hydrogenation of the coke. solvent. The hydrogenation of the solvent facilitates the transfer of hydrogen between the solvent and the biomass and / or the conversion products throughout the hydroconversion. The effluent thus treated in the boiling bed stage proves to have a much higher reactivity than the feedstock with respect to hydroconversion reactions in slurry. As a result, the loss of material in the form of gas or small hydrocarbons by overcracking is minimized, the level of hydrotreatment is maximized, the operability of the hydroconversion into slurry is greatly improved (compared with hydroconversion into slurry receiving the feedstock) and that overall the conversion of the feed into recoverable products is maximum. The first step in bubbling bed thus favors the hydrotreatment reactions while the second step in slurry reactor promotes conversion. As a result, there is a significant gain in process economics and increased overall performance in conversion and hydrotreating.

According to the second embodiment with the sequence hydroconversion slurry then bubbling bed it was found that the first step in slurry promotes conversion, then the second step promotes hydrotreating. Using slurry technology in the first stage allows high temperature work because there is less diffusive diffusion limit for a dispersed catalyst and less coking. This allows to obtain a strong conversion from the first step. In addition, the fact of starting to treat the slurry reactor feed then bubbling bed makes it possible to pass dispersed catalyst slurry in the bubbling bed. It is thus possible to work with two types of catalysts in the bubbling bed, which increases the conversion and modifies the selectivity towards more gases and lighter liquids.

Thus according to the first or second embodiment, a wide range of biomass can be processed with very high conversion levels. The liquifiers obtained are of good quality with an oxygen content generally of between 0.1 and 5 wt.% Depending on the severity of the treatment. This allows subsequent treatments under less severe conditions (with respect to each of the separate steps) with good yields to achieve the product qualities required by commercial specifications at lower processing and production cost.

The combination of bubbling bed / slurry / slurry / bubbling bed increases the life of the supported catalyst and the slurry catalyst, and thus increases the cycle time of the entire process. In hydroconversion processes in slurry or bubbling bed, the production of solids that may come from unconverted or partially converted feedstock, or possibly from coking reactions, can lead to an increase in pressure losses and therefore to a halt. of the unit. If the cycle time of the units operating with a bubbling bed of catalyst is generally around 2-4 years, that of the units operating with a catalyst bed in slurry around 2 years, in the process according to the invention. invention, the lifetimes are 3-5 years. This means that the presence of the slurry technology did not impact the operability of the bubbling bed and / or that the unit operating with the slurry catalyst had its cycle time significantly increased, in particular because of a decrease in of coke production. When the bubbling bed is in front of the slurry bed, the temperature of the bubbling bed can be lowered due to the increased activity of the catalyst dispersed in the slurry bed, thereby increasing the life of the supported catalyst. When the slurry bed is located before the bubbling bed, the dispersed catalyst is still partially active when it enters the bubbling bed at the side of the supported catalyst, the latter being less stressed, it sees its elongated life.

Because of the optimization of the hydrotreatment and hydroconversion reactions in the two types of processes operated in series and this according to the first or second embodiment, it follows that the total consumption of the bubbling bed catalyst can be reduced and that the concentration of slurry catalyst can be decreased, thereby reducing the consumption of this catalyst in slurry. It is estimated that for the bubbling bed this reduction is at least 10% wt and could even be up to 50% or more. Depending on the operating conditions and the treated feedstock, the total catalyst consumption of the boiling bed can be reduced to such a level that the step of separating and recycling the slurry catalyst from the unconverted fraction becomes unnecessary. In all cases, the combination bubbling bed / slurry or slurry / bubbling bed allows a significant reduction in the consumption of slurry catalyst, which reduces the size of the recovery / recycling unit of the catalyst in slurry (if this is necessary), thus reducing the operating cost significantly. The addition of new catalyst is further reduced.

Another advantage of the process according to the invention is that the hydrogen consumption can be adapted, thus making the process very interesting economically, especially compared to a slurry technology taken alone. For example, the present technology makes it possible to increase the hydrogen content in the recoverable liquid products resulting from the process according to the invention, to the detriment of the production of incondensable gases C1-C2 and unconverted biomass. In addition, if a bubbling bed technology operates with a volume ratio hydrogen on charge (ratio H2 / load) low (0.1 to 2 normal cubic meters (Nm3) per kg load), it is not the same with a slurry technology (H2 / HC ratio of 0.2 to 4 Nm3 / kg of charge) in general, and in particular in the absence of a recycling pump. By cons, the method according to the invention can operate generally with a ratio H2 / load established between (0.1 to 2 Nm3 / kg load) for bubbling bed technology and between 0.1 and 2 (Nm3) / kg load for the slurry technology, for conversion and hydrotreatment levels at least equal, and most often superior to each of the technologies taken alone.

Similarly, it is possible to treat the biomass in co-treatment with other charges, allowing the recovery of loads often considered as waste. Another advantage of the present invention lies in the optional pretreatment of biomass which allows the optimal preparation of the biomass in terms of moisture content and particle size for its hydroconversion.

Detailed Description Biomass Load The biomass load is selected from algae, lignocellulosic biomass and / or one or more lignocellulosic biomass components selected from the group consisting of cellulose, hemicellulose and lignin. By lignocellulosic biomass is meant fillers rich in cellulose and / or hemi-cellulose and / or lignin. Cellulose and hemicellulose are essentially composed of sugar polymers (hexoses and pentoses). Lignin is essentially composed of crosslinked polymers comprising elementary units of the propyl-methoxy-phenol type. Only one of the constituents of this lignocellulosic biomass can be extracted for hydroconversion. This extract or the other remaining fraction may also constitute a filler that can be used in the invention, in particular lignin.

The lignocellulosic raw material can be consists of wood or vegetable waste. Other non-limiting examples of lignocellulosic biomass material are farm residues (straw ...), logging residues (first thinning products), logging products, dedicated crops (coppice short rotation), residues from the food industry, household organic waste, waste from wood processing facilities, used timber from construction, paper, recycled or not. Lignocellulosic biomass can also come from by-products of the paper industry such as Kraft lignin, or black liquors from pulp manufacturing.30 The algae that can be used in hydroconversion are macroalgae and / or microalgae. Macroalgae are large seaweeds or giant algae that are fixed on a bedrock, with the exception of sea sargassa that float without being caught. We can mention green algae (causing green tides), kelp or seaweed (also called kelp). Macroalgae are essentially made up of proteins and polysaccharides, such as alginates or alginic acid and minerals. The term microalgae is used to designate microscopic algae in the strict sense (diatoms, chlorophyceae, etc.) and cyanobacteria. Unicellular or multicellular undifferentiated, these are microorganisms living in highly aqueous media and may have flagellar mobility. Thus, the charge may consist of prokaryotic organisms such as blue-green algae or cyanobacteria, or eurokaryotic organisms such as groups with unicellular species (Euglenophytes, Cryptophytes, Haptophytes, Glaucophytes, etc.), groups with unicellular species or multicellular like red algae or Rhodophyta, and Stramenopiles including diatoms and brown algae or Phéophycées. Microalgae consist essentially of proteins, lipids, polysaccharides and fibers.

