RU2766091C1 - Rotor element for use in an ablative pyrolysis reactor, an ablative pyrolysis reactor and a pyrolysis method - Google Patents

Abstract

FIELD: technological processes.

SUBSTANCE: invention relates to processing of liquid and / or solid hydrocarbon wastes into useful products, waste such as oil sludge, waste oil, tires, wood and any types of plastic. Invention relates, in particular, to a rotor element for use in an ablative pyrolysis reactor, a reactor and a method of ablative pyrolysis, and their use in the process of processing wastes into fuel, in particular, to the process of plastic processing into fuel. Rotor element for use in an ablative pyrolysis reactor comprises a central longitudinal shaft and ablation blades having a fixed end and a free end configured to be in contact with the inner wall of the reactor housing, as well as one or more screw blades passing in radial direction from central longitudinal shaft, wherein the ablation blades are located in the space between the helical blade turns and/or in the space between the adjacent helical blades. Reactor for ablation pyrolysis comprises a reactor housing equipped with an inlet for supply of raw material for pyrolysis, an outlet for pyrolysis products, and a rotor which contains a rotor element. Another aspect of the invention relates to a pyrolysis method, comprising steps of a) preparation of raw material for pyrolysis from wastes, b) feeding raw material for pyrolysis into an ablation pyrolysis reactor according to the invention and pyrolysis of the raw material to obtain pyrolysis products.

EFFECT: conversion of organic wastes into useful products with maximum output of useful product with minimum consumption of energy and minimum amount of unsuitable product residues, as well as with minimum emission of generated exhaust gases into environment.

21 cl, 4 tbl, 5 dwg

Description

Technical field

[0001] The invention relates to the field of processing liquid and/or solid hydrocarbon waste into useful products, such as oil sludge, used oil, tires, wood and any kind of plastic. The invention relates, in particular, to a rotor element for use in an ablative pyrolysis reactor, an ablative pyrolysis reactor and a process, and their use in a waste-to-fuel (WTF) process, in particular, to a plastic-to-fuel (PTF) process - plastic to fuel).

Description of the prior art

[0002] The WTF pyrolysis process in the initial stages typically includes a waste pre-treatment step in which the waste is treated to convert it into a suitable pyrolysis feedstock. This stage may include one or more stages of cleaning, sorting, drying, grinding, compacting, heating, degassing, melting. The second significant step in the process is the pyrolysis step, during which the pyrolysis feedstock is heated in the absence of air, in particular in the absence of oxygen, to about 400-600° C. to produce mainly pyrolysis gas or steam and liquid, partially pyrolyzed feedstock, which may contain coke or tar. The third stage is a condensation stage in which the pyrolysis gas generated during the pyrolysis process is separated into a condensable liquid phase and a non-condensable gas phase of the pyrolysis products. It should be noted that the term pyrolysis gas in this document covers both pyrolysis gas and steam. In addition, one or more additional steps in the WTF process may be distillation, condensation, separation, refining, purification, filtration, etc. At these stages, the formation of useful pyrolysis products occurs, as well as conversion into electrical energy, cooling, heating, storage, etc.

[0003] Typical waste materials used as feedstock in the pyrolysis process are organic material selected from the group consisting of biomass, agricultural and forestry waste, municipal solid waste, construction and demolition waste, oil spills, contaminated oils and various types of plastics. Typical primary products obtained from the WTF pyrolysis process are light, medium and heavy distillate fuels (gasoline and diesel), as well as secondary products such as charcoal, synthetic fuel gas and a mixture of solid hydrocarbons. It should be noted that while this process is referred to as a waste-to-fuel (WTF) process, the end product need not be a fuel, but useful end products typically include fuel. Another important goal of the WTF recycling process may be to recover the monomers from which it was originally produced from plastic. In terms of fuel, the challenge is to produce high-grade, ultra-low sulfur fuels.

[0004] The preferred source type of waste is plastic. It is estimated that by 2025, the global production of municipal solid waste (MSW) will be 2.2 billion metric tons per year, of which various types of plastic will account for approximately 13% of the total MSW. Of all the plastic produced, only about 9% is recycled, 12% is incinerated, and 79% ends up in landfills or pollutes the oceans. Therefore, the most difficult task arises - to increase the percentage of recycling of useful products. Technologies for converting various types of plastic into fuel, in particular pyrolysis processes, have become one of the possible solutions to reduce the amount of plastic marine litter and dispose of end-of-life plastic.

[0005] The overall goals in WTF pyrolysis processes, as well as in the process of the present invention, are to convert organic waste into useful products with the maximum yield of useful product with minimum energy consumption and a minimum amount of unusable product residues, as well as with a minimum emission generated exhaust gases into the environment. Another problem with turning waste into useful products in general is that the waste has to be transported to the plant, which creates logistical problems and also leads to pollution. Thus, another common goal is to develop mobile recycling systems that are compact and self-contained (not dependent on local infrastructure) so that they can be easily transported to the waste source. A related problem for the offline process is to reduce the design capacity to process less waste. A typical small volume is 10 to 60 tons of plastic waste per day.

[0006] WO 2013064864, for example, describes a mobile modular system for harnessing the energy of logging residues at their source by producing liquid biofuels. An integrated pyrolysis plant can be placed on two or more trucks that deliver the equipment to the waste source, where the equipment components are quickly connected to each other. The pyrolysis plant includes, but is not limited to, a drying unit, a pyrolysis unit, a condensing unit, a biofuel storage unit, and a non-condensable gas storage unit. Pyrolysis is carried out in a fluidized bed pyrolyzer. This pyrolysis plant has a large volume, relatively low productivity, low yield and low quality of bio-oil, and too much waste.

[0007] In pyrolysis, the rate of heat transfer plays an important role in the qualitative and quantitative distribution of solid and liquid yields. Depending on the heating rate of the particles and the residence time of vapors under pyrolysis conditions, pyrolysis is further classified as slow, medium and fast pyrolysis. Fast heating leads to increased release of volatiles, while slow heating leads to an increase in the formation of solids, which is undesirable, since these substances are usually waste products that reduce the yield of useful products, reduce the quality of the final product and complicate the process.

[0008] A variety of fast pyrolysis reactor configurations have been proposed to achieve high heat transfer rates. Known configurations include vortex cyclonic centrifugal pyrolysis, fine moving bed or transport bed pyrolysis, vacuum pyrolysis, fluidized beds. Despite the simplicity of design, the disadvantage of reactors using this approach is the need for large volumes of carrier gases compared to the amount of feedstock. In addition to increasing cost, a large volume of gases requires complex gas separation procedures and also leads to thermodynamic losses. One of the promising methods of fast pyrolysis is ablative pyrolysis, in which heat transfer occurs through direct contact of solid particles with a heated heat transfer surface of the reactor. This type of pyrolysis has the potential to provide a reactor with high specific productivity, reduced size, reduced costs, and improved process control.

[0009] WO 20146945 describes a horizontal reactor and method for the ablative pyrolysis of solid organic feedstock such as biomass, comprising a reactor with a cylindrical vessel, a heated surface, a cylindrical concentric rotor with blades, configured to provide centrifugal force and axial horizontal propagation of solid feedstock, while the heated surface has a temperature of not less than 300°C and not more than 650°C, and the cylindrical rotor is designed to rotate at a speed of not less than 500 rpm and not more than 20,000 rpm. The rotor blades are elongated along the axis of the rotor on the axis in the axial direction, which allows you to transport the solid mass horizontally, as in a screw / extruder. The disadvantage of this reactor is that the efficiency and rate of heat transfer is still not as high as desired and it is difficult to achieve uniform temperature distribution. In addition, such a reactor is only suitable for solid waste.

[0010] US 2010077711 describes an ablative thermochemical reactor in which dried biomass is pressed against the outside of a rotating cylindrical heated surface, which is provided with holes to allow the generated pyrolysis gas to enter the interior of the cylinder. The pressing device compacts and preheats the dry waste by forcing it through the tapering heated channels so that the air pockets do not reach the surface of the heat exchanger and pyrolyzer rings and provides sufficient contact for efficient heat transfer. Such equipment is complex, large and expensive, but, nevertheless, does not have high efficiency and productivity and is suitable only for solid waste.

