EP3247775A1 - Method and system for transferring plastic waste into a fuel having properties of diesel/heating oil - Google Patents

Abstract

The invention relates to a method for recovering hydrocarbons from plastic wastes, in particular polyolefin-rich waste, by means of purely thermolytic cracking without the use of catalysts, comprising melting the plastic waste in two heating devices (3) and (4), wherein a recycle stream derived from the cracking reactor (5) and purified in a separator system (8, 9) is admixed with the molten plastic waste from the heating device (3). The mixed plastic stream is further heated in the second heating device (4), and from there is guided into the cracking reactor (5), where the plastic materials are cracked, and by means of subsequent distillation are separated into diesel and low boilers. A special entry system allows the prior separation of water and acidic gases, and the saving of inert gas. The invention further relates to a system for carrying out the method.

Description

 Method and system for transferring

Plastic waste in a fuel with properties of diesel / fuel oil

Field of the invention

The invention relates to a method and a plant for processing plastic waste, in particular plastic waste based on (i) the basis of polyolefins and / or (ii) organic oil-based fluids, by converting such waste plastics into hydrocarbons with 1 C atom ( Methane) to hydrocarbons with more than 22 C atoms.

background

In view of the finite oil reserves, the increasing consumption of plastics and the increasingly restrictive requirements of the governments with regard to the treatment of waste materials and the recycling of Wert ^¬ substances, the treatment of plastic waste, which are sorted out, for example, from the residual waste wins more and more Importance.

 There are already some methods for plastic waste treatment known but they still have several disadvantages.

 WO 2005/071043 A1 discloses a processing method in which plastic waste is processed into oil.

Thereby be obtained ^¬ hydrocarbon materials from waste plastics and / or from oily residues fractionated, wherein the plastic waste and / or residual materials by first and compacted using a system entry of air. The compressed mass is fed to a melting vessel and heated therein, so that a separation into a first liquid phase, a first gas phase and a residue portion takes place, after which the first liquid phase and the first gas phase are transported to an evaporation vessel, in which further heat input a second liquid phase and a second gas phase, wherein the second liquid phase is transferred to a reheater and there further heated with further heat input, so that a third gas phase is formed, after which the second gas phase from the evaporation tank and the third gas phase from the reheater a cracking reactor where further cracking (cracking) of the long-chain hydrocarbons into short-chain hydrocarbons takes place and the resulting oil gas is then fed to a condenser in which the oil gas is condensed to liquid oil, the oil being the target product.

 This process does not meet today's environmental requirements in terms of sulfur and chlorine contents, leads to a high proportion of carbon-rich residues and has shortcomings in terms of flexibility and quality of the final product.

 WO 2008/022790 describes a process for the treatment of plastic-containing wastes and organic liquids based on crude oil, cooking oil, fats or the like, with the following steps:

 Introducing the substance mixture into a reactor which is subdivided into a melting and a cracking zone, or into two reactors connected in series,

Melting of the substance mixture in a melting zone of the reactor at 250 ^° C to 350 ^° C,

 Discharging contaminants from the melt,

Cracking of long-chain polymers contained in the melt in a cracking zone of the reactor at 420 ^° C. to 450 ^° C. until they change into the gaseous state, Discharging the gas phase from the reactor,

Condensing the gas phase in a cooler,

 • Remove impurities from the light liquid after cooling (quenching) and store the light liquid.

The gas phase present after the cracking zone of the reactor is fed, for example, to a distillation device which is operated in such a way that long-chain polymers condense and are returned to the cracking zone of the reactor. Relatively short chain, after the distillation device and a subsequent condenser are gaseous hydrocarbons (C1-C4) can be energetically ge ^¬ uses as fuel.

 In the prior art processes, relatively large amounts of slag are produced and the final products are only massively adaptable to the needs and of moderate purity.

Presentation of the invention

The aim of the present invention was to provide an improved process for the treatment of plastic waste (hereinafter also referred to as plastic materials) and a plant for carrying out this process. The improvements include reduction of slag formation and / or more flexible product control and / or optimized product purity.

 This object has been achieved by providing a process for recovering hydrocarbons from preferably polyolefin waste by means of purely thermolytic cracking in a cracking reactor, preceded by a first heating device and a second heating device, without the use of catalysts

(bl) the optionally and preferably already partially melted plastic materials of a first heating device are fed, in which they are melted at a temperature of 300 ^° C to 380 ^° C (further),

 (b2) the molten plastic materials, together with recycle stream pumped out of the cracking reactor, are passed to a second heating device, where they are further heated to temperatures of 380 ° C to 400 ° C,

(b3) the molten plastics materials, together with hydrocarbonaceous vapors already formed from the second heating device, are fed to the cracking reactor in which the molten plastic materials are further cracked (cracked) at about 400 ^° C, the gaseous hydrocarbons being fed to a partial condenser condense long-chain hydrocarbons and be recycled to the cracking reactor, preferably a condenser, which is preceded by a packed column,

(B4) emerge short-chain hydrocarbons from the cracking reactor and fed to a distillation apparatus in which they are decomposed into a gaseous and a liquid fraction and from which the liquid fraction is withdrawn as product diesel, and passed the gas ^¬ shaped fraction through a cooler in which it is split into low boilers (C5-C7), which are gela ^¬ siege, and in the non-condensed gases (C1-C4), which are preferably used as fuel for heating the thermal oil,

(b5) high-energy but not in the gaseous state passing pitch and tar-like substances, as well as in the thermolytic cracking of polymers resulting carbon excess are pumped together with the return ^¬ lead stream from the cracking reactor and separated by means of a separator in the recycle stream and residue, the Return flow between the first heater and the second heater The molten plastic ertstoffen mixed and the residue is passed into a collecting container.

