FR3141183A1 - HYDROCONVERSION OF A PLASTIC FILLER PROMOTED BY SULFUR AND IN THE PRESENCE OF A BI-FUNCTIONAL ZEOLITHIC CATALYST - Google Patents

Abstract

The present invention relates to a process for hydroconverting a plastic filler comprising: (a1) a step of non-catalytic hydroconversion of said filler in the presence of hydrogen, in contact with a source of radicals, said source comprising sulfur and being introduced so that the sulfur content is between 3% and 20% by weight of the feed, to produce first conversion products; (a2) a step of catalytic hydroconversion of the first conversion products in the presence of hydrogen, in contact with at least one hydroconversion catalyst, said hydroconversion catalyst comprising at least one hydro-dehydrogenating element chosen from the group formed by the non-noble elements of group VIB and group VIII of the periodic table, taken alone or as a mixture, and a porous support comprising a porous mineral matrix and at least one zeolite, said steps (a1) and (a2) being implemented at an absolute pressure of between 1 MPa and 38 MPa, at a higher temperature or equal to 200°C and less than 400°C, at an hourly space speed relative to each hydroconversion reactor of between 0.05 h-1 and 10 h-1, and with a quantity of hydrogen of between 50 Nm3/m3 and 5000 Nm3/m3.

Description

HYDROCONVERSION OF A PLASTIC FILLER PROMOTED BY SULFUR AND IN THE PRESENCE OF A BI-FUNCTIONAL ZEOLITHIC CATALYST

The present invention relates to the field of the conversion of solid plastic feedstocks into a mixture of recoverable hydrocarbons, in particular the conversion of such feedstocks at high pressure and temperature in the presence of hydrogen and a hydrocracking catalyst.

In a context of circular economy and waste reduction, there is particular attention paid to plastics, which are classically products derived from petroleum, in order to valorize them.

The recovery of plastic waste may consist of transforming said plastics, by mechanical and/or chemical means, in order to once again allow the production of plastics or plastic-based objects. This is the recycling of plastic waste.

This recovery of plastic waste can also follow the path of energy recovery, in particular for non-recyclable or difficult to recycle plastic waste, as an alternative, in certain cases, to landfilling. Typically, energy recovery from plastic waste consists of producing energy, in the form of electricity and/or heat. For example, it is known to subject plastics from collection and sorting sectors to a pyrolysis step to produce, among other things, plastic pyrolysis oils, which are generally burned to generate electricity and/or used as fuel in industrial or district heating boilers.

Plastic waste can also be transformed by high-pressure hydroconversion processes of hydrogen into hydrocarbon cuts, which can be used in particular as fuels, for example to produce gasoline or diesel, or raw materials for petrochemicals.

The French patent application registered under the filing number 21/14.037 of the Applicant thus relates to the incorporation of a fraction of plastics, typically from waste, to a heavy fossil hydrocarbon feedstock, in a bed hydroconversion process. bubbling or bubbling-entrained hybrid, for the production of fuel bases and other recoverable hydrocarbons. The plastic fraction, initially solid, is introduced into the hydroconversion reactor in different ways, and the process shows overall conversion levels close to those obtained with this same type of processes dealing with more traditional heavy loads, 100% original fossil.

More generally, the liquefaction of plastic waste by thermal cracking or acid catalytic cracking to produce fuels has been the subject of laboratory studies since the 1990s.

The concatenated review of Munir et al. 2018, (Munir et al., Renewable and Sustainable Energy Reviews 90, 2018, 490-515) summarizes the prior art in the hydrocracking of plastics by direct liquefaction in the absence of co-charge. The authors conclude that increasing the reaction temperature results in an increase in conversion but also in the quantity of unwanted gases and coke produced. The authors recommend temperatures no higher than 400°C in the presence of a catalyst. The authors also indicate that bifunctional catalysts having both hydrogenation-dehydrogenation and cracking capabilities are the most suitable for cracking plastic materials.
This review refers in particular to the publication by Joo and Curtis 1998 (Catalytic coprocessing of LDPE with coal and petroleum residue using different catalysts. Fuel Process Technol 1998, 53, p. 197–214), in which a bifunctional NiMo/zeolite catalyst ( presulfurized) is tested, among others, for the hydrocracking of low density polyethylene PEBD (or LDPE for “low density polyethylene” according to Anglo-Saxon terminology). At 400°C the conversions obtained are less than 30%. At 430°C the conversions become more significant. At this high reaction temperature, the bifunctional catalysts with zeolite tested show better activity compared to other alumina-based catalysts. However, the quantities produced of gases and products lighter than naphtha are high.
The review also refers to the publication by Walendziewski and Steininger 2001 (Thermal and catalytic conversion of waste polyolefins. Catal Today 2001, 65, p.323–330), which presents the results of hydrocracking of waste polyethylene (PE) using using a commercial bifunctional catalyst NiW+10%HY. The authors conclude that the optimal temperature for the liquefaction of plastics is between 410°C and 430°C or at least 390°C. At 410°C in the presence of this catalyst the quantities of gas produced are very significant.

Among the studies listed in the review by Munir et al. 2018, some have shown the potential of using sulfur in promoting plastics conversion.

Thus, Nakamura and Fujimoto (Development of new disposable catalyst for waste plastics treatment for high quality transportation fuel. Catalysis Today 27, 1996, p.175-179) studied the conversion of polypropylene (PP) in an autoclave reactor between 380°C and 400°C, under an initial hydrogen pressure of 3MPa, in the presence or absence of iron-based catalysts supported on an activated carbon or an amorphous silica-alumina and in the presence of carbon disulfide (CS ₂ ). The authors observed that, with or without catalyst, the presence of CS ₂ increases the yield of liquid products and reduces the yield of solid residue. The authors conclude that sulfur in the reactor is a promoter for the conversion of PP, and propose an explanatory mechanism according to which hydrocarbon radicals would be formed by thermal cracking of the CC bonds of the polymer; a majority of these radicals would recombine with each other in the absence of H ₂ S, whereas in the presence of H ₂ S, the latter could diffuse into the structure of the polymer, a hydrogen atom of H ₂ S which can be captured by a hydrocarbon radical so as to form a stable hydrocarbon and HS• radical. The life time of the hydrocarbon radical would thus be reduced and its recombination prevented, as well as its potential to continue thermal cracking which generally leads to unfavorable gas yields. Thermal cracking therefore makes it possible to transform enormous polymer molecules into long molecules which would not be too cracked thanks to the stabilization of the radicals by H ₂ S. These long molecules can then undergo selective catalytic cracking. Depending on the catalyst used, the yields in various cuts vary in fact, in particular the yield of gaseous product which remains high in particular with the catalyst tested based on iron supported an amorphous silica-alumina, and even higher when CS ₂ is associated.

Ibrahim and Seehra (Ibrahim and Seehra, Energy & Fuels 11, 1997, 926-930) studied the depolymerization temperature (Td) of a mixture of plastics followed by electron spin resonance (or ESR for “Electron Spin Resonance” according to the Anglo-Saxon terminology) under an initial hydrogen pressure of 500 psig (3.45 MPa). A sample of plastics composed of 5% PP, 95% high density polyethylene (HDPE) and traces (< 3%) of polyethylene terephthalate (PET) was mixed with other compounds: elemental sulfur, or a mixture of elemental sulfur (S) and a NiMo/Al ₂ O ₃ catalyst, or an HSZSM-5 zeolite. The authors found that the Td of the plastic sample decreased by 80°C when the plastic was mixed with elemental sulfur, but was not impacted by the presence of HSZSM-5. Increasing the quantity of elemental sulfur S introduced does not change the Td. The authors conclude that the sulfur in the reactor is a promoter for the conversion of plastic during its thermal cracking by a radical mechanism. No information on the conversion of plastics into fuels is given in their study.

Shiro et al. (Shiro et al., Energy & Fuels 16, 5, 2002, 1314-1320) studied the decomposition of low density polyethylene (LDPE) in an autoclave reactor between 300°C and 425°C under an initial hydrogen pressure of 5 MPa. Sulfur compounds, such as H ₂ S, elemental sulfur, dimethyl disulfide (DMDS of formula (CH ₃ S) ₂ ) etc. are added. The authors conclude that the addition of sulfur compounds has a promoting effect on the decomposition of LDPE.

The addition of sulfur or sulfur compounds is rather known, in hydroconversion processes, to sulphurize the catalysts, and thus make them “active”. Conventionally, the catalysts are advantageously subjected to a sulfurization treatment making it possible to transform, at least in part, the metal species into sulfurized form before they are brought into contact with the charge to be treated. This activation treatment by sulfurization is well known to those skilled in the art.
The formation of the active phase of the catalyst by sulfurization can be done in situ, ie in the hydroconversion process after loading the catalyst or catalyst precursor, typically in the reactor, for example through the addition of organic sulfur molecules such as DMDS, thioacetamide, etc. to the hydrocarbon feedstock to be treated, under conditions of hydrogen pressure and temperature, or even be done ex-situ, ie before loading the catalyst at one of the stages of the hydroconversion process, under conditions suitable for activation.
For example, in the field of the conversion of fillers comprising plastics, the French patent application filed under the discussed number 21/14.037 already mentioned above, describes the possibility of forming and activating in situ a colloidal or molecular catalyst, which is a type of dispersed catalyst (also called entrained catalyst or slurry) extremely small (eg of size less than 1 μm), by the interaction of sulfur with a soluble catalyst precursor, generally at high temperature, and thus form the type catalyst metal sulfide. A source of sulfur can be H ₂ S dissolved in the fossil hydrocarbon feed, or H ₂ S contained in hydrogen recycled to the hydroconversion reactor, or coming from organic sulfur molecules introduced into the hydrocarbon fraction. fossil of the load to be treated (e.g.: injection of DMDS or thioacetamide).
Patent application CA2171803, relating to the liquefaction of plastic waste mixed with a suspending agent in a container under pressure of H ₂ or N ₂ , alone or in mixture, and optionally in the presence of a solid catalyst, describes the possibility of add a sulfur donor agent to sulphurize any metals present used as catalysts, in particular iron.

With the issue of plastic waste management and environmental concerns being more relevant than ever, effective processes for converting plastic waste to make fuels or raw materials for petrochemicals, which are particularly energy efficient, are still being sought. and lower cost, and which can satisfy varied or changing needs for products, for example fuels.

Objectives and Summary of the Invention

In the context described above, an objective of the present invention is to provide a process for converting plastics in the presence of hydrogen to a mixture of recoverable hydrocarbons, which allows maximum conversion of plastics while minimizing the energy required. for the conversion, and while minimizing the production of gas during the conversion in order to improve the relative yield of liquid products of interest.