[0011] EP 1879980 also describes a mobile plant for collecting biomass from a growth site and producing pyrolysis products. A special ablative thermochemical centrifugal reactor is also described, in which the dried solid biomass supplied to the reactor is centrifugally directed outward and pressed against the inner surface of the heated reactor wall using a rotor placed along the axis, with partitions along the direction of its axis, which is a cylinder with openings allowing the resulting pyrolysis gas to flow into the interior of the cylinder, the rotor also being axially located in the rotor cylinder and the condenser. Such equipment is very complex and expensive, prone to problems with continuity of production, especially with regard to the treatment of solid particles formed in the reactor, and yet does not have high efficiency and productivity.

[0012] WO 2015/150265 describes a rotor for a centrifugal ablative pyrolysis reactor and a reactor containing it. Said rotor includes a rotor housing having a longitudinal central axis and at least one hinged blade adapted for free rotation around the rotation axis when the rotor housing rotates around the longitudinal central axis, which ensures good contact with solid wastes of various sizes. particles. The rotor housing has a large diameter, allowing the reactor volume to be reduced to minimize residence time, typically to less than 2 seconds, to maximize liquid recovery after cooling. The rotor speed may be less than 1000 rpm.

[0013] RU 2688568 describes an ablative pyrolysis reactor for the gasification of dry solid waste, which is a cylinder with spiral troughs inside and made of stainless nickel-containing heat-resistant steel, the walls of which are initially heated by an external electric inductor to a temperature of 750 degrees Celsius, while the raw material in in the form of dry solid waste is fed into the upper part of the vertical reactor on a rotating conical disk and dispersed along the heated walls of the reactor, equipped with spiral chutes, along which the raw material moves down under the action of gravity, during which it decomposes into a vapor-gas fraction and pyrolysis coke.

[0014] US 8,128,717 B2 describes ablative pyrolysis in a vertical cylindrical tank with a rotating rotor inside it, which is located coaxially with the tank and has blades that provide heating of the raw material due to contact with the heated walls of the tank.

[0015] US 2020/0291301 describes the disadvantage of the vertical pyrolyzer described in US 8,128,717 B2, which consists in the impossibility of ensuring the same residence time of the particles of the raw material in the reaction zone, that is, ensuring the same degree of destruction of the raw material and the stable quality of the product resulting from the ingress of particles raw materials into the reactor with the formation of ascending flows of steam-gas products of decomposition and partial condensation of these vapors on the particles of raw materials, clogging of the space between the blades and the rotor, poor contact of the raw materials with the heated walls of the tank and problems with the smooth operation of the equipment and stable quality of the products obtained.

[0016] In US 2020/0291301, these problems are solved by creating a horizontal pyrolyzer, preheating the raw materials to temperatures close to the pyrolysis temperature after drying, but before feeding into the pyrolyzer, and thermal decomposition in successive stages in several pyrolyzer zones equipped with independent temperature control systems. The rotor is equipped with blades for mechanical ablation, which are hinged on the rotating surface of the pyrolyzer and have at least one degree of freedom with elastic adjustment of the angle of inclination of the blades, which makes it possible to provide elastic pressure with the required frequency and force in the direction of the ablation surface. Elastic adjustment of the angle of inclination of the blades is carried out by pneumatic, mechanical, electromagnetic and other methods. The blades are arranged in a spiral to provide axial movement of the loaded mass.

[0017] US 2015/0001061 describes a waste PTF recycling process based on a premelter reactor designed to melt various types of plastic prior to pyrolysis.

[0018] In US 2012/0261247, waste plastic material is processed into granules or flakes and heated to melt before being fed into a pyrolysis chamber equipped with an agitator, which is a double helical mixing screw with helical blades moving at a distance of approximately 5 mm from the inner surface of the chamber for improved heat transfer.

[0019] US 7,758,729 describes a low-temperature WTF process consisting of a vacuum process for removing steam from a pyrolytic heat treatment chamber, including a series of graduated temperature setpoints, where each graduated setpoint corresponds to the vaporization temperature of an individual by-product of the specified plastic, and creating an inert vacuum gas in the treatment chamber at each predetermined temperature to selectively remove a single by-product corresponding to the predetermined temperature.

[0020] In US 2005/0173237, selected as a prototype, a reactor for ablative pyrolysis is described, containing a reaction vessel equipped with a cylindrical reactor wall with an internal heated surface and an axial rotor located axially in the specified cylindrical reactor. A rotor which is provided with blades so that the raw material is pressed between the surface of the rotating blade and said ablation surface and is moved along the heated ablation surface by means of the surface of the rotating blade. The free ends of the blades are spaced from the inner wall of the reaction vessel forming the ablation surface by about 1 mm or less. In the known reactor, it is not possible to ensure the same residence time of all particles of raw materials in the pyrolysis process, which is especially important in the production of target products with a low molecular weight.

[0021] Thus, there is a need for an improved pyrolysis process and an improved ablative pyrolysis reactor that has improved heat transfer, higher yields of liquid and gaseous pyrolysis products, but less coke formation, equal residence time of all feed elements in the reactor, and preferably has a high compactness, since it provides a higher throughput per unit volume of the reactor, and, desirably, has full operational autonomy.

SUMMARY OF THE INVENTION

[0022] The present invention solves the identified problems by providing a rotor element for use in an ablative pyrolysis reactor, which includes a central longitudinal shaft and ablative blades having a fixed end and a free end configured to be in contact with the inner wall of the reactor vessel, as well as one or a plurality of helical blades extending radially from a central longitudinal shaft, wherein the ablative blades are located in the space between the turns of the helical blade or in the space between adjacent helical blades. The ablative pyrolysis reactor (APR) comprises a reactor body provided with an inlet for feeding raw materials for pyrolysis, an outlet for pyrolysis products, and a rotor that contains a rotor element.

[0023] The claimed ablative pyrolysis reactor provides a very efficient heat transfer with an even residence time of the feedstock in the pyrolysis process, a high yield of liquid and gas pyrolysis products with less coke formation, and can be very compact, yet having a high throughput per unit volume reactor.

[0024] Another aspect of the invention relates to a pyrolysis process comprising the steps of a) preparing a pyrolysis feedstock from waste, b) feeding the pyrolysis feedstock to an ablative pyrolysis reactor of the invention, and pyrolyzing the feedstock to produce pyrolysis products.

BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The essence of the claimed invention is illustrated with the help of drawings.

[0026] FIG. 1 is a side view of one embodiment of the invention showing a cross section of a cylindrical body of an ablative pyrolysis reactor in a vertical position.

[0027] FIG. 2a and 2b are views of the rotor element which can be seen in section I in FIG. 1 at various viewing angles.

[0028] FIG. 3 is a sectional view of the ablative pyrolysis reactor along line A-A' in FIG. one.

[0029] FIG. 4 is a side view of another embodiment of the invention showing a horizontal cross section of an ablative pyrolysis reactor comprising 7 rotor elements in a cylindrical reactor vessel.

[0030] FIG. 5 is a process diagram depicting the claimed method.

[0031] The figures indicate 10 - inlet for supplying raw materials for pyrolysis, 20 - outlet for pyrolysis products, 30 - reactor vessel, 40 - rotor, 45 - rotor element, 50 - helical blade, 55 - space between the turns of the helical blade , 60 - ablative blade, 61 - upper edge of the ablative blade, 62 - lower edge of the ablative blade, 63 - fixed end of the ablative blade, 64 - free end of the ablative blade, 65 - outer edge of the helical blade, 70 - rod, 80 - lower element plate rotor, 90 - upper plate of the rotor element, 100 - additional inlet for purge gas, 110 - engine, 115 - end of the reactor vessel opposite the end on which the inlet is located, 120 - central longitudinal shaft of the rotor, 130 - angle of inclination of the helical blade to plane perpendicular to the axis of the central longitudinal shaft of the rotor, 140 - recesses in the helical blade, 150 - connecting element, 160 - collection tank, 165 - inlet 166 - outlet of the collection tank, 170 - outlet of the reactor, 175 - cleaning unit, 180 - pump, 185 - heater, 200 - mixing plant, I - waste stream, II - stream of a mixture of waste and purified recycled raw materials, III - feed stream for pyrolysis, IV - pyrolysis products stream, V - purified recycle feed stream, VI - internal contaminated recycle feed stream, VII - external recycle feed stream.

DESCRIPTION OF AN ILLUSTRATIVE EMBODIMENT

[0032] Embodiments of the invention are described with reference to the drawings. However, it should be understood that the described embodiments of the present invention are provided solely as examples, which can be implemented in various forms. The figures are not necessarily drawn to scale, and some features may be enlarged or reduced to show details of particular elements. Specific structural and functional features set forth in the present description of the invention should not be construed as limiting, and are given only as an illustrative example to familiarize those skilled in the art with the applications of the disclosed invention.