 The withdrawn liquids (product diesel and low boilers) may be purified in special adsorption and / or filtration systems prior to transfer to storage tanks and any interfering components (e.g., organic acids) that may have been formed removed.

 A feed system which is preferred for the system according to the invention but which can also be used together with other systems comprises the feeding of the plastic waste to the first heating device via a delivery system in which

(a2) steam is removed in a first stage in a mechanical compressor system at from 120 to 150 ^° C. and compression and drying take place,

 (A3) in a second stage, in an extruder, at 250 to 300 ° C at least partial melting and removal of acidic gases, in particular of HCl and H2S, by means of vacuum.

 These acidic exhaust gases are preferably one

Gas scrubbing with lye, such as sodium hydroxide, subjected, whereupon the wash liquor, which contains virtually no hydrocarbons, can be disposed of uncritically.

 The compression in the first stage (a2) is suitably carried out by means of a screw compressor and the second stage (a3) by means of an extruder, wherein the compressor as well as the extruder should be heatable. A preferred heating medium is thermal oil.

The feeding of the plastic recyclable materials in egg ner of step (a2) connected upstream of step (al) is carried out ge ^¬ is enough, via a system of at least two and preferably two buffer tanks, which are preferably supplied with stick ^¬ material and / or rinsed, and of which the one is filled while the other is being emptied, and both of which are connected to a weighing system which permits metered filling of the plastic waste introduction system. The recycle stream mentioned in (b5) above is obtained by pumping plastic melted down from the cracking reactor by means of a high-temperature pump, high-energy but non-gaseous pitch and tar-like substances, and carbon excess resulting from the cracking of polymers, and a separator System is supplied. In this, separator system is preferably a cyclone separator, optionally and preferably connected to a sedimentation (settling).

The gaseous hydrocarbons from the cracking reactor are preferably fed to the partial condenser via a packed column, so that the route for the separation of the still insufficiently cracked hydrocarbons (usually more than 22 C atoms) becomes longer. This has the positive effect that the partial condenser can be operated at a higher temperature, without a significant proportion of excessively long hydrocarbons can leave the cracking reactor, or that the temperature in the partial condenser must not be set so low that a significant An ^¬ part of Hydrocarbons with 22 or fewer carbon atoms in the cracking reactor is recycled and further cracked there, which would reduce the proportion of longer-chain hydrocarbons in the product diesel.

The exiting from the cracking reactor to the packed column and the condenser gases / vapors who performs the ^¬ a distillation device with reboiler and Des ^¬ distillation column which is at least partially designed as a packed column, and with an intermediate floor, supplied ^¬. In this Deatillationseinrichtung the gases / vapors are decomposed into a gaseous and a liquid fraction. The liquid fraction is withdrawn at the intermediate bottom as product diesel and the gaseous fraction at the top of the distillation column. The gaseous fraction is cooled so that low-boiling components (C5-C7 / C8) condense and can be withdrawn as a liquid fraction. The Uncondensed gases (C1-C4) are preferably used as fuel for heating the thermal oil.

 The lengths of the hydrocarbons in the individual fractions can be well controlled, on the one hand by the temperature of the partial condenser, then by the length of the distillation column and the temperature in this and in the cooler.

 Thanks to the entry of the plastic ingredients via two buffer systems, the system can be operated continuously.

 Preferred first and second heaters in the context of this invention are tube heat exchangers surrounded by thermal oil.

 So that the chain length can be adapted to the particular requirements, it is preferred if the temperature of the partial condenser is adjustable, for example in a range from 150 ° C. to 350 ° C., for chain lengths of a maximum of 22 C atoms, preferably to 300 ° C.

 The thermal 'fine separation of the from

Crack reactor emerging gas takes place, preferably by means of countercurrent distillation, in which a portion of the Pro ^¬ dukt diesel recycled above the sampling point in the distillation column, in particular sprayed. As a result of this recycling of product diesel into the distillation column, the temperature in this column can be varied or adjusted, for example in such a way that, depending on the setting, hydrocarbons having 8-9 to 20-22 C atoms are withdrawn at the intermediate bottom as product diesel become. The type of hydrocarbon mixture of the low boilers or noncondensed gases can also be varied or determined via the temperature setting during cooling.

