WO2021116720A1

WO2021116720A1 - An apparatus and a method for working up plastic grist/chips by thermal cracking

Info

Publication number: WO2021116720A1
Application number: PCT/HU2019/000042
Authority: WO
Inventors: Zoltán SZINAY; Beata MOLNAROVA; Martin Juhas; János ΝÉΜΕΤΗ
Original assignee: Szinay Zoltan; Molnarova Beata; Martin Juhas; Nemete Janos
Priority date: 2019-12-12
Filing date: 2019-12-12
Publication date: 2021-06-17

Abstract

Object of the invention is an apparatus for processing plastic grist / chips by thermal cracking, which comprises elements for feeding the grist, a vertical batch reactor, in the lower half thereof the reactor space and the combustion chamber is located, and its upper part is a dome, burners located in the combustion chamber of the reactor, agitators, cooling devices, material supply lines, and gas, liquid and solid material handling and processing units, and units for handling the sludge remaining in the reactor. The apparatus is characterised in that it has a sludge lock (5) forming a structural and functional unit with the connecting surfaces, emptying into the enclosed part of the sludge screw (6), which has a sludge bolt (5/a) moving in the plane of the bottom plate (5/c) of the reactor, a guide rail (5/b) receiving the sludge bolt (5/a), an arched bushing seal (5/d) fixed by an undetachable joint to the reactor wall, to the guide rail (5/b) and to the sludge bolt (5/a), the upper plane of the guide rail (5/b) is located in the plane of the bottom plate (5/c) of the reactor, the sludge rod (4) of the sludge lock (5) are located outside of the reactor, and further characterised in that a separate wax collector (19) is inserted between the reactor and the gasoline-, light oil-, diesel oil-, and gas recovery units.

Description

AN APPARATUS AND A METHOD FOR WORKING UP PLASTIC GRIST/CHIPS BY THERMAL CRACKING

This invention relates to an apparatus and process for working up plastic grist / chips i.e. plastic afterproduct by thermal cracking, and producing alternative fuels and other useful products from them, while eliminating secondary contaminants.

The process according to the invention is a dry process based on thermal cracking, and preferably it is feasible in pilot plants. Valuable products received during the work-up method such as wax, diesel oil, gasoline, and synthesis gas are separated. The main equipment of the apparatus according to the invention for conducting the work-up method according to the invention is a vertical batch reactor which serves for the so-called dry process i.e. closed-space heating, cracking of the introduced afterproducts. During the process the gases and vapours from the filling are transferred to further units of the apparatus, and from the said units separate wax, diesel, gasoline, and synthetis gas products, and the carbon black powder remaining in the reactor by each cycle is outlet into closed storage tanks. The products obtained during the separation are pumped into a repository intermittently, or blown down.

It is known, that the pyrolysis technology has a history of nearly 100 years, already were the practical benefits of cracking methods of organic materials / polymers in the 30s of the last century recognized. In the 1950s, researchers, mainly academics did several laboratory experiments to model a prospective industrial process. However, no actual industrial implementation was at that time available yet.

It was a major breakthrough, when implementation on an industrial scale took place in the Tosco-Goodyear pilot plant, built in 1969 in Akron, Ohio, the USA, which had been producing fuel oil from used rubber grist in a drum reactor through dry distillation. Years later, firma Texaco also achieved similar results, but these cited early processes are largely known from practice, relevant publications are nowadays difficult to access, and with the advancement of technology, these solutions have become outdated.

Among European developers - also relating to rubber pyrolysis and drum reactor - the operational testings of the Kiener and Mannesmann process may be considered as outstanding. From the 1980s the researchers recognised, that the work-up of the several million tons of accumulating plastic packaging waste cannot keep up with the ever increasing quantity arising, and the oil crisis allowed the emergence of relatively cheap kinds of oil to be produced from secondary raw materials, so professionals were more and more motivated to develop new solutions.

The Japanese Matsui et al built an incipient batch reactor, in which they tried to utilize the advantages of the dry process. In the 1990s several Japanese concerns were using a simple batch reactor model necessary for developing industrial processes, but practically those were not different from each other significantly.

Since the turn of the milleneum Chinese manufacturers have also established pyrolisis plants, but their technical standards and safety did not meet the expectations. Closer to the state of the art is patent No. HU226541 aiming at a process and an apparatus for pyrolysis of rubber waste.