[0033] Referring to FIG. 1, the ablative pyrolysis reactor (APR) is shown in a vertical position and includes a reactor body (30), preferably cylindrical, provided with an inlet (10) for supplying raw materials for pyrolysis, an outlet (20) for pyrolysis products and an additional inlet (100) for purge gas, located at the end (115) of the reactor vessel, opposite the end, which is located inlet (10). In the reactor body (30) the rotor (40) is positioned so that its longitudinal axis is on the longitudinal axis of the reactor body (30). The rotor (40) is connected to a motor (110) which can rotate the rotor inside the reactor. The location of the inlet (10) and outlet (20) holes, as well as the outlet (170) for partially pyrolyzed raw materials is selected based on the form of execution and / or location of the reactor and the presence of gaseous, liquid and solid products in the pyrolysis products. The outlet (20) for condensable and non-condensable gaseous pyrolysis products can be located both near the inlet (10) and at the opposite end of the reactor. With a vertical arrangement of the reactor, the inlet (10) is located in the upper part and the outlet (20) for pyrolysis gases formed in the entire volume of the reactor can also be made there, for liquid pyrolysis products, the outlet (20) can be made in the lower part of the reactor . In addition, it is possible to make an outlet (20) through which both the gaseous and liquid phases of pyrolysis products, including partially pyrolyzed raw materials, are discharged.

[0034] The rotor (40) includes a central longitudinal shaft (120) equipped with a helical blade (50) extending radially from the central longitudinal shaft (120) to the inner wall of the cylindrical reactor body (30). The helical blade (50) has an angle of inclination (130) to a perpendicular cross-sectional plane (A-A'). Ablative blades (60) are located in the space (55) between the turns of the helical blade (50). The helical blade (50) extends in the radial direction from the central longitudinal shaft (120) to the inner wall of the cylindrical housing (30) of the reactor, leaving a distance between the outer edge (65) of the helical blades (50) and the inner surface of the wall of the reactor housing (30). Said distance is 0.1 to 3 mm, preferably 1 to 2 mm.

[0035] Referring further to figures 2a and 2b, which shows two versions of the element (45) of the rotor. Fig. 2a shows the element (45) of the rotor, which contains one helical blade (50) in the space (55) between the turns of which the ablative blades (60) are located. Fig. 2b shows the element (45) of the rotor, which contains several helical blades (50) in the space (55) between the turns of which and between which the ablative blades (60) are located. It should also be noted that such an embodiment of the element (45) of the rotor is possible, in which several ablative blades (60) are located between the helical blades (50), preferably up to 6 in each space between the helical blades (50).

[0036] Ablative blades (60) have one fixed end (63) and a free opposite end (64), which during operation is in contact with the inner wall of the reactor housing (30) due to the elastic force and / or due to centrifugal force. The ablative blade (60) can be of any shape, but it is important to choose such a shape in order to maximize the contact area of the ablative blade (60) with the inner wall of the reactor vessel (30). For example, the top (61) and bottom (62) edges may run parallel to the helical blade (50). However, for convenience, the ablative blade (60) preferably has a rectangular shape. At least the free end (64) of the ablative blade (60) is a flexible metal plate, preferably structural spring steel. The blade (60) is designed to renew the material on the surface of the inner wall of the vessel (30) of the reactor in order to avoid its overheating and heat transfer intensification. In addition, the blades (60) are designed to remove coke in case of its deposition on the heating surface. The elastic properties of the blade make it possible to avoid excessive impact of the blade on the surface. Preferably, the impact force is from about 10 to 50 N. Smaller pressing forces (less than 10 N) can lead to deflection of the blade from the surface by hydrodynamic forces when the blade runs into the liquid medium with the formation of a gap. Large clamping forces (more than 50 N) will lead to an increase in the wear rate of the blade and body of the apparatus.

[0037] The fixed end (63) of the ablative blade (60) can be fixed in the space between the turns of the helical blade (50) and/or in the space between adjacent helical blades (50) by means of an element configured to adjust the clamping force. In particular, the pressing force can be changed by turning and fixing said element or by deflecting it by a predetermined angle. Shown in FIG. 2a and 2b, the rotor element (45) consists of an upper plate (90) and a lower plate (80) and two rods (70) for fixing the fixed end (63) of the ablative blade (60), located in the longitudinal direction parallel to the central longitudinal shaft (120 ) connected to the top and bottom plates (80, 90) and passing through holes or recesses (140) in the helical blade (50). Instead of the rods (70), it is possible to use other elements made with the possibility of adjusting the clamping force, for example, plates, corners, etc. To regulate the pressing force at the end of the rod (70), it is preferable to make a bolt head for turning with a key, on which there is a neck with a hole into which, after the blade (60) is tensioned, a pin is inserted, which excludes the possibility of returning the rod (70) and the blade (60) to their original position. position after unloading the wrench. FIG. 3 is a sectional view of the APR taken along the line A-A' shown in FIG. 1, which shows that the ablative blades (60) extend from the rotor to the inner wall of the reactor vessel (30). The ablative vanes (60) can also be fixed in the space (55) between the helical vanes (50) in other ways, for example with bolts.

[0038] The element (45) of the rotor is provided with a connecting element (150) for connection in rotational motion with the connecting element (150) of the neighboring element (45) of the rotor or for connection with the engine (110). The rotor may contain one or more elements (45) of the rotor. In the embodiment shown in FIG. 1, the rotor (40) comprises 2 rotor elements (45) connected in series. On FIG. 4, the rotor (40) contains 7 rotor elements (45) connected in series.

[0039] The distance between the outer edge (65) of the helical blades (50) and the inner surface of the wall of the reactor housing (30) is 0.1 to 3 mm, preferably 1 to 2 mm, and is selected, for example, depending on the nature of the supplied waste . When feeding melted plastic waste, it is preferable that this distance be very small, for example, from 0.1 to 1 mm, and for raw materials containing solid particles, the preferred distance may be from 0.5 to 3 mm. The close distance design of the rotor between the outer edge (65) of the helical blades (50) and the inner wall surface of the reactor housing (30) ensures that all feed follows a defined path through the ablative pyrolysis reactor, that back-mixing of pyrolyzed feed with fresh feed is minimal. , which will provide a well-defined controlled residence time of the pyrolysis feedstock in the reactor with small variations in residence time. Due to the negligible effect of gravity on residence time distribution, the ablative pyrolysis reactor can be operated in a vertical position, which can provide significant space savings. Since the element (45) of the rotor includes ablative blades (60), which take on the function of preventing the formation of coke on the walls of the housing (30), the gap between the helical blade (50) and the housing (30) ensures that the shaft does not jam. Values less than 0.1 mm increase the risk of shaft jamming due to insufficient compensation of radial beats and misalignment of the shaft and the reactor vessel. At large values of the gap (more than 3 mm), the helical blades (50) prevent longitudinal mixing to a lesser extent, which leads to a spread in the residence time of the raw material in the reaction zone.

[0040] Helical blade (50) preferably has an angle of inclination (130) to a plane perpendicular to the axis of the Central longitudinal shaft, in the range from 0.1 to 45 degrees. The angle of inclination (130) may be minimal, but not less than the value that ensures the free passage of solid particles between adjacent turns of the helical blade (50). In this case, we can talk about one helical blade or several helical blades with a longitudinal dimension of one pitch, located at a certain distance from each other. If the section of the helix of the helical blade (50) is less than 360 degrees (for example, 350 degrees), adjacent turns do not create obstacles for the free passage of solid particles, the angle of inclination (130) can be minimal - 0.1 degrees, the helix degenerates into an almost flat partition, performing the function of sectioning reaction volume at a minimum level of the transport function, in this case, the ablative blades (60) are located in the space between adjacent helical blades (50). If it is necessary to enhance the transport function, the angle of inclination (130) can be increased to values of 45 degrees, in this case, the ablative blades (60) are located in the free gap between the turns of the helical blade (50).

[0041] When justifying the configuration of the reaction zone and its design parameters, one should be guided by the following conditions and functions: a) effective heat removal; b) transportation of processed raw materials from inlet to outlet; c) no or minimal deposition of coke on the heat transfer surface; d) the same residence time of all flow elements in the reaction zone. Efficient heat removal, no coke deposits ensure long-term operation of the device without stopping at maximum performance. Continuous transportation of processed raw materials from inlet to outlet is a necessary condition for the operation of the device in continuous mode. The same residence time contributes to the production of pyrolysis products with a small variation in fractional composition (molecular weight).

