Patent ID: 12203032

DETAILED DESCRIPTION OF THE INVENTION AND OF SOME OF ITS PREFERRED EMBODIMENTALS

Hereinafter, “M plastics” means long-chain polymeric materials in the most general sense and substantially all classes of polymers are included, regardless of the chemical composition, homopolymers and copolymers, pure or mixtures thereof. Conveniently, the plastics can comprise organic or inorganic fillers or additives, in any concentration. Preferably, the plastics or plastics to be treated include polyolefins, such as HDPE, LDPE, PP, PS, both alone and mixed together, but they could also be mixed with other materials such as PET, PVC, paper, etc. plastics or polymers to be treated include plastic waste.

Hereinafter, by “P particles” it is meant inert particles P which, preferably, include quartz or silica sand, ceramic spherules or the like. Conveniently, said particles P have an average diameter ranging from 50 microns to a few centimeters, preferably a few millimeters, and a high hardness and heat capacity. Conveniently, said particles can be heated to high temperatures (for example up to about 750-800° C.) without giving rise to coalescence and/or fusion processes and/or without causing chemical reactions. Preferably, the particles P comprise sand and, more preferably, comprise particles P of silica (including any impurities) with a particle size ranging from a few tenths of a millimeter to a few millimeters.

Hereinafter, the term “intermediates” refers to organic compounds—in solid, liquid and/or gaseous state—which derive from pyrolysis and/or thermolysis reactions of plastic materials M and which can therefore undergo further reactions. For example, the intermediates include compounds which have not yet become waxes and/or liquid hydrocarbons and/or gaseous hydrocarbons. For example, the waxes can comprise organic compounds comprising at least about 20 carbon atoms, which are therefore solid at room temperature, and have a melting point of around 40-50° C. Conveniently, waxes can be used in the chemical industry as reagents, or as lubricants in the mechanical industry or for the preparation of paints, cosmetics and ointments. For example, gaseous hydrocarbons can comprise organic compounds comprising from one to four carbon atoms, and which therefore are in the gaseous state at room temperature. Conveniently, gaseous hydrocarbons can be used as fuels or as raw materials for use in the petrochemical or chemical industry. For example, liquid hydrocarbons can comprise organic compounds which have a molecular mass between that of waxes and that of gaseous hydrocarbons, and which therefore occur in the liquid state at room temperature. Conveniently, liquid hydrocarbons can be used as fuels (diesel fuels) or as raw materials for use in the petrochemical or chemical industry.

Hereinafter, the term “reaction products in the gaseous and/or aeriform state” A refers to the products of the pyrolysis and/or thermal cracking reaction of the plastic materials M which are in the gaseous and/or aeriform state.

Hereinafter, the term “undesirable reaction compounds” IR refers to undesirable organic compounds such as TAR, CHAR and/or other undesirable compounds deriving from organic or inorganic fillers or additives contained in the plastics introduced and treated in the reactor. For example, these compounds are characterized by a high molecular mass and low oxidation level or by a solid residue consisting mainly of carbon.

In general, hereinafter, with “pyrolysis” or “thermolysis” or “thermal cracking” we mean the breakdown reactions of chemical bonds within a molecule or a macromolecule, for example of a plastic material, which occur at due to high temperatures. In particular, said processes take place in the absence of oxygen or other oxidizing and/or oxidizing agents, in order to avoid combustion and/or incineration reactions.

As is clear from the figures, the treatment apparatus for plastic materials M, indicated as a whole with the reference number1, comprises a reactor100.

Conveniently, the reactor100has a prevalent development which is substantially vertical. Conveniently, the reactor100is configured to be oriented substantially vertically.

In particular, the reactor100comprises a container2substantially closed and isolated from the outside, inside which chemical reactions take place pyrolysis of plastics M.

Suitably materials, the reactor100includes vertically extending inside a first zone12, a second zone24and a third zone30which are in direct communication with each other and which are vertically superimposed, in particular the first zone12is vertically superimposed on the second zone24and the latter is vertically superimposed on the third zone30.

Preferably, the first zone12, the second zone24and the third zone30are coaxial.

Preferably, the second zone24defines an injection chamber since it is the chamber/environment in which the plastic materials M are injected into the reactor100. Conveniently, the second zone24defines the main chamber for the pyrolysis reactions since inside, most of the pyrolysis reactions take place.