For the sake of simplification, the term biomass subsequently used includes algae, lignocellulosic biomass or one or more components of lignocellulosic biomass selected from the group consisting of cellulose, hemicellulose and lignin.

The present invention also makes it possible to convert the biomass into co-treatment with other charges that are difficult to convert in fixed bed hydrotreating / hydroconversion processes. These charges may be of hydrocarbon (petroleum), non-petroleum or renewable nature. The hydrocarbon (petroleum) feedstocks concerned are fillers such as petroleum residues, crude oils, synthetic crudes, toasted crudes, deasphalted oils, deasphalting resins, deasphalting asphalts, derivatives of oil (such as: light cycle oil (LCO), heavy cycle oil (HCO), fluidized catalytic cracking residue (FCC), heavy gas oil / vacuum gas oil (VGO) coking, residue of visbreaking or similar thermal processes, etc.), oil sands or their derivatives, oil shales or their derivatives, or mixtures of such fillers. The non-petroleum feedstocks concerned are fillers such as coal or coal liquids obtained by hydroliquefaction, or hydrocarbon waste and / or industrial polymers, for example recycled polymers from used tires, used residues of polymers originating, for example, from vehicles. recycled automobiles, organic waste or household plastics, or mixtures of such loads. The feedstocks constituted by at least a portion of the Fischer Tropsch synthesis effluents produced from synthesis gas produced by gasification of petroleum, non-petroleum (coal, gas) or renewable (biomass) type feedstocks may also undergo co-treatment of conversion with biomass. Tars and residues that are not or difficult to recover from said gasification can also be used as a co-treatment feedstock.

All products or mixtures of products resulting from the thermochemical conversion of biomass, such as for example charcoal or pyrolysis oil of lignocellulosic biomass or algae, pyrolytic lignin (obtained by extraction of the pyrolysis oil ) or the products of the hydrothermal conversion of lignocellulosic biomass or algae in the presence of high water concentration and under high water pressure under subcritical or supercritical conditions of water and in the absence or in the presence of catalysts also present usable co-charges. Lignocellulosic biomass can also be treated with fillers from other renewable sources, for example oils and fats of vegetable or animal origin, or mixtures of such fillers, containing triglycerides and / or free fatty acids and / or esters. Vegetable oils can advantageously be crude or refined, wholly or in part, and derived from the following plants: rapeseed, sunflower, soybean, palm, palm kernel, olive, coconut, jatropha, this list not being limiting. Algae or fish oils are also relevant. Oils can also be produced from genetically modified organisms. Animal fats are advantageously chosen from lard or fats composed of residues from the food industry or from the catering industries. Activated sludge from water treatment plants can also be used as a co-load.

Pretreatment The present invention preferably comprises pretreatment of the biomass for subsequent processing in the process according to the invention. Preferably, the pretreatment comprises a step of partial reduction of the water content (or drying), followed by a step of reducing the size of the particles until reaching the size range suitable for the constitution of the biomass / solvent suspension for treatment in hydroconversion reactors. Other pretreatments, adapted to the nature of the load, can complete the stages of drying and grinding, including roasting in the case of lignocellulosic biomass or demineralization in the case of algae.

The pretreatment of the lignocellulosic biomass and / or one or more lignocellulosic biomass constituents selected from the group consisting of cellulose, hemicellulose and lignin advantageously comprises at least one of the following steps: a) a drying step and / or or a roasting step, b) a grinding step. The lignocellulosic biomass may be subjected to a drying step followed by a grinding step or may be subjected to a drying step, then to a roasting step, then to a grinding step. The drying and roasting steps can be done in a single step in the same equipment, followed by a grinding step. The grinding stage may also take place after drying and may be supplemented by additional grinding after roasting. Pretreatment of the biomass may also be limited to the grinding stage. A coarse milling step (shredding) may precede all pretreatment steps. In the case of using wood as lignocellulosic raw material, the moisture content is around 50% at the time of cutting the tree in the forest. Natural air drying of tree trunks reduces moisture content to around 30-35%. Then, the trunks are crushed roughly into forest chips in the form of particles of a few centimeters (shredding). Drying and roasting are different heat treatments. The former essentially removes the water contained in the biomass while the second causes changes in the chemical structure of the constituents. Roasting can be defined as a pyrolysis at moderate temperature and controlled residence time because it is accompanied not only by drying, but also by partial destruction of the lignocellulosic material. The biomass particles after roasting are of a more spherical and less rough shape thus creating fewer agglomerates during the formation of the suspension. Roasting thus allows a more homogeneous fluidization in the bubbling bed. The drying step is carried out at a temperature below 250 ° C, preferably below 200 ° C, preferably for 15 to 120 minutes, to arrive at a water content of the biomass to be treated of about 1 at 10%. The roasting step is carried out at a temperature between 200 ° C and 300 ° C, preferably between 225 ° C and 275 ° C, in the absence of air preferably for 15 to 120 minutes, to arrive at a water content of the biomass to be treated of about 1 to 10%, preferably between 1 and 5%.

In the case of a single drying / roasting step in the same brand, the water content of the biomass to be treated can also reach 1 to 10%, preferably between 1 and 5%. Known technologies for drying or roasting are for example the rotary furnace, the moving bed, the fluidized bed, the heated worm, the contact with metal balls providing heat. These technologies may optionally use a gas flowing at co or countercurrent such as nitrogen or any other gas inert under the conditions of the reaction. Other drying techniques are, for example, flocculation assisted by a chemical or physical adjuvant or by an electromagnetic field, decantation, centrifugation or gentle drying under conditions close to the point of vaporization of the water. The biomass particles resulting from the drying and / or roasting stages are then advantageously sent to a mill which makes it possible to reach the desired particle size with a view to hydroconversion. The grinding delivers biomass particles smaller than 600 μm, preferably less than 150 μm. Grinding prior to hydroconversion facilitates transport to the reaction zone and promotes gas / liquid / solid contacts.

The grinding stage is considerably facilitated by the roasting stage which makes it possible to reduce the energy consumption compared to grinding without prior roasting. The pretreatment of the lignocellulosic biomass preferably comprises a roasting treatment. In the case of hydroconversion of lignin alone, the roasting step is not necessary.