Typically, the product diesel and / or the low boilers are withdrawn and stored for later use, while the uncondensed gases (Cl-C4) are used directly as fuel for heating the thermal oil. Any impurities present in the product diesel and / or the low-boiling components, in particular sulfur-containing compounds, halogen acids and organic acids, can be removed by absorption and / or filtration.

 An apparatus for treating plastic-containing wastes and organic liquids based on crude oil, which is particularly suitable for carrying out the method described above, comprises a first heating device, a second heating device, a cracking reactor, and a recirculation flow line, which of a Lower region of the cracking reactor via a separator system in the feed line of the molten plastic waste from the first heater into the second heater leads.

 In a preferred embodiment, the first and the second heating device are each a tube heat exchanger flushed with thermal oil. The first and / or the second heating device may also consist of a plurality of series-connected or parallel-connected heating devices, but as a whole have the characteristics of the first and second heating devices.

 For optimum flexibility, the first and second heaters and the cracking reactor have independently controllable heaters.

 Preferred heaters are heat exchangers, which are designed as a tube heat exchanger, wherein the tubes are filled with the melt and are lapped by thermal oil. This ensures the largest possible heat transfer surface, which offers the advantage that it is possible to work with a small temperature difference (usually at most 20 ° C.) between the desired temperature in the melt and the temperature of the heat transfer medium, the thermal oil.

In addition to plastic melt, the recycle stream comprises carbon-rich particles as well as non-melting contaminants that accumulate in the bottom of the cracking reactor. This recycle stream is pumped out of the cracking reactor continuously and passed through a Separator- system in which particles are deposited, whereupon the residual stream is supplied to the plastic melt before the second heater again. A preferred separator system comprises a cyclone separator. This cyclone separator comprises a cylindrical part with centrally arranged pipe. As a result of the centrifugal force larger particles will move outward, so that primarily plastic melt and possibly small particles are recycled via the second heating ^¬ device in the cracking reactor via the centrally located pipe.

 Through this cycle, in particular the continuous pumping, a continuous mixing is effected in the cracking reactor, which makes additional stirring unnecessary in many cases.

 In a further preferred embodiment, in addition to the cyclone separator, the separator system has a sedimentation tank arranged outside the recycle stream line but connected to the cyclone separator, which, however, may optionally be connected to the recycle stream line via the heater side by-pass and preferably connected.

The cracking reactor is equipped with a partial condenser which has a cooling / heating device which is designed in such a way that a defined temperature can be set in the partial condenser. A ^¬ be ferred cooler / heater comprises, as heat transfer medium in a heat transfer medium, which can be brought to a temperature by means of a temperature control that is required to set the required temperature inside the partial condenser. A preferred heat transfer medium is a thermal oil.

Upstream of this partial condenser, ie between the cracking reactor and the partial condenser. ordered, may be a packed column, which is usually not heated. This packed column serves for better separation in the partial condenser.

 The partial condenser, in particular in combination with a packed column, has the effect that only-or at least predominantly-molecules of defined chain length emerge from the cracking reactor.

 Connected downstream of the cracking reactor or the partial condenser is a distillation device which can be operated in such a way that long-chain molecules condense (product-diesel) and escape from the short-chain molecules as gas phase. This gas phase can be partially condensed in a condenser downstream of the distillation column (low boilers and non-condensed gases).

 The distillation device comprises a reboiler and a distillation column, which preferably has a region designed as a packed column and also preferably an intermediate bottom, to which the liquid fraction, e.g. condensed product diesel, is withdrawn. A portion of this liquid fraction, this product diesel, can be recycled to optimize the temperature above the sampling point in the distillation column, which serves to better separation of the hydrocarbon fractions.

 The cooler intended for further separation of the gas phase into low boilers and noncondensed gases has a heating / cooling device with which a defined temperature in the cooler - and thus the composition of the hydrocarbon fractions - can be set.

Downstream of the distillation column or the cooler, adsorption and / or filter units for adsorbing impurities from the light liquid and / or the product diesel can be provided. These adsorption or filter units can comprise a plurality of adsorbers or filters, which alternately can be switched on or off for adsorption or regeneration.

 In the following, an overall process from the delivered waste to the final products will now be described in detail.

 Purified and presorted polyolefin-rich wastes, also referred to below as plastic materials, are stored in a bunker. The presorting can be carried out by means of common methods. The plastics, e.g. PVC, PET by their IR spectra or other features recognized and foreign substances such. removed by means of a punctually placeable air flow. Despite this presorting, the plastic materials may still contain small amounts of impurities, such as e.g. chlorine- and / or sulfur-containing compounds, rubber, metals, sand, etc., which are removed later in the process.

Since the treatment process for preventing unwanted oxidation must be carried out with extensive exclusion of oxygen, the plastic materials of the plant are preferably supplied by means of the injection system described below. This system has the advantage that it is possible to dispense with a permanent flushing with inert gas (nitrogen) during the filling of the melting zones and the cracking reactor, since the introduction system filled with at least partially molten plastic material constitutes an airtight ^seal . In principle, however, the system can also be filled with another injection system.

