Patent ID: 12252592

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENT(S)

A process of treating polymeric material, such as waste polymeric material, within a reactor of a system is described below. Suitable waste polymeric material includes waste plastic material. Virgin plastics can also be used.

FIG.1illustrates Process10for treating polymeric material. Process10can be run in batches, but more preferably is a continuous process. The parameters of Process10, including but not limited to temperature, flow rate of plastic and total number of pre-heat, reaction, or cooling segments, can be modified to create end products of varying molecular weights. For example, raising the temperature and/or decreasing the flow rate through the reaction sections or changing the number of reaction sections will result in the product of a lower molecular weight.

In Material Selection Stage1, polymeric feed is selected and/or prepared for treatment. In some embodiments, the polymeric feed in sorted/selected to include polyethylene material. In other embodiments, the polymeric feed in sorted/selected to include polypropylene material. In other embodiments, the polymeric feed in sorted/selected to include both polyethylene and polypropylene material. In some embodiments, the feed can contain up to 5% polypropylene, small quantities of polystyrene, and trace quantities of undesirable additives, such as PVC, ash, grit, or other unknown particles.

In some embodiments, the material selected in Material Selection Stage1comprises recycled plastics. In other or the same embodiments, the material selected in Material Selection Stage1comprises recycled plastics and/or virgin plastics.

In some embodiments, the material selected in Material Selection Stage1is heated in an extruder and undergoes Pre-Filtration Process3. In some embodiments, the extruder is used to increase the temperature and/or pressure of the incoming plastic and is used to control the flow rates of the plastic. In some embodiments, the extruder is complemented by or replaced entirely by pump/heater exchanger combination.

Pre-Filtration Process3can employ both screen changers and filter beds, along with other filtering techniques/devices to remove contaminants from and purify the heated material. The resulting filtered material is then moved into an optional Pre-Heat Stage4which brings the filtered material to a higher temperature before it enters Reaction Stage5. Pre-Heat Stage4can employ, among other devices and techniques, static and/or dynamic mixers and heat exchangers such as internal fins and heat pipes.

Material in Reaction Stage5undergoes depolymerization. This depolymerization can be a purely thermal reaction and/or it can employ catalysts. Depending on the starting material and the desired end product, depolymerization might be used for a slight or extreme reduction of the molecular weight of the starting material. In some embodiments, the catalyst used is a zeolite or alumina supported system or a combination of the two. In some embodiments, the catalyst is [Fe—Cu—Mo—P]/Al2O3prepared by binding a ferrous-copper complex to an alumina or zeolite support and reacting it with an acid comprising metals and non-metals.

Reaction Stage5can employ a variety of techniques/devices including, among other things, fixed beds, horizontal and/or vertical reactors, and/or static mixers. In some embodiments, Reaction Stage5employs multiple reactors and/or reactors divided into multiple sections.

After Reaction Stage5, the depolymerized material enters optional Cooling Stage6. Cooling Stage6can employ heat exchangers, along with other techniques/devices to bring the depolymerized material down to a workable temperature before it enters Purification Stage7.

In some embodiments, cleaning/purification of the material via such methods such as nitrogen stripping occurs before Cooling Stage6.

Purification Stage7involves the refinement and/or decontamination of the depolymerized material. Techniques/devices that can be used in Purification Stage7include, but are not limited to, flash separation, absorbent beds, clay polishing, distillation, vacuum distillation and filtration to remove solvents, oils, color bodies, ash, inorganics, and coke. In some embodiments, a thin or wiped film evaporator is used to remove gas, oil, and/or grease from the depolymerized material. In some embodiments, the oil, gas and grease can in turn be burned to help run various Stages of Process10.

Process10ends at Finished Wax Stage8in which the initial starting material selected in Material Selection Stage1has been turned into wax. In at least some embodiments, the wax at Finished Wax Stage8is commercially viable and does not need additional processing and/or refining.

Referring toFIG.2, system1000includes reactor100with five reactor modules102(a) through102(e). Reactor modules102can vary in dimensions and/or be connected in parallel and/or series. In other embodiments, various numbers of reactor modules102can be used. For example,FIG.3shows system1000with four reactor modules,102(a) through102(d) Similarly,FIG.4shows system1000with six reactor modules102(a) through102(f). The ability to customize the number of reactor modules102allows for greater control of the amount of depolymerization.

System1000can include hopper111for receiving polymeric material and/or directing the supply of the polymeric material to optional extruder106. In some embodiments, extruder106processes the polymeric material received from hopper111by generating a molten polymeric material. The temperature of the polymeric material being processed by extruder106is controlled by modulating the level of shear and/or the heat being applied to the polymeric material by extruder heater(s)105. Extruder heaters can use a variety of heat sources including, but not limited to, electric, thermal fluids, and/or combustion gases. The heat is modulated by a controller, in response to temperatures sensed by temperature sensor(s)107.

In some embodiments, pressure sensor109measures the pressure of the molten polymeric material being discharged from extruder106, to prevent, or at least reduce, risk of pressure spikes. The discharged molten polymeric material is pressurized by pump110to affect its flow through heating zone108and reactor100. While flowing through reactor100, the reactor-disposed molten polymeric material contacts a catalyst material which causes depolymerization.

Pressure sensor(s)109and/or temperature sensor(s)107can also be used to measure temperature and/or pressure, respectively, of the reactor-disposed molten polymeric material as it flows through reactor100. Pressure sensor(s)109can monitor for plugs before and/or after each reaction zones. Pressure sensor(s)109can also maintain system pressure below a maximum pressure such as the maximum pressure of reactor100is designed for. Over-pressure can be controlled by feedback from pressure transmitter109to a controller which transmits a command signal to shut down extruder106and pump110, and thereby prevent the pressure from further increasing.

In cases when shutdown of extruder106does not relieve the over pressure, dump valve117can be opened into a container to remove material from system1000and avoid an over pressure situation. During shutdown dump valve117can be opened to purge system1000with nitrogen to remove leftover material to avoid clogs and degraded material during the next start up.

System1000can also include a pressure relief device, such as a relief valve or a rupture disk, disposed at the outlet of extruder106, to relieve pressure from system1000, in case of over-pressure.

Temperature sensor(s)107can facilitate control of the temperature of the reactor-disposed molten polymeric material being flowed through reactor100. This allows more precise control of the chemical reaction and the resulting polymerization. Temperature sensor(s)107also aid in maintaining the temperature below a predetermined maximum temperature, for example the maximum design temperature of reactor100.