[0042] Ablative pyrolysis involves the effective interaction of raw materials with the heating surface of the reactor in the pyrolysis process. In this case, efficiency is understood as the heat transfer coefficient and equal conditions for interaction with the heating surface for the entire volume of raw materials. The heat transfer coefficient is equal to the heat flux, expressed in watts, per unit area and per unit of the driving force of the heat transfer process and determines (together with the values of the surface and the driving force of the heat transfer process) the total amount of heat transferred and the overall productivity of the reactor. Intensive mixing provides an increase in the heat transfer coefficient.

[0043] Another aspect of efficiency is equal conditions for the entire volume of raw materials in the reactor. Since at a certain point in time, individual sections of the raw material are at different distances from the wall of the housing (30), then, taking into account the low thermal conductivity of the raw material, the sections remote from the wall at the considered moment of time receive less thermal energy than those directly adjacent to the wall of the housing (30) volumes of raw materials. Inevitably, in the immediate vicinity of the heating surface, an overheated layer (wall layer) of the raw material is continuously formed, which leads to unequal conditions and, as a result, to a different degree of conversion of the raw material and a decrease in the heat transfer coefficient. The non-uniformity of heat supply in space can be compensated by averaging the conditions of heat transfer by the raw material over time due to the continuous replacement of the superheated layer with a new, less heated layer and the removal of the heated raw material from the wall. This function is performed by the blades.

[0044] Given the need to ensure an equal and certain residence time of the raw material in the reaction zone, the use of only a helical blade, which performs both the transport function and the function of mixing the material in the radial direction, does not provide this condition. Stirring in the radial direction requires a high shaft speed. In this case, the transport function of the helical blade may be redundant. In the proposed reactor, in addition to the helical blade (50), there are radial ablative blades (60) that provide pressure and radial mixing of the raw material, therefore, the need for this function to be performed by the helical blade is eliminated. In order to reduce the excess level of the transport function at high speeds of rotation of the rotor (40), the helical blade (50) can be made with a minimum angle of inclination (130) and with a large degree of discontinuity - as already described above, in this case the helical blade (50) represents sections of the screw with a length of one step with a minimum helix angle, located at a distance from each other of several steps.

[0045] It is especially important to ensure this condition when the target pyrolysis products are high molecular weight products, such as paraffin. Equal residence time makes it possible to ensure that at the outlet of the reactor there are no residues of undecomposed raw materials (plastic) with a minimum content of products with a molecular weight lower than paraffin. Pyrolysis is carried out in this case at low temperatures (300-350 C), and the target reaction product leaves the reaction zone in liquid form. Low molecular weight products with a molecular weight lower than paraffin leave the reaction zone in the gas phase.

[0046] To ensure equal residence time of the feedstock in the reaction zone, the mode of motion in the reactor must approach the full displacement mode, which is difficult to implement under conditions of intensive mixing. The way out of this situation is to section the reaction zone - that is, to divide the reaction zone into cells of complete mixing, following one after another along the reactor axis. In this case, intense mixing is maintained within each cell, but longitudinal (along the reactor axis in the direction from inlet to outlet) mixing is almost absent. The residence time distribution in this case corresponds to the cell model, the parameter of which is the number of cells into which the reaction zone is divided. With the number of cells approaching infinity, the motion mode becomes close to the full displacement mode, and the residence time of individual elements of the flow (molecules, microvolumes of matter) becomes the same. However, an infinite number of cells is difficult to implement in practice. From a practical point of view, it is sufficient to have 3 to 10 cells, more preferably 5 to 10 cells, for a satisfactory residence time distribution. A smaller value of the parameter will lead to a significant spread in the residence time, increasing the number of cells to more than 10 does not lead to a significant improvement in working conditions in terms of residence time, however, it complicates the design.

[0047] As elements dividing the reaction zone into cells, sections of the helical blade (50) separated from each other at a certain distance (at a distance of one or several steps of the helix), or turns of a continuous spiral without breaks (auger) can serve. As mentioned above, the absence of a helical blade (50) in certain sections of the rotor (40) is used in order to exclude an excessive transport function. The remaining coils, representing sections of the helical blade (50) one step long and separated from each other by several steps at a small angle of inclination (130), are partitions that section the reaction zone and prevent longitudinal mixing of the substance. The flow of matter between the cells occurs as a result of the rise in the liquid level in one cell relative to the level in the other cell, and not as a result of the mass being thrown by the agitator. Thus, the effect of longitudinal mixing is minimized, and the distribution of residence time becomes more uniform, which helps to improve the quality of the target product in terms of homogeneity of the molecular composition.

[0048] Thus, compared to reactors using only a screw (helical blade), it is possible to ensure that there is no gap between the body and the blades due to the presence of radial ablative blades (60). In this case, the helical blades (50) are separated from the heating surface at a distance of a guaranteed gap and are released from performing the function of removing coke from the heating surface. At the same time, compared to reactors using only flat ablative blades, sections of the helical blade (50) additionally contribute to partitioning the volume of the reaction zone, leveling the residence time by reducing the effect of longitudinal mixing.

[0049] The dimensions of the reactor can in principle vary widely, but in view of the desire for portability and compactness, it is preferred that the reactor be as small as possible. Due to the efficient design of the rotor, APR can be compact, i.e. have a small internal pyrolysis volume, while ensuring a high yield of processed products. The internal volume of pyrolysis is the volume of space in which pyrolysis takes place, including the volume including the inlet (10) and the rotor (40) equipped with helical blades (50) and ablative blades (60), and not including the motor, additional tanks, etc. .d. The ratio of the length and diameter of the reactor is selected from design considerations and the need to ensure greater productivity. A reactor of greater length and, accordingly, a greater ratio of length to diameter has a larger volume, a larger heating surface and, accordingly, will provide greater productivity or, with equal productivity, will provide a greater degree of conversion of raw materials into final products. The length of the reactor is limited by the complexity of manufacturing, assembly and maintenance during operation. The relative free volume of the reactor is related to the degree of its filling and is equal to the ratio of the volume of the reactor free from products to its total volume. The value of this parameter is selected based on the purpose of processing and the conditions of the pyrolysis process, leading to the goal. Changing this setting can affect both the performance of the device and the quality of the final product.

[0050] In the case of an excess amount of raw material in the reactor, mixing with its blades deteriorates. When the internal space of the vessel (30) of the reactor is completely filled with raw materials, its movement can go into a mode called quasi-solid rotation, while the trajectories of individual particles are similar to the trajectories of particles in a rotating solid body. Under these conditions, mixing in the radial direction stops, the heating of the inner layers of the raw material is impossible to the extent necessary for the purposes of pyrolysis, and it is impossible to achieve equal heating conditions under these conditions. Efficient radial mixing and mass exchange of raw materials near the wall is achieved with a sufficiently thin layer of material and, accordingly, a significant relative free volume of the reactor. That is, the raw material should be only near the wall, and the rest of the internal volume of the housing (30) should be free from raw materials. However, approaching the value of the relative free parameter to one or to 100% reduces the reaction volume and the total residence time of the raw material in the reaction zone. Therefore, the optimal values of the relative free volume can be considered values close to but less than 100%. For example, 70%, even more preferably 90%, and 99%. The exact values for each specific case can be determined during the commissioning of the equipment, taking into account the required degree of conversion and the size of the reactor. A larger value of the parameter corresponds to equal conditions for heating the raw material, a smaller value corresponds to a larger reaction volume and a longer residence time with an equal feed of the starting material - the productivity of the feedstock.

[0051] In view of the above conditions and as a result of practical tests, the following parameters were selected. The APR is generally cylindrical in shape and has an internal pyrolysis space with a longitudinal length of 50 to 200 cm, preferably 75 to 150 cm, and typically about 100 cm, and the inner diameter of the reactor is preferably 5 to 50 cm, more preferably 10 to 40 cm, and typically about 30 cm. The length to diameter ratio is preferably between 2 and 10. The reactor can easily be scaled up and down depending on the needs of the waste stream. Inside the reactor, the free volume varies from 50 to 99%, preferably from 70 to 99%, depending on the design of the rotor.

[0052] The reactor is equipped with heating means (not shown in the figures) located on the outer wall of the reactor housing (30). The APR operates at temperatures typically between at least 300°C and at most 650°C, depending on the nature of the feed waste. Considering temperature uniformity, the heating means most preferably heat the entire surface of the reactor, preferably along the entire length of the part of the rotor (40) containing the helical blades (50) and the ablative blades (60). The heating means may comprise sections providing different temperature zones in the longitudinal direction. The heating means may be fuel oil, burners or an electrical heater, preferably an electrical heating means in view of temperature uniformity and control.