The present invention relates to an apparatus for pyrolizing mixed, coarse mbber grist containing mainly metal rubber composed from waste mbber, and separating the obtained products; the apparatus comprises a structure for preparing, feeding die grist, a pyrolysis reactor, burners located in the combustion chamber thereof, agitators, cooling devices, material supply lines, and gas-, liquid- and solid material handling and processing units, and is characterised in that between its feeding system and the inner chamber of its reactor the feeder designed as a lower boundary element of the stuffing screw, suitable for gas-tight closing has a latch; the feeder stub receiving the feeder latch is in an elevated position relative to the reactor due to the raised design of the dome neck; its mixing device has a ribbon screw conveyor and is combined with an excavator member, on the reactor wall, inside the combustion chamber thereof there is an assembly of tubes disposed, and has a column with sieve plate rows for fine separation of the liquid mixtures.

The Hungarian patent application No. PI 100572 is aimed at utilizing degradable milled wastes, separated from compostable organic wastes and metallic and nonmetallic solid contaminants, withdrawn from household and coming from production lines, by decomposing the dehalogenated polymers in a closed area above their degradation temperature in the processing equipment. Utilisation of the gas, oil and solid products as alternative energy sources in an energy center is subject to the BAT requirement system. This solution is essentially aimed at a two-step cracking of PVC-containing waste, which is a pilot plant model waiting for an industrial solution. Furthermore, several US patents related to the subject are known, such as the following: the patent No. US 8344195 is a dolomite catalyst technology conducted at 340-440°C for processing PE, PP, PS secondary raw materials; the patent application No. US 001061/2015 describes a low temperature process for producing diesel and other propellant fractions; the patent No. US 0008194 relates to the treatment and utilisation of high- density waste; the patent US 9493713 relates to a mobile device with two reactors, an extruder, and direct product separation.

The above solutions have several disadvantages.

Namely, their common technical disadvantages are as follows; inadequate degree of efficiency or work-up efficiency; product quality difficult to maintain due to variable input characteristics; the existence of environmental problems such as harmful emissions; insufficient verticum-type production due to the immaturity of the industrial sector.

As a result, market opportunities are generally unregulated and unstable.

We came to the conclusion that considering the apparatus currently used in practice, the yet unsolved problems of emptying accumulator and standing cylinder-shaped reaction chambers, the frequent malfunction and difficult repair, are largely due to the inadequacy and frequent failure of the sludge drainage system, more specifically the sludge drainage lock, have been found.

The reasons for this problem are usually the following:

In all cases, the lock is a stand-alone device mounted on the bottom of the pan, which is located in a sludge neck enclosed by the bottom plate and the combustion chamber, and is therefore exposed to high temperatures, since the neck insulation would result in a significant loss of the size of the combustion chamber.

The housing mounted on the bottom plate is sealed, and is screwed that way; therefore, the section between the bolt and the bottom is clogged by the partially processed material, which bums into it, or the goo creates a blockage.

Due to the construction of the lock or the latch applied, plugging is unavoidable because it cannot be removed by operation. During closing, the contamination / build-up is pushed into the enclosure by the action of the bolt, or the operation pushes the goo into the valve-sediment, so that no gas-tight closing occurs. During service the problem is worsening, even after fifty - one hundred hours disassembly and repair may be necessary, the deformation of the tool, abrasion, possible crack because of misuse are visually perceptible, which mostly happen because at closing the arched-edge bolt pushes into a socket with a bigger arch, and abrades and cracks the insert thereof made of softer material.

Similarly, regarding the so-called taper lock, the breaker component initially fits into its companion piece, but during operation due to build-ups / bums, it does not fit metallically to the stepped surface, furthermore tilting down the operating lever at opening presents a problem because there is a solid residue on the tool left in the sludge hopper.

Regarding the apparatus used in practice a further significant problem during thermal cracking is the treatment of end-point synthesis gas, which is received with a simple drip separator, but its efficiency is not sufficient to separate effluent-gas, gasoline and other aggressive, mainly aromatic liquid vapours, so they damage the burner by decomposing the burner valves and other fittings and seals, and possible dissolving the copper and tinplate surfaces thereof. This effect occurs due to the corrosive effect of the acidic aqueous solution delivered with the gasoline. A further disadvantage of the flares is the disordered combustion of a large amount of propellant causing carbon black contamination.

It is also known that it is required for various purposes an increasing amount of PE- based plastic afterproduct to be processed. There is a strong need for a solution to a high quality industrial wax production process from low cost, massive PE waste.