The temperature is controlled by a controller (not shown), which modulates the heat being applied by heaters118disposed in heat transfer communication with the reaction zones102(a) through102(e) of reactor100, in response to the temperatures sensed by temperature sensor(s)119.

Flow control can also be provided for within system1000. In some embodiments, system1000includes valve115, disposed at the discharge of extruder106, for controlling flow from extruder106to other unit operations within system1000. Valve116facilitates recirculation. Valve117enables collection of product.

During operation, valve115can be closed in order to recirculate the molten polymeric material and increase the temperature of the molten polymeric material to a desired temperature. In this case valve116would be open, valve117would be closed, extruder106would be “OFF”, and pump110would be recirculating.

Generated molten product material112is cooled within heat exchanger114, which can be, among other ways, water jacketed, air cooled, and/or cooled by a refrigerant. A fraction of the cooled generated molten product material can be recirculated (in which case valve116would be open), for reprocessing and/or for energy conservation.

In some embodiments, system1000is configured for purging by nitrogen to mitigate oxidation of the molten product material and the creation of explosive conditions.

In another embodiment illustrated inFIG.5, System2000includes reactor600. Reactor600has two reactor modules, namely, inlet reactor module300and outlet reactor module400. System2000also includes extruder606for receiving polymeric material. Extruder606processes polymeric material by generating a molten polymeric material. The temperature of the polymeric material being processed through reactor600is controlled by modulating the heat being applied to the polymeric material by process heaters HE01, HE02, HE04, HE06, HE08. Temperature sensors TC01, TC04, TC06, TC07TC09, TC10, TC12are provided to measure the temperature of the molten material within reactor600. Temperature controllers TC03, TC05, TC08, TC11are provided to monitor and control the temperature of process heaters HE01, HE02, HE04, HE06, and HE08. Flange heaters HE03, HE05, HE07, and HE09are also provided to mitigate heat losses through the flanged connections.

The discharged molten polymeric feed material is conducted through heater608and reactor600, in series. While flowing through reactor600, the reactor-disposed molten polymeric material is contacted with the catalyst material to affect the depolymerization. The generated molten product material is cooled within heat exchanger614, which can be, among other things, water jacketed, air cooled, or cooled by a refrigerant. In some embodiments, the waste heat from the cooling molten product can be used to run other processes. A cooling section heater HE10is provided to melt wax that solidifies in cooling section.

In both System1000and System2000reactors100and600include one or more reactor modules. Each reactor modules includes a respective module reaction zone in which the reactor-disposed molten polymeric material is brought into contact with a catalyst material over a module-defined residence time, thereby causing depolymerization of the flowing reactor-disposed molten polymeric material. In some of these embodiments, the module-defined residence time of at least two of the reactor modules is the same or substantially the same. In some of these embodiments, as between at least some of the plurality of module-defined residence times are different. In some of these embodiments the catalyst material of at least two of the reactor modules are the same or substantially the same. In some of these embodiments the catalyst material of at least two of the reactor modules are different.

In some embodiments, each of the reactor modules includes a reactor-disposed molten polymeric material-permeable container that contains the catalyst material. The container is configured to receive molten polymeric material such that at least partial depolymerization of at least a fraction of the received molten polymeric material is effected by the catalyst material, and to discharge a molten product material that includes depolymerization reaction products (and can also include unreacted molten polymeric material and intermediate reaction products, or both). Flowing of the reactor-disposed molten polymeric material through the reactor-disposed molten polymeric material-permeable container effects contacting between the catalyst material and the reactor-disposed molten polymeric material, for effecting the at least partial depolymerization of at least a fraction of the reactor-disposed molten polymeric material. In this respect, the flowing reactor-disposed molten polymeric material permeates through the catalyst material within the container, and while permeating through the catalyst material, contacts the catalyst material contained within the container, for effecting the at least partial depolymerization of at least a fraction of the reactor-disposed molten polymeric material.

In both System1000and System2000a first reactor is assembled from the reactor modules. The first reactor has a first reaction zone and includes a total number of “P” reactor modules from “N” reactor modules, wherein “N” is a whole number that is greater than or equal to one.

Each one of the “N” reactor modules defines a respective module reaction zone including a catalyst material disposed therein, and is configured for conducting a flow of reactor-disposed molten polymeric material through the respective module reaction zone, such that, flowing of the reactor-disposed molten polymeric material through the respective module reaction zone brings it into contract with the catalyst material, thereby causing at least partial depolymerization of at least a fraction of the flowing reactor-disposed molten polymeric material. In this respect, the first reaction zone includes “P” module reaction zones.

When “N” is a whole number that is greater than or equal to two, each one of the “N” reactor modules is configured for connection, in series, to one or more of the other “N” reactor modules such that a plurality of reactor modules are connected to one another, in series, and includes a plurality of module reaction zones that are disposed in fluid communication within one another, in series, such that the total number of module reaction zones correspond to the total number of connected reactor modules. The plurality of connected reactor modules is configured for conducting a flow of reactor-disposed molten polymeric material through the plurality of module reaction zones, such that it comes into contact with the catalyst material, thereby effecting at least partial depolymerization of at least a fraction of the flowing reactor-disposed molten polymeric material.

When “P” is a whole number that is greater than or equal to two, the assembling of the first reactor includes connecting the “P” reactor modules to one another, in series, such that “P” reaction zones are disposed in fluid communication with one another in series.

In the embodiment illustrated inFIG.2, “P” is equal to five, such that reactor100includes five reactor modules102(a) through102(e), the reaction zone consisting of five module reaction zones104(a) through104(e), each one respective to one of the five reactor modules. It is understood that “P” can be more or less than five.

In another embodiment illustrated inFIG.5, “P” is equal to two, such that reactor600includes two reactor modules: inlet reactor module300and outlet reactor module400.

Molten polymeric material, for supplying to the constructed reactor, is generated by heating a polymeric material. In some embodiments, the heating is caused by a heater. InFIG.2the heating is caused by a combination of extruder106and separate heater108. InFIG.5the heating is caused by a combination of extruder606and separate heater608. In such embodiments, the generated molten polymeric material is forced from the extruder, flowed through a separate heater, and then supplied to the module reaction zone. In some embodiments, the extruders are configured to supply sufficient heat to the polymeric material such that the generated molten polymeric material is at a sufficiently high temperature for supply to the reactor, and a separate heater is not required.

InFIG.2, pump110receives molten polymeric material from extruder106and effects transport (or “flowing”) of the molten polymeric material through heater108, and then through the first reaction zone. In some embodiments, extruder106is configured to impart sufficient force to affect the desired flow of the generated molten polymeric material, such that pump110is optional.FIG.5shows an example without a pump.