The pretreatment of the algae advantageously comprises at least one of the following steps: a) a demineralization step, b) a drying step, c) a grinding step. Preferably, the algae first undergo a demineralization step known to those skilled in the art to reduce the inorganic salts and harmful metals to the hydroconversion catalysts. Depending on the load and the operating conditions, the demineralization also makes it possible to value the alginates, products used as thickeners, gelling agents and emulsifiers. This demineralization step consists of passing the algae in several solutions or baths, possibly of different pH. Between each bath, there is generally a more or less coarse liquid / solid separation (decantation, filtration or centrifugation) which makes it possible to recover the algae in the aqueous medium. The algae are first washed with fresh water to rid them of chlorides and other soluble and possibly dilacerated species. They are then optionally macerated for a few hours in a dilute mineral acid, preferably sulfuric acid, then, optionally washed with fresh water, optionally neutralized with a base, preferably sodium carbonate, and optionally dilacerated. Optionally, the algae are macerated and dilacerated in a concentrated basic solution, preferably a sodium carbonate solution, to form sodium alginates which are soluble in the aqueous phase. This aqueous phase is then separated from the solid phase and then acidified with a mineral acid, preferably sulfuric acid to precipitate alginic acid which can be easily recovered by filtration or centrifugation, for example. The solid phase containing the algae thus pretreated then possibly undergoes other pretreatment steps while the aqueous phases from the different stages possibly undergo additional treatments before their release into the natural environment or their possible recycling in the process. The pretreatment then preferably comprises a drying step and / or a grinding step which is carried out under the same conditions as in the case of lignocellulosic biomass. The algae can be subjected to a drying step followed by a grinding step or the reverse sequence (especially for macroalgae). Pretreatment of algae can also be limited to the grinding stage. After pretreatment, biomass particles having a moisture content of 1 to 50%, preferably 1 to 35% and more preferably 1 to 10%, and a particle size of less than 600 μm, preferably less than 600 μm, are obtained. at 150 pm. Formation of the suspension Before introducing the biomass into the bubbling bed reactor or into the slurry reactor, the biomass, after any pre-treatment operations described above, is mixed with a solvent to prepare a biomass / solvent suspension. This biomass / solvent mixture is a suspension of biomass particles dispersed in said solvent, said suspension of fine solid particles in a liquid is also sometimes called "slurry" according to the English terminology (and should not be confused with reactor term " in slurry "or" slurry catalyst "which denotes a reactor containing a catalyst dispersed in this text). To constitute the suspension, the size of the biomass particles is less than 5 mm, preferably less than 1 mm, preferably less than 650 μm and still more preferably less than 150 μm. The mass ratio solvent / biomass is generally from 0.1 to 3, preferably from 0.5 to 2. The solvent has a triple role: suspending the feedstock upstream of the reaction zone, thus allowing its transport to this region. last, then partial solubilization of the primary products of conversions and hydrogen transfer to these primary products to allow conversion to liquid by minimizing the amount of solid and gas forms in said reaction zone. This transfer of hydrogen thus presents an additional source of hydrogen for the essential need for hydrogen in the transformation of biomass into biofuels. The solvent may be any type of solvent known in the art for the preparation of a suspension. The solvent is preferably a hydrogen donor solvent comprising, for example, tetralin and / or naphtheno-aromatic molecules. Advantageously, the solvent comprises vacuum distillate, preferably vacuum gas oil (or Vacuum Gas Oil (VGO) according to the English terminology). It may also contain atmospheric distillate such as diesel or be derived from a solid / liquid or liquid / liquid extraction step and thus consist at least partially of compounds having boiling points similar to the compounds of the atmospheric distillates or vacuum distillates. It is also possible to use LCO (light cycle cil) or HCO (heavy cycle oil) from a fluidized catalytic cracking (FCC) or even anthracene oil. In the case of a co-treatment with other charges, the solvent may also consist partially or completely of a liquid co-charge, such as, for example, vegetable oils or pyrolysis oils derived from a carbonaceous material ( biomass, coal, oil). According to a preferred variant, the solvent comes from a recycled fraction of the process. Preferably, the liquid fraction (s) free from solids and having a distillation range in the range of 180 ° C to 550 ° C, preferably between 200 ° C and 550 ° C is / are recycled, in part or in full, as a solvent to the suspension preparation step. This fraction preferably comprises vacuum distillate, and even more preferably vacuum gas oil. Part of the atmospheric distillates, such as diesel, can also be recycled, alone or as a mixture with the vacuum distillate fraction. According to a preferred variant, the liquid fraction (s) free from solids resulting from a boiling bed hydroconversion stage and then from a hydroconversion stage in a reactor containing a catalyst. dispersed undergoes / undergoes hydrotreatment prior to its / their recycling in the suspension. The objective of the hydrotreatment is to increase the content of the naphtheno-aromatics in the solvent and thus its role as hydrogen donor solvent in the hydroconversion.

The operating conditions of the hydrotreatment are in general a pressure of 2 to 35 MPa, preferably 10 to 25 MPa, and a temperature of between 300 ° C. and 400 ° C., preferably 300 ° C. to 380 ° C. The hydrotreatment can be carried out in a bubbling bed or in a fixed bed. Conventional hydrotreatment catalysts contain at least one amorphous refractory oxide support and at least one hydro-dehydrogenating element (generally at least one group VIB (for example molybdenum and / or tungsten) and non-noble VIII (for example nickel and / or cobalt), and most often at least one group VIB element and at least one non-noble group VIII element). The amorphous refractory oxide support is chosen from the group formed by alumina, silica, silica-aluminas, magnesia, clays and mixtures of at least two of these minerals. Preferably, the hydrotreatment catalyst is a catalyst optionally comprising a doping element chosen from phosphorus, boron and silicon. Preferably, the catalysts used are based on cobalt-molybdenum or nickel-molybdenum on alumina.

The biomass / solvent suspension thus formed is subsequently introduced into the bubbling bed reactor, according to the first embodiment, or into the slurry reactor, according to the second embodiment. In this second case, the catalyst, as well as the optional additive can be added to the suspension before introduction into the slurry reactor. Hydroconversion in a bubbling bed reactor The hydroconversion step in a bubbling bed reactor is carried out in the presence of hydrogen in at least one reactor operating with a catalyst supported in a bubbling bed. The ebullated bed technology being widely known, only the main operating conditions will be repeated here. The feedstock or a portion or all of the slurry reactor effluent is treated in the presence of hydrogen in at least one three-phase reactor, containing at least one hydroconversion supported catalyst, in a bubbling bed, operating with an upward flow of liquid and gas. Catalyst can be withdrawn from the reactor, without stopping the process, to add fresh catalyst. The catalysts used are widely marketed. They are granular catalysts whose size never reaches those of the catalysts used in slurry. The catalyst is most often in the form of extrudates or beads. Typically, they contain at least one hydro-dehydrogenating element deposited on an amorphous support. Generally, the supported catalyst comprises a Group VIII metal selected from the group consisting of Ni, Pd, Pt, Co, Rh and / or Ru, optionally a Group VIB metal selected from the group Mo and / or W, on a amorphous mineral support selected from the group consisting of alumina, silica, silica-aluminas, magnesia, clays and mixtures of at least two of these minerals. CoMo / alumina and NiMo / alumina catalysts are the most common. The total oxide content of Group VIII and VIB elements is often 5-40 wt% and generally 7-30 wt%. Generally, the weight ratio expressed as Group VI oxide (s) on Group VIII oxide (s) is 1-20 and most often 2-10. For example, a catalyst comprising from 0.5 to 10% by weight of nickel, preferably from 1 to 5% by weight of nickel (expressed as nickel oxide NiO), and from 1 to 30% by weight of molybdenum may be used. preferably 5 to 20% by weight of molybdenum (expressed as molybdenum oxide MoO3), on a support. This catalyst may also contain phosphorus (generally less than 20% by weight and most often less than 10% by weight, expressed as phosphorus oxide P2O5).