The present invention thus proposes, according to a first aspect, a process for hydroconversion of a plastic filler comprising the following steps:
(a1) a step of non-catalytic hydroconversion of said feed in the presence of hydrogen, in contact with a source of radicals, said source comprising sulfur and being introduced so that the sulfur content is between 3% and 20% by weight relative to the weight of the plastic filler, to produce first conversion products;
(a2) a step of catalytic hydroconversion of the first conversion products in the presence of hydrogen, in contact with at least one hydroconversion catalyst, said hydroconversion catalyst comprising at least one hydro-dehydrogenating element chosen from the group formed by the non-noble elements of group VIB and group VIII of the periodic table, taken alone or in a mixture, and a porous support comprising a porous mineral matrix and at least one zeolite,
said steps (a1) and (a2) being implemented at an absolute pressure of between 1 MPa and 38 MPa, at a temperature greater than or equal to 200°C and less than 400°C, at an hourly space speed relative to each hydroconversion reactor between 0.05 h ^-1 and 10 h ^-1 , and with a quantity of hydrogen between 50 Nm ³ /m ³ and 5000 Nm ³ /m ³ .

Compared to other plastic conversion technologies, in particular pyrolysis, the process according to the present invention has the advantage, among others, of being more economical in energy and in operating and investment costs, thanks to to its operation at a lower temperature than pyrolysis.

The process according to the present invention can also make it possible to vary the composition of the products obtained, in particular thanks to the selectivity provided by the catalyst during the second catalytic hydroconversion step, which can be chosen according to the targeted valorization (e.g. kerosene for the aeronautical sector, diesel or gasoline for the automobile sector, naphtha for steam cracking, etc.).

According to one or more implementations of the invention, steps (a1) and (a2) are carried out within the same reactor, preferably within the same bubbling bed reactor.

According to one or more implementations of the invention, steps (a1) and (a2) are carried out in two separate reactors, preferably steps (a1) and (a2) being carried out in two separate ebullated bed reactors or step (a1) being carried out in a bubbling bed reactor and step (a2) being carried out in a fixed bed reactor.

According to one or more implementations of the invention, said at least one zeolite of the hydroconversion catalyst support is chosen from the list consisting of zeolites of FAU groups, preferably zeolites of FAU group chosen from zeolites X, Y, USY, Y having undergone a dealumination treatment, BEA, ISV, IWR, IWW, MEI, UWY, MEL, MTW, MTT, MSE, FER and MFI, and preferably, said at least one zeolite is chosen from zeolites from the FAU or BEA groups.

According to one or more implementations of the invention, the catalyst support comprises a USY zeolite and/or a Beta zeolite.

According to one or more implementations of the invention, the support of the hydroconversion catalyst comprises at least one zeolite chosen from the group formed by the zeolites ZSM-12, IZM-2, ZSM-22, ZSM-23, SAPO- 11, ZSM-48, and ZBM-30.

According to one or more implementations of the invention, the hydroconversion catalyst comprises:

- between 0.1% and 50% by weight of said at least one hydro-dehydrogenating element from the group formed by the non-noble elements of group VIB and group VIII, expressed in weight of oxide relative to the total weight of said catalyst;
- between 0.1 to 99.9% by weight of a porous support relative to the total weight of said catalyst, said support comprising between 0.1% and 80% by weight of zeolite relative to the total weight of said support, and between 0, 1% and 99.9% weight of a porous mineral matrix expressed in weight of oxide relative to the total weight of said support;
- between 0 to 20% by weight, and preferably between 0.1% and 20% by weight, of at least one element chosen from the group formed by phosphorus, boron, and silicon, expressed in weight of oxide by relative to the total weight of said catalyst;
- between 0 to 20% by weight of at least one element from group VIIA, preferably 0.1 to 20%;
- between 0 to 20% by weight of at least one element from group VIIB, preferably 0.1 to 20%, 0 to 60% by weight of at least one element from group VB, preferably 0.1 to 60%;
the percentages being expressed as a weight percentage relative to the total mass of catalyst, the sum of the percentages of the elements constituting said catalyst being equal to 100%.

According to one or more implementations of the invention, the hydroconversion catalyst comprises a porous mineral matrix consisting of at least one refractory oxide chosen from the group formed by alumina, silica-alumina, clay, titanium oxide, boron oxide and zirconia, taken alone or as a mixture, and preferably the porous mineral matrix is alumina.

According to one or more implementations of the invention, the hydroconversion catalyst comprises, as hydro-dehydrogenating elements, at least one non-noble group VIII metal chosen from nickel and cobalt, preferably nickel, and at least one metal from Group VIB chosen from molybdenum and tungsten, preferably molybdenum.

According to one or more implementations of the invention, the source of radicals comprising sulfur is chosen from the list consisting of H ₂ S, elemental sulfur, carbon disulfide (CS ₂ ), dimethyl sulfide ( DMS), dimethyl sulfoxide (DMSO), diethyl sulfide (DES), dimethyl disulfide (DMDS of formula (CH ₃ S) ₂ ), mercaptans, polysulfides such as di-tert-nonyl polysulfide, taken alone or as a mixture, and preferably chosen from H ₂ S, DMS, DMDS, and DES.

According to one or more implementations of the invention, the sulfur content in step (a1) is between 3% and 15% by weight relative to the weight of the plastic filler, preferably between 3% and 10% by weight. of the load.

According to one or more implementations of the invention, the method further comprises:
(a0) a preliminary step of conditioning said load for its introduction into a reactor in which at least the first step (a1) is carried out, said step (a0) comprising:
- sending the plastic filler in the form of solid particles into an extruder, preferably with a plastic diluent, in which it is gradually heated to a temperature higher than the melting temperature of said plastic filler, and put to the pressure of the first hydroconversion reactor, during conveying, and
- the introduction of the extruded plastic filler into said reactor.

According to one or more implementations of the invention, the plastic filler is in solid form and comprises one or more polymers chosen from the list consisting of alkene polymers, diene polymers, vinyl polymers, and styrenic polymers. , polyesters, and polyamides, and preferably said plastic filler comprises at least 50% by weight of polyolefins relative to the total weight of the plastic filler, said polyolefins preferably being chosen from the list consisting of polyethylene, polypropylene and/or or copolymers of ethylene and propylene.

According to one or more implementations of the invention, steps (a1) and (a2) are implemented at an absolute pressure of between 2 MPa and 25 MPa, and at a temperature greater than or equal to 300°C and less than 400°C.

Other objects and advantages of the invention will appear on reading the following description of particular embodiments of the invention, given as non-limiting examples.

Detailed description of the invention

In the following detailed description, many specific details are outlined in order to provide a more in-depth understanding of the process. However, it will appear to those skilled in the art that the process can be implemented without necessarily all these specific details. In other cases, well-known features have not been described in detail to avoid unnecessarily complicating the description.

Some definitions are given below for a better understanding of the invention.

In this description, the term “comprising” is synonymous with (means the same as) “include” and “contain”, and is inclusive or open and does not exclude other elements that are not mentioned. It is understood that the term “understand” includes the exclusive and closed term “consist”.

In this description, the expression “between… and…” means that the limit values of the interval are included in the range of values described, unless otherwise specified.

In the present invention, the different ranges of values of given parameters can be used alone or in combination. For example, a preferred range of pressure values may be combined with a more preferred range of temperature values, or a preferred range of values of one compound or chemical element may be combined with a more preferred range of values of another chemical compound or element.

Within the meaning of the present invention, the different embodiments presented can be used alone or in combination with each other, without limitation of combination.

In the present description, the groups of chemical elements are given according to the CAS classification (CRC Handbook of Chemistry and Physics, publisher CRC press, editor-in-chief D.R. Lide, 81st edition, 2000-2001). For example, group VIII according to the CAS classification corresponds to the metals of columns 8, 9 and 10 according to the new IUPAC classification, and group VIB to the metals of column 6.

The term "hydroconversion" refers to a process whose primary purpose is to reduce the boiling point range of a hydrocarbon feedstock, and in which a substantial portion of the feedstock is converted to products with higher boiling point ranges. boiling points lower than those of the original charge. Hydroconversion generally involves the fragmentation of larger molecules, typically hydrocarbons, into smaller molecular fragments having a smaller number of carbon atoms and a higher hydrogen to carbon H/C ratio. The reactions carried out during hydroconversion make it possible to reduce the size of hydrocarbon molecules, mainly by cleavage of carbon–carbon bonds, in the presence of hydrogen in order to saturate the cut bonds and the aromatic rings. The mechanism by which hydroconversion occurs typically involves the formation of free radicals, commonly hydrocarbons, during fragmentation primarily by thermal cracking, followed by capping of the free radical termini or fragments with hydrogen in the presence of sites of active catalysts. Of course, during a hydroconversion process, other reactions typically associated with hydrotreatment can occur, such as, among others, the elimination of sulfur or nitrogen from the feed, or the saturation of olefins, and as defined more broadly below. In French terminology, the term hydroconversion is rather reserved for processes which deal with heavy petroleum feedstocks such as atmospheric residues and vacuum residues (but not only), while the term hydrocracking is rather reserved for processes which deal with feedstocks lighter ones such as vacuum distillates and gas oils. In English terminology, the terms hydroconversion and hydrocracking are often used interchangeably. In the present description, the terms hydrocracking and hydroconversion are synonymous, the treated feed being of plastic type.

The term "hydrotreating", commonly called "HDT" refers to a gentler operation whose main purpose is to remove impurities such as sulfur, nitrogen, oxygen, halides, and traces of metals from the charge, and to saturate olefins and/or stabilize free radicals, typically hydrocarbons, by reacting them with hydrogen rather than letting them react with themselves. The main purpose is not to change the boiling point range of the filler. Thus, hydrotreatment notably includes hydrodesulfurization reactions (commonly called "HDS"), hydrodenitrogenation reactions (commonly called "HDN") and hydrodemetallation reactions (commonly called "HDM"), accompanied by d hydrogenation, hydrodeoxygenation, hydrodearomatization, hydroisomerization, hydrodealkylation, hydrocracking, hydrodeasphalting and carbon reduction Conradson. Hydrotreating is most commonly implemented using a fixed bed reactor, although other reactors can also be used for hydrotreating, for example an ebullated bed hydrotreating reactor.

The terms "porous supported catalyst", "solid supported catalyst", and "supported catalyst" refer to catalysts that are typically used in conventional ebullated bed and fixed bed hydroconversion systems, including catalysts designed primarily for hydrocracking or hydrodemetallation and catalysts designed primarily for hydrotreating. Such catalysts typically comprise (i) a catalyst support having a large surface area and numerous interconnected channels or pores and (ii) fine particles of an active catalyst such as cobalt, nickel, tungsten, molybdenum sulfides , or mixed sulphides of these elements (e.g. NiMo, CoMo, etc.), dispersed in the pores. Supported catalysts are commonly produced as cylindrical extrudates (“pellets”) or spherical solids, although other shapes are possible.