The exact and reproducible dosage in the inventive delivery system is done with the help of two buffer containers, which are weighed. These buffer containers may optionally be charged or purged with nitrogen. From the respective buffer container, the filling of the system is done by means of a mechanical injection system. This introduction system itself is divided into at least two zones that perform different tasks. The plastic mixture to be processed is fed continuously to the introduction system from the buffer containers, which are alternately filled or emptied, first into a compressor in which it is homogenized and heated substantially by friction. If necessary, the heating can be supported by additional heating, in particular on the outer wall of the compressor, which can be heated, for example with thermal oil. In the compressor, the material should be heated to a temperature of 120 to 150 ° C., So that steam evaporated in this stage and, in particular by applying a slight vacuum, can be sucked off.

Thereafter, the material is conveyed to a preferably heated with thermal oil extruder and heated there to about 250 - 300 ° C. At these temperatures, sulfur-containing and chlorine-containing plastic components are destroyed. HCl and H2S are withdrawn from the extruder with a vacuum pump. The acidic pollutants are preferably neutralized with sodium hydroxide solution as part of a gas scrubber and disposed of. At max. 300 ° C the exhaust gas contains only small amounts of hydrocarbons, In addition to the removal of water, HCl and H2S at relatively clotting ^¬ gen temperatures, this technique also has the advantage that during filling of the heaters (Schmelzzo ^¬ NEN) and the cracking reactor to a permanent purging with inert gas (nitrogen) can be dispensed with, since the filling system filled with already partially molten plastic or the extruder forms an airtight seal.

The extruder compresses and conveys the plastic recyclable materials in a first heating device, in which the plastic ^¬ valuable materials flow through the pipes which are flushed with thermal oil as a heating medium a first tube heat exchanger. The entire heating surface of Tubes is chosen so large that with the smallest possible temperature difference between heating medium and

Plastic recyclables can be worked. This minimizes the deposition of coke by cracking processes on the tube walls. An added benefit of tube heat exchangers is that they are easy to clean. In order to completely melt the plastics, they are heated to approx. 380 ° C.

The output of the first heater, the first heat exchanger, is connected to a recirculation flow line. Through this recycle stream line, recycle stream which was passed from the cracking reactor via a cyclone separator acting as a slag discharge system is added to the plastic melt from the first heater. The mixed stream flows into a second heater, a second tube heat exchanger in which the plastic melt is heated to 400 ° C. From this second heat exchanger, the molten plastic materials, together with the cracking gases already produced at this temperature, reach the cracking reactor. In this reactor at about 400 ^° C, the plastic molecules purely thermolytically, ie without the use of catalysts, decomposed into a substantially gaseous hydrocarbon mixture (cracked).

 As well suited, for example, a

Proven process that works with large heat exchange surfaces, so that despite good throughput with heat transfer medium ^¬ a temperature can be worked that is a maximum of about 20 ° C above the target temperature. Due to this temperature limitation, coke formation can largely be avoided or at least greatly reduced.

The heat transfer in the cracking reactor is preferably carried out to avoid pyrolytic decomposition reactions not or not only by the reactor wall (boiler principle). Preferably, the heat input over a large area with the smallest possible temperature difference, thereby baking and coke formation avoided or at least greatly reduced. A suitable heating means are a plurality of tube heat exchangers arranged within the crack reactor or bundles of heating tubes which are filled with heat transfer medium, in particular thermal oil, or through which heat transfer medium flows.

 The tubular heat exchanger or heating tubes can be easily arranged within the cracking reactor so that even in their presence can be dispensed with a conventional, centrally arranged agitator, i. that due to the continuously pumped and recirculated return flow sufficient mixing of the melt is achieved.

Due to the large heat transfer surfaces, the heat transfer medium, which is used for heating the plastic melt in the cracking reactor, be maintained at a relatively low temperature of preferably 405 ^° C to a maximum of 420 ^° C.

At the bottom of the cracking reactor is an outlet leading to a high temperature liquid pump. This pump is able to pump fluids at a temperature of 400 ° C and is not affected by possible abrasive components in the plastic melt. High-energy but not in the gaseous state passing pitch and tar-like substances as well as the cracking of polymers resulting carbon excess are pumped through a Separator ^¬ system, in particular a cylindrical cyclone separator with associated sedimentation. When entering the cyclone separator, the tangenti ^¬ ale velocity of the fluid is increased due to the dimensions of the cyclone separator.

The increase in the speed of the ^plastic melt in combination with the cylindrical shape of the cyclone separator leads to a centrifugal effect. Higher density particles are swung to the outside of the cyclone, while lighter particles make their way into find the center of the cyclone separator. These lighter particles, along with most of the molten plastic, are passed through a tube out of the cyclone. This tube is advantageously parallel to the cylinder axis and arranged concentrically around it. This stream directed from the cyclone separator is again mixed with molten plastic coming from the first heater and returned to the cracking reactor via the second heater.

 The heavier parts flow down the cyclone separator, preferably into a settling tank, as these still contain larger quantities of molten plastic. The flow velocity in the sedimentation tank is very low, so that an additional separation between see parts high and. low density, or solid particles and molten plastic can be achieved.