Ethylene wax is produced in large-scale industry from ethylene gas or oil distillation, but it is not advisable to deliver large quantities of waste to refineries.

During the refinery production the starting material is the heavy oil to be drained from the crude oil column boiler, the boiling point thereof is above 400 °C. This is separated in support columns into lower boiling point medium oils and wax products. Ethylene wax can also be produced from PE waste by feeding the grist into an extruder and obtaining the wax product at boiling point. However, the high heat demand of the extruders is sometimes difficult to provide. The object of the present invention is to provide an apparatus capable of eliminating the above-mentioned drawbacks of the state of the art, and to provide a process suitable for recovering high quality polyethylene wax products from PE waste.

We have recognised that the problem of the sludge lock can be overcome if the sludge lock fits into its place forming a structural and functional unit with the connecting surfaces.

It is a further realization according to the present invention, that during thermal cracking the drip pan generally used for treating end-point synthesis gas has to be eliminated, and a four-member system consisting of a gas container, a refrigerator, an air conditioner apparatus and a separate air conditioner ventilator is required instead.

It is further realisation regarding the process, that high-quality polyethylene wax can be separated with high efficiency from the heavy oil product during thermal cracking.

The apparatus according to the invention comprises elements for feeding the grist, a vertical batch reactor, in the lower half of it there are a reaction chamber and combustion chamber, the upper half of it is a dome, comprises burners, agitators, cooling devices, material supply lines placed in the reactor combustion chamber, and gas-, liquid- and solid material handling and processing units, and units for the treatment of the sludge remaining in the reactor, which apparatus is characterised in that it has a sludge lock forming a structural and functional unit with the connecting surfaces, emptying into the enclosed part of the sludge screw, which has a sludge bolt moving in the plane of the bottom plate of the reactor, a guide rail receiving the sludge bolt, an arched bushing seal fixed by an undetachable joint to the reactor wall, the guide rail and the sludge bolt, the upper plane of the guide rail is located in the plane of the bottom plate of the reactor, the sludge rod of the sludge lock are located outside of the reactor, and a separate wax collector (19) is inserted between the reactor and the gasoline-, light oil-, diesel oil-, and gas recovery units.

Preferably, the apparatus has a reflux cycle consisting of a wax collector, an absorber, a forward coolant, a multitube cooler, a circulating pump, and a reflux tube.

Preferably, furthermore, a heating register is provided at the bottom of the wax collector.

Preferably for the gas product, the apparatus has a tail gas cooling system consisting of a gas tank, a single tube cooler, an air conditioner, and an air conditioner ventilator. Preferably, the brim of the bolt of the sludge lock located in the guide rail is trapezoidal.

It is also preferable that the edge of the bolt of the sludge lock is formed at about

70°.

The apparatus according to the invention can be designed as mobile and then can be mounted on a container chassis.

The essence of the process according to the invention is that it is carried out with the equipment according to the invention, where a wax collector is inserted between the reactor and the devices for recovering gasoline, light oil, diesel oil, gas.

Hereinafter, the apparatus according to the invention will be illustrated with reference to the drawings, in which Figure 1 schematically illustrates the device partly in view and partly in section,

Figure 2/a is a back view section of the sludge units, Figure 2/b is a side view section thereof, Figure 2/c is a top view thereof, and Figure 3 is a diagram of the properties of the product obtained.

The apparatus according to the invention is illustrated in more detail with reference to Figures 1 and 2; however, it will be apparent to professionals that the apparatus is not limited to the use of known parts shown in the figure, which are not essential to the present invention, since they may be replaced by known parts having the same function; and constructions thus obtained are also within the scope of the invention.

It is noted that the apparatus in Figure 1 implementing the small-works technology if desired, may be mounted on a container chassis (not illustrated).

Smaller differences from the standard container size are possible. In this case, the main equipment (vertical batch reactor) is suspended on the upper points of the chassis, without legs or a stand, to eliminate the difficulties caused by thermal dilatation. The separation units are placed on a single desktop or an equipment saddle.

The reactor of the apparatus is essentially a 2/3 kettle with a vertical longitudinal axis having a reaction space of about 1000 liters, the reactor is provided with an upper and side feed opening, and a vertical agitator axis 8 is introduced in the center of the dome lid 11.