In the present description, according to the IUPAC convention, “micropores” means pores whose diameter is less than 2 nm; by “mesopores” the pores whose diameter is greater than 2 nm and less than 50 nm and by “macropores” the pores whose diameter is greater than or equal to 50 nm.

By “specific surface” is meant the B.E.T. specific surface area of zeolites, supports or catalysts. determined by nitrogen adsorption in accordance with standard ASTM D 3663-78 established from the BRUNAUER-EMMETT-TELLER method described in the periodical "The Journal of American Society", 60, 309, (1938).

The quantitative analysis of microporosity (pores with a diameter less than 2 nm) is carried out using the "t" method (method of Lippens-De Boer, 1965) which corresponds to a transform of the adsorption isotherm of starting nitrogen as described in the work "Adsorption by powders and porous solids. Principles, methodology and applications" written by F. Rouquérol, J. Rouquérol and K. Sing, Academic Press, 1999. Eight pressure points are used, P /P0 = 0.075, 0.100, 0.125, 0.150, 0.175, 0.200, 0.250 and 0.300

In the same way, by “total pore volume” of zeolites, supports or catalysts is meant the volume measured by nitrogen adsorption for P/P0 = 0.99, pressure for which it is accepted that nitrogen has filled all the pores.

By “mesoporous volume” of zeolites is meant the difference between the total pore volume described above and the microporous volume.

The method according to the invention and its operation are described in more detail below.

The object of the invention is to propose a process for hydroconversion of a plastic filler comprising the following steps:
(a1) a step of non-catalytic hydroconversion of said feed in the presence of hydrogen, in contact with a source of radicals, said source comprising sulfur and being introduced so that the sulfur content is between 3% and 20% by weight relative to the weight of the plastic filler, to produce first conversion products;
(a2) a step of catalytic hydroconversion of the first conversion products in the presence of hydrogen, in contact with at least one hydroconversion catalyst, said hydroconversion catalyst comprising at least one hydro-dehydrogenating element chosen from the group formed by the non-noble elements of group VIB and group VIII of the periodic table, taken alone or in a mixture, and a porous support comprising a porous mineral matrix and at least one zeolite,
said steps (a1) and (a2) being implemented at an absolute pressure of between 1 MPa and 38 MPa, at a temperature greater than or equal to 200°C and less than 400°C, at an hourly space speed relative to each hydroconversion reactor between 0.05 h ^-1 and 10 h ^-1 , and with a quantity of hydrogen between 50 Nm ³ /m ³ and 5000 Nm ³ /m ³ .

Load

The feed treated in the hydroconversion process according to the invention is a plastic feed.

The plastic filler of the process according to the invention comprises plastics which themselves comprise more particularly polymers.

Plastics or plastic materials are generally polymers which are most often mixed with additives, with a view to forming, after shaping, various materials and objects (injection molded parts, tubes, films, fibers, fabrics, putties, coatings, etc.). etc.). Additives used in plastics can be organic compounds or inorganic compounds. These are, for example, fillers, dyes, pigments, plasticizers, property modifiers, combustion retardants, etc.

Thus, by plastic filler, we mean a solid filler of plastics comprising one or more polymers, and which may contain other compounds, such as additives of organic or inorganic origin and/or impurities of use in particular from the cycle life of plastic materials and objects, and/or from the waste collection and sorting circuit. For example, the usual impurities can be metallic, organic or mineral; it may be packaging residues, food residues or compostable residues (biomass). Usage impurities may also include glass, wood, cardboard, paper, aluminum, iron, metals, tires, rubber, silicones, rigid polymers, thermosetting polymers, products household, chemical or cosmetic products, used oils, water.

In this description, the term “plastic impurities” means all the compounds initially contained in the plastic filler which are not polymers and which are not likely to be converted during the step(s) of the process. For example, certain organic additives can be at least partly converted in the process according to the invention, in the same way as polymers. These are therefore not considered plastic impurities. On the other hand, some of the inorganic additives can be eliminated during the process, for example those containing metals, and/or sulfur, and/or nitrogen, and/or oxygen, and/or other heteroatoms. (Cl, Br, etc.). They are considered plastic impurities.

The plastics included in the plastic load of the process load according to the invention are generally production scraps and/or waste, in particular household waste, building waste or even waste from electrical and electronic equipment. Preferably, plastic waste comes from collection and sorting channels.

The plastic filler of the process according to the invention therefore comprises polymers, and in particular thermoplastics. The polymers included in the plastic fraction of the filler may be alkene polymers, diene polymers, vinyl polymers, styrenic polymers (e.g. polystyrene “PS”), polyesters, and/or polyamides.
Preferably, the polymers included in the plastic filler of the invention are alkene polymers, diene polymers, vinyl polymers and/or styrenic polymers (e.g. polystyrene “PS”). Preferably, the polymers included in the plastic filler are polyolefins (alkene polymers), such as polyethylene (PE), polypropylene (PP) and/or copolymers of ethylene and propylene.
For example, the plastic filler of the filler comprises at least 50% by weight, preferably at least 80% by weight, preferably at least 90% by weight, and very preferably at least 94% by weight, of polyolefins relative to the weight. total plastic load.

The plastic filler may comprise mixtures of polymers, in particular mixtures of thermoplastics and/or mixtures of thermoplastics and other polymers, and compounds other than these thermoplastics and polymers, in particular the additives advantageously used to formulate the plastic material and generally usage impurities from the life cycle of plastic materials and objects, and/or from the waste collection and sorting circuit. The plastic filler of the process according to the invention generally comprises less than 50% by weight of these usual additives and impurities, preferably less than 20% by weight, and preferably less than 10% by weight.

The plastic filler can advantageously be pretreated upstream of the process so as to at least eliminate all or part of the so-called coarse usage impurities, that is to say usage impurities in the form of particles of size greater than or equal to 10 mm, preferably greater than or equal to 5 mm, or even greater than or equal to 1 mm, for example impurities of use such as wood, paper, biomass, iron, aluminum, glass, etc., and to generally shape it in particulate form (divided solids) so as to facilitate processing in the process. This pretreatment may include a grinding step, a washing step at atmospheric pressure and/or a drying step. This pretreatment can be carried out on a different site, for example in a waste collection and sorting center, or on the same site where the treatment process according to the invention is implemented. Preferably, this pretreatment makes it possible to reduce the content of usual impurities to less than 6% by weight. At the end of pretreatment, the plastic filler is generally stored in the form of particles, for example in the form of ground material or powder, so as to facilitate handling and transport to the process.

(a0) Optional load conditioning step for his injection in the first hydroconversion reactor

The process according to the invention may include a step (a0) of conditioning the plastic filler for its injection into the first hydroconversion reactor.

In the present description, “first hydroconversion reactor” means the reactor in which at least step (a1) is carried out, that is to say when step (a1) is carried out or in which is the two steps (a1) and (a2) are carried out if they are implemented in the same reactor. Thus, if the two stages are carried out in separate reactors, the hydroconversion reactor of stage (a2) is not the first hydroconversion reactor.

By conditioning of the feedstock we mean its conditioning for the step (a1) which follows hydroconversion of the feed once introduced into the first hydroconversion reactor, that is to say its putting into a state and at temperature and pressure conditions suitable for hydroconversion in the first hydroconversion reactor.

The plastic filler initially in solid form can be conditioned before sending it to the first hydroconversion reactor, in particular to adapt to the type of hydroconversion reactor used and facilitate its conversion.

According to one or more embodiments, the plastic filler in the form of solid particles is sent to an extruder, preferably with a plastic diluent, in which it is gradually heated to a temperature higher than the melting temperature of said plastic filler. , and putting the first hydroconversion reactor under pressure, during conveying preferably for a period of less than 15 minutes, and the extruded plastic filler is introduced into the reactor.

According to these embodiments, the plastic filler introduced into the first hydroconversion reactor by extrusion is in an essentially liquid form.

Extrusion is classically a process which allows the injection or shaping of a polymer initially in the solid state. According to an extrusion process, the material is transported via one or more screws, kneaded and heated, which allows it to melt. And at the same time, the screw(s) convey the material and cause it to rise in pressure, which allows it to be injected into a die or into a mold.

According to these embodiments of the invention, the extrusion of the plastic filler is a means of introducing the plastic filler which is solid at room temperature into the first hydroconversion reactor operating under high pressure and temperature. Extrusion therefore makes it possible to heat, with a view to liquefying, and to pressurize the plastic filler under the operating conditions of the reactor described below.

The material is not injected into a die or a mold as in a classic extrusion process, thus not constituting a shaping process, but it is injected directly into the reactor.

The “plastic diluent” is for example formed by a hydrocarbon or a mixture of light liquid hydrocarbons. For example, the plastic diluent is a hydrocarbon oil composed of hydrocarbons of which at least 50% by weight, and preferably at least 80% by weight, relative to the weight of the plastic diluent, have a boiling point below 300°. vs. Examples of suitable hydrocarbon diluents include, but are not limited to, light liquid hydrocarbons, typically C5+ hydrocarbons, i.e. hydrocarbons which may have 5 and more carbon atoms per molecule, for example xylene, toluene, gasoline , their mixtures, etc. The plastic diluent can act as a solvent for the plastic fraction, in particular for the polymer(s) of the plastic filler.

During extrusion, the plastic filler is preferably gradually heated to a temperature higher than its melting temperature so as to melt. Advantageously, at least 80% by weight of the plastic fraction is in liquid form (molten) after extrusion, very advantageously at least 90% by weight, preferably at least 95% by weight, or even 98% by weight. . As described above, the plastic fraction generally contains compounds other than polymers, in particular plastic impurities. Some of these non-polymeric compounds, including plastic impurities, may be insoluble and/or have a higher melting point than the polymer(s) of the plastic fraction. Even if all of the polymer(s) melt, part of the liquid fraction, taking into account non-polymeric compounds, can therefore remain in solid form. This is true for all the steps described below in which heating results in total or almost total liquefaction of the plastic fraction.

The extrusion temperature depends on the polymer composition(s) of the plastic filler (nature and proportion(s) of the polymer(s).

Preferably, the extruder is operated at a temperature between a temperature of 25°C lower than the melting temperature of the plastic filler and a temperature of 25°C higher than the melting temperature of the plastic filler.

In the case where the plastic filler comprises a mixture of polymers, the extruder is operated at a temperature between a temperature of 25°C lower than the melting temperature of the least refractory polymer (i.e. which has the lowest melting temperature low) of the plastic filler and a temperature of 25°C higher than the melting temperature of the most refractory polymer (i.e. which has the highest melting temperature) of the plastic filler.