Conveniently, the container2, which substantially defines the reactor100, comprises an inlet6for high temperature particles P and, in particular, for particles P which have been previously heated outside the reactor100. Conveniently, the inlet6for high temperature particles P is positioned above said first zone12or near or at the upper end of said first zone12.

Conveniently, the inlet6for the high temperature heated particles P is defined in an upper zone4of the container2and, in particular, in an area which is superimposed on said first area12.

Conveniently, the inlet6can be directly connected with the first area12(seeFIG.1) or it can be connected directly with the second zone24through a channel7which crosses the first zone12(seeFIG.2). Advantageously, the channel7crosses internally—and preferably centrally—said first zone12and in such a way as to be spaced from the walls of said first zone (12).

Advantageously, the high temperature particles P—and in particular the heated sand particles P—enter the container2from the inlet6. In particular, therefore, the heated particles P pass through the container2by gravity—and in particular they fall by gravity along the container2until reaching the second zone24. Advantageously, the high temperature particles P which enter the container2have—and are suitably heated in advance and outside the container2—to a temperature higher than about 700° C., and preferably between about 750/800 and about 900° C.

Conveniently, said container2can be substantially watertight, ie there may be no further outlets other than the predefined ones from which gas can exit and/or enter.

In particular, suitably, oxygen is not substantially present inside the container2or oxygen may be present in insufficient quantities to allow the initiation of combustion and/or incineration reactions.

Advantageously, in a position substantially facing said inlet6, and preferably in a lower position than said inlet6, there may be an element10for spreading the particles P10which is configured to spread the particles P coming from the inlet6in a manner that, during their fall along the container2, these are distributed in a substantially homogeneous way inside the container itself, in particular within the cross section of the latter. For example, said spreading element10can comprise an element of conical or frusto-conical shape, which advantageously can have a plurality of holes (not shown) on its lateral surface, and arranged so that its apex or base the lower ones face the inlet6.

In a preferred embodiment, such as the one shown inFIG.2, said inlet6for the particles P can be associated with a substantially tubular channel7, which ends directly inside said second zone24; suitably, in this case, said element10for spreading the particles P can therefore also be positioned inside the second zone24.

Therefore, suitably, the high-temperature particles P can be introduced into the reactor100inside the upper zone4and/or the first zone12(seeFIG.1), or they can be introduced inside the reactor100directly inside the second zone24while crossing the first zone12inside the channel7(seeFIG.2). Basically, the particles P10can pass through the first zone12inside the environment delimited by the walls of said first zone, or they can pass through the first zone12inside the channel7which thus keeps said particles P separate from the environment. internally delimited by the walls of said first area.

As said, the container2further comprises a first zone12, preferably shaped like a column. In particular, the first zone12is defined by a vertically elongated portion.

The reactor100also comprises an outlet29for the reaction products A in the gaseous and/or aeriform state which is positioned above said first zone12and/or at or near the upper end of said first zone12.

Conveniently, the first zone12has a substantially column-like development with a first extremal portion which is fluidically connected to the outlet29for the reaction products A in the gaseous and/or aeriform state while the other extremal portion is connected to said second zone24. Conveniently, the inlet6for the high temperature particles P is also provided in correspondence with said first extremal section.

In particular, the first zone12communicates the upper zone4of the container2, in which the entrance6of the sand is provided, with the underlying second zone24.

In a preferred embodiment, around the first zone12, and in particular outside the latter, there are heating means14configured to heat the walls of the first zone12of the container2. Advantageously, said heating means14comprise means for indirectly heating the walls of the first zone of the container2by means of a heating fluid F which passes through/permeates a heating section16which is provided externally and around said first zone12. Preferably, the heating section16involves wholly or mostly the development in height of the first zone12.

Conveniently, said heating means14comprise a heating section16defined by a tube bundle, inside which a heated fluid can flow, and/or by a heated jacket, for example with an annular cross-section inside which a heated fluid. Conveniently, the heating section16is fluidically connected to at least one inlet port18for a hotter fluid and to at least one outlet port20for the fluid that has passed through the section16, thus yielding heat to the walls of the first zone12. Conveniently, said at least one inlet port18and said at least one outlet port20are fluidically connected to a heating device (not shown) configured to heat the fluid intended to be inlet and to pass through section16. Advantageously, section16and the heating device are connected fluidically so as to define a closed fluidic circuit, and this in order to reduce the consumption of hot fluid and the corresponding energy.