The carbon black outlet opening at the edge of the combustion chamber bottom 1 is enclosed by the sludge lock 5. The combustion chamber encloses the reactor from the side and bottom, where the oil burner 18 and gas burner 3, each with 300 kW of nominal heat output, have a lower tangential location. In this case, the burners are block burners, so that their power supply and, while providing fuel, their operation is continuous.

The mantel of the combustion chamber and the bottom of the combustion chamber 1 are provided with ceramic duvet heat insulation and protective cover from the outside. Between the combustion chamber bottom 1 and the bottom plate 5/c of the reactor shown in Figures 2/a and 21b preferably a stool 17 is placed, by screw connection of the two horizontal members, the combustion chamber is enclosed by the combustion chamber bottom 1, the combustion chamber mantel and the stool 17, which latter deflects the flame of the oil burner 18 and the gas burner 3 as desired.

In the reactor, the mixing paddle 7 mounted on a vertical mixing axis 8 serves for mixing the filling and has a spreading lever 9. The spreading lever 9 is used to smooth the disturbed filling during the initial period of the cycle to reduce swinging or mechanical stress caused by mixing.

The cubic chips feeds which are ground or agglomerated mainly from plastic waste, passes through the feeding neck 15 into the passage of the piston 16 where, when the piston 16 is moved inwardly, closes the feeding neck 15, and transfers all residual material into the chamber.

The sludge lock 5 is connected to a sludge screw 6 hopper which delivers the solid residue to the repository at an angle of 30°.

The sludge lock must form a structural and functional unit with the connecting surfaces.

This is achieved by moving the sludge bolt 5/a in the plane of the bottom plate 5/c of the reactor, thus avoiding the formation of a blockage. The upper plane of the rail 5/b receiving and guiding the sludge bolt 5/a is also disposed in the plane of the reactor bottom plate 5/c.

The upper part of the portion of the 5/a sludge bolt struts against the 5/c bottom plate when closed, so that it is not stopped by an end position set mechanically or electronically, but the control element is the torque apperaring in the actual end position. If minimal build-up occurs during one operation, the lower part of the portion in the plane below the bottom plate closes the connection metallically on a considerable surface. This is illustrated in Figure 2/a-2/c. The minimal build-up becomes carbonized during the next cycle and falls as powder into the sludge screw 6 housing.

The sludge lock 5 empties not within the scope of the combustion chamber, but into the enclosed part of sludge screw 6 housing, so that the sludge lock 5 is not located in the neck surrounded by the high temperature combustion chamber, but it is actuated mechanically by the arched bushing seal 5/d mounted on the reactor wall, following the arch thereof. This is accomplished by welding the arched bushing seal 5/d the 5/b guide rail and the 5/c bottom plate to the reactor. The sludge bolt 5/a alternates through the stable sealing system, where the sealing is provided. Thus, the actuating sludge lock rod structure 4 is located outside the device, at ambient temperature, and is actuated by a manual or pneumatic device. Further, the edge of the upper section of the sludge bolt 5/a forms a trapezoidal profile; the sludge bolt 5/a in the guide rail 5/b is ground to 70 degrees, thus, the bolt cannot move out of the horizontal plane, but, at closing, cleans the build-up on the guide rail 5/b. The angle of 70 degrees of the edge design is non-limiting, a few degrees of deviation are allowed for practical reasons.

The gases, vapours - and the aerosol condensed therefrom - passing through the lamellae demister pad 13 mounted on the dome cover 11 drip back into the reactor from the lamillae 13 while the gaseous products flow through the steam line tube 14 to the wax collector 19. The lamellae of the demister pad 13 are not constructed with a corrugated fold but with 20 mm 45 degree flans.

The wax collector 19 is configured as a vertical container at the bottom of which there is an electric heating register 20; a wax drainage unit is provided on its lower part for evapouration of lower boiling point products. From the wax collector 19, the diesel vapours enters through the oil vapour transfer tube 22 into the absorber 26 for condensation, and then the absorber ceramic filling 25 condenses the vapour countercurrent into a cooled reflux product and drips it into the tank 26 of the absorber. The reflux cycle is thus constists of the absorber 26, the forward coolant 29, the multitube cooler 31, the circulating pump 32, and the reflux tube 24, from where through a known reflux divider formed in the upper part of the absorber 26 across the entire cross-section, a blend, corresponding to the diesel fraction, drips back on the orderly ceramic filling 25 of the absorber 26, and collects at the bottom of the absorber 26.