Advantageously, the plastic filler is preferably gradually heated in the extruder to a temperature higher than the melting temperature of the polymer which has the highest melting point.

As an indication, the melting temperature of polypropylene (PP) is approximately 170°C, the melting temperature of polyethylene (PE) is between approximately 85°C and 140°C, and the melting temperature of polystyrene ( PS) is between approximately 240°C and 270°C.

Preferably, the extruder is operated at a temperature between 60°C and 295°C, more preferably between 60° and 195°C.

Advantageously, the extruder is operated at a temperature between 60°C and 165°C, so as to melt a plastic filler mainly comprising PE as polymer.

Advantageously, the extruder is operated at a temperature between 145°C and 195°C, so as to melt a plastic filler mainly comprising PP as polymer.

Advantageously, the extruder is operated at a temperature between 215°C and 295°C, so as to melt a plastic filler mainly comprising PS as polymer.

The operating temperature of the extruder is advantageously adapted according to the composition of the plastic filler.

Advantageously, the extruder comprises at least one screw conveying section, called the extrusion section, supplied with the plastic fraction.

The residence time in this extrusion section (volume of said section divided by the volume flow rate of plastic fraction) is advantageously less than 15 minutes, preferably less than 10 minutes, and preferably less than 2 minutes.

Said extrusion section is advantageously connected to a vacuum extraction system so as to remove impurities such as dissolved gases, light organic compounds and/or moisture which may be present in the plastic fraction.

Said extrusion section can also advantageously comprise a filtration system to eliminate solid particles of undesirable size, for example of a size greater than 200 µm, and preferably of a size greater than 40 µm, such as sand particles. If a diluent is used, as the viscosity may decrease, it is possible to filter particles of smaller size, for example larger than 3 µm.

According to one or more other embodiments, the plastic filler in the form of solid particles is mixed with a plastic diluent in a mixing section and heated in a heating section to a temperature higher than the melting temperature of said plastic filler, preferably between 60°C and 295°C, before its introduction into the first hydroconversion reactor, the heating step being able to be carried out before or after mixing with the plastic diluent, and preferably after mixing with the plastic diluent .

These embodiments thus correspond to a direct injection of the plastic filler in an essentially liquid form, after said plastic filler has been mixed with a plastic diluent to form a slurry then heated so as to obtain an essentially liquid plastic filler.

By plastic filler in an essentially liquid form, it is meant that at least 80% by weight of the polymer(s) of the plastic filler are in a liquid form, preferably at least 90% by weight, more preferably at least 95% by weight, and even more preferably at least 98% by weight. By polymers of the plastic fraction in a liquid form is meant polymers which are not in a solid form, the latter being generally considered to correspond to the crystalline, semi-crystalline and amorphous states of a polymer.

By slurry we mean a mixture of substances in suspension form, which usually corresponds to a system formed of solid particles dispersed in a liquid (liquid dispersion). More specifically, a plastic filler in suspension form corresponds to a system comprising solid plastic particles dispersed in a liquid, for example a system comprising between 1% by weight and 50% by weight of solid plastic particles dispersed in a liquid, or even between 1% weight and 30% weight or between 5% weight and 20% weight. The continuous liquid phase in which the solid plastic particles are dispersed can be a diluent.

These embodiments have the particular advantage of using simple and inexpensive equipment.

The plastic filler in the form of solid particles may be premixed with a plastic diluent in a mixing section to form a suspension, and then the suspension may be sent to a heating section to be heated to a temperature above the melting temperature of said plastic fraction, so that the solid particles of the plastic filler in suspension melt, and said heated plastic filler can then be introduced into the first hydroconversion reactor. The mixing of the plastic diluent and the plastic filler in particulate form in the mixing section is preferably carried out at atmospheric pressure or a pressure close to atmospheric pressure.

Preferably, during the mixing step in the mixing section, the temperature is such that the suspension has a kinematic viscosity of less than ^0.3.10-3 m ² /s, corresponding to the viscosity of a pumpable fluid. The temperature at this step is preferably lower than the temperature operated in the heating step described below, in the case where the mixing step is separated and precedes that of heating.

The mixing section may comprise a mixing tank comprising dynamic stirring means for suspension, for example an agitator and/or a recirculation pump.

After heating the suspension, the plastic filler is essentially in liquid form.

What has been described for the temperature conditions of the extruder of the other embodiments described above applies to the heating of the suspension, and is therefore not repeated here.

The heating temperature may also depend on the plastic thinner used, such a plastic thinner being able in particular, depending on its nature, to allow the plastic filler in suspension to melt at a lower temperature.

The heating section comprises any heating means known to those skilled in the art capable of heating a plastic load in suspension, and for example include an oven comprising at least one heating compartment, and/or tubes in which the suspension flows, some type of suitable heat exchanger, etc.

The mixing section and the heating section can be part of the same device configured to consecutively carry out mixing then heating.

Before its introduction into the first hydroconversion reactor, the heated plastic load can undergo a pressurization step to be adapted to the pressure operated in the first hydroconversion reactor, for example using a suitable pump. It can also be subjected to a filtration step aimed, for example, at eliminating solid particles from the plastic filler which may be part of plastic impurities, such as sand, glass, metals, certain additives called "fillers" in English, etc.

According to another variant, a direct injection of the plastic filler can be carried out in an essentially liquid form after said plastic filler has been heated so as to obtain an essentially liquid plastic fraction, then mixed with a plastic diluent to form a plastic filler. diluted introduced into the first hydroconversion reactor.

According to yet another variant, the mixing step and the heating step are carried out simultaneously, the mixing and heating sections then forming part of the same device configured to carry out mixing and heating simultaneously.

According to one or more other embodiments, a direct injection of the plastic filler suspended into the first hydroconversion reactor is carried out: the plastic filler in the form of solid particles is previously sent to a mixer to be mixed with a plastic diluent and form a suspension, preferably at a temperature greater than or equal to ambient temperature and lower than the melting temperature of said plastic filler, and said plastic filler in suspension form is introduced into the first hydroconversion reactor.

These embodiments also have the advantage of using simple and inexpensive equipment.

According to these embodiments, the plastic filler in the form of solid particles is first sent to a mixer to be mixed with a plastic diluent and form a suspension, then said plastic filler in the form of suspension is introduced into the first hydroconversion reactor.

The mixing of the plastic diluent and the plastic filler in the mixer is preferably carried out at a temperature greater than or equal to ambient temperature, e.g. 15°C, and lower than the melting temperature of said plastic filler (or lower than the temperature melting point of the polymer which has the lowest melting point if said plastic filler comprises a mixture of polymers). A temperature slightly lower than the melting temperature of the plastic filler can constitute the upper limit for the temperature of the mixture, because the plastic diluent used, depending on its nature, has an influence on the temperature at which the plastic filler can be dissolved ( in the case where the plastic thinner has a solvent function).

According to one configuration, the mixture can be carried out at a temperature greater than or equal to 50°C or even 75°C and less than 170°C, for example well suited to the use of a VGO as a plastic diluent and to a plastic filler mainly comprising PP as polymer, or at a temperature greater than or equal to 150°C and less than 170°C, for example well suited to the use of a vacuum residue as a plastic diluent and a plastic filler mainly comprising PP as polymer.

According to one configuration, the mixture can be carried out at a temperature greater than or equal to 50°C or even 75°C and less than 140°C, or even carried out at a temperature greater than or equal to 50°C or even 75°C and below 85°C, for example well suited to the use of a VGO as a plastic diluent and to a plastic filler mainly comprising PE as a polymer.

According to one configuration, the mixture can be carried out at a temperature greater than or equal to 50°C or even 75°C and less than 270°C, or even carried out at a temperature greater than or equal to 50°C or even 75°C and below 240°C, for example well suited to the use of a VGO as a plastic diluent and to a plastic filler mainly comprising PS as a polymer, or even at a temperature greater than or equal to 150°C and lower than 270°C, or even lower than 240°C, for example well suited to the use of a vacuum residue as a plastic diluent and to a plastic filler mainly comprising PS as polymer.

The mixture may or may not be active. Examples of active mixing devices that may be used include, but are not limited to, high shear mixing such as mixing created in a pump with a propeller or turbine rotor, multiple static in-line mixers, multiple static in-line mixers in combination with high-shear in-line mixers, multiple static in-line mixers in combination with high-shear in-line mixers, multiple static in-line mixers in combination with high-shear in-line mixers followed by recirculation pumping into the buffer tank, combinations of the above devices followed by one or more multi-stage centrifugal pumps.

Before their introduction into the first hydroconversion reactor, the suspended plastic load can undergo a pressurization step to be adapted to the pressure operated in the first hydroconversion reactor.

(a1) thermal conversion step promoted by sulfur

According to the invention, the process comprises a first step (a1) of non-catalytic hydroconversion of the plastic filler in the presence of hydrogen in contact with a source of radicals, to produce first conversion products.

By non-catalytic, we mean that the hydroconversion step (a1) is carried out without involving catalytic reactions by means of a catalyst, i.e. hydroconversion catalyst as it is known to be used during a classic hydroconversion, typically a porous supported catalyst or an entrained catalyst also called "slurry" (catalyst of very small size, e.g. less than 1 µm in diameter, dispersed in the reaction medium, distributed uniformly in the reactor, and entrained with the products leaving the reactor) formed for example from a soluble catalyst precursor of metallic or organometallic type.

No catalyst of this type (porous supported or slurry) participates in the reactions in step (a1) of the process according to the invention.

The radical source comprises sulfur, and may be referred to as sulfur radical source in the remainder of the description.

The source of sulfur radicals is introduced so that the sulfur content (elemental sulfur S) is between 3% and 20% by weight relative to the weight of the charge, preferably between 3% and 15% by weight, preferably between 3 % and 10% weight.

According to one or more embodiments of the invention, the source of sulfur radicals is chosen from the non-exhaustive list of the following compounds: H ₂ S, elemental S, carbon disulfide (CS ₂ ), dimethyl sulfide (DMS), dimethyl sulfoxide (DMSO), diethyl sulfide (DES), dimethyl disulfide (DMDS of formula (CH ₃ S) ₂ ), mercaptans, polysulfides (for example of general formula R ₁ -SSR ₂ or RSS-SH, with R, R ₁ and R ₂ which may be an H, an alkyl or an aryl) such as for example di-tert-nonyl polysulphide, taken alone or as a mixture. Preferably, the source of sulfur radicals is chosen from the list consisting of H ₂ S, DMS, DMDS, DES, and preferably is DMDS or H ₂ S.

The operating conditions are described in more detail below, along with those of the hydroconversion step (a2).

Without being bound by any theory, a radical mechanism involving H ₂ S and HS • radicals such as that highlighted in the prior art and described above, could explain at least in part the promotion of conversion of the plastic filler at this step (a1) of the process according to the invention.