Conveniently, said heating means14are configured so that the heating fluid passes through the heating section16in counter-current with respect to the direction of the force of gravity and/or the direction with which the particles P pass through the first zone12.

Advantageously, said at least one door inlet18of the heating fluid can be positioned at a lower height than said at least one outlet port20, so that the heating fluid passes through the section16in a direction opposite to that of the earth's gravitational force. Conveniently, this makes it possible to have (and preferably maintain) a higher temperature in correspondence with the lower portion of the first zone12in order to ensure greater heating in the portion of said zone where the heat requirement is greater. Advantageously, said heating fluid can comprise a liquid (for example water or diathermic oil) or a gas (for example air, inertized air or exhaust air), or a vapor (for example water vapor), or in general other fluids suitable for acting from thermal vectors.

Conveniently, at different heights along the longitudinal development of the heating section16, fluid equalization rings22can be provided which, preferably, consist of perforated plates, suitably shaped, which allow to equalize the flow of the fluid and its temperature along the heating section16.

Advantageously, by means of the heating means14, it is possible to have and/or maintain the temperature inside the first zone12between about 400° C. and about 600° C., and preferably between about 500° C. and about 550° C.

Conveniently, in the embodiment ofFIG.2, the channel7defines a closed channel which internally crosses the first zone12of the container2and is fluidically separated from the internal environment of said zone. Advantageously, said channel7can be made of material which allows indirect heat exchange between the particles P flowing inside the channel itself and the intermediates and/or reaction products that are present in and/or pass through the first zone12.

Preferably, the completion of the chemical pyrolysis reactions for the intermediates in the form of gas or vapor takes place in said first zone12. More in detail, in said first zone12—thanks to the heating means14and to the fact that the high temperature particles P pass through said first zone12—the pyrolysis reactions continue on the reaction products and/or intermediates in the gaseous and/or aeriform and deriving from the pyrolysis reactions which take place inside the second zone24.

As said, below said first zone12, the apparatus1comprises said second zone24. Advantageously, said second zone24can have a cross section with a greater radial development than that of the first zone12, thus substantially giving the container2the shape of a flask.

Conveniently, the second zone24is in direct connection with the first zone12and, in particular, no bottleneck or constriction is provided in the connecting section between said two zones.

Conveniently, inside said second zone24a plurality of nozzles26are mounted and/or housed for introducing the plastics M to be treated in the molten state inside said second zone24. Therefore, the plastics M and the high temperature particles P initially come into contact within the second zone24.

Conveniently, within the second zone24, the plastics M which are introduced in the molten state inside said second zone come into direct contact with the high temperature particles P, thus triggering the pyrolysis reactions (thermal cracking) of said plastic materials M. Conveniently, while the reaction products or intermediates in the gaseous and/or vapor state then rise towards the first zone12, the intermediates reaction in the liquid and/or solid state—together with the particles—descend towards the underlying third zone30. In particular, therefore, the plastic materials M come into contact with the particles P when the latter are already at a temperature equal to or higher than that necessary to activate the pyrolysis reactions.

Preferably, the second zone24has a bottom27having a substantially truncated cone shape. Preferably, the nozzles26are mounted on said bottom27of the second zone24.

Conveniently, the plastics M to be treated in the molten state are introduced into said second zone24through the nozzles26, while the high temperature particles P are introduced into said second zone24through at least one inlet17which is in communication with inlet6through the first zone12(and suitably through the upper zone4) or through the channel7. Therefore, the plastic materials M and particles P enter the second zone24through different entrances.

Conveniently, said plurality of nozzles26are mounted and/or positioned inside the second zone24so as to be oriented in one direction, a slightly angled direction and/or in the opposite direction with respect to the direction of the force of gravity and, in particular, with respect to the direction of entry of the particles P into said second zone24.

Conveniently, said plurality of nozzles26are mounted and/or positioned inside the second zone24so that, inside the latter, the spray of plastic materials M to be treated in the molten state is substantially in counterflow with respect to the direction in which the particles P enter and pass through said second zone24.

Conveniently, said plurality of nozzles26are mounted and/or positioned inside the second zone24so that, inside the latter, the spray of plastic materials M to be treated in the molten state is substantially angled or in the opposite direction with respect to the direction of the force of gravity and/or with respect to the direction in which the particles P pass through said second zone24.