Before the charge is injected, the catalysts used in the process according to the present invention are preferably subjected to a sulphurization treatment making it possible, at least in part, to transform the metallic species into sulphide before they come into contact with the charge. treat. This activation treatment by sulfurization is well known to those skilled in the art and can be performed by any method already described in the literature either in-situ, that is to say in the reactor, or ex-situ. The spent catalyst is partly replaced by fresh catalyst by withdrawal at the bottom of the reactor and introduction, either at the top of the reactor or at the bottom of the reactor, of fresh or new catalyst at a regular time interval, that is to say by example by puff or almost continuously. For example, fresh catalyst can be introduced every day. The replacement rate of spent catalyst with fresh catalyst may be, for example, from about 0.01 kilogram to about 10 kilograms per cubic meter of charge. This withdrawal and replacement are performed using devices for the continuous operation of this hydroconversion step. The unit usually comprises a recirculation pump for maintaining the bubbling bed catalyst by continuously recycling at least a portion of the liquid withdrawn at the top of the reactor and reinjected at the bottom of the reactor. It is also possible to send the spent catalyst withdrawn from the reactor into a regeneration zone in which the carbon and the sulfur contained therein are eliminated, and then to return this regenerated catalyst to the hydroconversion stage. It is also possible to send the spent catalyst withdrawn from the reactor into a rejuvenation zone in which at least a portion of the deposited metals, mainly vanadium and nickel, are removed before regenerating the catalyst by removing carbon and sulfur it contains and then send back this catalyst rejuvenated and regenerated in the hydroconversion stage. It is usually carried out under an absolute pressure of 2 to 35 MPa, usually 5 to 20 MPa, at a temperature of about 300 to 440 ° C, often about 325 to 400 ° C, at an hourly mass velocity of between 0.1 h -1 to 5 h -1 and a hydrogen / feed ratio of 0.1 to 2 Nm 3 / kg of feed and most often 0.1 to 0.5 Nm 3 / kg.

The conversion of the charge in the bubbling bed reactor is between 30 and 100%, preferably between 50 and 99%. The deoxygenation of the charge is between 30 and 100%, preferably between 50 and 99%.

Hydroconversion in slurry reactor The feedstock or part or all of the effluent from the bubbling bed stage is subjected to hydroconversion with a slurry catalyst, in the presence of hydrogen, with an upward flow of liquid, gas and of catalyst. The hydroconversion is carried out in at least one slurry reactor, and preferably at least one (and preferably all) of the reactors is provided with an internal recirculation pump, of the same type as that used by the bubbling bed. The slurry catalyst is in dispersed form in the reaction medium. It can be formed in situ but it is preferable to prepare it outside the reactor and to inject it, generally continuously, with the filler, preferably with the biomass / solvent suspension. The catalyst promotes the hydrogenation of radicals from thermal cracking and reduces coke formation. When coke is formed, it is removed by the catalyst. The catalyst is as dispersed as possible to obtain a hydrogenating activity as uniformly distributed as possible in the reaction zone. It is kept in suspension in the reactor, flows from the bottom to the top of the reactor with the feedstock, and is evacuated with the effluent. The slurry catalyst is a sulfurized catalyst preferably containing at least one member selected from the group consisting of Mo, Fe, Ni, W, Co, V, Ru. These catalysts are generally monometallic or bimetallic (by combining, for example, a non-noble group VIIIB element (Co, Ni, Fe) and a group VIB element (Mo, W) .The catalysts used may be heterogeneous solid powders ( such as natural ores, iron sulphate, etc.), dispersed catalysts derived from water-soluble dispersed catalyst ("water soluble dispersed catalyst") such as phosphomolybdic acid, ammonium molybdate, or a mixture of Mo or Ni oxide with aqueous ammonia.

Preferably, the catalysts used are derived from soluble precursors in an organic phase ("oil soluble dispersed catalyst"). The precursors are organometallic compounds such as the naphthenates of Mo, Co, Fe, or Ni or such as multi-carbonyl compounds of these metals, for example 2-ethyl hexanoates of Mo or Ni, acetylacetonates of Mo or Ni , C7-C12 fatty acid salts of Mo or W, etc. They can be used in the presence of a surfactant to improve the dispersion of metals, when the catalyst is bimetallic. The catalysts are in the form of dispersed particles, colloidal or otherwise depending on the nature of the catalyst. Such precursors and catalysts that can be used in the process according to the invention are widely described in the literature. In general, the catalysts are prepared before being injected into the feed. The preparation process is adapted according to the state in which the precursor is and of its nature. In all cases, the precursor is sulfided (ex-situ or in-situ) to form the catalyst dispersed in the feedstock.

For the preferred case of so-called oil-soluble catalysts, in a typical process, the precursor is mixed with a carbonaceous feedstock (which may be part of the feedstock to be treated, an external feedstock, a recycled fraction, etc.). the mixture is optionally dried at least in part, then or simultaneously is sulphurized by addition of a sulfur compound (H 2 S preferred) and heated. The preparations of these catalysts are described in the prior art. Additives may be added during the preparation of the catalyst or to the slurry catalyst before it is injected into the reactor. These additives are described in the literature. The preferred solid additives are inorganic oxides such as alumina, silica, mixed Al / Si oxides, supported spent catalysts (for example, on alumina and / or silica) containing at least one group VIII element (such as Ni, Co) and / or at least one group VIB element (such as Mo, W). For example, the catalysts described in the application US2008 / 177124. Carbonaceous solids with a low hydrogen content (for example 4% hydrogen), possibly pretreated, can also be used. Mixtures of such additives can also be used. Their particle sizes are preferably less than 1 mm. The content of any solid additive present at the inlet of the reaction zone of the slurry hydroconversion process is between 0 and 10% by weight and preferably between 1 and 3% by weight, and the content of the catalytic solutions is between 0 and 10% by weight. % wt, preferably between 0 and 1 wt%. The operating conditions of the slurry hydroconversion stage are generally in a range of 300 and 450 ° C, preferably 325 and 420 ° C, pressures of 2 to 35 MPa, preferably 10 to 25 ° C. MPa, preferably from 7 to 20 MPa, at an hourly mass velocity of between 0.1 hr to 5 hr -1 and a hydrogen / charge ratio of between 0.1 to 2 Nm3 / kg of filler and most often from 0.1 to 0.5 Nm3 / kg.

The conversion of the feed into the slurry reactor is between 50 and 100%, preferably between 70 and 99%. The deoxygenation of the charge is between 30 and 100%, preferably between 50 and 99%.