During this hydroconversion stage, a maximum amount of plastic filler is converted. In particular, the process according to the invention advantageously makes it possible to convert more than 50% by weight of the solid plastic filler into non-solid conversion products, i.e. liquid and gaseous, preferably more than 65% by weight, even more preferably more than 80%. weight, and even more preferably more than 90% weight.

The first conversion products are hydrocarbons which can be characterized by boiling point ranges. Conventionally, a hydrocarbon cut is defined by an initial boiling point greater than or equal to a first temperature, and a final boiling point lower than a second temperature greater than the first temperature. For simplification, we can use the expression “boiling range from… to…. » to express these initial (within range) and final (not within range) boiling points.

The first conversion products include hydrocarbon cuts lighter than naphtha (typical boiling range of PI at 80°C, PI being the initial point of the distillation curve), naphtha type (typical boiling range of 80°C). °C to 150°C), kerosene (typical boiling range 150°C to 250°C), diesel (typical boiling range 250°C to 370°C), heavy cuts (typical boiling range boiling 370°C to 540°C), very heavy (typical boiling range 540°C to 740°C) and extra heavy (typical boiling range above 740°C).

The first conversion products can also include small quantities of gaseous products, typically gases such as hydrocarbons from C1 to C6 (i.e. having between 1 and 6 carbon atoms).

(a2) catalytic hydroconversion step

According to the invention, the process comprises a second step (a2) of catalytic hydroconversion of the first conversion products in the presence of hydrogen, in contact with at least one hydroconversion catalyst.

This second step (a2) of catalytic hydroconversion forms second conversion products.

These second conversion products are a mixture of recoverable hydrocarbons, in particular hydrocarbon cuts which can in particular be characterized as described for the first hydroconversion products, by boiling point ranges. These cuts can serve as fuel bases or raw materials for petrochemicals (light hydrocarbons, distillates intended for a steam cracker in particular for the production of recycled polyolefins, bases for the production of bitumens, lubricants, etc.), in particular directly after fractionation or after fractionation followed by one or more subsequent treatments in step (a2), for example a hydrotreatment aimed at eliminating residual sulfur or other possible contaminants such as for example nitrogen, chlorine, silicon or metals.

Second conversion products include hydrocarbon cuts lighter than naphtha (typical boiling range of PI at 80°C), naphtha-like (typical boiling range of 80°C to 150°C), kerosene (typical boiling range of 80°C to 150°C), typical boiling range of 150°C to 250°C), diesel (typical boiling range of 250°C to 370°C), heavy cuts (typical boiling range of 370°C to 540°C), very heavy (typical boiling range 540°C to 740°C) and extra heavy (typical boiling range above 740°C).

The second conversion products may also include small quantities of gaseous products, typically gases such as C1 to C6 hydrocarbons. Preferably, less than 30% of gas is produced during step (a1), more preferably less than 20% by weight, and even more preferably less than 15% by weight relative to the charge.

The combination of the first hydroconversion step (a1) promoted by sulfur, without catalyst and of the catalytic hydroconversion step (a2) based in particular on a catalyst adapted to low temperature operation, thio-resistant, and selective, makes it possible to maximize the conversion of the plastic filler while minimizing the energy required for the conversion, and while minimizing the production of gas during the conversion in order to improve the relative yield of liquid products of interest.

Indeed, the inventors have demonstrated that with the combination of these two steps (a1) and (a2), it was surprisingly possible to minimize the yield of gaseous hydrocarbons at the end of the hydroconversion, i.e. hydrocarbons in C1 to C6, relative to the liquid products obtained.

The choice of the catalyst in step (a2), and in particular the selectivity provided by the catalyst, also makes it possible to modify the composition of the liquid products obtained, depending on the targeted recovery. For example, it may be advantageous to maximize a naphtha cut for a steam cracking application, or a kerosene cut for the aeronautics sector, or even a very heavy cut for the production of bitumen, for example by choosing a more selective catalyst in one or other of these cuts.

The catalyst

The hydroconversion catalyst used in the process according to the invention is a bifunctional type hydrocracking catalyst combining an acid function with a hydro-dehydrogenating function and at least one binder matrix.
Such catalysts are well known in the field of hydrocracking.
Such hydrocracking catalysts are generally classified on the basis of the nature of their acid function, in particular catalysts comprising an amorphous acid function of the silica alumina type and catalysts comprising a zeolite cracking function such as zeolite Y or zeolite beta. . Hydrocracking catalysts can also be classified according to the majority product obtained when used in a hydrocracking process (the two main products generally being middle distillates and naphtha in conventional hydrocracking processes dealing with a feedstock such as vacuum distillates or gas oils).

The hydroconversion catalyst used in the process according to the invention comprises at least one hydro-dehydrogenating element chosen from the group formed by the non-noble elements of group VIB and group VIII of the periodic table, taken alone or as a mixture, and a porous support which comprises, and is preferably constituted by, a porous mineral matrix and at least one zeolite.

The hydroconversion catalyst is thio-resistant, at least by the nature of the hydro-dehydrogenating element(s) it contains. It can thus support the presence of sulfur from sulfur radicals, in particular in the case where steps (a1) and (a2) are implemented in the same reactor.

Depending on the choice of catalyst, it may be possible to promote hydrotreatment reactions of the heteroatoms contained in the feed.

The hydroconversion catalyst advantageously comprises:

- between 0.1% and 50% by weight of said at least one hydro-dehydrogenating element from the group formed by the non-noble elements of group VIB and group VIII, expressed in weight of oxide relative to the total weight of said catalyst;
- between 0.1% and 99.9% by weight of a porous support relative to the total weight of said catalyst, said support comprising between 0.1% and 80% by weight of zeolite(s) relative to the total weight of said support, preferably between 2% and 70% by weight, and very preferably between 3 and 60% by weight, and between 0.1% and 99.9% by weight of porous mineral matrix (binder), expressed in weight of oxide relative to to the total weight of said support;
- between 0 and 20% by weight, and preferably between 0.1% and 20% by weight, of at least one element chosen from the group formed by phosphorus, boron, and silicon, expressed in weight of oxide by relative to the total weight of said catalyst (in weight of P ₂ O ₅ oxide for phosphorus, in weight of B ₂ O ₃ oxide for boron, and in weight of SiO ₂ oxide for silicon);
- between 0 and 20% by weight of at least one element from group VIIA, preferably between 0.1% and 20%;
- between 0 and 20% by weight of at least one element from group VIIB, preferably between 0.1% and 20%,
- between 0 and 60% by weight of at least one element from group VB, preferably between 0.1% and 60%,
the percentages being expressed as a weight percentage relative to the total mass of catalyst, the sum of the percentages of the elements constituting said catalyst being equal to 100%.

The hydro function - dehydrogenating

The hydroconversion catalyst in step (a2) comprises at least one hydro-dehydrogenating element chosen from the group formed by the non-noble elements of group VIB and group VIII of the periodic table, taken alone or as a mixture.

Advantageously, the hydroconversion catalyst of the process according to the invention does not contain noble metals, which can make the catalyst sensitive to certain compounds such as sulfur compounds, and harm its activity.

Preferably, the non-noble group VIII elements are chosen from iron, cobalt, and nickel, taken alone or in a mixture, and preferably from nickel and cobalt.

Preferably, the elements of group VIB are chosen from chromium, tungsten and molybdenum, taken alone or in a mixture, and preferably from molybdenum and tungsten.

The following combinations of metals are preferred: nickel-molybdenum (NiMo), nickel-molybdenum-tungsten (NiMoW), and nickel-tungsten (NiW), and very preferably nickel-molybdenum (NiMo).

The non-noble Group VIII element content of the catalyst is advantageously between 0 and 20% by weight of oxide relative to the total weight of said catalyst, preferably between 0.5% and 10% by weight of oxide and very preferably between 1% and 8% by weight of oxide.

The group VIB element content of the catalyst is advantageously between 1% and 50% by weight of oxide relative to the total weight of said catalyst, preferably between 5% and 40% by weight of oxide, and more preferred between 10% and 35% by weight of oxide.

Preferably, the hydroconversion catalyst used in the process according to the invention also contains a promoter element chosen from phosphorus, boron, silicon, and very preferably phosphorus.

According to one or more preferred embodiments, the hydroconversion catalyst comprises nickel and molybdenum, and optionally phosphorus.

When the catalyst contains phosphorus, the phosphorus content is generally less than 15% by weight of P ₂ O ₅ oxide relative to the total weight of said catalyst, preferably between 0.1% and 10% by weight of P ₂ O ₅ oxide, and more preferably between 0.2% and 6% by weight of P ₂ O ₅ oxide.

The hydroconversion catalyst may also contain at least one group VIIA element, preferably chosen from chlorine and fluorine.

The hydroconversion catalyst may also contain at least one group VIIB element, preferably manganese.

The hydroconversion catalyst may also contain at least one group VB element, preferably niobium.

The catalyst support

The hydroconversion catalyst in step (a2) comprises a porous support which comprises and is preferably constituted by at least one porous mineral matrix and at least one zeolite.

Preferably, said zeolite is chosen from 10MR zeolites (zeolite having channels whose opening is defined by a ring of 10 oxygen atoms) or 12MR (zeolite having channels whose opening is defined by a ring of 12 oxygen atoms).

According to one or more preferred embodiments, the support of the hydroconversion catalyst comprises at least one zeolite chosen from zeolites belonging to the FAU groups (including zeolites X, Y, USY and any other designation of zeolites Y having undergone a treatment of dealumination), BEA, ISV, IWR, IWW, MEI, UWY, MEL, MTW, MTT, MSE, FER or MFI, and preferably, among zeolites of the FAU or BEA groups.
Some examples of zeolites from the preceding families without restricting the list of possible choices are cited below: ZSM-5 (MFI), ZSM-11 (MEL), ZSM-12 (MTW), ZSM- 23 (MTT), ZSM-35 (FER), ZSM-48 (MRE), CP841E, CP814C, CP811C-300, HSZB25, HSZB30, HSZB150, HSZ931, HSZ940, HSZ980 (BEA), or Y82, Y84, CP300-56 , CBV712, CBV720, CBV760, CBV780, CBV500, HSZ320, HSZ330, HSZ331, HSZ385, HSZ350, HSZ360, HSZ390, HSZ341, or HSZ371 (FAU, or USY).

Preferably the support comprises a USY zeolite and/or a Beta zeolite, alone or in a mixture, and preferably, it comprises and preferably consists of a USY zeolite. All methods of preparing zeolites can be applied to obtaining the zeolites used in the preparation of the catalyst.

According to one or more embodiments, the support of the hydroconversion catalyst comprises a USY zeolite and a Beta zeolite.

