PRIORITY

This patent application claims priority from the provisional application 202221055486 dated 28 ^th September 2022 titled “A Novel Pyrolysis Reactor” filed with the Indian patent office, Mumbai, which is fully incorporated herein as a reference.

FIELD OF THE INVENTION:

This disclosure relates to a novel pyrolysis reactor that offers enhanced operational performance and extended life. More particularly it relates to a carbon discharge screw attached inline into a pyrolysis reactor which eliminates agitation dead zones in the pyrolysis reactor, minimizes carbon deposition in the pyrolysis reactor, and minimizes stresses in the pyrolysis reactor.

BACKGROUND OF THE INVENTION:

Polymers are widely used in industry and in daily use for diverse applications such as packaging, molded goods, automobile and in electrical industry. The volume of polymer wastes discarded by the general public is enormous, while the availability of landfills is limited. Technologies are therefore being developed for recycling polymeric materials.

US 5744668 “Process of producing gasoline, diesel, and carbon black with waste rubbers and / or waste products” describes a process for the preparation of gasoline, diesel and carbon black with waste rubber and waste plastics. US 6423878 “Process and apparatus for the controlled pyrolysis of plastic materials” describes an apparatus for the pyrolysis of polymers, which converts the waste plastics into hydrocarbons.

While both continuous pyrolysis processes (US 10,968,394, US 2019/0002765 Al, US 2019/0119191 Al, US 2020/0308492) and specialized reactors (US 9,365,775 B l, US 6,807,916 B2, US 10,711,202 B2) are being developed, their performance is limited by the fact that both the feedstock composition as well as product specifications vary. US 8,349.285 B2 describes a method of reclaiming carbonaceous materials from scrap tyres and products derived therefrom. US 9,944,857 discloses a catalytic biomass pyrolysis process for converting a biomass starting material into a low oxygen containing, stable liquid intermediate that can be refined to make liquid hydrocarbon fuels. The PCT Publication WO2014032843 Al “Process and system for whole tyres and plastic composites pyrolysis to fuel conversion and compound recovery” describes an oil extraction system and method for pyrolyzing waste plastic materials.

Indian patent application 1727/MUM/2014, “An apparatus for pyrolysis of polymer waste and the process thereof’ discloses a pyrolysis apparatus for energy recovery from polymer wastes including plastics and tyres. It describes a feeding system, pyrolysis reactor system, heating system, carbon handling system, fractional condenser assembly, gas handling system and emission control system. The said application is fully incorporated herein as a reference. More specifically the reactor comprises a discharge screw tangentially attached to the pyrolysis reactor as shown in FIG. 1. This describes the assembly of a discharge screw attached tangentially to the pyrolysis reactor (104). The discharge screw assembly (403) is attached to the pyrolysis reactor to remove the carbon formed in pyrolysis reaction. The discharge screw assembly (403) contains a discharge screw shell (401) and a discharge screw jacket (402). The outlet (405) is attached to knife edge gate valve (404) to offer airlock during carbon removal. The outlet (405) releases the carbon coming out of the pyrolysis reactor (104) into a discharge system (111) for cooling and safe packing of carbon.

The discharge screw shell (401) is welded to the reactor shell (301) tangentially to the axes of the reactor shell (301). Both the reactor shell (301) and the discharge screw conveyor are externally heated. The pyrolysis reactor (104) with the agitator (302) parallel to the axis of the reactor shell (301) and the discharge screw conveyor welded to reactor shell (301) are covered in a single hot air jacket (303) attached to one or more hot air generators (601). A three-dimensional view of the equipment is shown in FIG. 2.

During the operation of the reactor, it was observed that the heat exchange efficiency of the reactor deteriorated over time. The reactor had to be opened every 10-15 days to remove the carbon deposits formed in the agitation dead zones as shown in FIG. 3. The presence of agitation dead zones in the pyrolysis reactor is undesirable as it impairs heat transfer due to the formation of carbon deposits. The deposits have to be mechanically removed which leads to frequent shut down of the operations and wear of the reactor surface. During the operation of the pyrolysis reactor, it was also observed that the cracks developed along welding joint between the discharge screw conveyor and reactor shell (FIG.S 4-6). It is well established in the art that the cracks propagate further leading eventually to the failure of the reactor.