Very preferably, the bubbling bed stage operates under the temperature conditions of 325 to 400 ° C., with a pressure of 5 to 20 MPa, and an hourly mass ratio of 0.1 to 5 hours, with an H2 ratio. / charge of 0.1 to 0.5 Nm3 / kg and the slurry stage operates under the temperature conditions of 325 to 420 ° C, pressure of 7 to 20 MPa, hourly mass velocity of 0.1 to 5h- 1, with an H2 / feed ratio of 0.1 to 0.5 Nm3 / kg.On course, the converted effluent from the first hydroconversion stage (whether bubbling or slurry) is subject to a separation of the light fraction.It contains very predominantly (at least 90% vol.) the compounds boiling at not more than 300 ° C, even up to 450 ° C, they correspond to the compounds present in the gases, the naphtha, the light gas oil or even heavy diesel It is indicated that the cut contains very predominantly these compounds, because the separation is not made according to a precise cutting point, it is more like a flash, if you had to speak in terms of cutting point, you could say that it is between 300 and 450 ° C. The residual effluent is at least partly, preferably wholly, treated in the second hydroconversion stage. This separation, called inter-stage separation, avoids overcracking of the light fraction in the second step. It also makes it possible to reduce the economic investment on the reactor of the second stage (less charge to be treated, less catalyst to inject, etc.) or to bring an external charge on the reactor of the second stage or of increase the residence time in the reactor of the second stage.

In the case of the second embodiment with the hydroconversion sequence in slurry then in bubbling bed, the effluent leaving the slurry reactor can be subjected to a step of separation of at least a part of the dispersed catalyst particles contained in the effluent liquid. This step may be carried out by filtration, centrifugation, distillation or any other technology used in the treatment of hydrocarbons for the separation or concentration of solids in a liquid stream containing solids and provides a highly concentrated solid phase. This phase may be recycled, in part or in full, to the preparation of the slurry catalyst after possible treatment (s) for the preparation of the catalytic precursor.

According to a preferred variant of the second embodiment, the effluent leaving the slurry reactor is injected directly (without separation of the solid particles) in the bubbling bed stage, after a possible separation of the light fraction.

Figures 1 and 2 illustrate the invention. FIG. 1 describes the first embodiment with the hydroconversion sequence in a bubbling bed and then in slurry. FIG. 2 describes the second embodiment with the hydroconversion sequence in slurry then in bubbling bed. The installation and the method according to the invention are essentially described, without including the separation or the subsequent treatments of the separated fractions which will be described later.

In FIG. 1, the biomass feedstock (1), preferably previously dried and / or coarsely ground and / or roasted and / or demineralized, is milled in the mill (22) in order to produce particles of suitable size to form a suspension and be more reactive in hydroconversion conditions. The biomass is then contacted with the recycling solvent (VGO (96)) from the process in the enclosure (23) to form the suspension. A sulfur compound to maintain catalytic activity may be injected (not shown) into the line exiting the enclosure. The feedstock fed to the boiling bed hydroconversion reactor (3) is preheated in the furnace (2). The reactor contains a catalyst supported in a bubbling bed, the internal separator (4) and the recycling pump (3b) are distinguished from the separated liquid ensuring the maintenance of the bed in the "bubbling" state, which are part of the conventional technology of the bubbling bed. The effluent that emerges from the pipe (5) is advantageously sent into the inter-stage separator (6) (remember that this separation is optional). A light fraction is separated by line (7) and the residual fraction is recovered via line (8). This light fraction contains very predominantly (at least 90% vol) compounds boiling at not more than 300 ° C, or even at most 450 ° C. The residual fraction (or all of the effluent in the absence of inter-stage separator) is sent to the slurry hydroconversion reactor (9) which contains a slurry of catalyst (also called dispersed catalyst) injected by the pipe. (10). This reactor can, in the same way as the bubbling bed reactor, contain an internal separation zone and a separate liquid recycling pump improving dispersion of the slurry catalyst and its circulation in the reactor under the conditions that fall within the scope of the invention. classic conditions of beds trained in slurry. The method and the means for the preparation of the catalyst slurry are not shown in the figure, these means being widely described in the literature. Fig. 1 shows an advantageous (10a), but not mandatory, arrangement wherein one or more additives (as previously described) are added to the filler along with the slurry catalyst. The dispersed catalyst (10) as well as the optional additive may also be injected upstream of the bubbling bed reactor (3), either in the preparation of the suspension (23) or directly in the bubbling bed reactor (3). The effluent from the reactor (9) withdrawn from the pipe (11) is subjected to separation, here in a separator (12) HPHT (high pressure, high temperature), to separate a light fraction by the pipe (13) and it is recovered by the pipe (14) the residual fraction. The hydrogen supply to the reactors by the compressor (21) and the lines (15) and (16) respectively comes from the make-up hydrogen (31) and the recycled hydrogen (29) and (30). The hydrogen may be wholly (duct 18) or partly (ducts 18 and 19 on the one hand and ducts 18 and 20 on the other hand) heated in the oven (17). In general, the management of the different thermal levels required by the bubbling bed and the slurry bed is ensured by the final adjustment of the temperatures of the bubbling bed reactor (s) and reactor (s). in slurry which is performed on the one hand by the preheating furnace (17) of the recycle gas and make-up hydrogen and on the other hand by the possible bypass around this furnace. This arrangement is not repeated in FIGS. 3 and 4, so as not to weigh down the diagrams, but it is of general application and can therefore be combined, in particular with the various embodiments described. FIG. 2, describing the second embodiment with the hydroconversion sequence in slurry then in bubbling bed, is identical to FIG. 1 except for the order of the reactors, the feed first passes through the slurry reactor (9 ), then the bubbling bed reactor (3). The slurry catalyst (10) or its precursor, as well as the optional additive (10a) may be injected directly into the reactor via the pipe (73) or into the enclosure forming the suspension (23) via the pipe (74). After the hydroconversion step in the slurry reactor (9), the dispersed catalyst (10) is preferably entrained with the effluent in the bubbling bed reactor (3) via line 8.

Separation The effluent obtained at the end of the second hydroconversion stage undergoes at least one separation step, possibly supplemented by further additional separation steps according to different embodiments. In general, the separation for separating the gases, a residual fraction containing at least a portion of the solid particles of the dispersed catalyst, and one or more liquid fractions without solids of the naphtha, kerosene, gas oil and gas oil type under vacuum.