In some embodiments, the molten polymeric material is derived from a polymeric material feed that is heated to effected generation of the molten polymeric material. In some embodiments, the polymeric material feed includes primary virgin granules of polyethylene. The virgin granules can include low density polyethylene (LDPE), linear low density polyethylene (LLDPE), high density polyethylene (HDPE), polypropylene (PP), or a mixture including combinations of LDPE, LLDPE, HDPE, and PP.

In some embodiments, the polymeric material feed includes waste polymeric material feed. Suitable waste polymeric material feeds include mixed polyethylene waste, mixed polypropylene waste, and a mixture including mixed polyethylene waste and mixed polypropylene waste. The mixed polyethylene waste can include low density polyethylene (LDPE), linear low density polyethylene (LLDPE), high density polyethylene (HDPE), polypropylene (PP), or a mixture including combinations of LDPE, LLDPE, HDPE, and PP. In some embodiments, the mixed polyethylene waste includes grocery bags, milk pouches, stationery files. In some embodiments, the waste polymeric material feed includes up to 10 weight % of material that is other than polymeric material, based on the total weight of the waste polymeric material feed.

The molten polymeric material is supplied to the reactor, and the molten polymeric material is flowed through the first reaction zone (that is, including the “P” reaction zones) as reactor-disposed molten polymeric material. The flowing of the reactor-disposed molten polymeric material through the first reaction zone brings it into contact with the catalyst material generating a molten product material, including a depolymerization product material (and, in some embodiments, also includes unreacted molten polymeric material and/or intermediate reaction products). The molten product material is collected.

In some embodiments, the catalyst material includes [Fe—Cu—Mo—P]/Al2O3. The catalyst is prepared by binding a ferrous-copper complex to an alumina support and reacting it with an acid comprising metals and non-metals to obtain the catalyst material. Other suitable catalyst materials include zeolite, mesoporous silica, H-mordenite and alumina. The system can also be run in the absence of a catalyst and produce waxes through thermal degradation.

The generated molten product material is discharged from and collected/recovered from the reactor. In some embodiments, the collection of the molten product material is effected by discharging a flow of the molten product material from the reactor. In those embodiments with a plurality of reactor modules, the molten product material is discharged from the first reactor module and supplied to the next reactor module in the series for effecting further depolymerization within the next reactor module in the series, and this continues as-between each adjacent pair of reactor modules in the series.

In some embodiments, the generated depolymerization product material includes waxes, greases, and grease-base stocks. Commercially available greases are generally made by mixing grease base stocks with small amounts of specific additives to provide them with desired physical properties. Generally, greases include four types: (a) admixture of mineral oils and solid lubricants; (b) blends of residuum (residual material that remains after the distillation of petroleum hydrocarbons), uncombined fats, rosin oils, and pitches; (c) soap thickened mineral oils; and (d) synthetic greases, such as poly-alpha olefins and silicones.

In some embodiments, the polymeric feed material is one of, or a combination of, virgin polyethylene (any one of, or combinations of, HDPE, LDPE, LLDPE, and MDPE), virgin polypropylene, or post-consumer, or post-industrial, polyethylene or polypropylene (exemplary sources including bags, jugs, bottles, pails, and the like), and it is desirable to convert such polymeric feed material into a higher melting point wax (having a melting point from 106 degrees Celsius to 135 degrees Celsius), a medium melting point wax (having melting point from 86 degrees Celsius to 105 degrees Celsius), a lower melting point wax (having a melting point from 65 degrees Celsius to 85 degrees Celsius), an even lower melting point wax (having a melting point from 40 degrees Celsius to 65 degrees Celsius) using an embodiment of the system disclosed herein. In each case, the conversion is effected by heating the polymeric feed material so as to generate molten polymeric material, and then contacting the molten polymeric material with the catalyst material within a reaction zone disposed at a temperature of between 325 degrees Celsius and 450 degrees Celsius. The quality of wax (higher, medium, or lower melting point wax) that is generated depends on the residence time of the molten polymeric material within the reaction zone. When operating in a continuous system depending on the flowrate of the extruder or gear pump residence times vary from 1-120 minutes, preferably 5-60 minutes, with 1-12 reactor modules attached in series. In some of these embodiments, the supply and heating of the polymeric feed material is effected by a combination of an extruder and a pump, wherein the material discharged from the extruder is supplied to the pump. In some of these embodiments, extruder106is a 10 HP, 1.5-inch (3.81 cm) Cincinnati Milacron™ Pedestal Extruder, Model Apex 1.5, and the pump110is sized at 1.5 HP for a 1.5-inch (3.81 cm) line.

In some embodiments, the polymeric feed material can consist of virgin crosslinked polyethylene. In some embodiments, the crosslinked polyethylene feed material is a blend of low density crosslinked polyethylene and high density crosslinked polyethylene.

Tests have concluded that crosslinked polyethylene can be used to produce various waxes when run through the depolymerization process. It is believed the virgin crosslinked polyethylene that was used in these tests was synthesised using a radical initiator (likely a peroxide).

Low density crosslinked polyethylene and high density crosslinked polyethylene are similar to their non-crosslinked precursors at least in the sense that they have a melting point from ˜105 degrees Celsius to 130 degrees Celsius; and there are limits to what end products can be reached depending on which feed material is used. For example, starting with low density crosslinked polyethylene as a feed material does not allow one to produce Al2O3.

One unique outcome of using crosslinked polyethylene as a feed stock is the increase in a noticeable odor in the final product. It was discovered that these odors arise from a family of aromatics created during the crosslinking process, further the belief that the polyethylene was synthesized using a radical initiator.

Several techniques have been found to help reduce, if not eliminate, the odor from the end product. These techniques, in order of their success, include aspiration and degassing with nitrogen (N2).

It was also concluded that low density crosslinked polyethylene can successfully be combined with high density polyethylene as a feedstock to create wax. It should be noted that these blends do, at least initially, contain an odor.

A pressure transducer PT01monitors for plugs within the extruder (as well as prior to PT02, see below) for maintaining system pressure below a maximum pressure (for example, maximum design pressure of the reactor100). Likewise, pressure transducer PT02monitors for plugs elsewhere within the system. Over-pressure is controlled by feedback from the pressure transmitted by PT01and PT02to a controller which transmits a command signal to shut down the extruder106and the pump110, and thereby prevent the pressure from further increasing.

In some embodiments, reactor100is first reactor100, and the reaction zone of the first reactor is a first reaction zone, and the flowing of the molten polymeric material, through the first reaction zone, is suspended (such as, for example, discontinued). After the suspending, the first reactor is modified.