Conveniently, said plurality of nozzles26are mounted and/or positioned inside the second zone24so that the axis D1which it emerges from the outlet hole of said nozzles intersecting the falling direction D2of the particles P inside said second zone defining an angle A of about 90-180°, preferably greater than 150°.

Preferably, said plurality of nozzles26are mounted and/or positioned inside the second zone24so as to be at least partially facing the inlet mouth17of the particles P inside said second zone24

In a preferred embodiment, on the lower surface of said second zone24can be mounted a plurality of nozzles26configured to spray the plastic materials M in the molten state inside the second zone24. Advantageously, the lower surface of said second zone24can be inclined with respect to the horizontal, and in particular forming an acute angle with the horizontal, so as to define that the nozzles26which are mounted on said surface point substantially towards the center of the second zone24. In particular, the nozzles26can be positioned according to any arrangement and advantageously they can have an outlet hole with a diameter ranging from the fraction of a millimeter up to and to a diameter of the order of centimeters.

Advantageously, said nozzles26can be fluidically connected to a circuit28for feeding the plastics M in the molten state. Conveniently, said supply circuit28can be provided with heating elements33, for example heating plates, configured to carry and/or maintain said plastics M to be treated in the molten state, and preferably to heat them to a temperature at which their viscosity is such as to allow the creation of a turbulent flow out of the nozzles26. Advantageously, the heating elements33allow the plastic materials M to be kept in the fluid state inside the circuit28and also act as a support during the operation phase of the reactor100.

Preferably, the supply circuit28comprises a chamber35provided below the frusto-conical bottom27of the second zone24and—preferably—also around the walls which internally delimit the third zone30. Preferably, the chamber35develops—at least in part—around the third zone30. Conveniently, the nozzles26are in fluid communication with the interior of the chamber35. Conveniently, the chamber35is provided with corresponding inlet conduits39for the plastic materials M—preferably already in the molten or semi-melted state—inside the chamber itself. Conveniently, the heating elements33are associated with the walls of the chamber35.

Advantageously, the plastics M in the molten state can be sent under pressure—in particular at high pressure—towards the nozzles26, and this in order to increase the flow rate of the molten plastic and improve the turbulence and mixing conditions inside the second zone24and, in particular, in order to achieve an effective heat exchange between the particles P and the plastic materials M and to make the temperature uniform. Preferably, the temperature of the molten plastic is about 200° C.-450° C. and the pressure is preferably higher than 2 bar. Conveniently, the plastic materials M are introduced into the second zone24at high pressure and, in particular, they can be injected at a pressure higher than about 2 bar and lower than about 12 bar. In a preferred embodiment, the plastics M in the molten state can be injected, through the nozzles26, into the second zone24at a pressure of about 4-5 bar. Advantageously, this allows to obtain an optimal throw and/or flow in order to obtain the required mixing effects. In particular, the plastics M in the molten state which emerge from the nozzles26can be injected into the second zone24so as to form a jet or spray of liquid. Conveniently, this jet may not comprise a significant amount of air bubbles, and preferably may not be in the form of an aerosol and/or nebulized spray.

Advantageously, the supply circuit28of the plastic materials M can comprise a unit for removing the chlorine from the plastic materials M themselves (not shown). In particular, said unit can provide an outlet duct for the chlorine-based gases that can be formed following the heating of materials including chlorine (such as PVC, PCTFE or other materials that include chlorine as an impurity), suitably connected or provided with filters. Furthermore, said unit can comprise a device configured to add calcium-containing materials in order to promote suitable chemical reactions suitable for the sequestration of chlorine.

Advantageously, in some possible embodiments (seeFIGS.6and7), around the second zone24, and in particular outside the latter, second heating means75configured to heat the walls of the second zone of the container2can be provided 24. Advantageously, said second heating means75comprise means for indirect heating of the walls of the second zone24of the container2by means of a heating fluid F which passes through/permeates a second heating section76which is provided externally and around said first zone12. Preferably, the second heating section76covers all or most of the height extension of the second zone24. Conveniently, said second heating means75are configured so that the heating fluid F passes through the second heating section76in counter-current with respect to the direction of the force of gravity and/or the direction in which the particles P attr pour into the second zone24. Conveniently, the second heating means75can be of a type corresponding to that described above in more detail for the heating means14.