There is therefore a need to minimize the dead zones and carbon layer deposition in the pyrolysis reactors and to avoid /delay crack formation in the pyrolysis reactors.

SUMMARY OF THE INVENTION:

It has now been surprisingly found that the agitation dead zones in the pyrolysis reactor are minimized/eliminated when the carbon discharge screw is attached inline to the pyrolysis reactor.

It has been even more surprisingly found that incorporation of the carbon discharge screw attached inline to the pyrolysis reactor, minimizes the stresses in the pyrolysis reactor.

According to an embodiment of the disclosure, the carbon discharge screw attached inline is a single screw.

According to an embodiment of the disclosure, the carbon discharge screw attached inline is a twin screw, (see FIG.s 7, 8)

According to an embodiment of the disclosure, the twin screw attached inline is co- rotatable.

According to an embodiment of the disclosure, the twin screw attached inline is counter-rotatable . According to an embodiment of the disclosure, angle of the carbon discharge screw attached inline, with respect to the pyrolysis reactor axis depends on the length of the screw.

According to an embodiment of the disclosure, angle of carbon discharge screw attached inline, with respect to the pyrolysis reactor axis depends on the carbon discharge screw design i.e., whether the carbon discharge screw is a single screw or a twin screw and in the latter case whether it is co-rotatable or counter-rotatable. According to an embodiment of the disclosure, the twin screw can be rotated with the help of single gearbox motor arrangement.

According to an embodiment of the disclosure, the twin screw can be rotated using two individual gearboxes motor arrangement.

According to an embodiment of the disclosure, the twin screw can be rotated using a difference mechanism to co-rotate or counter-rotate.

According to an embodiment of the disclosure the angle (0) between the axis of the carbon discharge screw and the axis of the pyrolysis reactor is maintained such that the molten polymer mass undergoing pyrolysis inside the reactor does not overflow from the screw outlet (001), (FIG. 9). The angle (0) also ensures that (a) the molten pyrolysis material from the pyrolysis reactor is not discharged or does not leak through the outlet during the pyrolysis process (b) the carbon is discharged through the outlet when the carbon discharge screw is operated

According to an embodiment of the disclosure, the said angle 0 is in the range 3 to According to an embodiment of the disclosure, the incorporation of a carbon discharge screw attached inline, minimizes /eliminates agitation dead zones in the pyrolysis reactor.

According to an embodiment of the disclosure, incorporation of carbon discharge screw attached inline enhances the mechanical stability of the pyrolysis reactor at various locations especially at locations susceptible to the development of cracks in the pyrolysis reactor as exemplified by the factor of safety as well as stress values. According to an embodiment of the disclosure, incorporation of an inline discharge screw lowers the stresses at any point along the length of the reactor vis a vis the stresses developed in the reactor when the discharge screw is attached tangentially. According to an embodiment of the disclosure, the capacity of the pyrolysis reactor is in the range 100 kg/day to 50 tons/day.

According to an embodiment of the disclosure the reactor carbon screw length is in the range 0.5 mtr to 6 mtr.

According to an embodiment of the disclosure the pitch of the agitator of the pyrolysis reactor is in the range of 40% to 200% of the pyrolysis reactor shell diameter.

According to an embodiment of the disclosure, the pitch of the carbon discharge screw is in the range 40% to 200% of the carbon discharge screw shell diameter.

According to an embodiment of the disclosure, the gap between the pyrolysis reactor screw and the pyrolysis reactor shell varies between 3 mm to 50 mm. According to an embodiment of the disclosure, the gap between the edge of the carbon discharge screw and the internal surface of the shell enclosing the carbon discharge screw varies between 3 mm to 50 mm.

According to an embodiment of the disclosure, the pyrolysis reactor is operated as a batch operation.