The reflux divider and the absorber 26 orderly ceramic filling 25 are manufactured by Sulzer, Switzerland. The overhead product of the absorber 26 is the light fraction, so the pipe leading to the Eckler cooler 34 of the gasoline is called the gasoline steam tube 27. The Eckler cooler 34 includes a spiral tube bundle 35 to provide a larger heat transfer surface. It is not necessary to insert a gasoline drip pan into the gas tank 39 because some of the gasoline content of the aerosol gas flowing through the primary gas line 36 into the gas tank 39 is condensed, and it is discharged through the drainage region of the gas tank 37, on the other hand, the final cooling unit is formed above the gas tank 39 dome, consisting of a single tube cooler 41, air conditioner 42, and air conditioner ventilator 43 for supplying a dry, syngas-mixture to the gas burner 3 through the gas line 40, avoiding the damage of the valves of the gas burner 3. The gas tank flare line 38 is a safety line for blowing the system down, through which the pressurized gaseous product reaches the profile.

An example of construction, description of operation

During the operation of the apparatus, the processing temperature is between 450 °C and 550 °C in the reaction chamber, and a pressure of 5-60 mbar is maintained, which decreases with only a few mbars till the end point, thus ensuring the operating pressure level of the gas burner 3 to meet the heat demand of the cycle. The pressure in the combustion chamber is, as required, created by the atmosphere of the gas burner 3, or by the combustion chamber pressure maintained by the operation of the oil burner 18, in the range of 0-5 mbar. The effect of the capacity change due to the varying heat demand of the reaction was solved by electronic control of a ventilation controller 10 installed in the exhaust fitting.

During operation of the apparatus, the apparatus is energized by switching on the control cabinet of the central control unit, whereby the status of the whole operation can be monitored. The main apparatus is preheated by heating the combustion chamber and the reactor to operating temperature with the help of a gas cylinder, or feeding of the oil burner 18 is started from the charged system so that the reactor reaches operating temperature in about 15-20 minutes. The process is significantly faster than previous solutions because not a heavy furnace type is used, but a reactor with an approximately 8 mm thick wall.

The chips are fed into the preheated reactor through a horizontal feeding neck 15, into which for example an inclined angle screw conveyor feeder feeds the material until the chips are discharged from the tank. The material remaining in the feeding neck 15 may alternate with a piston 16 or pneumatic actuation or an N2 gas injection for increased safety, but in both cases in the feeding neck 15 it closes the inlet of said inclined angle screw conveyor feeder. As a result of the operation, the closing operation provides a gas- tight closing to both the surroundings and the dispenser.

During the feeding, the agitator axis 8 and the agitator blade 7 attached to it, as well as the spreading lever 9 rotate, so that the feedstock almost completely occupies the lower half of the reactor by the end of the feeding. Steam backflow is prevented by the increasing filling and closing of mechanical elements. The batch amount is 250-350 kg, depending on the density / actual volume of the material. The vapour arising from the heating leaves the reaction space in about 70 minutes. Approximately half of the cycle time in the literature is described in 36 minutes - as the kinetic reaction time - during this time the polymers are degraded to the molecular size (C1-C35) of the desired target product, mixing and getting the material to the heated surface take the other approximately 34-35 minutes, which is a really favorable residence time and efficiency compared to previous solutions which, in addition to the manifold of above residence time and poor efficiency, have resulted in a mass of poor quality or even harmful products.

During the work-up procedure the vapour containing gas, oil and gasoline components goes upwards through the demister pad 13, where the contaminants of the aerosol fix the heavy oil colloids, these colliding on the edges of the 45° lamellae of the demister pad 13 arrange into bigger drops, and even at a 12-14 m/s flow rate fall back into the reactor.

In connection with the outlet of the solid product at the previous solutions it represented a constant problem that the half degraded material always almost scorches in the sludge opening, and the blockage always prevented the removal of the carbon black. Regarding the apparatus according to the invention the sludge bolt 5/a closes in the reactor bottom plane 5/c of the reactor, until it stops, its lower brim moves on the lower surface of the reactor bottom 5/c. Thus, both end-point and surface closing are achieved, while during the closing procedure it removes the bum from the profile of the guide rail 5/b, at opening a few turns of the agitator blade 7 eliminates the solid residue into the sludge screw 6 hopper.