[0053] In a preferred embodiment of the invention, the inner wall surface of the reactor vessel (30) is at least partially coated with a cermet coating, preferably nickel boride, zirconium oxide, boron nitride, titanium nitride, titanium oxide, or titanium carbide. The coating prevents the feedstock from coming into contact with iron and nickel on the inner wall of the reactor vessel (30), as these materials have been found to act as catalysts for coke formation. Titanium nitride is most preferred for making the inner wall of the reactor vessel (30) due to the optimum resistance to the ablative forces applied by the ablative blades (60) to the rotor and minimal coke formation. Preferably, the coating is applied to at least those parts of the inner wall of the reactor vessel (30) that are in contact with the ablative blades (60). Preferably they should cover parts of the surface that are in contact with the hot pyrolysis feed, including the ablative blades (60) as well as the helical blades (50). The thickness of the coating layer is chosen based on the raw materials used, the operating parameters of the reactor, etc. The coating layer can be applied by vacuum plasma spraying. It is also possible to apply a modified layer, in particular, by modifying the surface of aluminum or duralumin with aluminum oxide. The coating layer of the inner wall of the housing (30) significantly reduces the formation of coke. This invention can be successfully used in any reactor in which the hydrocarbon feed is in contact with the hot metal surface at high temperatures, in particular at temperatures above 400°C.

[0054] The ablative pyrolysis reactor is equipped with sensors and control components, including but not limited to pressure sensors or temperature sensors, which provide the controller with various data regarding the operation of the system. The APR controller can change the operating parameters of the APR in response to data received from the sensors, in accordance with the programmed functions of the control system. The main control system is configured to communicate with the APR controller as well as communicate with additional controllers, each of which can be dedicated to other subsystems of the WTF processing system.

[0055] In the preferred embodiment, as shown in FIG. 5, the ablative pyrolysis reactor further comprises an outlet (170) in the reactor body (30) for removing partially pyrolyzed contaminated recycle feed, located at an end (115) opposite the feed inlet (10) for pyrolysis feed. An outlet (170) in the reactor vessel is preferably connected to a reservoir (160) for collecting partially pyrolyzed contaminated recycle feedstock.

[0056] The collection tank (160) connected to the APR outlet (170) is preferably also connected to a mixing plant (200) for preparing a mixture (II) from the waste stream (I) and the purified recycle stream (V), while a mixing unit (200) is connected to an inlet (165) of a collection tank (160) to supply this mixture (II) to a tank (160) where it is mixed with contaminated partially pyrolyzed APR feedstock to produce a contaminated recycle pyrolysis feedstock stream (VI ) that is pumped from the outlet (166).

[0057] The invention also relates to a pyrolysis process comprising the steps of a) preparing pyrolysis feedstock from waste, b) supplying pyrolysis feedstock to an ablative pyrolysis reactor of the invention, and pyrolyzing the feedstock to produce pyrolysis products.

[0058] The pyrolysis process, as a first step, includes a pretreatment step for the feedstock stream (I) in which the waste is processed to convert it into a suitable feedstock for the pyrolysis step in the APR. This step may include one or more washing, cleaning, sorting, drying, grinding, compacting, heating, melting and degassing steps to reduce the oxygen content.

[0059] Pyrolysis feedstock preparation waste can be biomass, agricultural and forestry waste, municipal solid waste, construction and demolition waste, oil spills, contaminated oils, and various types of plastics, in particular polyolefins. The preferred waste feedstock for the process of this invention is plastic. Different types of plastics are made from many different polymers, the most common of which are: PET, PP, PS, polyvinyl chloride (PVC), HDPE, LLDPE, LDPE and nylon. Preferred plastics for use in the inventive pyrolysis process are polyolefins, such as HDPE, LDPE, PP and PS, because they do not contain heteroatoms (atoms other than C and H). Oxygen-containing plastics such as PET are less preferred because they have a low oil yield and contain oxygen, which can push the pyrolysis reaction into a combustion reaction and can cause a number of dioxins to form. Therefore, it is preferable to extract them from waste raw materials before carrying out the pyrolysis process and process them. In addition, PET can be easily and economically recycled to pure PET. PVC and other chlorinated resins are less preferred because they form hydrochloric acid, so they are also preferentially removed from the plastic waste stream.

[0060] Waste feedstock may contain trace amounts of non-plastic contaminants or impurities. For example, impurities may be of an external nature (eg, water, food, labelling, soil, paper, or cellulose waste) or may result from internal changes (eg, glass, metal, iron, bromine, and/or chlorine). The feedstock may be in shredded, crushed, granular or other form which may assist in the transfer of heat to it. Contamination levels should preferably be as low as possible, since they are directly related to the formation of coke and reduce the economics of the process.

[0061] Thus, it is preferable to first remove PET, PVC, cellulose, metal, mineral and food waste from the plastic waste stream. PVC and pulp waste can be processed in a separate reactor of the same configuration or in a separate cycle in the same reactor. In the case of processing PVC waste and cellulose, further conversion into pyrolysis products will occur differently. It is desirable to remove the cord from the tires.

[0062] The presence of sulfur and nitrogen in the feed is not preferred, but is not a problem. Raw materials with a high content of sulfur and nitrogen can be pyrolyzed at relatively high temperatures, preferably above 450 or 500°C, so that sulfur and nitrogen will predominantly remain in the pyrolysis gas, which, when burned, is oxidized to NOx and SOx containing exhaust gas, which can relatively easy to remove. Alternatively, lower pyrolysis temperatures can also be used, where nitrogen and sulfur are also present in the condensed liquid pyrolysis product, from which sulfur or nitrogen can be removed by filters, such as membranes.

[0063] Wooden sleepers and chemically treated wood in general are useful raw materials for pyrolysis because pyrolysis does not cause environmental problems associated with combustion, which leads to the formation of toxic exhaust gases and phenol. Preferably, wooden sleepers and chemically treated wood are pyrolyzed at high temperatures from 500°C, at which the wood is almost completely converted into pyrolysis gas, and virtually no liquid pyrolysis products are formed.

[0064] The feed stream for pyrolysis, according to the claimed method, may be a liquid or solid particles. The liquid waste stream, for example, may be a contaminated oil stream. The solid waste stream is, for example, shredded plastic, tires or wood. The solid waste is preferably crushed to a size of 5 to 50 mm, more preferably 10 to 30 mm, even more preferably 15 to 20 mm. The size to which the grinding is carried out is determined based on the types of waste, the complexity of the depolymerization, the temperature of the process, etc. If the waste stream is a solid organic material, it can be crushed and processed directly in the APR.

[0065] The pyrolysis feed stream may be fed directly into the APR through the inlet (10). The pyrolysis product stream (IV) exits through the pyrolysis product outlet (20). Pyrolysis products can be either in the liquid phase or in the gaseous phase.

[0066] However, in terms of heat transfer efficiency, APR yield and productivity, it is preferable that the pyrolysis feed stream is a liquid waste mixture dissolved and/or dispersed in an organic solvent, so that the solid organic material is crushed and mixed with the organic solvent to create liquid feedstock for pyrolysis, which is a solution, dispersion or emulsion of waste feedstock in an organic solvent. It should be noted that the term "solvent" here also means a dispersing agent in case the feedstock contains a material that cannot be dissolved or can only partially. Optionally, a liquid pyrolysis feedstock is prepared by mixing a preheated feedstock with a hot organic solvent. In the case of insoluble wastes such as wood or tires, their percentage in the total mass of the raw material for pyrolysis is relatively small; typically 10 to 60% by weight, while in the case of plastic waste the amount may be higher, preferably 50 or even 60 to 90% by weight. When using an organic solvent, the temperature of the liquid pyrolysis feedstock that is fed into the APR is selected based on the nature of the feedstock and solvent used, preferably it has a temperature in the range of 250 to 400°C, more preferably 300 to 375°C, typically about 350 °C At these temperatures, most plastic melts or dissolves. The temperature can be set by selecting a hot organic solvent temperature high enough to achieve the desired temperature after mixing.

[0067] High boiling solvents such as shale oil, coal oil, vacuum gas oil can be used as the organic solvent. However, it is preferable to use as an organic solvent a purified recycle feedstock (V) resulting from the withdrawal from the reactor and purification of the contaminated recycle feedstock (VI), which is a partially pyrolyzed feedstock that has passed through the reactor.

