Patent Description:
The invention relates to a method and system for continuously treating polystyrene material.

Polystyrene is among the fastest growing solid waste. Further polystyrene is non-biodegradable, leading to its accumulation in nature. The vast majority of polystyrene waste in general is either land-filled or burnt. The former leads to the loss of material and waste of land, while the latter results in emission of green-house-gases. Only a small proportion of polystyrene waste is currently being recycled (at a rate less than <NUM>% in North America and Europe) as secondary polymers, which have poor quality and give low financial returns.

It would be advantageous to employ readily available polystyrene waste as the feedstock for conversion into higher value specialty chemicals, but not limited to, styrenic polymers, macromonomers, solvents, and polymer precursors. Employing this solid waste to produce useful specialty chemicals would address growing disposal problems.

It would also be advantageous to have a relatively inexpensive process for producing specialty chemicals, such as macromonomers, solvents, and polymer precursors. Such a process would ideally employ a readily available inexpensive feedstock and use an inexpensive process. Waste polystyrene has been used in known processes for the manufacture of solvent and polymer precursors.

In recent times, there have been considerable efforts to convert polystyrene wastes into useful products such as organic solvents, and back to the monomer styrene, often through thermal degradation. Existing conversion processes are not efficient and can release green-house gases and/or volatile aromatic compounds into the environment. Further, current techniques can be sensitive to the quality and quantity of polystyrene feed which can have an impact on the end product quality. This is especially troublesome as polystyrene sources can vary in their consistency due to the varying plastic grades and applications.

It is desirable to provide a reactor system which is sufficiently versatile so as to be able to generate different grades of products without requiring substantial changes to operating conditions or throughput.

<NPL>, discloses a thermomechanical depolymerisation of polystyrene.

In a first aspect of the present invention, there is provided a method for continuously treating polystyrene material as claimed in claim <NUM>. In a second aspect of the present invention, there is provided a system for continuously treating polystyrene material as claimed in claim <NUM>.

The process of generating reaction products from polystyrene material may comprise:.

A method for continuously treating polystyrene material can include selecting a solid polystyrene material; heating the solid polystyrene material in an extruder to create a molten polystyrene material; filtering the molten polystyrene material; placing the molten polystyrene material through a chemical depolymerization process in a reactor to create a depolymerized polystyrene material; cooling the depolymerized polystyrene material; and purifying the depolymerized polystyrene material. In some arrangements the method can also include using the gas and oil created during the purification of the depolymerized polystyrene material to run part of the method.

In some arrangements, the polystyrene material can be dissolved in certain solvents to create products with various properties. In some arrangements, organic solvents, such as toluene, xylenes, cymenes, or terpinenes, are used to dissolve the polystyrene before it undergoes depolymerisation within the reactor bed/vessel. In certain arrangements, the desired product can be isolated via separation or extraction and the solvent can be recycled.

In at least some arrangements, solvents are not required.

In some arrangements, the filtering involves a screen changer or a filter bed. In certain arrangements, the solid polystyrene material is a recycled polystyrene.

In some arrangements the depolymerization process utilizes a catalyst such as [Fe-Cu-Mo-P]/Al<NUM>O<NUM>. In other or the same arrangements, the depolymerization process utilizes a second reactor. In certain arrangements the reactors are connected in series, stacked vertically, and/or stacked horizontally.

In some arrangements, the reactor(s) include(s) static mixer(s).

In some arrangements, the purification utilizes one of flash separation, absorbent beds, clay polishing or film evaporators.

A system for continuously treating recycled polystyrene material can include a hopper configured to feed the recycled polystyrene material into the system; an extruder configured to turn the recycled polystyrene material in a molten material; a first reactor configured to depolymerize the molten material; a heat exchanger configured to cool the depolymerized molten material; a second reactor; and/or a separate heater configured to aid the extruder.

In some arrangements, the recycled polystyrene is a pellet made from recycled polystyrene foam and/or rigid polystyrene.