The steams flowing through the steam line tube 14 flow into the wax collector accumulator 19, and primarily condense, and then enter the absorber 26 through the oil vapour transfer tube 22 formed on the upper side mantel of the vessel. The bottom of the wax collector 19 is provided with a heating register 20 which has a power of 3.5 kW in the case of the assembly illustrated and fed by single-phase electric current. The boiling point temperature of the heavy oil product - paraffin wax - with a boiling point above 400 °C, which is extracted from the wax collector 19, is provided by the heating register 20, thus lighter distillates leave for the absorber 26 as overhead products. The wax drain 21 allows the product to be drained at both boiling point and lower temperature, by evaluating the amount on the level indicator thereof it can be decided whether to drain it per shift or cycle. The heating register 20 is turned on by the instrument automation when a steady mass flow has been achieved, but it is at least 3.6 kg / min., and then a stable boiling point as a bottom temperature is required in the boiling unit, which is the wax collector 19, to separate the heavy fraction. As the pressure in the reactor decreases, the heating register 20 stops because its production would flow back into the reactor, resulting energy loss. In the oil refineries, the wax is produced by refining the product drained from the boiler of the columns, in the dry process according to the invention, a heavy fraction of the primary distillate is captured in the wax collector 19. The tank is emptied when out of service or cycle time.

The operation of the absorber is known. It is the starting point of the reflux cycle from which through the forward coolant 29 the circulating pump 32 pumps the diesel product to a multitube cooler, which flows into a unit placed gravitationally also at a lower point, however, with the circulating pump 32, with the help of the ratio control through the reflux tube 24 it flows to the upper point of the absorber 26, from there flows downwardly on the orderly ceramic filling 25, or to the oil burner pre-reservoir, to feed the oil burner 18. Ratio control is ensured by a three-way solenoid valve controlled by instrument automation, depending on the operating state.

The medium oil product, i.e. the diesel fraction, is let out by opening the 28 diesel drain valves, taking into account the fluid level of the absorber 26. The multitube cooler drain 30 is used to empty the unit. The multitube cooler 30 is a 45 kW fixed bed tubular device between two standing, so-called distributing and collecting trunks. In the tube bundle section two parallelly operating ventilators are disposed, by switching them on and off, and by the discharge control of the circulating pump 32 it is to obtain the instantaneous cooling capacity.

The overhead product enters from the absorber 26, at the lower end of the Eckler cooler 34 for gasoline, passing through a drum-like distributor upwards on the parallel spiral tube bundle 35, which operates with a direct-flow air cooler. Its application is more advantageous than that of horizontal cross-flow devices, which are not efficient enough and difficult to handle and maintain. The unit does not have a deadlock, it can be emptied at any time, it is self-cleaning.

The aerosol leaving the Eckler cooler 34 enters the gas tank 39 through the primary gas line 36, from which the gas tank flare line 38 lets the overpressured blend to be blown down to the safety fittings, a wired link formed at the top of the gas tank 39 connects to the air conditioner apparatus 42, so that the end-point product contains only real gases to feed the gas burner 3 or to operate any other auxiliaries. Real gases are aeriform at temperatures below 40 °C, but the gas tank may be heated by the temperature, radiating elements, etc., so it is advisable to provide a stable 6 °C outlet temperature for the use of synthesis gas. There is a separate air conditioner ventilator 43 connected to the air conditioner apparatus 42, which sucks air form the working space or the outside surroundings. The drainage of the condensate is carried out by opening the condensate pipe 36 of the gas container.

In pilot plants carrying out thermal cracking of plastic afterproducts, it is possible to separate the wax product effectively in the main technology the following way.

The temperature of the reactor overhead product is approximately 450 °C, which enters the steam line tube 14 at approximately 380-400 °C on the dome of the wax collector 19, and protrudes approximately 400 mm on the longitudinal axis of the column. The aerosol, vertically with a flow rate of about 12 m/sec, collides with the surface of the product formed at the bottom of the wax collector 19 or yet having small quantities, and as an elementary drip pan, the higher boiling drops condense. In order to obtain a homogenous product, the heating register 20 directly mounted on the bottom of the wax collector 19 is controlled so that it maintains the product to be separated at a boiling point between 390-407 °C. The lower temperature is the boiling point of the so-called nano-wax (paraffin oil), while the upper is that of the intermediate wax. During the process there is a possibility of drainpoint at the downside, or of lowset fluid drainage above 65 °C after cooling the unit. Thus, the wide fraction does not pass through the oil vapour transport tube 22, which is also formed at the upper point, but the heavy product is separated effectively by the siphon, avoiding the waxing of the diesel.