When “P” is equal to one, the modifying includes connecting a total number of “R” of the “N−1” reactor modules, which have not been used in the assembly of the first reactor, to the first reactor, wherein “R” is a whole number from 1 to “N−1”, such that another reactor is created and includes a total number of “R+1” reactor modules that are connected to one another, in series, and such that the another reactor includes a second reaction zone including “R+1” module reaction zones. The another reactor is configured to conduct a flow of molten polymeric material, such that flowing of the reactor-disposed molten polymeric material through the second reaction zone effects generation of another depolymerization product material and its discharge from the another reactor;

When “P” is a whole number that is greater than or equal to two, but less than or equal to “N−1”, the modifying includes either one of:(a) removing a total number of “Q” of the “P” reactor modules from the first reactor, wherein “Q” is a whole number from one to “P−1”, such that another reactor is created and includes a total number of “P−Q” reactor modules that are connected to one another, in series, and such that the another reactor includes a second reaction zone including “P−Q” module reaction zones, wherein the another reactor is configured to conduct a flow of molten polymeric material, such that flowing of the reactor-disposed molten polymeric material through the second reaction zone effects of generation of another depolymerization product material and its discharge from the another reactor, or(b) connecting a total number of “R” of the “N−P” reactor modules, which have not been used in the assembly of the first reactor, to the first reactor, wherein “R” is a whole number from 1 to “N−P”, such that another reactor is created and includes a total number of “P+R” reactor modules that are connected to one another, in series, and also includes a second reaction zone including “P+R” module reaction zones, wherein the another reactor is configured to conduct a flow of molten polymeric material, such that flowing of the reactor-disposed molten polymeric material through the second reaction zone effects generation of another depolymerization product material and its discharge from the another reactor;

When “P” is equal to “N”, the modifying includes removing a total number of “Q” of the “P” reactor modules from the first reactor, wherein “Q” is a whole number from one to “P−1”, such that another reactor is created and includes a total number of “P−Q” reactor modules that are connected to one another, in series, and such that the another reactor includes a second reaction zone, including “P−Q” module reaction zones. The another reactor is configured to conduct a flow of molten polymeric material, such that flowing of the reactor-disposed molten polymeric material through the second reaction zone effects generation of another depolymerization product material and its discharge from the another reactor.

In some embodiments, after the modifying of the first reactor to effect creation of another reactor (by either one of connecting/adding or removing reactor modules), another reactor is used to generate a second depolymerization product material. In this respect, polymeric material is heated to generate a molten polymeric material, and the molten polymeric material is flowed through the second reaction zone, to effect generation of a second depolymerization product material. The second depolymerization product material is then collected from the reactor.

In some embodiments, the same catalyst material is disposed within each one of the “N” reactor modules.

In some embodiments, the reaction zone of each one of the “N” reactor modules is the same or substantially the same.

Referring toFIGS.6-14, in at least some embodiments, each reactor modules200includes pipe spool201. In some embodiments, reactor module200includes pipe spool201with opposite first and second ends (only one is shown in the illustrated embodiment), with flanges230at each end, for facilitating connection with other reactor module(s)200.

Reactor module200includes inlet202A at a first end of the spool, outlet202B at the opposite second end of the spool, and fluid passage206extending between inlet202A and outlet202B. Fluid passage206includes a catalyst material-containing space that is disposed within the reactor-disposed molten polymeric material-permeable container, with catalyst material204disposed within catalyst material-containing space216. Catalyst material-containing space216defines module reaction zone205of reactor module200.

Reactor module200is configured for receiving reactor-disposed molten polymeric material by inlet202A and conducting the received molten polymeric material through fluid passage206such that it is brought into contact with catalyst material204. This causes at least partial depolymerization of at least a fraction of the molten polymeric material such that molten product material, including depolymerization reaction products (and, in some embodiments, unreacted molten polymeric material and/or intermediate reaction products (such as partially depolymerized material)), are produced. Reactor module200then discharges the molten product material from outlet202B.

Relatively unobstructed fluid passage portion218of fluid passage206extends between inlet202A and outlet202B and is disposed in fluid communication with catalyst material-containing space216via a wire screen. Wire screen208is disposed within pipe spool201, segmenting fluid passage206into relatively unobstructed fluid passage portion218and catalyst material comprising space. Wire screen208contains catalyst material204within catalyst material-containing space216, and thereby defines molten polymeric material-permeable container203.

Wire screen208is disposed in spaced apart relationship relative to fluid passage-defining internal wall210of pipe spool201and extends longitudinally through the length of pipe spool201. The space between wire screen208and internal wall210defines relatively unobstructed fluid passage portion218of fluid passage206. Fluid communication between fluid passage portion218and catalyst material-containing space216is made possible via spaces within wire screen208. Thus wire screen208permits permeation of the molten polymeric material from relatively unobstructed fluid passage portion218to catalyst material-containing space216(and thereby facilitates contact of the molten polymeric material with catalyst material204within the reaction zone), and also from catalyst material-containing space216to relatively unobstructed fluid passage portion218(for discharging the molten product material including the depolymerization reaction products and unreacted molten polymeric material and/or intermediate reaction products), while preventing, or substantially preventing, egress of catalyst material204from catalyst material-containing space216to relatively unobstructed fluid passage portion218.

In some embodiments, pipe spool201is cylindrical, and wire screen208is also cylindrical and is nested within pipe spool201, such that relatively unobstructed fluid passage portion218is defined within the annular space between internal wall210of pipe spool201and wire screen208, and catalyst material-containing space216is disposed within wire screen208. In these embodiments, the catalyst material-containing fluid passage portion216is radially spaced outwardly, relative to relatively unobstructed fluid passage portion218, from the axis of pipe spool201.

In some embodiments, spacer tube214extends through the space defined by wire screen208and encourages flow of the reactor-disposed molten polymeric material to the portions of pipe spool201that are in close disposition to a heat transfer element (see below). This embodiment helps maintain the reactor-disposed molten polymeric material at a desired temperature. Also, by occupying space, spacer tube214effectively reduces the volume of module reaction zone205, thereby increasing the velocity of the flowing reactor-disposed molten polymeric material.

In some embodiments, spacer tube214extends longitudinally through the length of pipe spool201. In some embodiments, catalyst material-containing space216is defined within the annular space between spacer tube214and wire screen208.