In certain arrangements, the extruder utilizes thermal fluid(s) and/or electric heater(s). In some arrangements, the reactors are connected in series and/or utilize a catalyst such as [Fe-Cu-Mo-P]/Al<NUM>O<NUM>, Zeolite or alumina supported systems, and/or thermal depolymerization. In some arrangements, the catalyst can be contained in a permeable container.

In certain arrangements, the reactor(s) contains spacer tube(s), static mixer(s) and/or annular insert(s). In certain arrangements, the static mixer(s) and/or annular insert(s) are removable.

A process of treating polystyrene material, such as waste polystyrene material, within a reactor of a system is described below. Suitable waste polystyrene material includes, but it not limited to, expanded, and/or extruded polystyrene foam, and/or rigid products. Virgin polystyrene can also be used.

<FIG> illustrates Process <NUM> for treating polystyrene material. Process <NUM> can be run in batches, but more preferably is a continuous process. The parameters of Process <NUM>, including but not limited to temperature, flow rate of polystyrene, monomers/copolymers grafted during the reaction and/or modification stages, and total number of pre-heat, reaction, or cooling segments, can be modified to create end products of varying molecular weights, such as macromonomers, or polyaromatic products. 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 Stage <NUM>, polystyrene feed is sorted/selected and/or prepared for treatment. In some arrangements, the feed can contain up to <NUM>% polyolefins, PET, EVA, EVOH, and lower levels of undesirable additives or polymers, such as nylon, rubber, PVC, ash, filler, pigments, stabilizers, grit or other unknown particles.

In some arrangements, the polystyrene feed has an average molecular weight between <NUM> amu and <NUM> amu. In some of these arrangements, the polystyrene feed has an average molecular weight between <NUM> amu and <NUM> amu.

In some arrangements, the material selected in Material Selection Stage <NUM> comprises recycled polystyrene. In other or the same arrangements, the material selected in Material Selection Stage <NUM> comprises recycled polystyrene and/or virgin polystyrene.

In some arrangements, the material selected in Material Selection Stage <NUM> is can be heated in Heat Stage <NUM> an extruder and undergoes Pre-Filtration Process <NUM>. In some arrangements, the extruder is used to increase the temperature and/or pressure of the incoming polystyrene and is used to control the flow rates of the polystyrene. In some arrangements, the extruder is complimented by or replaced entirely by pump/heater exchanger combination.

Pre-Filtration Process <NUM> can 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 Stage <NUM> which brings the filtered material to a higher temperature before it enters Reaction Stage <NUM>. Pre-Heat Stage <NUM> can employ, among other devices and techniques, static and/or dynamic mixers and heat exchangers such as internal fins and heat pipes.

Material in Reaction Stage <NUM> undergoes 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 arrangements, the catalyst used is a zeolite or alumina supported system or a combination of the two. In some arrangements, the catalyst is [Fe-Cu-Mo-P]/Al<NUM>O<NUM> prepared by binding a ferrous-copper complex to an alumina or zeolite support and reacting it with an acid comprising metals and non-metals.

Reaction Stage <NUM> can employ a variety of techniques/devices including, among other things, fixed beds, horizontal and/or vertical reactors, and/or static mixers. In some arrangements, Reaction Stage <NUM> employs multiple reactors and/or reactors divided into multiple sections.

Reaction Stage <NUM> can also involve grafting various monomers and/or copolymers such as, but not limited to, acids, alcohols, acetates, and alkenes such as hexene onto the depolymerized product.

After Reaction Stage <NUM>, the depolymerized material enters optional Modification Stage <NUM>. As in Reaction Stage <NUM>, Modification Stage <NUM> involves grafting various monomers and/or copolymers such as, but not limited to, acids, alcohols, acetates, and alkenes such as hexene onto the depolymerized product.

Cooling Stage <NUM> can employ heat exchangers, along with other techniques/ devices to bring the depolymerized material down to a workable temperature before it enters optional Purification Stage <NUM>.

In some arrangements, cleaning/purification of the material via such methods such as nitrogen stripping occurs before Cooling Stage <NUM>.