More specifically, the effluent obtained at the end of the second hydroconversion stage is separated (generally in an HPHT separator) into a so-called light fraction which contains very predominantly (at least 90% vol.) The compounds boiling at at most 200 ° C, or not more than 300 ° C, or not more than 450 ° C, and not more than 540 ° C; they correspond mainly to the compounds present in gases, naphtha, kerosene, light diesel or even heavy diesel. The other fraction is called the residual fraction. It is indicated that the cut contains very predominantly these compounds, because the separation is not made according to a precise cutting point, it is more like a flash. If we had to speak in terms of cutting point, we could say that it is between 100 and 300 ° C or 200 and 450 ° C, even 200-540 ° C. The so-called light fraction can be sent to a low temperature high pressure separator (HPBT) via a heat exchange equipment from which a gas phase containing the gases (H2, H2S, NH3, H2O, CO2, CO, C1 hydrocarbons) is recovered. -C4, ...), an aqueous phase and a liquid phase. The high temperature low pressure separator (HPBT) can also treat the gas phase from the inter-stage separator (ISS), via a heat exchange equipment that can be common to the one processing the so-called light fraction from the HPHT separator. The aqueous phase and / or the liquid phase of the low-temperature high-pressure separator (HPBT) are advantageously expanded in one or two low-temperature low-temperature separators (BPBT) so as to be at least partially degassed. An intermediate expansion step in a low temperature medium pressure separator (MPBT) may also be considered. The gases extracted from the HPBT separator undergo a purification treatment to recover the hydrogen and recycle it to the hydroconversion reactors and / or the subsequent hydrotreatment and / or hydrocracking treatments. It is the same for the gaseous effluents from any subsequent treatment units such as hydrotreating and / or hydrocracking of hydrocarbon cuts. It is also possible to add the gaseous phase coming from the inter-stage separator. The aqueous phase extracted from the HPBT separator essentially consists of oxygenated compounds (in particular phenols) and water being present initially (incomplete drying) or being produced during the hydrodeoxygenation reactions taking place during the hydroconversion or being introduced voluntarily. in the process to dissolve ammonium sulphide salts formed in the exchangers. The oxygenated compounds of the aqueous phase can be recovered. In general, the elimination of the aqueous phase and the elimination or the recovery of the oxygenates can be carried out by all the methods and techniques known to those skilled in the art, such as for example by drying, passing through a desiccant or molecular sieve, flash, solvent extraction, distillation, decantation and membrane filtration or by combination of at least two of these methods. The aqueous phase is generally sent to a wastewater treatment plant comprising physicochemical and / or biological steps (activated sludge) and / or filtration and / or incineration steps.

The residual phases coming from the separators HPHT, HPLT and optionally MPBT and BPBT, are advantageously sent to a fractionation system (also called non-integrated scheme) which comprises atmospheric distillation and / or vacuum distillation. Atmospheric distillation produces a gaseous effluent, so-called light fractions derived from atmospheric distillation containing in particular naphtha, kerosene and diesel and an atmospheric residue fraction. Vacuum distillation produces a vacuum gas-containing fraction (VGO) and a vacuum residue fraction (VR) which may contain solids such as unconverted biomass, fines from the supported catalyst, and slurry catalyst particles. The products obtained can be integrated into fuel pools or undergo additional refining steps. All or part of the vacuum gas oil fraction (VGO) separated after the two hydroconversion stages can be recycled upstream of the two hydroconversion reactors as a solvent to the suspension preparation stage, and this according to both. embodiments bubbling bed / slurry or slurry / bubbling bed. In the case of the slurry / bubbling embodiment and in order to increase its quality as a hydrogen donor solvent, the VGO preferably undergoes hydrotreatment before recycling (optionally mixed with at least a portion of the recycled diesel fraction) as described in the section "formation of the suspension". The recycling of this phase, acting as a hydrogen donor solvent, provides a portion of the hydrogen necessary for hydroconversion. Apart from its role as a solvent, the portion of the recycled VGO cut also represents raw material for the hydrocracking reactions in the hydroconversion reactor and thus allows an increase in the net conversion to fuel bases of the biomass. Part of the vacuum gas oil fraction can also be recycled to the second hydroconversion reactor either in the bubbling bed / slurry configuration or vice versa.

The VGO-rich cup may also be used as a base for heavy fuel oil or bunker oil or sent to refinery units, such as hydrocracking or catalytic cracking units. The VGO rich cup can also be gasified to produce hydrogen. VGO can also be used in small amounts for the preparation of the dispersed catalyst.

The residual fraction containing at least a portion of the solid particles of the dispersed catalyst (vacuum residue or atmospheric residue) may be partly (preferred) or completely recycled directly to at least one hydroconversion stage, preferably to the first stage of the hydroconversion stage. hydroconversion whether in slurry or bubbling bed. It can be recycled in part or in full directly or after having undergone various preparation treatments of the catalytic precursor. Part of the residual fraction can be recycled directly and another part regenerated and recycled. Generally, instead of recycling directly to the slurry reactor the residual fraction containing the solid particles of catalyst, it undergoes separation (s) and possible treatment (s) preparation of catalytic precursors, for example combustion, solvent washing, chemical treatments, gasification or any other separation technique (these steps can be combined). This (these) treatment (s) make it possible to recover particles containing the slurry catalyst (or more exactly a catalyst precursor) which will be recycled to the catalyst preparation (thus including the sulfurization). The residual fraction containing the solid particles of dispersed catalyst is advantageously recycled, in part or in full, to the preparation of the dispersed catalyst after having undergone separation (s) and possible preparation treatment (s) for catalytic precursors. Such methods of treatment are well known to those skilled in the art.

Alternatively, a part of the residual fraction, optionally after separating the solid catalyst particles, may be subsequently burned, for example in a cement kiln, or to provide energy on site, or may feed a plant. gasification unit to produce hydrogen and energy. The hydrogen thus produced can be introduced into the hydroconversion process and / or in the subsequent hydrocracking and / or hydrotreatment treatments.

Figures 1 and 2 show, in general, the separation scheme of the hydroconversion effluent and the hydrogen recycle loop with a single compression system. In this embodiment, the separated phase in the pipe (13) is a gas phase containing hydrogen, the gases resulting from hydroconversion (NH3, H2S, H2O, CO, CO2, etc.) and light hydrocarbons. (C1-C4). The gas phase is here cooled in the cooler (32) before being sent to the separator (33) HPLT (high pressure, low temperature) to separate a hydrogen-rich gas (34) sent to the gas treatment, an aqueous phase ( 39) and a liquid fraction (35).

In the figure, it is noted that the gaseous phase (13) is added the gas phase (7) from the inter-stage separator. This provision is not mandatory and the separator may not be present. The residual liquid fraction (14) from the separator (12) HPHT (high pressure, high temperature) is sent in the continuation of the separation section.