A obtained in the sedimentation tank phase which is rich in molten plastic can be fed back via the bypass in the recycle stream line from ^¬ divorced phase of higher density, which comprises the solids, is removed and can be used as high-energy fuel.

The gaseous coal formed in the cracking reactor lenwasserstoff mixture flowing from the cracking reactor in egg ^¬ NEN partial condenser, and preferably by first

 4

a packed column and then only in a Partialkon ^¬ capacitor. This partial condenser is preferably ak ^¬ tiv heatable and / or coolable, in particular, be cooled and also preferably adjusted so that hydrocarbon ^¬ substances which do not correspond to the desired character of the product, such as diesel / fuel oil character, condense and flow back to the cracking reactor where they further are cracks overall until they are shorter than, for example, hydrocarbons with a maximum of 22 carbon atoms and the capacitor passie ^¬ ren can. With this technology, it is possible to largely or even completely avoid the formation of long-chain hydrocarbons (wax / paraffins).

 The lower boiling part (for example, less than C20 or C22) is not retained by the condenser and sent from it to a quench / distillation apparatus which separates the low boilers and gases (C1-C7 / C8) from the middle distillate (C8 / C8). C9 - C20 / C22).

This quench / distillation device comprises a

Reboiler (evaporator) and a distillation column.

The bottom temperature in the quench / Destil- lationseinrichtung is preferably controlled by an evaporation ^¬ fer, a so-called reboiler, which up to 400 ° C can be heated. Hydrocarbons containing more than 22 C atoms are accumulated in the reboiler and pumped back from the reboiler to the cracking reactor.

The distillation column is at least in part ^¬ be designed as a packed column. In a central region, for example in the middle of the Destillationsko ^¬ lonne also a bottom is preferably provided, in which at least a portion of the liquid hydrocarbons is collected. These hydrocarbon liquids ^¬ the withdrawn and - preferably in a heat exchanger - cooled. A portion of the cooled liquid is returned as a recycle stream (reflux) for temperature control at the top of the distillation column, preferably after addition of a free radical inhibitor, which acts as a stabilizer ^¬ gate and prevents the formation of paraffins in the product diesel.

As already mentioned above, the product diesel taken from the distillation step and preferably (as a result of the reflux added with such an inhibitor) containing a free radical inhibitor is preferably finally cooled in a further heat exchanger and optionally filtered by adsorption and / or filtration means and edited. After this Filtration step or before introduction into a storage container, an antioxidant is preferably added to prevent the degradation of the product diesel.

 The vapor exiting the upper part of the distillation means comprises the lower boiling components (gasoline-type hydrocarbons, for example Cl to C8). This steam is cooled in an actively coolable condenser. The condensate, a low boiler (e.g., C5-C8), is discharged into a reservoir. The uncondensed at room temperature part, Cl to C4 or methane to butane - optionally after purification, e.g. by adsorption / desorption - either spent by a compressor in a reservoir, from which it can be used at a later time in a burner for heating the heat transfer medium, or it is fed directly to such a burner.

 Although an overall process is described here, it contains individual inventive aspects that can also be used to improve existing plants. Such aspects are:

 (i) Entry of the plastic materials via the special entry system. This entry system allows process control without or with small amounts of inert gas (nitrogen), which is the flammability of the

System discharged hydrocarbonaceous gases (C1-C4) improved.

 (ii) By using the special feeding system operating in the first zone, the compressor, at temperatures of 120 ° C - 150 ° C, the

Share of water vapor greatly reduced, which leads to an optimization of the gas volume.

(iii) The placement of the extruder in front of the heaters and in front of the cracking reactor and through its operation at 250-300 ° C expels pollutant gases, such as HCl and H2S, without losing appreciable amounts of hydrocarbons went. This early separation of acidic gases results in greatly reduced corrosion of subsequent devices operating at higher temperatures.

(iv) The partial condenser, in particular with an upstream filler column, prevents hydrocarbons exceeding a desired length from entering the distillation system.

(v) The distillation apparatus allows a very accurate separation of the hydrocarbon fractions into a liquid fraction, e.g. Product diesel, and a gaseous fraction, e.g. Low boilers / noncondensed gases. By adjusting the bottom temperature in the reboiler on the one hand, and by adjusting the temperature or the temperature profile in the distillation column by adjusting the reflux of product diesel, the separation of the gas stream coming directly from the cracking reactor into short-chain and long-chain fractions. to control specifically.

 (vi) A portion of the molten plastic mixture is pumped out of the cracking reactor and through a cyclone separator where the particles are separated at high density. In order to achieve a better separation, the high-density fraction from the cyclone is fed into a sedimentation / settling tank in which the liquid has enough time to obtain a stable

 To achieve equilibrium between lighter and heavier particles, so that a further proportion of plastic melt can be attributed.

Due to this pumping of soil material from the cracking reactor and separating solids and products of high density in the separator system ei ^¬ is reduced or nerseits the formation of deposits in the cracking reactor even prevented, on the other hand is achieved by the recycled plastic melt mixing in the cracking reactor, which makes additional mixing often unnecessary.