[0068] In FIG. 5 shows a preferred embodiment of the invention, including feeding waste (I) to a mixing plant (200) where it is mixed with an internal stream of purified recycle feed (V). The shredded waste (I) may be fed into the mixing plant (200) continuously by means of a waste feeder which may include bins, hoppers, conveyors, mixers, heaters and compactors designed to provide a continuous supply of material. The mixing plant (200) may further comprise mixing, grinding, compacting and heating means. The mixing plant (200) may include agitators, high shear in-line mixers, extruders, etc. and to produce a continuous flow of low viscosity mixture of waste and purified recycle feedstock.

[0069] In a preferred embodiment, the pyrolysis process includes step a), in which the raw material for pyrolysis (III) is a waste liquid mixture, which is obtained by dissolving and/or dispersing the waste in an organic solvent, adding to said liquid mixture (II) waste and organic solvent of the contaminated partially pyrolyzed feedstock coming from the ablative pyrolysis reactor, obtaining a contaminated recycled pyrolysis feedstock (VI), which is then purified from impurities. The resulting raw material for pyrolysis (III) is then fed into the ablative pyrolysis reactor in step b). Here, preferably, part of the pyrolysis feedstock in the form of a purified recycle feedstock stream (V) is used as the organic solvent in step a). The partially pyrolyzed APR feedstock is typically heavy oil contaminated with impurities such as coke, charcoal, and possibly inorganic or metallic impurities. By adding this partially pyrolyzed feedstock when preparing the feedstock for pyrolysis, it can be further pyrolyzed.

[0070] In FIG. 5 also shows a purification unit (175) which can receive and purify a contaminated recycle stream (VI) by removing impurities. The cleaning unit (175) may be a filter or a cyclone cleaning system. Optionally, other external recycle streams (VII) can also be mixed and passed through the purification unit (175). The recycle stream (VI) after cleaning in the block (175) and/or the external stream (VII) of the recycle feed form the pyrolysis feed stream (III), which is fed by a pump (180) to the APR inlet (10) and/or through an optional a heater (185) at the inlet of the mixing plant (200) in the form of a stream (V) of purified recycled raw materials.

[0071] The pyrolysis liquid feedstock preferably has a viscosity in the range of 0.1 to 10, more preferably 0.2 to 5, even more preferably 0.3 to 3 Pa*s, typically about 0.5 Pa*s, as measured by ASTM D445 at 40°C. In step b), the APR is preferably operated at a reactor wall temperature Tr between 300°C and 650°C, more preferably between 350°C and 500°C, and the pyrolysis feed fed to the APR preferably has a temperature Tf in the range of 250 to 400° C, preferably from 300 to 375°C, where Tf is lower than Tr, preferably less than 50-100°C. The operating temperature of the reactor and the feedstock fed into the reactor is chosen based on the feedstock composition and pyrolysis conditions. If the raw material for pyrolysis is plastic, the temperature is preferably above 400°C, and may be above 500°C, at which many different molecular particles can be gasified at the same time. Preferably, before entering the reactor, the feedstock is heated to the maximum temperature at which the pyrolysis process has not yet begun or proceeds at a negligibly low rate. This condition is important in order to reduce or completely eliminate coking inside the reactor. This also improves the productivity of the line as a whole, since it eliminates the need to transfer the energy necessary for heating to the pyrolysis start temperature to the feedstock. All the energy in the reactor in this case is spent on the destruction of polymer chains. The upper and lower limits are determined by the suitability of the preheating equipment and the operating conditions of the reactor. The temperature of the pyrolysis feed entering the reactor can be achieved, in particular, by heating the recycle stream V in the heater (185) to a temperature of about 200 to 400°C. Working pressure can vary from 0.15 to 0.8 atm. izb.

[0072] High temperature liquid pyrolysis feedstock with relatively low viscosity allows more uniform pyrolysis feedstock, smaller temperature difference between feedstock and reactor inner wall, and higher heat transfer efficiency, resulting in less coke formation on APR reactor walls and higher pyrolysis gas yield and end products of pyrolysis. Another advantage of feeding liquid pyrolysis feed to the APR is that it is easier to remove and avoid oxygen formation prior to loading into the APR, and that this provides better control and output volume consistency. This is a significant advantage in terms of maintenance and repair of equipment, as well as the cost of its operation. In the pyrolysis process according to the invention, from 80 to 95% of the mass of the waste is converted into pyrolysis products and the amount of coke formed is less than 5% of the mass. In this case, the pyrolysis gas obtained in the pyrolysis process contains hydrogen in an amount of 25 to 50% by volume.

[0073] The amount of pyrolysis feed entering the APR is preferably in the range of about 0.25 to about 2.5 metric tons per hour. The residence time of the pyrolysis feedstock in the reactor and the pyrolysis operating temperature are chosen taking into account the desired pyrolysis conversion for the given waste and pyrolysis feedstock and intended pyrolysis products. The residence time of the feedstock in the reaction zone in an APR reactor of a given length can be varied by changing the speed of rotation of the rotor (40) and the angle of inclination (130) of the helical blade (50). The rotor speed is typically 6 to 300 rpm and the residence time of the raw material is typically 10 to 300 seconds. The advantage of the rotor elements according to the invention is that the design of the rotor can be changed and can provide both a short residence time due to efficiency and a long residence time, in cases where this is necessary. Another advantage of the APR according to the invention is that the APR, due to its efficiency and good temperature control, can operate at relatively lower temperatures and use less energy with an acceptable output. Lower pyrolysis temperatures can be beneficial for more temperature sensitive pyrolysis feedstocks to avoid coke formation. In combination with hot pyrolysis liquid feedstock, pyrolysis operating temperatures can be as low as approx. 340°C. Preferably, the residence time is short. In a preferred embodiment where the pyrolysis feedstock is a hot liquid mixture of plastic and organic solvent, the residence time may be shorter, preferably 0.5 to 30 seconds, more preferably 0.5 to 10 seconds.

[0074] The ablative pyrolysis reactor of the invention produces a very small amount of coke and tar. However, it is desirable to remove the resulting coke and tar. With the reactor in a vertical position, as shown in Fig. 1 and 5, the APR is provided with an opening (170) at the other end (115) which preferably leads into the reservoir (160). Partially pyrolyzed feedstock contaminated with coke and/or tar is moved by helical blades (50) into a tank (160). With the APR positioned horizontally, as shown in FIG. 4, the APR is preferably provided with an outlet (170) to remove contaminated partially pyrolyzed feedstock that may be collected in a reservoir (160).

[0075] The implementation of the claimed pyrolysis process is shown in FIG. 5 as a preferred embodiment. However, as noted earlier, this option does not limit the scope of possible implementations of the method and is not the only possible one. The pyrolysis feed stream can also be fed directly into the APR through the inlet (10), and the pyrolysis product stream (IV) can exit through the pyrolysis outlet (20), without using recycled feedstock.

[0076] In general, the process diagram may look as follows. The stream (I) of waste, preferably pre-cleaned and crushed, is fed into the mixing plant (200), where they are mixed with the stream (V) of the purified recycled feedstock. Next, the mixture (II) of waste (I) and purified recycled raw materials (V) is fed to the inlet (165) of the collection tank (160), where it is additionally mixed with contaminated partially pyrolyzed raw materials entering the collection tank (160) through the outlet (170 ) pyrolysis reactor. The resulting internal stream (VI) of contaminated recycle feed through the outlet (166) of the collection tank (160) is further fed to the purification unit (175), in which the stream (VI) of contaminated recycle feed is purified by removing impurities. Optionally, other external streams (VII) of recycled raw materials can also be fed to the purification unit (175). At the outlet of the purification unit (175), from the internal stream (VI) of the recirculating feedstock and/or the external stream (VII) of the recirculating feedstock, a feed stream (III) is formed for pyrolysis, which is fed by a pump (180) to the inlet (10) of the APR. Preferably, a portion of this flow through the heater (185) enters the mixing plant (200) as a purified recycle stream (V) for mixing with the waste stream (I).

[0077] When cold starting the reactor, it is preferable to use technical kerosene with an ultra-low sulfur content. After a cold start, it is possible to use a liquid pyrolysis product as an organic solvent, preferably from the pyrolysis of various plastics, in particular the recycle stream of heavy oil fractions taken after APR. Most preferably, the recycle stream (V) is a partially pyrolyzed product taken directly from the APR, or a heavy oil fraction obtained after pyrolysis gas condensation. The operating conditions within the reactor are preferably set such that the pyrolysis feed is partially pyrolyzed to a heavy hydrocarbon liquid that can be recycled for mixing as a solvent with the waste stream in the preparation of the pyrolysis feed in the mixing plant (200).