The drip pan in our case is essentially a four-unit system consisting of a gas tank 39, a single tube cooler, an air conditioner apparatus 42 and a separate air conditioner ventilator 43.

The effluent aerosol from the gas tank 39, which still has a high gasoline content, is fed to a single tube cooler 41 where the gas to be discharged cools down to even 6 °C moving parallelly with the cooled atmosphere of the air conditioner apparatus 42, the real gases continue to flow, and the precipitate, gasoline and aqueous solutions are discharged at the bottom of the gas tank 39. The syngas arrives at its place of use or blow-down with appropriate parameters. The air conditioner apparatus 43 can be located either in the work area or in lay-up operation. Thus, the system has three circles: the fluid of the air conditioner apparatus 42, the air of the air conditioner ventilator 43, and the cooled synthesis gas moving in a single tube cooler 41 which flows to its place of destination. The single tube cooler 41 may be direct- or cross-current, but preferably the primer gas stream 36 passes through in a shell, or also preferably in a rising spiral double-walled tube, in which the primary gas line 36 is surrounded by the jacket of the single tube cooler 41.

The physico-chemical characteristics of the medium oils produced in refinery practice are tested according to approximately 35 standards, however, during our pilot runs it has been proven about the products we produce that if all the four properties of the distillates falling in ranges A1 and A2 in the diagram illustrated in Figure 3 exist, the blend is suitable for operational use in stable diesel aggregates, thus for power generation.

So the products obtained are as follows:

Cetane number: between 47 and 60

Relative viscosity: between 2-6 Solidification point: between -20 and 6 °C Flash-point: between 40 and 60 °C

So the product is suitable to the above intended purpose.

For continuous operation, the instmment automation hierarchy has been designed to meet the requirements of the 3-stage security system, so under PCL monitoring adjustment mode or automatic control can be carried out. The safety preconditions comply in all respects with the gas safety requirements, and the system messages and alarm signals prevent emergencies.

Claims

Claims:

1. Apparatus for processing plastic grist / chips by thermal cracking, which comprises elements for feeding the grist, a vertical batch reactor, in the lower half thereof the reactor space and the combustion chamber is located, and its upper part is a dome, burners located in the combustion chamber of the reactor, agitators, cooling devices, material supply lines, and gas, liquid and solid material handling and processing units, and units for handling the sludge remaining in the reactor, characterised in that it has a sludge lock (5) forming a structural and functional unit with the connecting surfaces, emptying into the enclosed part of the sludge screw (6), which has a sludge bolt (5/a) moving in the plane of the bottom plate (5/c) of the reactor, a guide rail (5/b) receiving the sludge bolt (5/a), an arched bushing seal (5/d) fixed by an undetachable joint to the reactor wall, to the guide rail (5/b)and to the sludge bolt (5/a), the upper plane of the guide rail (5/b) is located in the plane of the bottom plate (5/c) of the reactor, the sludge rod (4) of the sludge lock (5) are located outside of the reactor, and further characterised in that a separate wax collector (19) is inserted between the reactor and the gasoline-, light oil-, diesel oil-, and gas recovery units.

2. An apparatus according to claim 1 characterised in that the wax collector (19) has a reflux cycle comprising an absorber (26), a forward coolant (29), a multitube cooler (31), a circulating pump (32) and a reflux tube (24).

3. An apparatus according to claims 1 and 2 characterised in that it has a heating register (20) at the bottom of the wax collector (19).

4. An apparatus to any one of claims 1 - 3 characterised in that for the gas product it has a tail gas cooling system consisting of a gas tank (39), a single tube cooler (41), an air conditioner apparatus (42), and an air conditioner ventilator (43).

5. An apparatus to any one of claims 1 - 4 characterised in that the brim of the bolt (5/a) of the sludge lock (5) located in the guide rail (5/b) is trapezoidal.

6. An apparatus to any one of claims 1 - 5 characterised in that the edge of the bolt (5/a) of the sludge lock (5) is formed at about 70°.

7. An apparatus to any one of claims 1 - 6 characterised in that it can be mounted on a container chassis.

8. A process for working up plastic chips/ grist, characterized in that it is carried out by an apparatus according to any one of claims 1-7 wherein a wax collector (19) is inserted between the reactor and the gasoline-, light oil-, diesel oil-, and gas recovery units.