Brief description of the drawings

Further embodiments, advantages and applications of the invention will become apparent from the dependent claims and from the following description with reference to FIG.

 The figure shows schematically the structure of a plant according to the invention preferred. Therein the reference signs have the following meanings:

 1 compressor

 2 extruders

 3 first heater (first heat exchanger)

 4 second heating device (second heat exchanger)

 5 cracking reactor

 6 Heating for cracking reactor (heat exchanger).

7 high-temperature pump

 8 cyclone separator

 9 sedimentation tank / settling tank

10 return flow line

 11 partial condenser

 12 packed column

 13 reboiler (evaporator)

 14 distillation column

 15 packed column

 16 intermediate floor

17 recycle stream line eg (e) for carrying out the invention

The process for production of hydrocarbons, in particular of individual fractions of hydrocarbons, from plastic waste, in particular finabfällen polyolefin, by means of pyrolytic cracking will now be described with reference to the system diagram shown in the figure ge ^¬ more precisely.

 The filling of the compressor 1 is preferably carried out by means of two buffer systems (not shown), which are charged or purged with nitrogen, and which can be weighed by the amount introduced

Accurately determine and regulate plastic materials. Thanks to the two buffer systems, the system can be operated continuously, as one buffer system is filled while the other buffer system is being emptied.

In the compressor 1, the plastic materials are homogenized, compressed and heated substantially by friction, if necessary supported by a thermal oil heating, preferably in the outer wall of the compressor, in particular a screw compressor. The heating in this compressor to 120-150 ° C, allows the removal of most of the water contained. Water removal can be by applying a vacuum un ^¬ terstützt and is preferably assisted by applying ei ^¬ nes vacuum.

From the compressor 1, the dried, compacted plastic materials are conveyed into an extruder 2, preferably heated with thermal oil, and further heated to about 250-300 ° C., so that at least part of the plastics material is melted. At the extruder 2, a vacuum pump sucks the noxious gases, in particular the acidic gases HCl and H2S. This entry system 1,2, formed from compressor 1 and the extruder 2, and this support ^¬ A technique has the additional advantage that during the loading ^¬ filling of the melting zones of the cracking reactor and to Permanent flushing with inert gas (nitrogen) can be dispensed with, since the system filled with molten plastic is an airtight seal.

 From this entry system 1,2, the at least partially molten plastic enters a first heating device, a first tubular heat exchanger, 3 in which the plastic materials are heated to a temperature of 300 ° C to 380 ° C, so that all plastic is molten ,

 After the heat exchanger 3, the plastic substances emerging from this are mixed with a recycle stream. This recirculation flow is taken from the cracking reactor 5 by means of the high-temperature pump 7 and conducted in the recirculation flow line 10 via the cyclone separator 8 into the stream of plastic materials emerging from the heat exchanger 3.

The liquid phase, formed from the melted KunstStoffwertstoffen derived from heat exchanger 3 and the recycle stream, in a second Heizvorrich- device, a second heat exchanger, 4 at a temperature of 380 ° C to 400 ° C - if still necessary - further melted, already can use a thermal cracking. The molten plastic recyclable materials, to ^¬ together with already-formed hydrocarbon-containing vapors are then the cracking reactor 5, respectively ^¬ leads, which can optionally be heated by means of heat exchanger 6 and in which the molten hydrocarbons split at about 400 ° C (cracked) are. The entire plastic melt, which is located in the cracking reactor 5 and in the second heat exchanger 4, is permanently circulated by means of the high-temperature pump 7. On the one hand a good mixing is achieved, on the other hand, it also serves to simultaneously pump the slag from the Crackre ^¬ actuator in the separator system 8,9, formed from cyclone separator 8 and the sedimentation tank 9, from which it can be discharged. This slag is for the most part high-energy but not in the gaseous state passing pitch and tar-like substances, as well as the cracking of polymers resulting excess carbon.

 The gaseous hydrocarbons leaving the cracking reactor are fed to a filler column with subsequent partial condenser 10, in which long-chain hydrocarbons (longer than, for example, C22) condense, are returned to the cracking reactor 5 and cracked until they have a chain length of, depending on the setting, a maximum of C20 to C22 have.

 The gases which do not condense in the usually unheated packed column 12 or in the partial condenser 11 (C1-C20 / C22) are fed to a distillation device 13, 14, 15, 16 in which they are decomposed into a gaseous and a liquid fraction and from which the liquid fraction as middle distillate, the gaseous fraction as low boilers and uncondensed gases from the distillation unit

13,14,15,16 are deducted.