[0078] During operation of the reactor, the rotation of the rotor (40) causes the helical blades (50) to move the pyrolysis feedstock longitudinally through the reactor from the inlet (10) of the reactor to its other end (115). The pyrolysis feedstock is centrifugally guided outwards towards the hot inner wall of the reactor vessel (30), and the ablative blades (60) located in particular in the space (55) between the helical blades (50) push and smear the pyrolysis feedstock over the vessel wall (30) reactor.

[0079] The heat provided by the heating means breaks down or depolymerizes the pyrolysis feedstock and converts it into pyrolysis gas and other pyrolysis products. In the ablative pyrolysis reactor, little coke is produced in the process according to the invention. 3-5% of the mass of waste raw materials is converted into coke, and the remaining amount of pyrolysis products is subjected to further processing to extract pyrolysis gas, as well as light, medium and heavy oil products. The resulting pyrolysis gases and/or other pyrolysis products are directed to the outlet (20) through the space between the helical blades (50) and the holes in the helical blades (for example, 140 in Fig. 2a). The gases are displaced from the APR by the generated pressure, but can also (optionally) be displaced by the purge gas flow through the auxiliary purge gas inlet (100). The purge gas flow through inlet (100) can also be used to remove oxygen from the system prior to start-up, for example with nitrogen. Residual non-pyrolyzed feedstock (heavy oil) contaminated with coke, tar or other impurities is taken from the other end (115) through the outlet (170) for further processing.

[0080] The pyrolysis gas may include depolymerized unsaturated vapors, which can be useful if collected and purified. The pyrolysis gas may include one or more paraffins, olefins, naphthenes, aromatic hydrocarbons, or other classes of hydrocarbon materials, and may include impurities such as inorganic acids, trapped metals or metalloids (eg, cadmium, iron, antimony), organic acids. If oxygen is present in the feed, the pyrolysis gas may include one or more alcohols, ketones, ethers, phenols, carboxylic acids, or other polar organic molecules. The pyrolysis gas from APR is rich in hydrogen, the content of which is from 25% to 50% (by volume), and has a low content of aromatic compounds.

[0081] The reactor is equipped with sensors, computer controls, valves, etc. to control flows I-VII, temperature, etc. The stream (IV) of the pyrolysis products exits through the outlet (20) and then it is sent to the condenser for the production of recycled oil.

[0082] The ablative pyrolysis reactor is preferably operated at a constant high temperature to maximize yield and produce a large amount of pyrolysis products. Alternatively, the reactor may also be operated in a sequential heating mode, in which the heating system and the pyrolysis feed go through a series of successive heating steps, with the heating system increasing the temperature of the reactor, and heating possibly interrupted occasionally to maintain discrete temperature levels allowing sequentially gasify individual molecular particles. This is preferably done in the APR embodiment described above and illustrated in FIG. 5, where the APR is provided with a recycle loop in which the recycle stream VI containing the partially pyrolyzed feedstock is sent to a blender (recycle feed stream V) for blending as an organic solvent in the pyrolysis feedstock preparation step.

[0083] The method provides more than 80% of the mass of synthetic fuel and more than 10% of the mass of non-condensable gas from the waste. The energy required to process waste into liquid fuels is about 0.2 kW per liter of liquid fuel produced, and this energy can be completely generated from non-condensable gas. The non-condensable pyrolysis gas has a very high energy content of about 40 to 60 MJ/kg. When implementing the claimed method, the reactor can continuously produce liquid fuel for 3 hours from the moment of cold start. This ensures the compactness and simplicity of the device compared to industrial counterparts. The condensed liquid pyrolysis product has a high transparency and a light yellowish color.

[0084] Accumulated contaminants from the cleaning unit (175) are continuously or periodically removed, for example, by periodically replacing contaminated filters with clean filters or by cleaning the line. When using a recycle stream as a solvent for preparing a liquid pyrolysis feedstock as described above, coke may accumulate during operation. If there is an excess content of coke ash in the recycle stream (VI), the liquid is preferably filtered and solid contaminants are removed through the purification unit (175). When the concentration of coke in the cleaning unit (175) reaches a level above about 10% by weight, the concentrated fraction of coke is discharged into the tank, and the discharged amount is replaced by pure pyrolysis oil. The concentrated coke fraction may be treated separately to concentrate the coke to useful products, or alternatively sent back to the reactor or to a separate pyrolyzer.

[0085] The performance of the ablative pyrolysis reactor depends on its selected size. The specific productivity per m ^{3 of} the internal volume of the reactor is not less than 5-20 metric tons (mt) of plastic waste per hour per m ^{3 of} the internal volume of the reactor. For the option where the pyrolysis feed is a liquid waste mixture dissolved and/or dispersed in the recycle feed, the overall throughput in the reactor itself is 1-2 metric tons (mt) of pyrolysis feed per hour per m ^{3 of} internal reactor volume. A processing capacity of 2 metric tons of waste per day was obtained on an APR with a length of only 1 meter and an internal diameter of 30 cm (internal volume of about 70 liters). In addition to high productivity, equipment downtime for maintenance is low. This is not only due to the low level of coke formation and the very good control and stability of the process, but also because the compact reactor is easier to maintain.

[0086] The pyrolysis gas may be directed to a pyrolysis gas treatment system (condenser) in which a phase change of at least a portion of the vapor occurs such that certain molecules change from a gaseous to a liquid state. The steam may include components that do not condense in the steam treatment system. Such non-condensable gases can be separately removed from the steam treatment system and can be used as fuel for an electric generator, providing both the necessary power and heat for the autonomous operation of the waste treatment equipment. Thus, the invention also relates to a pyrolysis process according to the invention, which comprises the steps of a) preparing a pyrolysis feedstock from waste, b) feeding the pyrolysis feedstock to an ablative pyrolysis reactor according to the invention, and pyrolysis to obtain pyrolysis products as described above. , and additionally includes the steps c) condensing and separating the pyrolysis gas into a condensed liquid pyrolysis product and a non-condensed pyrolysis gas product and d) optionally includes one or more additional stages, among which may be the stages of distillation, condensation, separation, refining, purification, filtration, conversion into electrical energy, cooling, heating, storage.

[0087] The invention can be used in a waste-to-fuel plant comprising an ablative pyrolysis reactor provided with a rotor element to implement the method according to the invention described above. The plant may be a stand-alone, compact and mobile waste-to-fuel plant comprising 1) a waste pre-treatment plant 2) a reactor according to the invention and 3) a condensation unit and one or more additional optional units for distillation, separation, refining, purification, filtration, power and heat generation, cooling, heating and storage. The waste-to-fuel plant is easy to transport, for example by truck, and does not rely on local infrastructure for energy or food.

Experiments

[0088] Example 1 In the ablative pyrolysis reactor shown in Figure 1, tests were carried out using a solution of municipal plastic waste (MPW) containing many different types of household plastics. The MPWs were cleaned, dried and ground to a size of about 20 mm and dissolved in a 5% fraction of the recycled oil coming from the APR collection tank (after starting with kerosene). The pyrolysis feed stream had a temperature of 250° C. and was introduced into the reactor through the inlet. The wall of the reactor vessel had a temperature of 350°C. The rotor contained one rotor element, which included 10 turns (steps) of the helical blade and 2 ablative blades for each turn, the angle of inclination of the helical blade was 25 degrees. The pressing force of the ablative blades to the surface of the reactor vessel was 40 N. The rotation speed of the rotor was 250 rpm. Pyrolysis gases were taken from the top of the reactor and analyzed using a gas chromatograph equipped with a thermal conductivity detector. The pyrolysis gas had the composition shown in Table 1.

Table 1. The result of the analysis of pyrolysis gas.

Component %(v) H2 43.85 methane 16.74 CO 2.12 CO2 1.21 ethane + ethene 14.31 propane 5.33 propene 8.19 isobutane 1.04 n-butane 0.29 isobutene + 1-butene 3.99 trans-2-butene 0.17 cis-2-butene 0.10 1.3-butadiene + isopentane 0.03 n-pentane 0.92 pentene 1.30 isoprene 0.06 Heavy fractions 0.36

[0089] The pyrolysis gas has a very high hydrogen content, and the heavy ends are no more than 0.36% by volume.