According to an embodiment of the disclosure, the pyrolysis reactor is operated as a continuous operation.

BRIEF DESCRIPTION OF DRAWINGS:

The objectives and advantages of the present invention will become apparent from the following description read in accordance with the accompanying drawings wherein,

FIG. 1 shows a pyrolysis reactor with the carbon discharge screw attached tangentially;

FIG. 2 depicts a three-dimensional view of the pyrolysis reactor with the carbon discharge screw attached tangentially as shown in FIG. 1;

FIG. 3 shows agitation dead zones in the pyrolysis reactor with the carbon discharge screw attached tangentially (The agitation dead zones result in carbon layer shown in black);

FIG.S 4 to 6 show welding cracks developed over time on the pyrolysis reactor with the carbon discharge screw attached tangentially;

FIG. 7 depicts a carbon discharge screw (twin screw arrangement) of the present invention; FIG. 8 depicts a carbon discharge screw (twin screw arrangement), attached in line with the pyrolysis reactor;

FIG. 9 shows an angle 0 between the axis of the carbon discharge screw and the axis of the pyrolysis reactor;

FIG. 10 indicates that the agitation dead zones eliminated in the pyrolysis reactor with the carbon discharge screw attached inline (no agitation dead zones are seen); FIG. 11 indicates that the agitation dead zones eliminated in the pyrolysis reactor with the carbon discharge screw attached inline (no agitation dead zones are seen, another view);

FIG.S 12-13 show the factor of safety analysis comparison for the pyrolysis reactor with the carbon discharge screw attached inline and attached tangentially;

FIG. 14 shows the factor of safety analysis for the pyrolysis reactor with the carbon discharge screw attached inline;

FIG. 15 shows the factor of safety analysis for the pyrolysis reactor with the carbon discharge screw attached tangentially;

FIG. 16 depicts the expansion in pyrolysis reactor incorporating a carbon discharge screw attached tangentially;

FIG. 17 depicts the expansion in pyrolysis reactor incorporating a carbon discharge screw attached inline;

FIG. 18 shows the stress values in the pyrolysis reactor with the carbon discharge screw attached tangentially;

FIG. 19 shows the stress values in the pyrolysis reactor with the carbon discharge screw attached tangentially (screw area); FIG. 20 shows the stress values in the pyrolysis reactor with the carbon discharge screw attached inline;

FIG. 21 shows the stress values in the pyrolysis reactor with the carbon discharge screw attached inline (screw area.);

FIG. 22 shows the stress value in the pyrolysis reactor with the carbon discharge screw (twin screw arrangement) attached tangentially (stress value 2200 MPa at the location shown);

FIG. 23 shows the stress value in the pyrolysis reactor with the carbon discharge screw (twin screw arrangement) attached inline (stress value 452.9 MPa at the location shown);

FIG. 24 depicts a pyrolysis reactor with the carbon discharge screw attached inline;

FIG. 25 shows the pyrolysis reactors arranged in parallel with the carbon discharge screw attached inline;

FIG. 26 shows the pyrolysis reactors arranged in series wherein pyrolysis reactor with the carbon discharge screw attached inline precedes the pyrolysis reactor without carbon discharge screw; and

FIG. 27 shows the pyrolysis reactors arranged in series wherein both reactors incorporate a carbon discharge screw attached inline.

DESCRIPTION OF THE INVENTION:

References in the specification to "one embodiment" or "an embodiment" means that a particular feature, structure, characteristic, or function described in connection with the embodiment is included in at least one embodiment of the invention. The appearances of the phrase “in one embodiment” in various places in the specification are not necessarily all referring to the same embodiment.

References in the specification to “preferred embodiment” means that a particular feature, structure, characteristic, or function described in detail thereby omitting known constructions and functions for clear description of the present invention.

The foregoing description of specific embodiments of the present invention has been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the present invention to the precise forms disclosed and obviously many modifications and variations are possible in light of the above teaching.