Reactor-disposed molten polymeric material is received by inlet202A at the first end of pipe spool201, and, while traversing pipe spool201, via fluid passage206, to the opposite end, is conductible, across wire screen208, between relatively unobstructed fluid passage portion218and catalyst material-containing space216. This produces a molten product material, including depolymerization reaction products (and, in some embodiments, unreacted molten polymeric material and/or intermediate reaction products), that is discharged via outlet202B at the opposite second end of pipe spool201. While being conducted through catalyst-material containing space216, the reactor-disposed molten polymeric material is brought into contact with catalyst material204causing at least partial depolymerization of at least a fraction of the reactor-disposed molten polymeric material.

Referring toFIGS.6and14, in some embodiments, baffles222,223are disposed within relatively unobstructed fluid passage portion218. In some embodiments, baffle222is welded to end cap212(a) and is in the form of a resilient wire that is wrapped about wire screen208. In some embodiments, baffle223is in the form of a resilient wire that is pressed through the space between pipe spool201and wire screen208, welded to end cap212(a), and biased against interior wall210of spool201.

Baffles222,223encourage mixing of the flowing reactor-disposed molten polymeric material and promote uniform distribution of heat and mitigate charring of the reactor-disposed molten polymeric material, which could result in depositing of solid organic material on the structures defining fluid passage206and contribute to fouling. Baffles222,223also encourages flow of reactor-disposed molten polymeric material from the relatively unobstructed fluid passage portion218towards catalyst material-containing space216and increase contact between the reactor-disposed molten polymeric material and catalyst material204.

Referring toFIGS.9-13, end cap assembly211is provided, and mounted within the interior space of pipe spool201. End cap assembly211includes rigid end caps212(a) and212(b), wire screen208, and spacer tube214. End cap212(a) is disposed proximate to one end of pipe spool201, and end cap212(b) is disposed proximate to an opposite end of pipe spool201. In some embodiments, end caps212(a), and212(b) are also permeable to flow of reactor-disposed molten polymeric material.

Wire screen208is disposed between end caps212(a) and212(b), and its axial positioning within pipe spool201, relative to pipe spool201, is determined by end caps212(a) and212(b). One end of wire screen208is welded to end cap212(a), while the opposite end of wire screen208is disposed within a recess formed in end cap212(b), such that catalyst material-containing space216, within which catalyst material204is contained, is defined within the space bounded by wire screen208and end caps212(a) and212(b).

Spacer tube214is disposed between end caps212(a) and212(b). One end of spacer tube214is welded to end cap212(a), while the opposite end of spacer tube214is disposed within a recess formed in end cap212(b).

Referring toFIGS.11and12, end cap212(a) is welded to pipe spool201, for effecting connection of end cap assembly211to pipe spool201. In this respect, end cap212(a) includes a plurality of rigid end cap spacers2120(a) to (c), projecting radially outwardly from end cap integrator2122(to which wire screen208and spacer tube214are welded). End cap spacers2120(a) to (c) are received within corresponding recess provided within end cap integrator2122. End cap spacers2120(a) to (c) are spaced-apart from one another such that fluid communication allowed between reactor modules200that are connected to one another, and, specifically between reaction zones of connected reactor modules200. End cap spacers2120(a) to (c) can be welded to the interior of pipe spool201, thereby determining the position of end cap212(a) relative to pipe spool201, and also determining the axial position of spacer tube214relative to pipe spool201(which is welded to end cap212(a)).

Referring toFIGS.9to11, positioning of end cap212(b) relative to pipe spool201is determined by disposing of end cap212(b) in contact engagement with pipe spool201, spacer tube214and by an adjacent piping structure, such as welded end cap212(a) of another reactor module200, or a conduit. Each one of spacer tube214, and the adjacent piping structure are relatively rigid structures, such that the substantially fixed axial positioning of each one of spacer tube214and the adjacent piping structure, relative to pipe spool201, determines the axial positioning of end cap212(b) relative to pipe spool201. When reactor module200is assembled, end cap212(b) is pressed between spacer tube214and the adjacent piping structure (in the embodiment illustrated inFIG.8, the adjacent piping structure is end cap212(b) of another reactor module200), such that axial positioning of end cap212(b), relative to pipe spool201(and, therefore, end cap212(a)) is determined by spacer tube214and the adjacent piping structure.

End cap212(b) also includes rigid end cap spacers2124(a) to (c), disposed within corresponding recesses within an end cap integrator2126. The end cap integrator includes recesses which receive spacer tube214and wire screen208. End cap spacers2124(a) to (c) are disposed in contact engagement with the interior wall of pipe spool201. End cap spacers2124(a) to (c) project radially outwardly from end cap integrator2126. End cap spacers2124(a) to (c) are spaced apart from one another such that fluid can flow between reactor modules200that are connected to one another, and, specifically between reaction zones of connected reactor modules200. When disposed in contact engagement with the interior wall of pipe spool201, and in co-operation with spacer tube214and the adjacent piping structure, end cap spacers2124(a) to (c) function to substantially fix vertical positioning of end cap212(b) relative to pipe spool201.

By configuring end cap212(b) such that end cap212(b) is removable from end cap assembly211, repairs and maintenance within the reaction zone including the replacement of catalyst material204, is made easier.

Heaters220are disposed in heat transfer communication with fluid passage206so as to effect heating of the reactor-disposed molten polymeric material that is flowing through fluid passage206. Maintaining the flowing reactor-disposed molten polymeric material at a sufficient temperature leads to at least partial depolymerization. In some embodiments, heaters220include electric heating bands that are mounted to the external wall of pipe spool201and are configured to supply heat to fluid passage206by heat transfer through pipe spool201.

Referring toFIGS.16to18, in some embodiments, reactor includes inlet reactor module300, outlet reactor module400, and, optionally, one or more intermediate reactor modules500.

In some embodiments, inlet reactor module300includes pipe spool301, having opposite ends, with respective flange330A,330B provided at each one of the opposite ends, for facilitating connection with an outlet reactor module400, and, in some embodiments, an intermediate reactor module500.

Inlet reactor module300includes inlet302A at a first end of pipe spool301, outlet302B at the opposite second end of the spool, and fluid passage306extending between inlet302A and outlet302B. Fluid passage306includes catalyst material-containing space316that is disposed within reactor-disposed molten polymeric material-permeable container303, with catalyst material304disposed within catalyst material-containing space316. Catalyst material-containing space316defines module reaction zone305of reactor module300.

Inlet reactor module300is configured for receiving reactor-disposed molten polymeric material by inlet302A, conducting the received molten polymeric material through fluid passage306, and while such conducting is being effected, contacting the molten polymeric material being conducted with catalyst material304such that at least partial depolymerization of at least a fraction of the molten polymeric material is effected and such that a molten product material is produced that includes depolymerization reaction products (and, in some embodiments, includes unreacted molten polymeric material and intermediate reaction products, or both), and discharging the molten product material from outlet302B.