According to one or more embodiments, the support of the hydroconversion catalyst comprises at least one zeolite chosen from the group formed by the zeolites ZSM-12, IZM-2, ZSM-22, ZSM-23, SAPO-11, ZSM-48 , and ZBM-30.

Said zeolites are advantageously defined in the classification “Atlas of Zeolite Framework Types, 6th revised edition”, Ch. Baerlocher, L. B. McCusker, D.H. Olson, 6th Edition, Elsevier, 2007, Elsevier".

These designations USY, Beta, ZSM-12 etc. are common in the literature but they do not however restrict the characteristics of the zeolites used in the process of the present invention to such a designation.

The USY zeolite which can be used in the catalyst support of the process according to the invention advantageously has at least one of the following characteristics:

- a specific surface area measured by nitrogen physisorption according to the BET method greater than 500 m ² /g, preferably between 600 m ² /g and 1100 m ² /g, even more preferably between 750 m ² /g and 1000 m ² /g,

- a mesoporous volume of between 0.05 mL/g and 0.9 mL/g, preferably between 0.08 mL/g and 0.7 mL/g and even more preferably between 0.1 mL/g and 0.6 mL/g,

- has a mesh parameter (which can be measured by even more preferably between 24.20 Å and 24.56 Å,

- a Si/Al molar ratio of between 2 and 300, preferably between 2.5 and 150, even more preferably between 2.5 and 100 (characterization possible by semiquantitative X-ray fluorescence for the Si content) and ICP ( Induced Coupled Plasma)).

The Beta zeolite which can be used in the catalyst support of the process according to the invention advantageously has a Si/Al molar atomic ratio of between 5 and 300, preferably between 6 and 200, and preferably between 6 and 100.

The Beta zeolite used can also have a specific surface area measured by nitrogen physisorption according to the BET method greater than 500 m ² /g, preferably between 550 m ² /g and 900 m ² /g, even more preferably between 550 m ² /g and 800 m ² /g, and a mesoporous volume of between 0.05 mL/g and 0.9 mL/g, preferably between 0.1 mL/g and 0.9 mL/g and even more preferably between 0.15 mL/g and 0.85 mL/g.

Preferably, the total weight content of zeolite(s) of the support is between 0.1% and 80% by weight relative to the weight of the support of said catalyst, preferably between 2% and 70% by weight and preferably between 3%. and 60% weight.

When the support comprises a mixture of a USY zeolite and a Beta zeolite, the weight ratio of USY relative to Beta is preferably between 1 and 20, more preferably between 1.5 and 18, and even more most preferred between 2 and 15.

The porous mineral matrix used in the catalyst support, also called binder matrix or binder, is advantageously made up of at least one refractory oxide, preferably chosen from the group formed by alumina, silica-alumina, clay, titanium oxide, boron oxide and zirconia, taken alone or in a mixture. Preferably, the porous mineral matrix is chosen from alumina and silica-alumina, taken alone or as a mixture. Even more preferably, the porous mineral matrix is alumina. Alumina can advantageously be in all its forms, known to those skilled in the art. For example, the alumina is chosen from the group composed of alpha, rho, chi, kappa, eta, gamma, theta and delta aluminas, preferably chosen from gamma, theta and delta aluminas, and even more preferably is gamma alumina, for example boehmite.
In the case where the support comprises alumina, the weight content of alumina in the catalyst support can be between 1% and 99.9% by weight relative to the total weight of said support, preferably between 30% and 98% by weight and even more preferably between 40% and 97% by weight.

According to one or more embodiments, the support of the hydroconversion catalyst also comprises an amorphous silica alumina. Such a catalyst support is called “composite”. These composite supports are known as supports consisting of a mixture of very acidic zeolite(s), for example USY zeolite, and a moderately acidic amorphous matrix, for example silica-alumina, and as having intermediate activity and selectivity. The acid function of the catalyst is mainly based on the mixture of zeolite(s) and amorphous silica alumina of the support. The weight content of amorphous silica-alumina in the support can be between 1% and 99.9% by weight relative to the total weight of said support, preferably between 30% and 98% by weight, and preferably between 40% and 97% by weight. % weight. In the case of using such a catalyst with a composite support, the support may also comprise a binder, other than amorphous silica alumina, and which may be chosen from the group formed by alumina, clay, titanium oxide, boron oxide and zirconia, taken alone or as a mixture, and preferably be alumina. Alumina can advantageously be presented in all its forms known to those skilled in the art. Very preferably, the alumina is chosen from the group composed of alpha, rho, chi, kappa, eta, gamma, theta and delta aluminas, preferably chosen from gamma, theta and delta aluminas. In the case where said support comprises alumina, the weight content of alumina in the catalyst support may be between 1% and 70% by weight relative to the total weight of said support, preferably between 2% and 60% by weight and even more preferably between 5% and 50% by weight.

Preferably, the porous support comprising at least one zeolite advantageously has a total porous volume of between 0.15 cm ³ .g ^-1 and 1.2 cm ³ .g ^-1 , preferably between 0.18 cm ³ .g ^{- 1} and 1.1 cm ³ .g ^-1 , and very preferably between 0.2 cm ³ .g ^-1 and 1.0 cm ³ .g ^-1 .

The BET surface of the support comprising at least one zeolite is advantageously greater than 150 m².g^-1, preferably between 150 m².g^-1and 900 m².g^-1, very preferably between 180 m².g^-1 and 850 m².g^-1, and even more preferably between 200 m².g^-1and 800 m².g^-1.

The support is advantageously in the form of balls, extrudates, pellets or irregular and non-spherical agglomerates whose specific shape can result from a crushing step. The support conventionally has a millimeter size, preferably a size between 0.4 mm and 4.4 mm.

The catalyst may also further comprise at least one organic compound containing oxygen and/or nitrogen and/or sulfur before sulfurization. Such additives are known to those skilled in the art. Generally, the organic compound is chosen from a compound comprising one or more chemical functions chosen from a carboxylic function, alcohol, thiol, thioether, sulfone, sulfoxide, ether, aldehyde, ketone, ester, carbonate, amine, nitrile, imide, oxime, urea and amide or even compounds including a furanic cycle or even sugars.

The content of organic compound(s) containing oxygen and/or nitrogen and/or sulfur on the catalyst is between 1 and 30% by weight, preferably between 1.5 and 25% by weight. , and more preferably between 2 and 20% by weight relative to the total weight of the catalyst.

The preparation of the catalyst is known to those skilled in the art and generally comprises a step of impregnation of metals from group VIII and/or group VIB and optionally phosphorus and/or the organic compound on the support comprising at least one zeolite, followed by drying, then optional calcination to obtain the metals in their oxide forms. Before its use in a hydrocracking process for hydrocarbon cuts, the catalyst is generally subjected to sulphurization in order to obtain the metals in their sulphurized or partially sulphurized forms.

When an organic compound is present, the catalyst preferably does not undergo calcination during its preparation, that is to say the impregnated catalytic precursor has not been subjected to a heat treatment step at a higher temperature at 200°C under an inert atmosphere or under an atmosphere containing oxygen, in the presence of water or not.

The catalyst can alternatively undergo a calcination step during its preparation, that is to say the impregnated catalytic precursor has been subjected to a heat treatment step at a temperature between 200°C and 1000°C and preferably between 250°C and 750°C, for a period typically between 15 minutes and 10 hours, under an inert atmosphere or under an atmosphere containing oxygen, in the presence of water or not.

An example of catalyst used in step (a2) comprises, and preferably consists of, at least one Group VI metal and at least one non-noble Group VIII metal, a USY zeolite and an alumina binder.

Another example of catalyst used in step (a2) comprises, and is preferably constituted by, nickel, molybdenum, a USY zeolite, optionally in mixture with a Beta zeolite, alumina, and optionally phosphorus.

Operation of steps (a1) and (a2)

Equipment

Steps (a1) and (a2) can be carried out within the same reactor, or carried out in two separate reactors.

Preferably, steps (a1) and (a2) are carried out within the same reactor.

According to one or more embodiments, steps (a1) and (a2) are carried out within the same bubbling bed reactor.

According to one or more embodiments in which steps (a1) and (a2) are carried out in two separate reactors, steps (a1) and (a2) are carried out in two separate bubbling bed reactors.

According to one or more embodiments in which steps (a1) and (a2) are carried out in two separate reactors, step (a1) is carried out in a bubbling bed reactor and step (a2) is carried out in a reactor with fixed bed.

Several reactors, arranged in series or in parallel, can be implemented to carry out step (a1) and/or step (a2).

When steps (a1) and (a2) are carried out in the same reactor, the hydroconversion is carried out "one pot", that is to say that the hydroconversion reactions of steps (a1) and (a2) have place concomitantly, in the same reaction medium. Carrying out steps (a1) and (a2) in the same reactor makes it possible in particular to limit the number of equipment necessary for hydroconversion and simplified operation.

Depending on the embodiment(s) in which steps (a1) and (a2) are carried out in separate reactors, it is possible to implement reactors of different technologies, for example for step (a1) a two-phase reactor (gas and liquid) or a three-phase reactor (gas, liquid and solid) of the bubbling bed or slurry type in which the solid phase is not a catalyst but the plastic filler, and a three-phase reactor of the fixed bed type for the stage (a2). In this way, the process presents in particular more flexibility with regard to the introduction of the plastic filler into the first hydroconversion reactor.

Carrying out steps (a1) and (a2) in two separate reactors also allows more flexibility in relation to the operating conditions, such as the possibility of operating at different pressures, for example with a higher pressure in step (a1). than in step (a2), or even at different temperatures or controlled differently, for example with a bubbling bed reactor in step (a1) and a fixed bed reactor in step (a2).

When steps (a1) and (a2) are carried out in separate reactors, it is possible to provide an intermediate gas/liquid separation between the two steps (a1) and (a2). This separation may have the advantage of using a second reactor, that for step (a2), which is smaller, or operating with a longer residence time. This also has the advantage of being able to use less catalyst, particularly in the case of an ebullated bed reactor.

Steps (a1) and (a2) of the process according to the invention use reactors, which may be hydroconversion reactors.

The term "hydroconversion reactor" refers to any vessel in which the hydroconversion of a feedstock is the primary purpose, e.g. cracking of the feedstock (i.e., reduction of the point range d boiling), in the presence of hydrogen and a hydroconversion catalyst. Hydroconversion reactors typically include at least one inlet port through which the feedstock and hydrogen can be introduced and at least one outlet port from which upgraded material can be withdrawn. Specifically, hydroconversion reactors are also characterized by possessing sufficient thermal energy to cause larger molecules to break up into smaller molecules through thermal decomposition. Typically hydroconversion reactors include, but are not limited to, entrained bed reactors, also called "slurry" reactors (three-phase reactors - liquid, gas, solid - in which the solid and liquid phases can behave as a homogeneous phase), bubbling bed reactors (three-phase fluidized reactors), moving bed reactors (three-phase reactors with downward movement of the solid catalyst and upward or downward flow of liquid and gas), and bed reactors fixed (three-phase reactors with downward trickling of liquid feed over a fixed bed of supported catalyst with hydrogen typically flowing simultaneously with the liquid, but possibly countercurrent in some cases).