A wide range of pyrolysis reactors have been disclosed in the prior art for the pyrolysis of plastics, rubbers, and biomass. In many cases carbon is produced and deposits on the reactor surface which needs to be removed to maintain the heat transfer across the pyrolysis reactor surface.

The pyrolysis reactor disclosed in the application 1727/MUM/2014, was provided with a carbon discharge screw attached tangentially to the pyrolysis reactor.

During the operation of the pyrolysis reactor, when it was opened for maintenance and equipment-health-check, it was found to contain carbon deposits. The formation of carbon deposits impairs heat transfer and have to be mechanically scraped off. During the operation of the pyrolysis reactor, it was also observed that the cracks developed along welding joint between the discharge screw conveyor and reactor shell (FIG.s 4-6). It is well established in the art that the cracks propagate further, leading eventually to the failure of the reactor.

There is therefore a need to minimize the dead zones and carbon layer deposition in the pyrolysis reactors and to avoid /delay crack formation in the pyrolysis reactors.

It was surprisingly found that the agitation dead zones in the pyrolysis reactor do not arise when the carbon discharge screw is attached inline to the pyrolysis reactor (FIG.s 10 and 11). Since the distance between the scraper and the pyrolysis reactor shell is maintained the same across the length of the reactor, the carbon discharge screw attached in-line does not enter the pyrolysis reactor shell as does the discharge screw, when attached tangentially to the reactor. Thus, there is no need to decrease the height of the agitator scrapper in the screw area. Thus, the agitation dead zone does not arise and also there is no carbon disposition. This ensures that there is no deterioration in the heat transfer performance of the reactor.

The influence of carbon layer deposition on the heat transfer was evaluated by calculating heat transfer coefficient for the pyrolysis reactor.

The heat transfer coefficient for the pyrolysis reactor was calculated as follows.

Heat transfer from hot air to the outer surface of the reactor. • This type of heat transfer is known as convective heat transfer and is calculated by the formula

Q= hAA T

Where, Q= Heat transfer rate (kcal/hr) h=convection heat-transfer coefficient (kcal/m2 hr °C)

A=exposed surface area (m2)

A T= Temperature difference (°C) Heat transfer from outer surface of the reactor to the inner surface of reactor • This type of heat transfer is known as conductive heat transfer and is calculated by the formula

Q= KAdT/dx

Where,

Q= Heat transfer rate (kcal/hr) h= Thermal conductivity of Stainless Steel 304 (W/m.°C)

A=exposed surface area (m2) dT= Temperature gradient (°C) dx= Thickness of SS304 (m) Heat transfer from the inner surface of the reactor to the plastic material inside the reactor.

• This type of heat transfer is known as convective heat transfer and is calculated by the formula Q= hAA T

Where,

Q= Heat transfer rate (kcal/hr) h=convection heat-transfer coefficient (w/m2 °C)

A=exposed surface area (m2) A T= Temperature difference (°C)

Overall heat transfer is calculated by the formula

Q= UAA T

Where,

U =Overall heat transfer coefficient. (kcal/m2 hr °C) A=exposed surface area (m2)

A T= Temperature difference (°C)

U= A T/(l/ho+X/K+l/hi)

Where, U =Overall heat transfer coefficient. (kcal/m2 hr °C)

A T= Temperature difference between outside surface and inside surface. (°C)

X- Thickness of SS304 shell (m) hi- Inside heat transfer coefficient (156 W/m2 °C -With Carbon layer),

(350 W/m2 °C without carbon layer) ho- Outside heat transfer coefficient (350 W/m2 °C) k- Thermal conductivity of the SS304 (16 W/m°C) The table shows that in a typical case due to the carbon layer deposition, the heat transfer coefficient is decreased to almost 20 % of the original value, when no carbon deposits existed. During the operation of the pyrolysis reactor, it was also observed that the cracks developed along the welding joint between the carbon discharge screw and the reactor shell. The cracks propagated further leading eventually leading to the failure of the reactor.