Optional Purification Stage <NUM> involves the refinement and/or decontamination of the depolymerized material. Techniques/devices that can used in Purification Stage <NUM> include, 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 arrangements, a thin or wiped film evaporator is used to remove gas, oil, and/or grease from the depolymerized material. In some arrangements, the oil, gas and grease can in turn be burned to help run various Stages of Process <NUM>.

Process <NUM> ends at Finished Product Stage <NUM> in which the initial starting material selected in Material Selection Stage <NUM> has been turned into a lower molecular weight polymer. In at least some arrangements, the lower molecular weight polymer at Finished Product Stage <NUM> is commercially viable and does not need additional processing and/or refining. In other arrangements, the plastic created at Finished Product Stage, needs additional modifications.

In Material Selection Stage <NUM>, polystyrene feed is sorted/selected and/or prepared for treatment. In some arrangements the feed can contain up to <NUM>% polyolefins, PET, EVA, EVOH, and lower levels of undesirable additives or polymers, such as nylon, rubber, PVC, ash, filler, pigments, stabilizers, grit or other unknown particles.

In some arrangements the material selected in Material Selection Stage <NUM> comprises recycled polystyrene. In other or the same arrangements, the material selected in Material Selection Stage <NUM> comprises recycled polystyrene and/or virgin polystyrene.

In Solvent Addition Stage <NUM>, solvents, such as toluene, xylenes, cymenes, or terpinenes, are used to dissolve the polystyrene before it undergoes depolymerisation within the reactor bed/vessels. In certain arrangements, the desired product can be isolated via separation or extraction and the solvent can be recycled.

In some arrangements, the material selected in Material Selection Stage <NUM> is heated in an extruder during Heat Stage <NUM> and undergoes Pre-Filtration Process <NUM>. In some arrangements the extruder is used to increase the temperature and/or pressure of the incoming polystyrene and is used to control the flow rates of the polystyrene. In some arrangements the extruder is complimented by or replaced entirely by pump/heater exchanger combination.

Material in Reaction Stage <NUM> undergoes 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 arrangements the catalyst used is a zeolite or alumina supported system or a combination of the two. In some arrangements the catalyst is [Fe-Cu-Mo-P]/Al<NUM>O<NUM> prepared by binding a ferrous-copper complex to an alumina or zeolite support and reacting it with an acid comprising metals and non-metals.

Purification Stage <NUM> involves the refinement and/or decontamination of the depolymerized material. Techniques/devices that can used in Purification Stage <NUM> include, 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 arrangements, a thin or wiped film evaporator is used to remove gas, oil, and/or grease from the depolymerized material. In some arrangements, the oil, gas and grease can in turn be burned to help run various Stages of Process <NUM>. In certain arrangements, the desired product can be isolated via separation or extraction and the solvent can be recycled.

Process <NUM> ends at Finished Product Stage <NUM> in which the initial starting material selected in Material Selection Stage <NUM> has been turned into a lower molecular weight polymer. In at least some arrangements, the lower molecular weight polymer at Finished Product Stage <NUM> is commercially viable and does not need additional processing and/or refining. In other arrangements, the plastic created at Finished Product Stage <NUM>, needs additional modifications.

In some arrangements, the finished product has an average molecular weight between <NUM> amu and <NUM> amu, a melt flow index equal to/greater than. <NUM> at <NUM> w/ <NUM>, and/or a glass transition temperature between <NUM> and <NUM>. In some of these arrangements, the finished product has an average molecular weight between <NUM> amu and <NUM> amu, a melt flow index greater than <NUM> at <NUM> w/ <NUM>, and/or a glass transition temperature between <NUM> and <NUM>.

Referring to <FIG>, system <NUM> includes reactor <NUM> with five reactor modules 102a through 102e. Reactor modules <NUM> can vary in dimensions and/or be connected in parallel and/or series. In other arrangements various numbers of reactor modules <NUM> can be used. For example, <FIG> shows system <NUM> with four reactor modules, 102a through 102d. Similarly, <FIG> shows system <NUM> with six reactor modules 102a through 102f. The ability to customize the number of reactor modules <NUM> allows for greater control of the amount of depolymerization.