Fluid passage306includes relatively unobstructed fluid passage portion318and catalyst material-containing fluid passage portion315that includes catalyst material-containing space316. Relatively unobstructed fluid passage portion318extends form inlet302A, and is disposed in fluid communication with catalyst material-containing fluid passage portion315via wire screen308. Catalyst material-containing fluid passage portion315extends into outlet302B.

Wire screen308is disposed within pipe spool301, segmenting fluid passage306into relatively unobstructed fluid passage portion318and catalyst material-containing fluid passage portion316. Wire screen308is mounted at one end to, and extends from, the first end of pipe spool301and, in some embodiments, is mounted at an opposite end to spacer tube314(see below). Wire screen308contains catalyst material304within catalyst material-containing space316. Wire screen308is disposed in spaced apart relationship relative to fluid passage-defining internal wall310of pipe spool301, and extends longitudinally through a portion of pipe spool301. The space between wire screen308and internal wall310defines a portion of catalyst material-containing fluid passage portion315and extends longitudinally across a portion of pipe spool301to define a portion of catalyst material-containing space316. In this respect, the relatively unobstructed fluid passage portion318extends longitudinally along, or proximate to, an axis of pipe spool301.

In some embodiments, wire screen308is cylindrical in shape, and is nested within pipe spool301. In this respect, in some embodiments, catalyst material-containing fluid passage portion315is radially spaced outwardly, relative to relatively unobstructed fluid passage portion318, from the axis of pipe spool301.

Fluid communication between relatively unobstructed fluid passage portion318and catalyst material-containing fluid passage portion315is effected via spaces within the wire screen. In this respect, wire screen308is configured to permit permeation of the molten polymeric material from relatively unobstructed fluid passage portion318to catalyst material-containing fluid passage portion315(and thereby facilitate contact of the molten polymeric material with catalyst material304within the reaction zone), while preventing, or substantially preventing, egress of catalyst material304from catalyst material-containing space316to relatively unobstructed fluid passage portion318.

In some embodiments, at a downstream end of relatively unobstructed fluid passage portion318, an end wall is tapered to encourage flow of the molten polymeric material towards the catalyst-material containing space via wire screen308, thereby mitigating pooling of the molten polymeric material.

The catalyst material-containing fluid passage portion315extends into an annular space defined between spacer tube314, that is mounted within pipe spool301, and internal wall310of pipe spool301. By occupying this space, spacer tube314encourages flow of the reactor-disposed molten polymeric material within catalyst material-containing fluid passage portion315to the portions of pipe spool301that are in close disposition to a heat transfer element, and thereby maintaining the reactor-disposed molten polymeric material at a desired temperature. Also, by occupying space, spacer tube314effectively reduces the volume of module reaction zone305, thereby increasing the velocity of the flowing reactor-disposed molten polymeric material.

Reactor-disposed molten polymeric material is received within relatively unobstructed fluid passage portion318via inlet302A at the first end of pipe spool301, and conducted across wire screen308to catalyst material-containing space316of catalyst material-containing fluid passage portion315(see directional arrows340). While being conducted through catalyst material-containing fluid passage portion315(see directional arrows342), the molten polymeric material becomes contacted with catalyst material304such that depolymerization reaction products are produced, and a molten product material, that includes depolymerization reaction products that are produced within catalyst material-containing fluid passage portion315(and, in some embodiments, also includes unreacted molten polymeric material and intermediate reaction products, or both), is then subsequently discharged via outlet302B at the second opposite end of pipe spool301.

In some embodiments, outlet reactor module400includes pipe spool401, having opposite ends, with flanges provided at each one of the opposite ends, for facilitating connection with an inlet reactor module300, and, in some embodiments, one an intermediate reactor module disposed between inlet and outlet reactor modules300,400.

The outlet reactor module400includes an inlet402A at a first end of pipe spool401, an outlet402B at the opposite second end of the spool, and fluid passage406extending between inlet402A and outlet402B. Fluid passage406includes catalyst material-containing space416that is disposed within reactor-disposed molten polymeric material-permeable container403, with catalyst material404disposed within catalyst material-containing space416. Catalyst material-containing space416defines module reaction zone405of reactor module400.

The outlet reactor module400is configured for receiving reactor-disposed molten polymeric material by inlet402A, conducting the received molten polymeric material through fluid passage406, and while such conducting is being effected, contacting the molten polymeric material being conducted with catalyst material404such that at least partial depolymerization of at least a fraction of the molten polymeric material is effected and such that a molten product material is produced that includes depolymerization reaction products (and, in some embodiments, also includes unreacted molten polymeric material and intermediate reaction products, or both), and discharging the molten product material from outlet402B.

The fluid passage406includes catalyst material-containing fluid passage portion415, that includes catalyst material-containing space416, and a relatively unobstructed fluid passage portion418. Catalyst material-containing fluid passage portion415extends from inlet402A, and is disposed in fluid communication with the relatively unobstructed fluid passage portion418via wire screen408. The relatively unobstructed fluid passage portion418extends into outlet402B.

In some embodiments, spacer tube414is mounted within pipe spool401at a first end of pipe spool401, such that the space (such as, for example, the annulus) between pipe spool401and spacer tube414defines a portion of catalyst material-containing fluid passage portion415that is extending from inlet402A. By occupying this space, spacer tube414encourages flow of the reactor-disposed molten polymeric material within the catalyst material-containing fluid passage portion415to the portions of pipe spool401that are in close disposition to a heat transfer element (see below), and thereby maintaining the reactor-disposed molten polymeric material at a desired temperature. Also, by occupying space, spacer tube414effectively reduces the volume of module reaction zone405, thereby increasing the velocity of the flowing reactor-disposed molten polymeric material.

The catalyst material-containing fluid passage portion415extends into an annular space defined between internal wall410of pipe spool401and wire screen408. Wire screen408is disposed within pipe spool401, segmenting fluid passage406into catalyst material-containing fluid passage portion415and the relatively unobstructed fluid passage portion418. Wire screen408is mounted at one end to, and extends from, the second end of pipe spool401and is mounted at an opposite end to spacer tube414. Wire screen408contains catalyst material404within catalyst material-containing space416. Wire screen408is disposed in spaced apart relationship relative to fluid passage-defining internal wall410of pipe spool401, and extends longitudinally through a portion of pipe spool401. The space between wire screen408and internal wall410defines a portion of catalyst material-containing fluid passage portion415. and extends longitudinally across a portion of pipe spool401. In this respect, the relatively unobstructed fluid passage portion418extends longitudinally along, or proximate to, an axis of pipe spool401, and into outlet402B.

