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 affecting 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 in FIG. 2, “P” is equal to five, such that reactor 700 includes five reactor modules 102(a) through 102(e), the reaction zone consisting of five module reaction zones 104(a) through 104(e), each one respective to a one of the five reactor modules. “P” can be more or less than five.

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. In FIG. 2 the heating is produced by a combination of extruder 106 and separate heater 108. 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.

In FIG. 2, pump 110 receives molten polymeric material from extruder 106 and affects transport (or flowing) of the molten polymeric material through heater 108, and then through the first reaction zone. In some embodiments, extruder 106 is configured to impart sufficient force to affect the desired flow of the generated molten polymeric material, such that pump 110 is optional.

In some embodiments, the molten polymeric material is derived from a polymeric material feed that is heated to affect 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 can include film bags, milk jugs or pouches, totes, pails, caps, agricultural film, and packaging material. 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 (i.e. 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 then collected.

In some embodiments, the catalyst is prepared by binding a ferrous-copper complex to an alumina support and reacting it with an inorganic acid to obtain the catalyst material. Other suitable catalyst materials include zeolite, mesoporous silica, alumina, H-mordenite and various combinations. 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 affected 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 affecting 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, oils, fuels, and C1-C4 gases, 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 medium-density polyethylene (MDPE)), virgin polypropylene, or post-consumer, or post-industrial, polyethylene or polypropylene (exemplary sources including bags, jugs, bottles, pails, and/or other items containing PE or PP), and it is desirable to convert such polymeric feed material into a higher melting point wax (having a melting point from 106° C. to 135° C.), a medium melting point wax (having melting point from 86° C. to 105° C.), and a lower melting point wax (having a melting point from 65° C. to 85° C.), an even lower melting point wax (having a melting point from 40° C. to 65° C.), 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° C. and 450° C. 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 affected 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, extruder 106 is a 10 HP, 1.5-inch (3.81 cm) Cincinnati Milacron Pedestal Extruder, Model Apex 1.5, and the pump 110 is sized at 1.5 HP for a 1.5 inch (3.81 cm) line.

A pressure transducer PT01 monitors for plugs within the extruder (as well as prior to PT02, see below) for maintaining system pressure below a maximum pressure (namely, the maximum design pressure of the reactor 100). Likewise, pressure transducer PT02 monitors for plugs elsewhere within the system. Over-pressure is controlled by feedback from the pressure transmitted by PT01 and PT02 to a controller which transmits a command signal to shut down the extruder 106 and the pump 110, and thereby prevent the pressure from further increasing.

In some embodiments, reactor 100 is first reactor 100, 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).

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, in which “R” is a whole number from 1 to “N−1”, such that another reactor is added 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. Then 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 affects 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 added 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 affects 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 employed 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 added 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 affects 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 added 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 affects generation of another depolymerization product material and its discharge from the another reactor.

In some embodiments, after the modifying of the first reactor to affect creation of another reactor (by either one of connecting/adding or removing reactor modules), another reactor is employed 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 affect 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.

FIG. 3 shows a cross-section side-elevation view of catalytic reactor 700 with removable static mixer 710 configured to be heated via thermal fluid and/or molten salt. Static mixer 710 provides greater mixing in catalytic reactor 700 and can result in the need of a lower operating temperature. In other embodiments, catalytic reactor 700 can include an annular insert. In other embodiments, catalytic reactor 700 can have empty internals. In certain embodiments, catalytic reactor 700 employs electric heating.

The tubular configuration of catalytic reactor 700 offers several advantages in addition to those already mentioned. 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 produces a more predictable and narrow range of end products than would be produced 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 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 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 sections 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 jacket 720 via inlet/outlets 730. In some embodiments, catalytic reactor 700a is configured to be mounted with a thermocouple/pressure transducer (not shown) and includes relevant notches 735. Notches 735 are employed to bring the thermocouple/pressure transducer in physical contact with the fluid. In some embodiments, the thermocouple/pressure transducer can be mounted in a well, which reduces the material in-between the fluid and the sensor.