The distillation device 13, 14, 15, 16 comprises a reboiler 13 and a distillation column 14. The distillation column 14 preferably has a region designed as a packed column 15 and, where appropriate, within this region containing filler or preferably above this range a Zwi ^¬ ash floor 16, on the liquid fraction (product diesel) is collected and can be derived. The product diesel derived from the distillation device 13, 14, 15, 16 is preferably cooled off by means of a heat exchanger, and part of this cooled product diesel can be returned to the distillation device via recycle stream line 17 to set optimum temperature conditions. Usually, the return, the reflux, takes place at the top of the distillation device, but in any case above the intermediate bottom 16, the removal point of the product diesel. Serving as reflux product Diesel a radical inhibitor term paraffin is preferably added, the langket the origin ^'etc. prevented. This ^■ addition is suitably carried out after the heat exchanger and after the branching of the reflux stream.

The withdrawn liquid may be purified in ad sorption and / or filter systems and the alternative ^¬ ell interfering components (eg, organic acids) are removed before the hydrocarbons are converted into a laser gertank.

 Before storing the product diesel, it is preferable to add at least one stabilizer to it.

 Radical inhibitors as well as stabilizers and antioxidants are familiar to the person skilled in the art. A suitable radical inhibitor is e.g. BHT (butylhydroxitoluene), suitable stabilizers are e.g. strong basic amines and a suitable antioxidant is e.g. Phenyldi- min.

While preferred embodiments of the invention are described in the present application, it is to be understood that the invention is not limited thereto and may be embodied otherwise within the scope of the following claims.