In some embodiments, wire screen408is cylindrical in shape, and is nested within pipe spool401. In this respect, in some embodiments, catalyst material-containing fluid passage portion415is radially spaced outwardly, relative to the relatively unobstructed fluid passage portion418, from the axis of pipe spool401.

Fluid communication between catalyst material-containing fluid passage portion415and the relatively unobstructed fluid passage portion418is effected via spaces within the wire screen. In this respect, wire screen408is configured to permit permeation of the molten polymeric material from the relatively unobstructed fluid passage portion418to catalyst material-containing fluid passage portion415(and thereby facilitate the contacting of the molten polymeric material with catalyst material404within the reaction zone), while preventing, or substantially preventing, egress of catalyst material404from catalyst material-containing space416to the relatively unobstructed fluid passage portion418.

Reactor-disposed molten polymeric material is received within catalyst material-containing fluid passage portion415via inlet402A at the first end of pipe spool401(such as, for example, from outlet302B of reactor module300, or such as, for example, from the outlet of intermediate reactor module500, see below), conducted through catalyst material-containing fluid passage portion415(see directional arrows440). While being conducted through catalyst material-containing fluid passage portion415, the molten polymeric material becomes contacted with catalyst material404such that a molten product material, that includes depolymerization reaction products (and, in some embodiments, also includes unreacted molten polymeric material and intermediate reaction products, or both), is produced. The molten product material, including the depolymerization products that are produced within catalyst material-containing fluid passage portion415, are conducted across wire screen408to relatively unobstructed fluid passage portion418(see directional arrows442) and subsequently discharged via outlet402B at the second opposite end of pipe spool401.

In some embodiments, the reactor includes one or more intermediate reactor modules500disposed between inlet and outlet reactor modules300,400.

In some embodiments, intermediate reactor module500includes pipe spool501, having opposite ends, with flanges530A,530B provided at each one of the opposite ends, for facilitating connection with a reactor module. The flange at a first end is provided for facilitating connection with either one of inlet reactor module300, or another intermediate reactor module500. The flange at the second end is provided for facilitating connect with either one of outlet reactor module400or another intermediate reactor module500.

Pipe spool501includes inlet502A at a first end of pipe spool501, outlet502B at an opposite second end of pipe spool501, and fluid passage506extending between inlet502A and outlet502B. Fluid passage506includes catalyst material-containing space516. Catalyst material-containing space516is disposed within reactor-disposed molten polymeric material-permeable container503, and catalyst material504is disposed within catalyst material-containing space516. Catalyst material-containing space516defines module reaction zone505of reactor module500.

Intermediate reactor module500is configured for receiving reactor-disposed molten polymeric material by inlet502A, conducting the received molten polymeric material through fluid passage506, and while such conducting is being effected, contacting the molten polymeric material being conducted with catalyst material504such that at least partial depolymerization of at least a fraction of the molten polymeric material is effected and such that a molten product material is produced that includes depolymerization reaction products (and, in some embodiments, also includes unreacted molten polymeric material and intermediate reaction products, or both), and discharging the molten product material from outlet502B.

Fluid passage506includes catalyst material-containing fluid passage portion515that includes catalyst material-containing space516.

In some embodiments, spacer tube514is mounted within pipe spool501at a first end of pipe spool501, such that the space between pipe spool501and spacer tube514defines catalyst material-containing space516. By occupying this space, the spacer tube encourages flow of the reactor-disposed molten polymeric material within catalyst material-containing fluid passage portion515to the portions of pipe spool501that are in close disposition to a heat transfer element (see below), and thereby maintaining the reactor-disposed molten polymeric material at a desired temperature. Also, by occupying space, spacer tube514effectively reduces the volume of module reaction zone505, thereby increasing the velocity of the flowing reactor-disposed molten polymeric material.

FIG.19shows a cross-section side-elevation view of catalytic reactor700awith removable static mixer710configured to be heated via thermal fluid and/or molten salt. Static mixer710provides greater mixing in catalytic reactor700aand can result in the need of a lower operating temperature. In some embodiments, static mixer710is removable which allows for easier cleaning and maintenance of reactor700a. Removable static mixer710also allows for repurposing of reactor segments. For example, jacketed reactors can be converted to pre-heat or cooling segments.

Thermal fluid and/or molten salt can be heated, among other ways, by natural gas, electric, waste process heats, and coal. In some embodiments, thermal fluid and/or molten salt reduces the costs of having to use electric.

The tubular configuration of catalytic reactor700aoffers several advantages in addition to those already mentioned above. In particular, use of tubular reactors connected in series allows for dependable and consistent parameters, which allows for a consistent product. Specifically, a consistent flow through the tubular sections creates a much more predictable and narrow range of end products than using a continuous stirred reactor, as the surface area of the catalyst and heat input is maximized. One advantage over continuous stirred reactors is elimination or at least reduction of shortcutting, flow in tubular section hypothetically moves as a plug. Each hypothetical plug spends the same amount of time in the reactor. Tubular catalytic reactors can be operated vertically, horizontally, or at any angle in between. Tubular catalytic reactors (the reactor sections) and the corresponding pre-heat sections and cooling sections (seeFIGS.28-30) can be a universal size (or one of several standard sizes). This allows not only for a consistent flow of the material, but also allows for tubular elements to be designed to be interchangeable among the various section and easily added, removed, cleaned, and repaired. In at least some embodiments the inner face of the tubular sections is made of 304 or 316 steel.

The thermal fluid and/or molten salt can enter jacket720via inlet/outlets730. In some embodiments, catalytic reactor700ais configured to be mounted with a thermocouple/pressure transducer (not shown) and includes relevant notches735. Notches735are used to bring the thermocouple/pressure transducer in physical contact with the fluid. In some embodiments, the thermocouple/pressure transducer will be mounted in a well, which reduces the material in-between the fluid and the sensor.

In some embodiments, catalytic reactor700aincludes removable screen760that can hold the catalyst. Removable screen760can be easily replaced overcoming disadvantages associated with packed bed reactors challenging maintenance requirements and resulting downtime. In some embodiments, the standardization of removable screen760results in a consistent product leaving each section and/or allows for standardization across multiple reactors.

In other or the same embodiments, catalytic reactor700acan include removable adaptor740with cut-outs for static mixer supports. Static mixer supports reduce the force on static mixers710allowing for more forceful/rapid removal. The cut-outs of adaptor740improve the seal between the adapter and the screens. Catalytic reactor700acan include flanges750on one or both ends to connect catalytic reactor700ato other reactors, extruders or the like.