Step (a1), if carried out in a reactor separate from step (a2), can be carried out in any type of reactor corresponding to the above definition of a hydroconversion reactor, but without catalyst.

According to one or more embodiments of the invention, the plastic filler is introduced into the first hydroconversion reactor by extrusion, and therefore in a substantially liquid form, as described above for the optional step (a0). In these cases, hydroconversion reactors such as fixed bed, moving bed or bubbling bed reactors, as mentioned above, can be implemented.

According to one or more embodiments, step (a2) is carried out in at least one bubbling bed hydroconversion reactor. When steps (a1) and (a2) are carried out in the same reactor, such an ebullated bed reactor is suitable for introducing the plastic filler in substantially liquid form, for example following an extrusion as already mentioned, and is even better suited to cases where the plastic filler is introduced in the form of solid particles, possibly suspended in a liquid, as for example described above also for optional step (a0).

The ebullated bed hydroconversion reactor includes the hydroconversion catalyst which is maintained in the reactor. According to one or more embodiments of the invention, one or more hydroconversion reactors, which can be in series and/or in parallel, operating in a bubbling bed, can be used as for the H-Oil™ process, such as described, for example, in patents US4521295 or US4495060 or US4457831 or US4354852, in the article Aiche, March 19-23, 1995, Houston, Texas, article number 46d, "Second generation ebullated bed technology", or in chapter 3.5 “Hydroprocessing and Hydroconversion of Residue Fractions” from the book “Catalysis by Transition Metal Sulphides”, Éditions Technip, 2013. According to these implementations, the reactor is operated in a fluidized bed called a bubbling bed. The reactor advantageously comprises a recirculation pump which makes it possible to maintain the porous supported solid hydroconversion catalyst in a bubbling bed by continuous recycling of at least part of a liquid fraction drawn off at the upper part of the reactor and reinjected at the lower part of the reactor.
The ebullated bed reactor preferably comprises at least one inlet orifice located at or near the lower part of the reactor through which the plastic filler is introduced together with the hydrogen, and at least one outlet orifice at or near the bottom of the reactor. proximity to the upper part of the reactor through which the conversion products are withdrawn. The reactor further preferably comprises an inlet and an outlet for the supported catalyst in connection with means for injecting and withdrawing the supported catalyst.
The ebullated bed reactor further comprises an expanded catalyst zone comprising the porous supported catalyst. The ebullated bed reactor also includes a lower supported catalyst-free zone located below the expanded catalyst zone, and an upper supported catalyst-free zone located above the expanded catalyst zone. The feed in the ebullated bed reactor is continuously recirculated from the upper supported catalyst-free zone to the lower supported catalyst-free zone by means of a recycle conduit in communication with a boiling pump. At the upper part of the recycle conduit there is preferably a funnel-shaped recycle cup through which the charge is sucked from the upper supported catalyst-free zone. The internal recycled feed is mixed with “fresh” feed and additional hydrogen gas.
The catalyst injection and withdrawal means allow continuous replacement of the supported catalyst, which constitutes one of the advantages of ebullated bed technology, compared to other types of reactors, for example fixed bed, for which a shutdown of the reactor may be required to replace the spent catalyst (deactivated mainly by deposition of metals contained in the feed, for example in the form of vanadium sulphide and nickel sulphide, and by deposition of coke). The spent catalyst, withdrawn from the reactor, can be sent to a regeneration zone in which the carbon and sulfur it contains are eliminated. It is also possible to send the spent catalyst withdrawn from the reactor to a rejuvenation zone in which the majority of the deposited metals are eliminated, before sending the spent and rejuvenated catalyst to a regeneration zone in which the carbon and sulfur that it contains are eliminated. The regenerated or rejuvenated catalyst can then be reintroduced into the reactor, possibly in association with fresh catalyst, by the catalyst injection means. This withdrawal and addition of catalyst can be done, for example, on a daily basis. Typically, the means for injecting and withdrawing the supported catalyst comprise at least one conduit opening into the expansion zone of the supported catalyst of the reactor for the introduction of the fresh supported catalyst (and/or regenerated and/or rejuvenated) into the expansion zone of the supported catalyst of the reactor and the withdrawal of spent catalyst from said zone. The introduction and withdrawal can be done with the same conduit, or through separate conduits, then requiring at least two conduits, an injection conduit for the injection of catalyst supported in the reactor and a conduit for withdrawal of the spent catalyst. Through this continuous replacement of the catalyst, bubbling bed technology ultimately increases the time between two stops of the conversion process.

The bubbling bed hydroconversion reactor, due to the fact that the supported catalyst is kept in agitation by significant recycling of liquid, presents a pressure loss on the reactor which remains low and constant, and the reaction exotherms are quickly averaged over the catalytic bed, which is therefore almost isothermal and does not require the injection of cooling flows (“quenches” in English).

Operating conditions

The hydroconversion process according to the invention is implemented in each reactor or in the single reactor at an absolute pressure of between 1 MPa and 38 MPa, at a temperature greater than or equal to 200°C and less than 400°C, at an hourly space velocity (“VVH” for hourly volume velocity, commonly called “LHSV” for “Liquid Hourly Space Velocity” in English) relative to each reactor, between 0.05 h ^-1 and 10 h ^-1 , and with a quantity of hydrogen between 50 Nm ³ /m ³ and 5000 Nm ³ /m ³ .

It is understood that the temperature at these stages is the temperature at the start of the operation, also called the “start of run” (“start of run” according to Anglo-Saxon terminology), when an implementation comprising a bed fixed is operated. In the case of other types of reactor, for example an ebullated bed, there is no concept of start-of-run temperature, because the temperature is substantially constant during the operation. However, we can consider that the operating temperature given for these steps (a1) and (a2) is in all cases the temperature at the start of operation, which for example for the case of the bubbling bed reactor remains the same during the operation.

In the case of a fixed bed reactor, the VVH is generally expressed as the ratio of the volume flow rate of feed, preferably liquid, to the volume of catalyst loaded into the reactor, taken under standard conditions of temperature and pressure.
In the case of a bubbling bed reactor, the VVH is generally expressed as the ratio of the volume flow rate of feed, preferably liquid, to the volume of the reactor, taken under standard conditions of temperature and pressure.

The two steps (a1) and (a2) are therefore implemented under the conditions mentioned above.

According to one or more embodiments, steps (a1) and (a2) are implemented:
- at an absolute pressure between 2 MPa and 25 MPa, preferably between 3 and 20 MPa,
- at a temperature greater than or equal to 250°C and less than 400°C, preferably greater than or equal to 300°C and less than 400°C, more preferably greater than or equal to 320°C and less than 400°C , more preferably greater than or equal to 330°C and less than 390°C, for example 380°C,
- at an hourly space speed relative to each reactor of between 0.1 h ^-1 and 10 h ^-1 , preferably between 0.1 h ^-1 and 5 h ^-1 ,
- with a quantity of hydrogen between 50 Nm ³ /m ³ and 5000 Nm ³ /m ³ , preferably between 100 Nm ³ /m ³ and 2000 Nm ³ /m ³ and very preferably between 200 Nm ³ / m ³ and 1000 Nm ³ /m ³ .

According to one or more other embodiments, at least one bubbling bed reactor is used to implement step (a1) or steps (a1) and (a2), operated at an hourly space speed, relative to the volume of each reactor, between 0.15 h ^-1 and 2 h ^-1 , and even more preferably between 0.15 h ^-1 and 1 h ^-1 .

According to one or more other embodiments, at least one ebullated bed reactor is used to implement step (a1) or steps (a1) and (a2), and the overall VVH, i.e. say the flow rate of liquid feed in step (a1) taken from standard conditions of temperature and pressure, relative to the total volume of the reactors of steps (a1) and (a2), is between 0.05 h ^-1 and 0 .09 a.m. ^-1 .

The operation at relatively low temperature, below 400°C, allows the process to be economical in energy and in operating and investment costs, particularly in comparison to other hydroconversion processes at higher temperatures or other technologies such as pyrolysis.

Examples

The examples below aim to show certain performances of the process according to the invention, in comparison with processes according to the prior art.

Examples 1 to 4 are not in accordance with the invention. Examples 5 and 6 are in accordance with the invention.

In the examples below, a plastic filler of polypropylene (weight average molecular weight Mw=456000 Da and number average molecular weight Mn=76800 Da) is introduced in the form of solid particles into an autoclave reactor, also called below “batch” reactor.

The operating conditions are as follows:

reaction temperature 380°C,

partial pressure H ₂ : 7 MPa,

duration of the test: 150 minutes,

stirring speed: 1400 rpm

Procedure for all of the examples below: the batch reactor is loaded with the plastic filler, the catalyst previously activated by a sulfurization procedure as known to those skilled in the art, and the DMDS, when they are used. The reactor is closed, purged with nitrogen and purged with hydrogen, then pressurized with hydrogen to a pressure of approximately 3 MPa. The reactor is then heated up to the test temperature. Agitation is activated from 300°C. When the reaction temperature is reached, the pressure in the reactor is instantly adjusted to the targeted value by adding H ₂ . At this point, the reaction time is counted down. At the end of the experiment duration, the reactor is cooled quickly to stop the reaction and stirring is stopped. Liquid and gaseous effluents are recovered and separated from any unconverted solid products.

The results concerning the conversion products and the hydroconversion performances are summarized in Table 1 below.

Example 1: Hydroconversion process without a source of sulfur radicals and without a catalyst (non-compliant)

Without adding a source of sulfur radicals or a catalyst, no conversion of the plastic filler is observed: 100% of the plastic filler is solid at the end of the test.

Example 2: Hydroconversion process with a source of sulfur radicals at 4% weight S and without catalyst (non-compliant)

In this example 2, the source of sulfur radicals which is DMDS, is added in the proportion of 4% by weight of sulfur relative to the weight of the plastic filler. We observe a conversion of the plastic filler of 93.5% relative to the filler (yield of non-solid products), with a yield of liquid products of 93% by weight relative to the filler.

The product yield and composition of liquid products is given in Table 1.

Example 3: Hydroconversion process without a source of sulfur radicals and with a C1 catalyst (non-compliant)

Catalyst C1 is in a mass proportion of 10% catalyst relative to the charge. Catalyst C1 is a catalyst composed of 16.2% by weight of MoO ₃ and 2.9% by weight of NiO relative to the catalyst on a support comprising 30% by weight of a USY zeolite with a mesh parameter of 24.37 Å in an alumina matrix, relative to the support.