Claims

claims 1. A process for recovering hydrocarbons from plastic-containing wastes and organic liquids based on petroleum, collectively referred to as plastic materials, preferably from polyolefin-rich plastic materials, by means of purely thermolytic cracking in a cracking reactor (5) to which a first heating device (3 ) and a second heating device (4) are connected upstream, without the use of catalysts, wherein (bl) the optionally and preferably already partially melted plastic materials are fed to a first heating device (3), in which they are melted (further) at a temperature of from 300 ^° C. to 380 ^° C.,  (b2) the molten plastic materials, together with recycle stream, which has been pumped out of the cracking reactor (5), are fed to a second heating device (4), in which they are further heated to temperatures of 380 ° C to 400 ° C, (b3) the molten plastic materials together with already formed hydrocarbon-containing vapors from the second heating device (4) are fed to the cracking reactor (5), in which the molten plastic materials further split (cracked) at about 400 ^° C, wherein the gaseous hydrocarbon ^¬ materials are fed to a partial condenser (11), condense in the long-chain hydrocarbons, and in the cracking reactor (5) are returned,  (b4) short-chain hydrocarbons leave the cracking reactor (5) and are fed to a distillation unit in which they are decomposed into a gaseous fraction and a liquid fraction, (b5) high-energy but not in the gaseous state passing pitch and tar-like Sub ^¬ punching, as well as in the thermolytic cracking of polymers Resulting excess carbon are pumped together with the recycle stream from the cracking reactor (5) and separated by means of a separator system (8.9) in the recycle stream and residue, wherein the recycle stream between the first heater (3) and the second heater (4) in Heating device (3) mixed molten plastic materials and the residue is passed into a collecting container.  2. Process for recovering hydrocarbons from waste containing plastic and organic Liquids based on petroleum, collectively referred to as plastic materials, preferably of polyolefin-rich plastic materials, by means of purely thermolytic cracking in a cracking reactor (5) to which a first heating device (3) and a second heating device (4) are connected upstream, without Use of catalysts, in particular according to claim 1, wherein the supply of the plastic waste to the first heating device via an entry system (1,2) takes place in the (a2) is removed in a first stage in a mechanical compressor (1) at 120 to 150 ^° C water vapor and a compression and drying,  (a3) in a second stage, in an extruder (2), at 250 to 300 ° C at least partial melting and removal of acidic gases, in particular of HCl and H2S, by means of vacuum and optionally ^{anschlies ¬} sender gas scrubbing takes place.  3. The method according to claim 2, wherein the compression in the first stage (a2) by means of a Screw compressor is done. 4. The method according to claim 2 or 3, wherein (al) the plastic materials via a system of at least two and preferably two optionally with inert gas, in particular nitrogen, purged buffer container in the entry system (1.2) are introduced, wherein at least and preferably one buffer container is filled, while at least one other and preferably one other buffer container in the entry system (1,2) is emptied, and wherein all (both) buffer containers are connected to a weighing system, which allows a metered filling of the injection system with plastic waste. 5. The method according to any one of the preceding claims, wherein the recycle stream is obtained by down from the cracking reactor (5) by means of high-temperature pump (7) melted plastic materials, high-energy but not in the gaseous state überge ^¬ rising pitch and tarry substances, and pumped off during the cracking of polymers resulting carbon excess and fed to a separator system (8.9), wherein the separator system (8.9) comprises a cyclone separator (8) and a sedimentation / Abset zbehälter (9).  6. The method according to any one of the preceding claims, wherein the gaseous hydrocarbons from the cracking reactor (5) are fed to the partial condenser (11) via a packed column (12).  7. Method according to one of the preceding Claims, wherein the gases from the cracking reactor (5) downstream of the partial condenser (11) are fed to a distillation device (13, 14, 15, 16) comprising a reboiler (13) and a distillation column (14), the distillation column (14) a packed column (15) and an intermediate bottom (16), wherein the gases from the cracking reactor (5) in the distillation device  (13,14,15,16) are decomposed into a gaseous fraction and a liquid fraction, wherein the liquid fraction at the intermediate bottom (16) are withdrawn as product diesel and the gaseous fraction at the top of the column, wherein the condensed gaseous fraction of the low-boiling (eg C5-C7) condensed and separated from the non-condensed gases (eg C1-C4).  8. Method according to one of the preceding Claims, wherein the system is operated continuously. 9. The method according to any one of the preceding claims, wherein the first heating device (3) and the second heating device (4) are each a tube around the heat exchanger with thermal oil.  10. The method according to one of the preceding Claims, wherein the partial condenser (11) is adjustable to a temperature of 150 ° C to 350 ° C, preferably ^¬ to 300 ° C, whereby the chain length of the molecules that can pass through the partial condenser can be set. 11. The method according to any one of the preceding claims, wherein the thermal separation of the exiting the cracking reactor (5) gas in the distillation column (14) is carried out by countercurrent distillation, such that a part of the intermediate ^bottom (16) drawn off ^¬ product -Diesels, preferably after cooling and preferably added with radical inhibitor, via a Rezyklierstrom line (17) is returned to the top of the distillation column. 12. The method according to claim 10 or 11, wherein the temperature of the distillation in the distillation column (14) and / or in the condenser, in which a part of the gaseous fraction is condensed, the type of Koh ^¬ lenwasserstoffgemische is defined.  13. Method according to one of the preceding Claims, wherein in the product diesel and / or in the low-boiling possibly still present impurities, in particular ^¬ special sulfur compounds, halogen acids and organic acids, are removed by adsorption and / or filtration. 14. A method according to any preceding claim, wherein short-chain gas ^¬ shaped according to the present capacitor hydrocarbons (for example C1-C4), gege ^¬ appropriate, after compression and storage to be used energetically as fuel. 15. An apparatus for processing plastic waste and organic liquids on the base of petroleum, collectively referred to as plastic materials, comprising a first heating device (3), a second heating device (4), a cracking reactor (5), and a recycle stream line (10) emerging from a lower portion of the cracking reactor via a separator system (8, 9) into the feed of the molten plastic feedstock the first heater (3) in the second heater (4) leads.  16. The apparatus of claim 15, wherein the. first heater (3) and the second heater (4) are each a tubular heat exchanger with circulating thermal oil.  17. The apparatus of claim 15 or 16, wherein the heaters (3,4) and the cracking reactor (5) have independently controllable heaters.  18. Device according to one of claims 15 to 17, wherein the heating devices (3,4) are heat exchangers., Which are designed as a tube heat exchanger, wherein the tubes are filled with the molten plastic materials and are lapped by thermal oil. 19. Device according to one of claims 15 to 18, wherein the separator system (8,9) comprises a cyclone separator ^¬ Se (8).  20. The apparatus of claim 19, wherein the separator system (8,9) next to the cyclone separator (8) outside the recirculation flow line (10) but connected to the cyclone separator sedimentation / settling tank (9) which is connected via the bypass heater device side with the recirculation flow line (10). 21. Device according to one of claims 15 to 20, wherein the cracking reactor (5) a Partialkondensa- tor (11) having a cooling / heating device, which is designed so that in the Partialkonden- (11) a defined Temperature is adjustable, in particular a cooling / heating device with a heat transfer medium, which by means of a temperature control to a temperature necessary for setting the defined temperature can be brought, wherein a preferred heat transfer medium is a thermal oil.  22. Device according to one of claims 15 to 21, wherein in the cracking reactor (5) the partial condenser (11) upstream of a packed column (12) is arranged.  23. Device according to one of claims 15 to 22, wherein the cracking reactor (5) downstream of a distillation unit (13,14,15,16) comprising a Reboi- 1er and a distillation column (14) is arranged, wherein the distillation column (14 ) has an intermediate bottom (16), such that at the intermediate bottom liquid fraction and at the top of the column gaseous fraction can be removed.  24. Device according to one of claims 15 to 23, wherein the distillation column (14) connected downstream, a cooler for cooling the liquid fraction and / or a condenser for partially condensing the gaseous fraction is arranged, wherein the condenser and / or the condenser a heating / cooling device with the cooler and / or in the condenser a defined temperature is adjustable.  25. Device according to one of claims 15 to 24, wherein the distillation column (14) is at least partially designed as a packed column (15). 26. Device according to one of claims 15 to 25, wherein the distillation column (14) is provided with a Rezyklierstrom-line (17), such that a portion of the withdrawn from the distillation column (14) liquid fraction abge above the intermediate bottom (16 ), the removal point, in the distillation column (14) can be returned to ^¬ . 27. Device according to one of claims 15 to 26, with at least one adsorption or filter unit for adsorbing impurities from the liquid fraction or the condensed part of the gaseous fraction. 28. Device according to claim 27, wherein the adsorption or filter unit has a plurality of adsorbers or filters which can be switched on or off alternately for adsorption or regeneration.