Conveniently, the reactor1comprises an outlet29for the reaction products A in the gaseous and/or aeriform state. Conveniently, the outlet29is in fluid communication with the first zone12. Conveniently, said outlet29is provided in correspondence with said upper zone4and/or said first zone12. Conveniently, the outlet29comprises a duct for configured to convey products A to suitable storage and/or further processing points. Conveniently, the outlet29for the reaction products A in the gaseous and/or aeriform state can be connected to a filter system in order to remove any unwanted products leaving the apparatus1.

Conveniently, within the upper zone4there are no mechanical mixing means.

Conveniently, inside the first zone12there are no mechanical mixing means.

Conveniently, inside the second zone24there are no mechanical mixing means.

Conveniently, the reactor100comprises a third zone30which is connected with said second zone24. Preferably, said third zone30is positioned below said second zone24and, therefore, the three zones12,24and30are vertically superimposed.

Preferably, the second zone24is in communication with said third zone30by means of at least one passage32which is preferably defined by a hole formed at the bottom of the second zone24. Preferably, said second zone24and said third zone30are always in communication between them. Preferably, said third zone30defines a zone for completing the pyrolysis reactions of the plastic residue and is configured to remove any plastic waste and/or reaction residues that have remained glued to the sand—as will become clear later—and to allow for the advancement. of pyrolysis reactions.

Advantageously, said third zone30is connected inferiorly to said second zone24in order to thus allow particles P and reaction intermediates in the liquid and/or solid state which, among others, can also include undesired IR compounds, such as for example TAR and CHAR to fall. In particular, said third zone30can be fluidically connected to the second zone24through the passage32. Advantageously, said third zone30is positioned below, preferably immediately below, the nozzles26for the injection of the plastic materials M in said second zone24.

Advantageously, said third zone30can have smaller volume and dimensions—in particular in terms of the radial development of its cross section—than the second zone24.

Inside said third zone30substantially further cleaning of the particles P. In particular, the particles P arriving inside said third zone30can be coated/covered with intermediates comprising both not completely pyrolyzed compounds, such as for example long-chain polymeric or organic compounds, and unwanted IR compounds deriving from residues of the pyrolysis reaction, such as for example carbonaceous compounds such as TAR and CHAR, or other impurities. Conveniently, the intermediates entering said third zone30—and in particular the compounds not yet completely pyrolyzed—are reacted further inside said third zone30in order to thus obtain particles P coated only with undesirable IR compounds (which do not have been pyrolyzed or have been partially pyrolyzed) and impurities, thus allowing to increase the yield of the reactor100. Basically, within said third zone30, the particles P are further cleaned of the reaction intermediates in the liquid and solid state which enter said third zone, thus allowing the pyrolysis reactions to continue and complete in the latter. Conveniently, therefore, at the exit from the third zone30—in particular on the bottom of the latter—there are substantially particles P coated with undesirable compounds IR.

Advantageously, even inside said third zone30there is no oxygen or other oxidizing agents.

Advantageously, also said third zone30can have a substantially vertical development.

Furthermore, said third zone30can comprise—and in particular house inside it—at least one mechanical mixing device36. Preferably, said mechanical mixing device36is configured to keep the particles P, coated by the intermediates, which enter the inside of said third zone30, so as to prevent coagulation and packing thereof and—advantageously—so as to also keep the temperature homogeneous. Advantageously, the mixing device36can comprise an agitator, in particular a reel, comprising a shaft38from which radially protrude a plurality of blades (transverse)40, preferably suitably shaped, and spaced along the longitudinal development of the shaft itself. Conveniently, the blades40can all have substantially the same radial development. Conveniently, at least the blades40which act in correspondence with the passage32can be suitably shaped—and for example their length and/or shape can be suitably defined—in order to prevent the occlusion of the passage32. Advantageously, the shaft38can be rotatably fixed at both ends and rotated around its longitudinal axis by a suitable actuator. In particular, the shaft38can be rotatably supported, in correspondence with the passage32, by means of a suitable support member48. Preferably, the support member48is configured not to obstruct the passage32and, for example, can comprise a hub51with a plurality of arms49extending radially outwards to engage in an area surrounding the passage32obtained on the bottom27of the second area24. Conveniently, the shaft38can be associated with a suitable member (not shown) for centering the shaft itself inside said third zone30.