We obtain a conversion of the plastic load of 7% compared to the load, with in addition all of the liquid products belonging to an extra heavy cut with an initial boiling point greater than or equal to 740°C.

The product yield and composition of liquid products is given in Table 1.

Example 4: Hydroconversion process with sulfur radical source at 1% weight S and a catalyst C1 ( No compliant)

Catalyst C1 is in a mass proportion of 10% catalyst relative to the charge.

In this example 4, the source of sulfur radicals which is DMDS, is added in the proportion of 1% by weight of sulfur relative to the weight of the plastic filler.

We observe a conversion of the plastic filler with a low yield of liquid products, of 58% by weight relative to the filler, with in addition all of the products belonging to an extra heavy cut with an initial boiling point greater than or equal to 740 °C.

The product yield and composition of liquid products is given in Table 1.

Example 5: Hydroconversion process with sulfur radical source at 4% weight S and one catalyst VS 1 (compliant)

Catalyst C1 is in a mass proportion of 10% catalyst relative to the charge.

In this example 5, the source of sulfur radicals which is DMDS, is added in the proportion of 4% by weight of sulfur relative to the weight of the plastic filler.

A conversion of the plastic filler is observed with a yield of non-solid products of 96% by weight relative to the filler, including a yield of liquid products of 93% by weight and a yield of gaseous products of 3% by weight.

Compared to Example 2 with the same source of sulfur radicals, in the same proportion, but without catalyst, we note the following differences on the following sections: -16 percentage points of heavy products (370°C-740°C ), +3 percentage points of diesel cut (250°C-370°C), +9 percentage points of kerosene (150°C-250°C), +4 percentage points of naphtha (80°C-150 °C), showing more selectivity towards diesel, kerosene and naphtha cuts, which can be more easily recovered.

Compared to Example 3 without a source of sulfur radicals but with catalyst C1, we note a much higher conversion and the following differences on the following cuts: -76 percentage points of extra-heavy products with initial boiling point greater than or equal to 740°C and +76 percentage points of products with a final boiling point lower than 740°C (including recoverable cuts).

The product yield and composition of liquid products is given in Table 1.

Example 6 : Hydroconversion process with source of sulfur radicals at 4% weight S and one catalyst C2 (compliant)

Catalyst C2 is in a mass proportion of 10% catalyst relative to the charge.

Catalyst C2 is a catalyst composed of 20% by weight of MoO ₃ and 3.8% by weight of NiO by mass relative to the catalyst on a support comprising 16% by weight of a USY zeolite with a mesh parameter of 24.37 Å and 6% by weight of a beta zeolite with a Si/Al molar ratio of 27 in an alumina matrix, relative to the support.

In this example 6, the source of sulfur radicals which is DMDS, is added in the proportion of 4% by weight of sulfur relative to the weight of the plastic filler.

A conversion of the plastic filler is observed with a yield of non-solid products of 98% by weight relative to the filler, including a yield of liquid products of 86% by weight and a yield of gaseous products of 12% by weight.

Compared to Example 2 with the same source of sulfur radicals, in the same proportion, but without catalyst, we note the following differences on the following sections: -44 percentage points of very heavy products (540°C+), - 2 percentage points in heavy products (370°C-540°C), +6 percentage points in diesel cutting (250°C-370°C), +16 percentage points in kerosene (150°C-250°C) ), +13 percentage points in naphtha (80°C-150°C), showing more selectivity towards kerosene and naphtha cuts, which can be more easily recovered.

Compared to Example 5 with the same source of sulfur radicals, in the same proportion, but with a different catalyst, we note that the conversion into non-solid products is just as good as the quantity of gas produced, although more important, remains acceptable compared to liquid products, and that the selectivity is greater in light cuts (540°C-), in particular in kerosene cuts (150°C-250°C) and naphtha (80°C-150°C). VS).

The product yield and composition of liquid products is given in Table 1.

Table 1 below presents a summary of the main data, including the product yield and the composition of the liquid products of the examples described.

Ex.1 Ex.2 Example 3 Example 4 Example 5 Example 6 Source of sulfur radicals - DMDS - DMDS DMDS DMDS S content relative to the filler (% mass.) - 4 - 1 4 4 Catalyst - - C1 C1 C1 C2 Catalyst ratio to charge (% mass.) - - 10 10 10 10 Product yield (% mass.) gas - 0.5 3 4 3 12 liquids - 93 5 58 93 86 solid 100 6.5 92 38 4 2 Composition of liquid products by boiling point range in °C (% mass.) PI-80 - 1 - - 2 8 80-150 - 3 - - 7 16 150-250 - 4 - - 13 20 250-370 - 6 - - 9 12 370-540 - 18 - - 11 20 540-740 - 46 - - 35 8 740+ - 22 100 100 24 16

Claims (15)

Process for hydroconversion of a plastic filler comprising the following steps:
(a1) a step of non-catalytic hydroconversion of said feed in the presence of hydrogen, in contact with a source of radicals, said source comprising sulfur and being introduced so that the sulfur content is between 3% and 20% by weight relative to the weight of the plastic filler, to produce first conversion products;
(a2) a step of catalytic hydroconversion of the first conversion products in the presence of hydrogen, in contact with at least one hydroconversion catalyst, said hydroconversion catalyst comprising at least one hydro-dehydrogenating element chosen from the group formed by the non-noble elements of group VIB and group VIII of the periodic table, taken alone or in a mixture, and a porous support comprising a porous mineral matrix and at least one zeolite,
said steps (a1) and (a2) being implemented at an absolute pressure of between 1 MPa and 38 MPa, at a temperature greater than or equal to 200°C and less than 400°C, at an hourly space speed relative to each hydroconversion reactor between 0.05 h ^-1 and 10 h ^-1 , and with a quantity of hydrogen between 50 Nm ³ /m ³ and 5000 Nm ³ /m ³ . Hydroconversion process according to claim 1, in which steps (a1) and (a2) are carried out within the same reactor. Hydroconversion process according to claim 2, in which steps (a1) and (a2) are carried out within the same ebullated bed reactor. Hydroconversion process according to claim 1, in which steps (a1) and (a2) are carried out in two separate reactors, preferably steps (a1) and (a2) being carried out in two separate ebullated bed reactors or step (a1) being carried out in a bubbling bed reactor and step (a2) being carried out in a fixed bed reactor. Hydroconversion process according to any one of the preceding claims, in which said at least one zeolite of the hydroconversion catalyst support is chosen from the list consisting of zeolites of FAU groups, preferably zeolites of FAU group chosen from zeolites chosen from zeolites of the FAU or BEA groups. Hydroconversion process according to any one of the preceding claims, in which the catalyst support comprises a USY zeolite and/or a Beta zeolite. Hydroconversion process according to any one of the preceding claims, in which the support of the hydroconversion catalyst comprises at least one zeolite chosen from the group formed by the zeolites ZSM-12, IZM-2, ZSM-22, ZSM-23 , SAPO-11, ZSM-48, and ZBM-30. Hydroconversion process according to any one of the preceding claims, in which the hydroconversion catalyst comprises:
- between 0.1% and 50% by weight of said at least one hydro-dehydrogenating element from the group formed by the non-noble elements of group VIB and group VIII, expressed in weight of oxide relative to the total weight of said catalyst;
- between 0.1 to 99.9% by weight of a porous support relative to the total weight of said catalyst, said support comprising between 0.1% and 80% by weight of zeolite relative to the total weight of said support, and between 0, 1% and 99.9% weight of a porous mineral matrix expressed in weight of oxide relative to the total weight of said support;
- between 0 to 20% by weight, and preferably between 0.1% and 20% by weight, of at least one element chosen from the group formed by phosphorus, boron, and silicon, expressed in weight of oxide by relative to the total weight of said catalyst;
- between 0 to 20% by weight of at least one element from group VIIA, preferably 0.1 to 20%;
- between 0 to 20% by weight of at least one element from group VIIB, preferably 0.1 to 20%, 0 to 60% by weight of at least one element from group VB, preferably 0.1 to 60%;
the percentages being expressed as a weight percentage relative to the total mass of catalyst, the sum of the percentages of the elements constituting said catalyst being equal to 100%. Hydroconversion process according to any one of the preceding claims, in which the hydroconversion catalyst comprises a porous mineral matrix consisting of at least one refractory oxide chosen from the group formed by alumina, silica-alumina, clay, titanium oxide, boron oxide and zirconia, taken alone or as a mixture, and preferably the porous mineral matrix is alumina. Hydroconversion process according to any one of the preceding claims, in which the hydroconversion catalyst comprises, as hydro-dehydrogenating elements, at least one non-noble Group VIII metal chosen from nickel and cobalt, preferably nickel, and at least one metal from group VIB chosen from molybdenum and tungsten, preferably molybdenum. Hydroconversion process according to any one of the preceding claims, in which the source of radicals comprising sulfur is chosen from the list consisting of H ₂ S, elemental sulfur, carbon disulfide (CS ₂ ), sulfide dimethyl sulfide (DMS), dimethyl sulfoxide (DMSO), diethyl sulfide (DES), dimethyl disulfide (DMDS of formula (CH ₃ S) ₂ ), mercaptans, polysulfides such as di-tert-polysulfide nonyl, taken alone or as a mixture, and preferably chosen from H ₂ S, DMS, DMDS, and DES. Hydroconversion process according to any one of the preceding claims, in which the sulfur content in step (a1) is between 3% and 15% by weight relative to the weight of the plastic filler, preferably between 3% and 10% weight of the load. Hydroconversion process according to any one of the preceding claims, further comprising:
(a0) a preliminary step of conditioning said load for its introduction into a reactor in which at least the first step (a1) is carried out, said step (a0) comprising:
- sending the plastic filler in the form of solid particles into an extruder, preferably with a plastic diluent, in which it is gradually heated to a temperature higher than the melting temperature of said plastic filler, and put to the pressure of the first hydroconversion reactor, during conveying, and
- the introduction of the extruded plastic filler into said reactor. Hydroconversion process according to any one of the preceding claims, in which the plastic filler is in solid form and comprises one or more polymers chosen from the list consisting of alkene polymers, diene polymers, vinyl polymers, and styrenic polymers, polyesters, and polyamides, and preferably said plastic filler comprises at least 50% by weight of polyolefins relative to the total weight of the plastic filler, said polyolefins preferably being chosen from the list consisting of polyethylene, polypropylene and/or copolymers of ethylene and propylene. Hydroconversion process according to any one of the preceding claims, in which said steps (a1) and (a2) are carried out at an absolute pressure of between 2 MPa and 25 MPa, and at a temperature greater than or equal to 300°C and less than 400°C.