Having attached carbon discharge screw inline to the pyrolysis reactor, the mechanical stability of the reactor as exemplified by the factor of safety was assessed using software simulation. Autodesk fusion 360 software was used to calculate factors of safety at various points along the length of the pyrolysis reactor.

Given below is the description of the methodology adopted to evaluate efficiency of mechanical design and consequent improvement in reactor life using the simulation software.

Definition of factor of safety - It is the ratio of permissible stress of particular material to the actual stress developed because of various factor like operating pressure, static load etc. 3D models of the pyrolysis reactor along with carbon discharge screw attached tangentially as well as attached inline were developed in solid edge software. Subsequently they were exported in to the simulation software Autodesk Fusion 360. Data fed into Fusion 360 software comprise basic parameters like Material of Construction (MOC), Design pressure and Design Temperature, which indicate maximum allowable pressure, maximum allowable temperature, various loads along with load support points etc. When the software is run in simulation mode, it divides entire reactor and carbon discharge screw assembly into multiple numbers of very small finite elements. Subsequently the stresses developed at design conditions at every small finite element were calculated using the software. This eliminates the error likely to occur if the model were based on gross or average values.

Output from Fusion 360 is typically in the form of 3D sketch of the reactor assembly along with carbon discharge screw where safety factor values across the assembly are depicted in different color codes. Actual values of safety factor at various elements are also recorded. (See below.)

The results in FIG.s 12-15 show that the factor of safety improved considerably for the pyrolysis reactor incorporating carbon discharge screw attached in line as compared to the pyrolysis reactor incorporating carbon discharge screw attached tangentially. Specifically at the point where cracks were developed when the carbon discharge screw was attached tangentially, the factor of safety improved from 0.01273 to 1.038. The factor of safety improved for the side weld joint between the discharge screw shell and reactor shell from 0.1305 to 1.038. (Shown in FIG. 14 )

FIG. 16 illustrates that at pyrolysis temperatures expansion of the pyrolysis reactor incorporating carbon discharge screw tangentially is such that the expansion of the pyrolysis reactor and that of the carbon discharge screw is in opposite direction. This results in increase of the stress in the screw area.

FIG. 17 illustrates that the expansion of the pyrolysis reactor incorporating carbon discharge screw inline at pyrolysis temperatures is such that the expansion of the pyrolysis reactor and carbon discharge is in the same direction. The stress in the screw area in this case is lower in comparison to that generated when carbon discharge screw is attached tangentially to the pyrolysis reactor.

The analysis was then followed by calculation of stresses along the length of the pyrolysis reactors for both situations wherein a) the carbon discharge screw was attached inline and b) the carbon discharge screw was attached tangentially.

Simulation output for the stress values in the pyrolysis reactor with the carbon discharge screw attached tangentially is shown in FIG.18 and 19. Similar output for the pyrolysis reactor with the carbon discharge screw attached inline is shown in FIG.s 20 and 21. Output for pyrolysis reactor with carbon discharge screw (twin screw arrangement) attached tangentially and attached inline is shown in FIG.s 22 and 23.

FIG. 18 shows that stress developed at the weld joint between the discharge screw when attached tangentially to the reactor shell is 16891 Mpa.

FIG. 20 shows that stress developed at the weld joint between the discharge screw when attached in line to the reactor shell is 8940 Mpa. which is almost half of the stress developed between the discharge screw when attached tangentially and the reactor shell. It would be obvious to those skilled in the art that this would delay the crack formation and enhance the life of the reactor.

The results in all cases show that when the carbon discharge screw is attached in line to the pyrolysis reactor, the stresses in the screw area are lower than the stresses developed in the same area when the carbon discharge screw is attached tangentially to the pyrolysis reactor.