Advantageously, in an embodiment not shown, the shaft38can be suitably lubricated, in order to facilitate its rotation. This can for example be achieved by spraying or injecting plastic materials M in the molten state at the shaft itself, for example by means of further nozzles (not shown), preferably at the rotatable support member48of said shaft.

Advantageously, in some possible embodiments (seeFIG.7), third heating means85are provided around the third zone30, and in particular outside the latter, configured to heat the walls of the third zone30of the container2. Advantageously, said third heating means85comprise means for indirect heating of the walls of the third zone30of the container2by means of a heating fluid F which passes through/permeates a third heating section86which is provided externally and around said third zone30Preferably, the third heating section86covers all or most of the extension in height of the third zone30. Conveniently, said third heating means85are configured so that the heating fluid F passes through the third heating section86counter-current with respect to the direction of the force of gravity and/or the direction in which the particles P pass through the third zone30. Advantageously the third heating means85can be of a type corresponding to that described above in more detail for the heating means14.

Conveniently, the second heating means75and/or the third heating means85are useful in the transient phase, in particular at the moment switching on and off of the reactor100.

Conveniently, the third zone30can be directly connected at the bottom with an outlet zone42(which conveniently defines an expulsion zone), which allows to remove the particles P coated with undesirable compounds IR from said third zone30, and therefore from the apparatus1. In particular, said third zone and said outlet zone42can be connected by a radial narrowing positioned below said third zone30and which defines a passage section between said third zone30and said outlet area42. Conveniently, the third area30comprises a truncated cone bottom which opens below towards the area of outlet42, in order to facilitate the passage of the particles P coated with IR undesirable compounds towards the latter.

Advantageously, transport means44—preferably comprising a cochlea or a worm screw—configured to advance the particles P coated with undesirable compounds can be advantageously provided inside said outlet area42, which is also preferably substantially vertical. IR towards a drain46(for example defined by a duct).

Advantageously, the transport means44are integral in rotation with the mixing device36. Preferably, the transport means44and the mixing device36are coaxial and vertically superimposed. Preferably, the same rotating shaft38of the mixing device36extends inside the outlet area42to also act as a rotating shaft for the worm screw of the transport means44. Conveniently, the same shaft38centrally crosses both the third zone30and the exit zone42.

Conveniently, the particles P coated with undesirable compounds IR leaving the exhaust46—after having been suitably treated—can be sent back to the inlet6of the reactor100to be re-introduced and reused within the latter. Advantageously, particles P coated with undesirable compounds IR leaving the exhaust46, which—as mentioned—can still be at least partially coated with carbon residues such as TAR and/or CHAR or other impurities, can be recovered by sending the particles P thus coated, at the outlet from the discharge port46, to a combustion unit of the carbon residues and/or to a treatment unit of the impurities deposited on the surface of the particles P themselves, to be then redirected at the desired temperature towards the inlet6below form of regenerated particles P.

Conveniently, the reactor100—within which the various zones are defined—has a substantially vertical development and, in particular, the inlet zone6, the first zone12, the second zone24, the third zone30and the outlet zone42are vertically overlapping and—preferably—are coaxial.

The operation of the apparatus1according to the invention is clearly evident from what has been said above, and provides for a step of introducing said plastic materials M in the molten state inside the second zone24and a mixing step inside said second zone24of said plastic materials M in the molten state with particles P heated to a temperature sufficient to trigger pyrolysis reactions of said plastic materials M. Conveniently, the heated particles P are introduced into said second zone24from a substantially opposite direction and/or a different direction, in particular defining an angle greater than 90° and preferably greater than 135°, with respect to the direction of introduction of the plastics M into said second zone24. Preferably, the plastics M in the molten state they are introduced into the second zone24in counterflow with respect to the inlet of the heated particles P into said second zone a24.

In particular, the particles P (for example the sand granules) are heated—due to the combustion of the carbon residues present on their surface—beforehand and outside the reactor100to a suitable temperature, preferably above 700° C., and more preferably between about 800° C. and about 900° C., and subsequently they are introduced into the container2of the reactor100through the inlet6. Conveniently a part of the heat obtained from said combustion process can be used to melt the plastic materials M.

Conveniently, the particles P are scattered by the spreading element10, so as to distribute themselves in a substantially homogeneous manner during the fall through the first zone12. Alternatively, in the embodiment illustrated inFIG.2, the particles P can travel the channel7until it comes out directly in the second zone24.