This comprises according to FIGS. 1 and 2, a high temperature medium or low pressure separator (36) which separates a gas phase (37) sent to the gas treatment unit described below. Here, it is shown that this phase can be pre-cooled (80), separated at low temperature (81) to improve its purification. The liquid fraction (generally a fraction containing predominantly compounds boiling at at least 150 ° C) (line 83) is treated with fraction (35), this being preferred. The gas phase (line 84) is sent to the gas treatment unit. An aqueous phase (82) is also recovered. At the end of the separator (36), a residual liquid phase (38) is obtained which can be fractionated (90) (distillation or atmospheric flash and distillation or flash under vacuum), with the fraction (35) to obtain the GPL fractions (C3, C4) (91), naphtha (92), kerosene, (93), gas oil (94), VGO (vacuum distillate) (95) and VR (vacuum residue) (97). At least a portion of the VGO (96) is preferably recycled to the enclosure (23) to form the biomass / solvent slurry. In the case of the slurry / bubbling mode (FIG. 2), the VGO preferably undergoes hydrotreatment (99) before it is recycled. At least a portion of the VR containing the slurry catalyst particles may be recycled via lines (98 and 98b), preferably after various treatments to prepare the catalyst precursor, to the slurry reactor (9) and / or the bed reactor. bubbling (3). Preferably, it is recycled to the first reactor.

Figs. 1 and 2 also generally illustrate the use of a single compressor (21) with n stages (here 3, with the highest pressure at the nth stage) for the makeup hydrogen (31) and the recycle hydrogen (29 and 30) for supplying both the bubbling bed reactor (s) and the slurry reactor (s). There could have been two separate compressors, one for make-up hydrogen and one for recycling hydrogen. The recycling hydrogen loop conventionally comprises a hydrogen purification treatment. The hydrogen-rich gas treatment unit conventionally comprises an HP (high pressure) adsorber (25) and a membrane unit (26), the hydrogen thus separated is sent via the pipe (24) to the compressor (preferably at ter or the third stage by the pipes (29 and 30), while the residual gas can be treated with PSA ("pressure swing adsorption") (27) to separate the residual hydrogen, also sent in compression, the contaminants going to fuel gas (28).

Subsequent treatments The recovery of the various fuel base cuts is not the subject of the present invention and these methods are well known to those skilled in the art.

In general, the fraction (s) naphtha, kerosene, gas oil and VGO may be subjected to one or more treatments (hydrotreating, hydrocracking, alkylation, isomerization, catalytic reforming, catalytic or thermal cracking or other) for bring to the required specifications (sulfur content, smoke point, octane, cetane, etc.) separately or in a mixture. The naphtha can be hydrotreated in a dedicated unit, or it can be sent to a hydrocracking unit where it is brought to the characteristics of a load acceptable for catalytic reforming and / or isomerization. Naphtha after possible purification stage (s) can also serve as a base for petrochemicals. Kerosene and product gas oil can undergo hydrotreatment followed by hydrocracking to specifications.

In general, the hydrotreatment and / or hydrocracking after hydroconversion can be done either conventionally via an intermediate conventional separation section as described in FIG. 3 (here called non-integrated scheme, it is ie separation with decompression), either by directly integrating the hydrotreatment / hydrocracking section with the hydroconversion section with or without prior separation of the effluents and without intermediate decompression between the two stages as described in Figure 4 (here called integrated scheme) .

According to a variant of the invention, the liquid fraction or fraction (s) free from solids obtained by at least one separation undergoes all or part of a hydrotreatment step and / or hydrocracking with intermediate decompression. According to another variant of the invention, the liquid fraction or fraction (s) free from solids obtained by at least one separation undergoes all or part of a hydrotreating step and / or or hydrocracking without intermediate decompression.

Figure 3 illustrates the non-integrated scheme, that is to say without decompression between the hydroconversion reactors and the treatment of the effluent. The separation section of the residual fraction (14) comprises atmospheric distillation (40) and vacuum distillation (41). The product gas oil (line 42) is hydrotreated (43) to specification.

After fractionation (unit 44), the gas oil is recovered as well as the lighter fractions that could have been produced, including a gas rich in hydrogen (54), which after a purification treatment (45) is sent to the compressor (21) (the 3rd floor is here adequate) (line 46). VGO (vacuum gas oil, line 47) is hydrocracked (48) and fractionated (49).

On the gas phase duct (13), the HPLT separator (high pressure, low temperature) (33) which separates a hydrogen-rich gas (50) which, after treatment (51), is sent (lines 52, 53) at the proper stage of the compressor.

Advantageously, a single compressor is used and the hydrogen for the treatment (43) of diesel (hydrotreatment) will be provided by an intermediate stage (here the 2nd), while the process according to the invention will be fed by the 3rd stage of the compressor (55). The use of this unique n-stage compressor with hydrogen recycling and a clever combination of units allows optimized hydrogen management to ensure the correct coverage rate (H2 / HC) at the reactor (s). ) in a bubbling bed and slurry reactor (s).

As regards the naphtha (56), it can be hydrotreated in a dedicated unit, or it can be mixed with the diesel hydrotreating unit or the hydrocracking unit where it is brought to the characteristics of an acceptable charge for catalytic reforming and / or isomerization.

Fig. 4 shows an embodiment according to the integrated scheme, that is to say without decompression between the hydroconversion reactors and the treatment of the effluent. Through the conduit (11) arrives the effluent from the second hydroconversion stage, it passes into the separator HPHT (high pressure, high temperature) (70) to separate a hydrocarbon fraction (line 56) containing very predominantly (at least 90%) compounds with a boiling point of not more than 540 ° C, or not more than 450 ° C or not more than 440 ° C.

The residual fraction (line 57) contains, for the most part (at least 90%), compounds with a boiling point greater than 440 ° C, or even 500 ° C or 540 ° C. In the same way as before, the separation is not clear; if it were necessary to give a cutting point, it would be between 440 and 540 ° C, preferably between 450 and 540 ° C. This residual fraction is distilled under vacuum (58) in order to recover the recoverable VGO (gas oil under vacuum) (line 59) and a residue under vacuum (line 60) on which the slurry catalyst will be recovered according to methods already mentioned. The VGO (59) can be recycled upstream of the hydroconversion reactors to form the biomass / solvent suspension.

The lighter fraction (56) is hydrotreated only (eg before FCC, fluidized catalytic cracking unit) or hydrotreated and hydrocracked (hydrotreatment (61) followed by hydrocracking (62)) in the presence of hydrogen (68). ) and the effluent is fractionated (63) to obtain an LPG cut (C3-C4) (71), naphtha (64), kerosene (65), diesel (66) and VGO (67). In the case of hydrocracking with VGO recycling, the conversion of the feed into light and medium distillates (LPG, naphtha, kerosene, diesel) is then total.

An external cut generally coming from another process existing in the refinery or possibly outside the refinery (line 69) can be brought before the hydrotreatment; advantageously the external cut is for example the VGO from fractionation of crude oil (VGO straight-run), the VGO resulting from a conversion, a LCO (light cycle oil) or a HCO (heavy cycle oil) FCC. Very advantageously, it is sent to hydrotreatment or hydrocracking with all or part of the VGO generated by the distillation of the residual fraction (line 72).

The advantage of this process is its integration at the pressure and thermal levels, hence a process that consumes less energy overall and emits less CO2 (compared to each of the technologies separately). Another advantage is the obtaining of products (kerosene, diesel, VGO which can serve as oil bases for example) directly to the specifications (sulfur, cetane ...) by the adjustment of the operating conditions (in the forms of known conditions) according to the separated fraction (56).