Moreover, in the case of the pyrolysis reactor when the carbon discharge screw was attached tangentially, cracks were observed (See FIG.s 4,5 and 6) at the welding joints where the stresses developed were higher. (See FIG.s 18 and 19). This established that the development of stresses led to the cracks in the welding joint, thereby limiting the service life of the pyrolysis reactor. Further, at any point along the length of the pyrolysis reactor, the stresses developed in the pyrolysis reactor when the carbon discharge screw was attached inline, were lower than those developed in the pyrolysis reactor when the carbon discharge screw was attached tangentially. FIG. 24 illustrates the pyrolysis reactor (200) incorporating the agitator

(209) which includes a rotating shaft (210) at the center, an agitator ribbon or paddles (202) positioned spirally at the center of the rotatable shaft (210). The agitator ribbon (202) has supports that extend radially away from the center of the rotatable shaft

(210) up to the inner periphery of the ribbon (202).

As illustrated in FIG. 24, the carbon discharge screw (204) comprises a conduit (211) having a rotatable helical single/twin screw blade/ribbon conveyor (flighting) assembly (203) capable of forcing the carbon residues through the discharge port. The conduit (211) has a rotatable helical screw blade (flighting) assembly (203) that can be heated with hot air, electric heaters, molten salt or radiant heat furnace heating etc. to maintain the temperature of the contents close to the temperature of the reactor and optionally as to avoid accumulation/sticking of the solids in the screw. The conduit (211) of the discharge mechanism (204) comprises a downwardly outlet (213) positioned at the end of the conduit for discharging the contents out of the reactor. Further, the position of the discharge mechanism (204) is at an angle between 3 to 50° with respect to the axis of the reactor length and is in line with the reactor (200) for conveying the solids upward and providing further a downwardly outlet (213) to avoid spilling of the molten contents from the pyrolysis reactor.

The said angle 0 varies depending on the feedstock used. For example, for biomass feedstock the angle of this screw can be as low as 3°, for tyre as a feedstock the angle of this screw can be around 15 to 20° and for plastic/oil-sludge as a feedstock, the angle of this screw can be up to 50°C. Operation of the pyrolysis reactor with carbon screw attached in line (FIG. - 24)

The pyrolysis reactor (200) is operated in the temperature range, room temperature to 750°C. The reactors are heated externally. The empty reactor (200) is heated in the range 200°C to 350°C as to ensure uninterrupted flow and agitation of the feedstock. Once the temperature is reached, the agitator (210) is set in motion in the range 0.5 to 140 RPM.

The raw material, plastic waste, biomass or a combination of the two, is then fed through the air-lock feeding system (201) into the reactor. The reactor temperature is then raised to pyrolysis temperature in the range (250°C-750°C). Pyrolysis vapors generated in the reactor are passed through the vapor line (206) and sent to condensers. The peak value of the vapor line (206) temperature indicates the completion of the pyrolysis reaction. Pyrolysis carbon accumulated in the pyrolysis reactor is discharged via the carbon discharge screw (213).

Pyrolysis reactor operation for the pyrolysis reactors in parallel (FIG. 25)

The pyrolysis reactors (300, 400) are operated in the temperature range, room temperature to 750°C. The reactors are heated externally. The empty reactors (300, 400) are heated to a temperature in the range 200°C to 350°C as to ensure uninterrupted flow and agitation of the feedstock. Once the temperature is reached, the agitators (310, 410) are set in rotation in the range 0.5 to 140 RPM.

The raw material, plastic waste, biomass or a combination of the two, is then fed through the air-lock feeding system (301 and 401) into the pyrolysis reactor. The pyrolysis reactor temperature is then raised to temperature in the range (250°C- 750°C). The vapors generated in the pyrolysis reactor are passed through the vapor line (306 and 406) and sent to condensers. The peak value of the vapor line (306 and 406) temperature indicates the completion of the pyrolysis reaction. Carbon accumulated is discharged through the carbon discharge screw (311 and 411).

The parallel arrangement of pyrolysis reactors (FIG. 25) helps to increase the plant capacity reducing the capital expenditure by combining downstream equipment like condensers, receivers etc.