As mentioned, the plastic materials M—that were previously melted and suitably brought to high pressure, and from which any chlorine-based impurities have been removed—are sprayed and introduced in the molten state inside the second zone24through the nozzles26. Advantageously thanks to the high pressure (approximately 2-12 bar, preferably about 4-5 bar), due to the viscosity of the plastic material and to the use of nozzles of adequate size and number, the flow that is established inside the second zone24is of the turbulent type. This allows to mix the plastic materials M with the high temperature particles P which enter the second zone24without the use of a mechanical mixer, and thus to achieve a high and effective heat exchange with the high temperature particles P, keeping the temperature.

In particular, the heated particles P which, by falling, enter the second zone24exchange heat with the plastics M introduced in the molten state through the nozzles26, and this in order to bring the temperature of the mixture that forms to the inside the zone itself above 400° C. and preferably at a temperature of about 500-550° C. In this way it is possible to carry out the thermal cracking and/or pyrolysis reactions in the optimal conditions for yield, which allow to transform the macromolecules that make up the plastic materials M into shorter molecules, and in particular into waxes, liquid hydrocarbons and gaseous hydrocarbons.

The heated particles P passing through the first zone12exchange heat with the intermediates and/or products, in gaseous and/or vapor form, of the pyrolysis reactions that take place inside the second zone24. In particular, in the embodiment ofFIG.1the particles P exchange heat directly with the intermediates and/or reaction products in gaseous and/or aeriform state which rise through the first zone12. In particular, in the embodiment illustrated inFIG.2, the particles P exchange heat indirectly, through the walls of channel7, with the intermediates and/or products of the pyrolysis reactions that rise through the first zone12.

Basically, the reaction products and/or intermediates, which are formed in the second zone24and which at the reaction temperature are in the gaseous state, then rise along the first zone12where the pyrolysis reaction continues due to the heating means14and also of the o heat exchange (direct or through the walls of channel7) with the high temperature particles P which, entering from inlet6, fall through the first zone12towards the second zone24. In particular, in fact, the pyrolysis reactions are endothermic reactions, and therefore, if it is necessary to make them continue, it is necessary to continue to supply heat to the reactants and intermediates that pass through the first zone12. This occurs—in correspondence with the first zone12—thanks to the heating means14and the heat exchange that can be direct with the falling particles P and/or indirect with the walls of the channel7heated by the falling particles P passing through said channel. Advantageously, this allows to reduce the amount of intermediates and products that are too heavy to be used, and thus obtain a higher conversion and a greater yield in desired products.

Advantageously, therefore, on the basis of the process temperature and the residence time of the products inside the second zone24and/or the first reaction zone12, it is possible to control the relative quantities of waxes, liquid hydrocarbons and gaseous hydrocarbons which, suitably, constitute three desired types of reaction products.

During the reactor operation, a part of the particles P and of the intermediates in the liquid and solid state which are formed inside the second zone24fall by gravity—through the passage32—inside said third zone30. In particular, inside said third zone30, particles P enter coated by intermediates comprising not completely pyrolyzed compounds, such as polymeric compounds or long chain organic compounds, and/or by undesired compounds and residues of the pyrolysis reaction, for example TAR and CHAR.

Inside said third zone30the pyrolysis reactions of the compounds still not completely pyrolyzed continue and, at the same time, the particles P coated with the intermediates in the liquid and/or solid state are suitably and continuously stirred by the action of the mixing device36. In particular, this allows to avoid clots and packings which would cause the blocking of the apparatus1. Conveniently, the presence of the mixing device30inside the third zone30is particularly advantageous since inside said third zone30for the most part partially coagulated particles P enter due to the presence of partially pyrolyzed intermediates and tarry and carbonaceous residues, which are sticky and which—if not remixed—could create compresses capable of undesirably blocking the functioning of the apparatus1and, in particular, the outflow from said third zone30.

Furthermore, since the third zone30passes kept at a high temperature, the pyrolysis reactions continue, going further to pyrolyze the intermediate compounds present within the area itself. This allows to improve the reaction products, and in particular to make them “cleaner”, and also helps reduce the risk of packing.

In particular, therefore, said third zone30prevents the packing of particles, reactants, reaction intermediates and residues and, moreover, within said third zone30the advancement of the pyrolysis reactions for compounds which are not completely pyrolyzed yet.