In some embodiments, catalytic reactor 700 includes removable screen 760 that can hold the catalyst. Removable screen 760 can be easily replaced overcoming disadvantages associated with packed bed reactors, including thermal gradients and challenging maintenance requirements and resulting downtime. In some embodiments, the standardization of removable screen 760 results in a consistent product leaving each section and/or allows for standardization across multiple reactors.

In other or the same embodiments, catalytic reactor 700a can include removable adaptor 740 with cut-outs for static mixer supports. Static mixer supports reduce the force on static mixers 710 allowing for more forceful/rapid removal. The cut-outs of adaptor 740 improve the seal between the adapter and the screens. Catalytic reactor 700a can include flanges 750 on one or both ends to connect catalytic reactor 700a to other reactors, extruders or the like.

FIG. 4 is a cross-section front-elevation view of a group of catalytic reactors 700 like the one shown in FIG. 3 arranged in parallel. Parallel arrangements allow 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.

Housing 800 allows catalytic reactors 700 to be bathed in thermal oil/molten salt which is often more effective than electric. The thermal oil/molten salt is contained in chamber 780. In some embodiments, flange 770 allows for multiple housings to be joined together.

FIG. 5 is a cross-section side-elevation view of the parallel catalytic reactor arrangement of FIG. 3 shown 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 arrangement. Horizontal configurations are often more convenient to operate/maintain. The parallel catalytic reactor arrangement can also be oriented in a vertical configuration.

FIG. 6 is a cross-section side-elevation view of vertical helical internal catalytic reactor arrangement 500 with two reactors 700 like the one shown in FIG. 3 connected in series. Horizontal helical mixer pre-heat section 820 is connected to one reactor 700. Helical mixers can lead to better mixing by avoiding stagnancies and hot spots.

Helical mixer cooling segment 830 is shown connected to the other reactor 700 at a 45° decline. The decline allows for the product to flow via gravity, while the 45° angle allows for sufficient contact between the cooling medium and the product.

In the embodiments shown, vertical helical internal catalytic reactor arrangement 500 has several inlets/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 employed as well. In other embodiments, annular catalytic reactor and/or reactors with empty internal volumes can be employed. In the same or other embodiments, electric heating can be employed to heat reactor 700.

FIG. 7 is a perspective view of horizontal reactor configuration 910 with internal helical reactor 700 configured to employ electric heaters 870 like the one shown in FIG. 3. In FIG. 7 the reactor shell has been removed from part of horizontal reactor configuration 910 to aid in visualizing the location of internal helical reactor 700

Specific Examples of Plastics Modified by Synthetic Waxes

TABLE 1

Materials Used

Ingredient
Grade/Type
Source

Control Plastic
Clean PCR Pellet
KW Plastics

(HDPE milk jugs)

Wax A
AW125
Applicant

Wax B
AW105LV
Applicant

Example 1

In a first illustrative embodiment of the present process, wax was produced from the depolymerization of post-consumer polyethylene. Various percentages of the wax (by weight of the wax) were mixed with a recycled plastic (HDPE clear milk jugs). The melt flow rate of the resulting products was increased, leading to greater output.

In the above embodiment, blending/extrusion was conducted on a TEC 1.5″ single screw extruder. Melt flow index testing was conducted on an Arburg Injection Machine with a 3 MM plaque mold. Barrel diameter was 9.5320 mm, die length was 8.015 mm, and orifice diameter was 2.09 mm. A six-minute preheat was utilized. Melt Flow index testing was conducted per ASTM D1238: Standard Test Method For Flow Rates Of Thermoplastics at 190° C. and 2.16 Kg Load.

The preparation and testing of the blends in Example 1-3 were as follows.

- (1) The materials were blended with waxes to create the following mixtures
  - Control (100% Control Plastic)
  - Mixture A (92% Control Plastic with 8% Wax A)
  - Mixture B (92% Control Plastic with 8% Wax B)
  - Mixture C (98% Control Plastic with 2% Wax A)
- (2) The mixtures were extruded into pellets (screen pack start 40/100/40)
- (3) The pressure, temperatures, and throughput (time to weight) were recorded.
- (4) Amps were recorded every 10 minutes.
- (5) The final extruded mixtures were tested for melt flow.

Graph 900 in FIG. 8 illustrates the decrease in amount of pressure required to push the wax-modified polymeric material 920 through an extruder when compared to a non-modified polymeric material