Pyrolysis reactor operation for the pyrolysis reactor in series. (Pyrolysis reactor with the carbon discharge screw attached inline preceded by pyrolysis reactor without carbon discharge screw.) When two or more pyrolysis reactors are arranged in series, as shown in FIG. 26 and the continuous pyrolysis operation is enabled wherein feeding of the raw material and discharge of pyrolysis residue can be carried out in a continuous manner. Such arrangement of multiple reactors enables residence time for plastic waste at different temperatures before reaching the final discharge point for the end product. Such arrangement of multiple reactors in series prevents discharge of unprocessed plastic raw material which is not possible in case of a single reactor operation.

Both pyrolysis reactors (500 and 600) are operated in the temperature range, room temperature to 850°C. The reactors can be heated externally by hot air or electricity or liquid heating media. Once the temperature in the reactor 500 has reached approximately 200°C to 350°C as to ensure the uninterrupted flow of the feedstock, and temperature in pyrolysis reactor 600 is attained (approximately 350°C to 750°C), the agitators (510 and 610) are set in rotation in the range 0.5 to 140 RPM. Raw material (polymers waste or biomass waste or mixture thereof) is fed through the hopper (501) of the airlock feeding system of the reactor (500). In the first reactor (500) the feedstock temperature is raised to 250 to 350°C which is maintained for 2 to 4 hours, the contents are then discharged into the second reactor (600). In the second reactor the temperature of the contents is raised from 350 to 750°C over the period of 4 to 5 hours. Pyrolysis yields gaseous and vapour products and a solid residue which is essentially a char. Vapours are condensed into liquids in the condenser downstream and the gases are recovered from the condenser. In the reactor (500) Partition plate (514) has been provided to prevent spillage of the contents from the reactor 500 to reactor 600. The molten mass overflows from the partition plate (514) and then discharged from (513) in to the pyrolysis reactor (600) using the agitator (510). The pyrolysis reactor (600) is maintained at a higher temperature compared to the reactor (500). Vapors generated in the reactors are passed through the reactors (500 and 600) into vapor lines (506) and (606) and sent to condensers. In this manner, by arranging multiple reactors in series, a continuous pyrolysis operation is achieved and at the discharge end of last reactor, pyrolysis residue/carbon is removed through the nozzle (613).

Pyrolysis reactor operation for the reactor in series. Both reactors incorporating a carbon discharge screw attached inline. (FIG. 27)

Both pyrolysis reactors (700 and 800) are operated in the temperature range, room temperature to 850°C. The reactors can be heated externally by hot air or electricity or liquid heating media. Once the temperature in the reactor 700 is reached as to ensure the uninterrupted flow of the feedstock (Approx 200°C to 350°C), and pyrolysis temperature in reactor 700 is attained (Approx 350°C to 750°C), the agitators (710 and 810) are set in rotation in the range 0.5 to 140 RPM. Raw material (polymers waste or biomass waste or mixture thereof) is fed through the hopper (701) of the airlock feeding system of the reactor (700). In the first reactor (700) the feedstock is heated to a temperature to 250 to 350°C which is maintained for 2 to 4 hours, the contents are then then discharged into the second reactor (800) with the help of the agitator (710) and carbon discharge screw attached inline (711), and in the second reactor the temperature of the contents is raised from 350 to 750°C over the period of 4 to 5 hours. Vapors generated in the pyrolysis reactors are passed through into vapor lines (706) and (806) and sent to condensers while pyrolysis residue or char remains in the 2nd reactor. Vapours are condensed into liquids in the condenser downstream and the gases are recovered from the condenser. In this manner, pyrolysis is achieved by arranging multiple pyrolysis reactors in series. Pyrolysis residue/carbon is removed through the nozzle (813) at the discharge end of the last reactor.

Those skilled in the art will realize that the number of reactors in parallel and in series can be varied. Pyrolysis can be carried out as a continuous operation by combining two or more reactors in series.

The embodiments were chosen and described in order to best explain the principles of the present invention and its practical application, to thereby enable others, skilled in the art to best utilize the present invention and various embodiments with various modifications as are suited to the particular use contemplated. It is understood that various omission and substitutions of equivalents are contemplated as circumstance may suggest or render expedient, but such are intended to cover the application or implementation without departing from the scope of the present invention.