FIG.20is a cross-section side-elevation view of catalytic reactor700bwith removable static mixer710configured to use electric heating. In some embodiments, electric heating is preferred over using thermal oil/molten salt as it can be more convenient, requires reduced ancillary equipment such as boilers, heating vessels, high temperature pumps, valves, and fittings, and is easier to operate. Further, in some embodiments, reduce of electric heating reduces the overall footprint of the system. In some embodiments, catalytic reactor700bis configured to be mounted with a thermocouple/pressure transducer (not shown) and includes relevant notches735.

In some embodiments, catalytic reactor700bincludes removable screen760that can hold the catalyst. In other or the same embodiments, catalytic reactor700bcan include removable adaptor740with cut-outs for static mixer supports. Catalytic reactor700bcan include flanges750on one or both ends to connect catalytic reactor700bto other reactors, extruders or the like.

FIG.21is a cross-section side-elevation view of catalytic reactor700cwith removable annular insert712configured to be heated via thermal fluid and/or molten salt. Annular insert712can create an annular flow which can lead to improved heat transfer, increases in superficial velocity and can be easier to maintain than an empty reactor.

The thermal fluid and/or molten salt can enter jacket720via inlet/outlets730. In some embodiments, catalytic reactor700cis configured to be mounted with a thermocouple/pressure transducer (not shown) and includes relevant notches735.

In some embodiments, catalytic reactor700cincludes removable screen760that can hold the catalyst. In other or the same embodiments, catalytic reactor700ccan include removable adaptor740with cut-outs for removable annular and screen support. Catalytic reactor700ccan include flanges750on one or both ends to connect catalytic reactor700cto other reactors, extruders or the like.

FIG.22is a cross-section side-elevation view of catalytic reactor700dwith removable annular712insert configured to use electric heating. In some embodiments, catalytic reactor700dis configured to be mounted with a thermocouple/pressure transducer (not shown) and includes relevant notches735.

In some embodiments, catalytic reactor700dincludes removable screen760that can hold the catalyst. In other or the same embodiments, catalytic reactor700dcan include removable adaptor740with cut-outs for removable annular and screen support. Catalytic reactor700dcan include flanges750on one or both ends to connect catalytic reactor700dto other reactors, extruders or the like.

FIG.23is a cross-section side-elevation view of a catalytic reactor700ewith empty internals configured to be heated via thermal fluid and/or molten salt. Having a reactor with empty internals can increases the residence time of a given material spends in reactor700ewhich reduces the number of reactors needed to make a specific product along with the volume of the catalyst that can be used. Reactors with empty internals can also be more economic to manufacture when compared to reactors with static mixers. The thermal fluid and/or molten salt can enter jacket720via inlet/outlets730. In some embodiments, catalytic reactor700eis configured to be mounted with a thermocouple/pressure transducer (not shown) and includes relevant notches735.

In some embodiments, catalytic reactor700eincludes removable screen760that can hold the catalyst. In other or the same embodiments, catalytic reactor700ecan include removable adaptor740with cut-outs for removable screen support. Catalytic reactor700ecan include flanges750on one or both ends to connect catalytic reactor700eto other reactors, extruders or the like.

FIG.24is a cross-section side-elevation view of catalytic700freactor with empty internals configured to use electric heating. In some embodiments, catalytic reactor700fis configured to be mounted with a thermocouple/pressure transducer (not shown) and includes relevant notches735.

In some embodiments, catalytic reactor700fincludes removable screen760that can hold the catalyst. In other or the same embodiments, catalytic reactor700fcan include removable adaptor740with cut-outs for screen support. Catalytic reactor700fcan include flanges750on one or both ends to connect catalytic reactor700fto other reactors, extruders or the like.

FIG.25is a cross-section front-elevation view of a group of catalytic reactors700like the one shown inFIG.19arranged in parallel. Parallel arrangements such as that shown inFIG.25allow for the total rate of production to be more readily increase/decreased as desired with minimal changes to the overall arrangement and allow multiple different levels of depolymerization to occur at once.

Housing800allows catalytic reactors700to be bathed in thermal oil/molten salt which is often more effective than electric. The thermal oil/molten salt is held in chamber780. In some embodiments flange770allows for multiple housings to be joined together.

FIG.26is a cross-section side-elevation view of the parallel catalytic reactor arrangement ofFIG.25show in a horizontal configuration. Parallel arrangement allows for higher flowrate units to be built with smaller pressure drops that could cause issues as compared to a single tube arrangements. Horizontal configurations are often more convenient to operate/maintain.

FIG.27is a cross-section side-elevation view of the parallel catalytic reactor arrangement ofFIG.25show in a vertical configuration. Vertical configurations can reduce stratification of liquid/gas products and can eliminate or at least reduce a need for static mixers.

FIG.28is a cross-section side-elevation view of vertical helical internal catalytic reactor arrangement900A with two reactors700alike the one shown inFIG.19connected in series. Horizontal helical mixer pre-heat section820is connected to one reactor700a. Helical mixers can lead to better mixing by avoiding stagnancies and hot spots.

Helical mixer cooling segment830is shown connected to the other reactor700aat a 45-degree decline. The decline allows for the product to flow via gravity, while the 45-degree angle allows for sufficient contact between the cooling medium and the product.

In the embodiments shown, vertical helical internal catalytic reactor arrangement900A has several inlet/outlets to allow for the use of thermal fluid/molten salt mixtures however other warming techniques (such as, but not limited to, electric heating) can be used as well.

FIG.29is a cross-section side-elevation view of a vertical annular catalytic reactor arrangement900B with two reactors700clike the one shown inFIG.21connected in series.

FIG.30is a cross-section side-elevation view of a vertical catalytic reactor arrangement900C with two empty reactors700flike the one shown inFIG.23connected in series.

FIG.31is a perspective view of horizontal reactor configuration910with internal helical reactor700bconfigured to use electric heaters870like the one shown inFIG.20. InFIG.31the reactor shell has been removed from part of horizontal reactor configuration910to aid in visualizing the location of internal helical reactor700b.

While particular elements, embodiments and applications of the present invention have been shown and described, it will be understood, that the invention is not limited thereto since modifications can be made without departing from the scope of the present disclosure, particularly in light of the foregoing teachings. For example, the numerous embodiments demonstrate that different combinations of components are possible within the scope of the claimed invention, and these described embodiments are demonstrative and other combinations of the same or similar components can be employed to achieve substantially the same result in substantially the same way. Further, all of the claims are hereby incorporated by reference into the description of the preferred embodiments.