EXAMPLE: Hydroconversion of roasted beech

This example compares the performances on the same charge of the bubbling bed process (with 2 reactors), the slurry process (with 2 reactors), and the new process integrating a bubbling bed reactor and a slurry reactor according to the two embodiments. .

The biomass load considered in this example is beech, previously roasted at 250 ° C. for 1 hour, crushed and sieved so as to obtain particles of size less than 100 μm (see simplified composition Table 1). The filler is mixed with tetralin before introduction into the reactors. Inorganics are mainly composed of ash and metals, traces of chlorine and sulfur.

Table 1: Simplified composition of the roasted beech load water% m / m Organic 1.7 C% m / m 53.3 H organic% m / m 5.6 O organic% m / m 38.4 inorganic% m / m 0.9 The following table summarizes the conditions operating and performance for the 4 cases: 2 Reaction Process Method Process 2 Reactor Reactor Reactor in bed bed in slurry slurry then bubbling bubbling bed reactor then bubbling reactor slurry 1st reactor 335 400 400 350 temperature, ° C 2nd reactor 400 400 400 400 temperature, ° C Total pressure 16.0 16.0 16.0 16.0 output 2nd reactor, MPa Conversion,% 99.0 99.3 99.6 99.4 pds Yield 28.0 32.0 34.0 33.0 liquids from biomass 99.6 99.4 99.3 99.6 rate deoxygenation% wt The new process according to the invention thus makes it possible to obtain the highest conversion and the yield of liquids from the highest biomass compared with the bubbling bed processes. nt or slurry taken separately. In addition, the rate of deoxygenation remains at a very high level.

Claims (15)

REVENDICATIONS1. A method of hydroconversion of biomass selected from algae, lignocellulosic biomass and / or one or more lignocellulosic biomass components selected from the group consisting of cellulose, hemicellulose and lignin to produce fuel bases comprising the steps of: a ) a step of preparing a suspension of the biomass particles in a solvent, b) then a hydroconversion step in the presence of hydrogen in at least one reactor containing a bubbling bed supported catalyst and a hydroconversion step in the presence hydrogen in at least one reactor containing a dispersed catalyst, and optionally a solid additive, c) then at least one step of separating the effluent from the two hydroconversion stages for separating the gases, a residual fraction containing at least one at least a portion of the solid particles of the dispersed catalyst, and one or more liquid fractions lacking solids of type na phta, kerosene, diesel and vacuum gas oil. 2. Method according to claim 1 wherein the residual fraction containing at least a portion of the solid particles of the dispersed catalyst is partially or completely recycled directly to at least one hydroconversion stage, preferably to the first hydroconversion stage. 3. Method according to one of the preceding claims wherein the residual fraction containing the solid particles of dispersed catalyst is recycled, in part or in full, to the preparation of the dispersed catalyst after undergoing separation (s) and possible treatment (s) for the preparation of catalytic precursors. 4. Method according to one of the preceding claims wherein the liquid fraction (s) free (s) solids obtained (s) by at least one separation undergoes / undergo in part or in whole a step of hydrotreatment and / or hydrocracking with intermediate decompression. 5. Method according to one of claims 1 to 3 wherein the liquid fraction (s) (s) free (s) solids obtained (s) by at least one separation undergoes / undergo part or all of a step hydrotreating and / or hydrocracking without intermediate decompression. 6. Method according to one of the preceding claims wherein the fraction (s) liquid (s) free (s) of solids and having a distillation range in the range of 180 ° C to 550 ° C, preferably from 200 ° C to 550 ° C is / are recycled (s), in part or in full, as a solvent to the suspension preparation step. 7. Method according to the preceding claim wherein the liquid fraction (s) free (s) of solids issued (s) of a boiling bed hydroconversion stage and a hydroconversion step in a reactor containing a dispersed catalyst undergoes / undergo hydrotreatment prior to its / their recycling in the suspension. 8. Method according to one of the preceding claims wherein the lignocellulosic biomass and / or one or more lignocellulosic biomass constituents selected from the group formed by cellulose, hemicellulose and lignin undergo a pretreatment comprising at least one of the following steps a) a drying step and / or a roasting step, b) a grinding step. 9. Method according to one of claims 1 to 7 wherein the algae undergo a pretreatment comprising at least one of the following steps: a) a demineralization step, b) a drying step, c) a grinding step. 10. Method according to one of the preceding claims wherein the biomass is co-treated with a filler selected from petroleum residues, crude oils, synthetic crudes, topped crude oils, deasphalted oils, deasphalting resins, deasphalting asphalts, derivatives of processes for the conversion of petroleum, oil sands or derivatives thereof, bituminous shales or derivatives thereof, coal or coal liquefied coal obtained by hydroliquefaction, hydrocarbon waste and / or industrial polymers, organic waste or household plastics, vegetable or animal oils and fats, tars and residues that are not or difficult to recover from the gasification of biomass, coal, gas or petroleum residues, charcoal, pyrolysis oil, activated sludge or mixtures of such fillers. 11. Method according to one of the preceding claims wherein the effluent from the first hydroconversion stage is subjected to a separation which separates a light fraction containing at least 90% by volume of compounds boiling at at most 300 ° C or at at most 450 ° C, and at least a portion, preferably all, of the residual effluent is treated in the second hydroconversion step. 12. Process according to one of the preceding claims, in which the slurry catalyst is a sulphurized catalyst containing at least one element selected from the group consisting of Mo, Fe, Ni, W, Co, V, Ru. 13. Method according to one of the preceding claims wherein the additive is selected from the group consisting of inorganic oxides, the supported catalysts supported containing at least one element of group VIII and / or at least one element of group VIB, the carbonaceous solids having a low hydrogen content or mixtures of such additives, said additive has a particle size of less than 1 mm. The method according to one of the preceding claims wherein said supported catalyst comprises a Group VIII metal selected from the group consisting of Ni, Pd, Pt, Co, Rh and / or Ru, optionally a Group VIB metal selected from the group Mo and / or W, on an amorphous mineral support selected from the group consisting of alumina, silica, silica-aluminas, magnesia, clays and mixtures of at least two of these minerals. 15. Method according to one of the preceding claims wherein the hydroconversion step in at least one bubbling bed reactor is operated at a temperature between 300 ° C and 440 ° C, at a total pressure between 2 and 35 MPa , at a hourly mass velocity of between 0.1 and 5 h -1 and at a hydrogen / charge ratio of between 0.1 and 2 Nm 3 / kg, and wherein the hydroconversion step in at least one reactor containing a The dispersed catalyst is operated at a temperature of between 300 ° C. and 450 ° C., at a total pressure of between 2 and 35 MPa, at an hourly mass velocity of between 0.1 and 5 h -1 and at a hydrogen / charge ratio. between 0.1 and 2 Nm3 / kg.