[0090] The gas-vapor mixture of pyrolysis products was condensed using heat exchangers and separated from non-condensable gases in a separator. The condensate was pyrolysis oil, a paraffin fraction, that is, a broad fraction of hydrocarbons with a boiling point above 30°C. MWP feedstock conversion data are shown in Table 2. Waste product (CO and CO ₂ ) is minimal. The non-condensable gas stream was used as fuel for the entire pyrolysis process without the use of an external energy source.

Table 2. Analysis result of MPW transformation:

Raw material Quantity, % Grocery list Quantity, % plastic waste one hundred pyrolysis oil 61.08 polymer wax 19.03 Non-condensable gases 15.00 coke and ash 1.20 Water 2.90 Losses 0.79 Total one hundred Total one hundred

[0091] Example 2 Ablative pyrolysis tests were conducted to process a solution of municipal plastic waste (MPW) containing various types of household plastics. Waste MPW was cleaned, dried and ground to a size of about 10 mm and dissolved in 50% of the fraction of recycled raw materials coming from the collection tank APR. Waste oil was used as a solvent to start the line. The pyrolysis feed stream had a temperature of 300°C. The wall of the reactor vessel had a temperature of 400°C. The rotor contained six helical blades. Between adjacent helical blades, 2 groups of counterbalancing ablation blades were located, spaced 180 degrees apart in the angular direction. Each group included 6 ablative blades between each pair of adjacent helical blades. Ablative blades were fixed on axes that could be rotated and fixed. The axles carrying the ablative blades were attached to two helical blades located on opposite sides. The pressing force of the ablative blades to the surface of the reactor vessel was 20 N. The angle of inclination of the helical blade was 5 degrees. The rotor speed was 120 rpm. Pyrolysis gases were taken from the top of the reactor and analyzed using a gas chromatograph equipped with a thermal conductivity detector. The pyrolysis gas had the composition shown in Table 3.

[0092] Table 3. The result of the analysis of pyrolysis gas.

Component %(v) H2 33.65 methane 14.04 CO 2.12 CO2 1.21 ethane + ethene 14.31 propane 10.33 propene 13.19 isobutane 2.04 n-butane 0.29 isobutene + 1-butene 3.99 trans-2-butene 0.17 cis-2-butene 0.10 1.3-butadiene + isopentane 0.03 n-pentane 0.92 pentene 1.30 isoprene 0.06 Heavy fractions 2.36

[0093] The pyrolysis gas has a very high hydrogen content, and the heavy ends are no more than 2.36% by volume.

The vapor-gas mixture of pyrolysis products was condensed using heat exchangers and separated from non-condensable gases in a separator. The condensate was pyrolysis oil, a paraffin fraction, that is, a broad fraction of hydrocarbons with a boiling point above 30°C. MWP feedstock conversion data are shown in Table 4. Waste product (CO and CO ₂ ) is minimal. The non-condensable gas stream was used as fuel for the entire pyrolysis process without the use of an external energy source.

Table 4. Analysis result of MPW transformation:

Raw material Quantity, % Grocery list Quantity, % plastic waste one hundred pyrolysis oil 66.08 polymer wax 15.03 Non-condensable gases 14.50 coke and ash 1.20 Water 2.90 Losses 1.29 Total one hundred Total one hundred

[0094] It should be understood that the embodiments described above are provided by way of example only, and are susceptible to various modifications and alternative forms well known to those skilled in the art.

[0095] Further modifications may be made to the described structures and methods without departing from the spirit and scope of the invention. Accordingly, while specific embodiments have been described, these are examples only and do not limit the scope of the invention.

Claims (25)

1. Rotor element for use in an ablative pyrolysis reactor, containing a central longitudinal shaft and ablative blades that have a fixed end and a free end configured to be in contact with the inner wall of the reactor vessel, characterized in that the central longitudinal shaft is equipped with one or more helical blades extending in the radial direction from the central longitudinal shaft, while the ablative blades are located in the space between the turns of the helical blade and/or in the space between adjacent helical blades. 2. Rotor element according to claim 1, characterized in that the fixed end of the ablative blade is fixed in the space between the turns of the helical blade and/or in the space between adjacent helical blades by means of an element configured to control the clamping force. 3. Rotor element according to claim 1, characterized in that the helical blade has an angle of inclination to a plane perpendicular to the axis of the central longitudinal shaft, in the range from 0.1 to 45 degrees. 4. Rotor element according to claim 1, characterized in that in the space between adjacent helical blades it contains from 1 to 6 ablative blades. 5. Rotor element according to claim 1, characterized in that at least the free end of the ablative blade is a flexible metal plate for applying an elastic force to the inner wall of the reactor vessel. 6. Rotor element according to paragraphs. 1 and 5, characterized in that the force that the free end of the ablative blade exerts on the wall of the reactor vessel is from 10 to 50 N. 7. Reactor ablative pyrolysis, containing a reactor housing, equipped with an inlet for feeding raw materials for pyrolysis, an outlet for pyrolysis products, and a rotor, characterized in that the rotor contains a rotor element made according to any one of paragraphs. 1-6. 8. The ablative pyrolysis reactor according to claim 7, characterized in that the distance between the outer edge of the helical blade of the rotor element and the inner surface of the wall of the reactor vessel is from 0.1 to 3 mm. 9. Reactor ablative pyrolysis according to paragraphs. 7, 8, characterized in that it is equipped with heating means, which may contain sections for creating temperature zones in the longitudinal direction of the reactor vessel. 10. Reactor ablative pyrolysis according to any one of paragraphs. 7-9, characterized in that the heating means are electrical heating means. 11. Reactor ablative pyrolysis according to any one of paragraphs. 7-10, characterized in that it contains an outlet in the reactor vessel for removing partially pyrolyzed feedstock in the liquid phase, located near the end of the rotor, opposite the inlet for feeding feedstock for pyrolysis. 12. The ablative pyrolysis reactor according to claim 11, characterized in that the outlet in the reactor vessel for removing partially pyrolyzed raw materials in the liquid phase is configured to be connected to a collection tank for collecting partially pyrolyzed raw materials. 13. Reactor ablative pyrolysis according to any one of paragraphs. 7-12, characterized in that the inner surface of the wall of the reactor vessel at least partially has a ceramic-metal coating. 14. The ablative pyrolysis reactor according to claim 13, characterized in that the ceramic-metal coating of the inner surface of the reactor vessel wall is made of a material selected from the group including nickel boride, zirconium oxide, boron nitride, titanium nitride, titanium oxide or titanium carbide. 15. The method of pyrolysis, including the steps: a) preparation of raw materials for pyrolysis from waste, b) supplying raw materials for pyrolysis in the ablative pyrolysis reactor according to any one of paragraphs. 7-14 and pyrolysis of raw materials to obtain pyrolysis products. 16. The pyrolysis method according to claim 15, characterized in that the waste for preparing raw materials for pyrolysis in step a) is selected from the group that includes biomass, agricultural and forestry waste, municipal solid waste, construction waste and demolition residues, oil spills, contaminated oils and various types of plastic. 17. Pyrolysis process according to claim 15 or 16, characterized in that the raw material for pyrolysis is liquid waste, crushed solid waste or liquid mixture of waste dissolved and/or dispersed in an organic solvent. 18. The method of pyrolysis according to p. 17, characterized in that the organic solvent is a stream of purified recycled raw materials taken after pyrolysis. 19. The method of pyrolysis according to any one of paragraphs. 15, 16, in which at stage a) the raw material for pyrolysis, which is a liquid waste mixture, is obtained by dissolving and / or dispersing the waste in an organic solvent, adding contaminated partially pyrolyzed raw materials coming from the ablative pyrolysis reactor to said liquid waste mixture, obtaining contaminated recycled feedstock for pyrolysis and purification of said recycled feedstock from impurities, and at stage b) the obtained feedstock for pyrolysis is fed into the ablative pyrolysis reactor and pyrolysis is carried out, and at the same time, part of the feedstock for pyrolysis in the form of a stream of purified recycled feedstock is used as an organic solvent for step a). 20. The method of pyrolysis according to any one of paragraphs. 15-19, characterized in that in step b) the ablative pyrolysis reactor operates at a reactor wall temperature Tr between 300°C and 650°C, and the pyrolysis feedstock has a temperature Tf in the range from 250 to 400°C, where Tf below Tr preferably less than 50-100°C. 21. The method of pyrolysis according to any one of paragraphs. 15-20, including additional stages c) condensing and separating the pyrolysis gas into condensed liquid pyrolysis products and non-condensed gaseous pyrolysis products, and d) optional stages of distillation, condensation, separation, refining, purification, filtration, conversion of the resulting pyrolysis products into electrical energy, cooling, heating, storage.

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