Then, from said third zone30, the particles P coated with the undesirable compounds IR (such as carbonaceous compounds, for example TAR and CHAR, or other impurities deriving from non-pyrolyzable fillers and/or additives present inside the treated plastic materials M) descend inside the outlet area42where the transport means44push them towards the discharge door46and, advantageously, then enter a circuit for regenerating, heating and recovering the particles P.

Advantageously, since the passage32between the second zone24and said third zone30does not provide for any type of interruption or closure, the residence time of the particles P and of the plastic materials M inside the reaction environment defined by the second zone24, by said third zone30and by first zone12—is substantially controlled by the speed of advancement of said transport means44.

Advantageously, thus controlling the movement of the transport means44—which, as mentioned, it influences the residence time of the plastic materials M inside the reaction environment—the temperature in the second zone24and in said third zone30can be controlled and the selectivity of the cracking reactions can also be controlled and therefore varied the respective proportions of waxes, liquid hydrocarbons or gaseous hydrocarbons which are produced during the reaction.

Preferably, the plastics M to be mixed with the particles P are introduced in the molten state inside the second zone24.

Advantageously, the plastics M in the molten state are introduced into said second zone24through nozzles26at a pressure comprised of about 2-12 bar, preferably of about 4-5 bar.

Preferably, the plastic materials M are introduced in the molten state inside the reactor100, and in particular inside the second zone24, so as to generate a turbulent flow inside said second zone.

Advantageously, said step of introducing the plastic materials M into the reactor100provides that said plastic materials M are injected into said second zone24so as not to generate a spray and/or an aerosol.

Advantageously, before being introduced into the reactor100, said plastic materials M are subjected to a step of removing chlorine-based compounds and/or impurities.

Conveniently, the residence time of said particles P inside the container2of said reactor100is determined by the actuation of transport means44, for example a cochlea or a worm, configured to allow the exit from said container of the particles P coated with IR undesirable compounds.

Advantageously, most of the pyrolysis reactions take place in said second zone24into which the plastic materials M are introduced, while a further part of pyrolysis reactions takes place in a third zone30.

In a preferred embodiment, the reaction intermediates in the liquid and/or solid state and the particles P, which enter inside said third zone30, are mixed by at least one mechanical mixing device36. Preferably, said at least one mechanical mixing device36is lubricated by direct spraying of molten M plastics.

Conveniently, the apparatus1is configured to convert the plastic materials M, which are introduced into it in the molten state, into basic organic chemistry products, such as waxes, liquid hydrocarbons and gaseous hydrocarbons, and into carbon residues linked to the particles P placed inside the reactor itself.

Conveniently, in the reactor100the mixing of the plastic materials M, the uniformity of the temperature and of the composition are obtained by introducing said plastic materials in the molten state into the second zone24through the nozzles26, while reaching the appropriate temperature for the reactions of pyrolysis is obtained from the interaction with the high temperature particles P which enter the second zone24in counterflow with respect to the plastic materials emerging from said nozzles.

From what has been said it is clear that the apparatus according to the invention is particularly advantageous as it allows:to treat plastics of any type, thus not requiring separation and/or rejection processes at the entrance,to control the type of products of the pyrolysis reactions, thus allowing high flexibility according to market demands,to obtain high yields thanks to the temperature control and the absence of thermal gradients inside the reactor, in particular in correspondence with the injection zone of the molten plastic,to heat the mass in reaction in a simple, effective, stable and homogeneous way thanks to the turbulence triggered and maintained in the injection zone of the molten plastic, thus allowing a rapid heat exchange and not requiring continuous cleaning and maintenance operations,a homogeneous temperature distribution thanks to the turbulence triggered and maintained in the injection zone of the molten plastic,to define three distinct reaction zones (respectively the first zone12, the second zone24and the third zone30), each differentiated and specialized according to the reaction needs and purposes,to intervene on the operating parameters quickly and effectively by varying the flow rate and/or temperature of the particles P and/or the heating fluid of the media14and/or the flow rate of the plastic materials M fed, with very fast system response times,to increase plant availability and greatly reduce the need for plant shutdowns due to maintenance operations for cleaning,to preserve the reactor walls from char and tar encrustations thanks to the abrasive action of the particles P continuously mixed and moved,to reduce the need for external energy thanks to the self-generation of heat by using the residues as a heat source for the reactor,to drastically reduce the amount of waste produced which, in particular, is limited to the ashes deriving from the combustion of residues.