System <NUM> can include hopper <NUM> for receiving polystyrene material and/or directing the supply of the polystyrene material to optional extruder <NUM>. In some arrangements, extruder <NUM> processes the polystyrene material received from hopper <NUM> by generating a molten polystyrene material. The temperature of the polystyrene material being processed by extruder <NUM> is controlled by modulating the level of shear and/or the heat being applied to the polystyrene material by extruder heater(s) <NUM>. 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) <NUM>.

In some arrangements, pressure sensor <NUM> measures the pressure of the molten polystyrene material being discharged from extruder <NUM>, to prevent, or at least reduce, risk of pressure spikes. The discharged molten polystyrene material is pressurized by pump <NUM> to affect its flow through heating zone <NUM> and reactor <NUM>. While flowing through reactor <NUM>, the reactor-disposed molten polystyrene material contacts a catalyst material which impacts rate and mechanism for depolymerization.

In at least some arrangements, the system operates at a moderate temperature and/or around atmospheric pressure.

In some arrangements, various monomers and/or copolymers such as, but not limited to, acids, alcohols, acetates, and alkenes such as hexene can be grafted onto the depolymerized product in reactor <NUM>.

Pressure sensor(s) <NUM> and/or temperature sensor(s) <NUM> can also be used to measure temperature and/or pressure, respectively, of the reactor-disposed molten polystyrene material as it flows through reactor <NUM>. Pressure sensor(s) <NUM> can monitor for plugs before and/or after each reaction zones. Pressure sensor(s) <NUM> can also maintain system pressure below a maximum pressure such as the maximum pressure of reactor <NUM> is designed for. Over-pressure can be controlled by feedback from pressure transmitter <NUM> to a controller which transmits a command signal to shut down extruder <NUM> and pump <NUM>, and thereby prevent the pressure from further increasing.

In cases when shutdown of extruder <NUM> does not relieve the over pressure, dump valve <NUM> can be opened into a container to remove material from system <NUM> and avoid an over pressure situation. During shutdown dump valve <NUM> can be opened to purge system <NUM> with nitrogen to remove leftover material to avoid clogs and degraded material during the next start up.

System <NUM> can also include a pressure relief device, such as a relief valve or a rupture disk, disposed at the outlet of extruder <NUM>, to relieve pressure from system <NUM>, in case of over-pressure.

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

The temperature is controlled by a controller (not shown), which modulates the heat being applied by heaters <NUM> disposed in heat transfer communication with the reaction zones 102a through 102e of reactor <NUM>, in response to the temperatures sensed by temperature sensor(s) <NUM>.

Flow control can also be provided for within system <NUM>. In some arrangements, system <NUM> includes valve <NUM>, disposed at the discharge of extruder <NUM>, for controlling flow from extruder <NUM> to other unit operations within system <NUM>. Valve <NUM> facilitates recirculation. Valve <NUM> enables collection of product.

During operation, valve <NUM> can be closed in order to recirculate the molten polystyrene material and increase the temperature of the molten polystyrene material to a desired temperature. In this case valve <NUM> would be open, valve <NUM> would be closed, extruder <NUM> would be "OFF", and pump <NUM> would be recirculating.

Generated molten product material <NUM> is cooled within heat exchanger <NUM>, 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 valve <NUM> would be open), for reprocessing and/or for energy conservation.

In some arrangements, system <NUM> is configured for purging by nitrogen to mitigate oxidation of the molten product material and the creation of explosive conditions.

In another arrangement illustrated in <FIG>, System <NUM> includes reactor <NUM>. Reactor <NUM> has two reactor modules, namely, inlet reactor module <NUM> and outlet reactor module <NUM>. System <NUM> also includes extruder <NUM> for receiving polystyrene material. Extruder <NUM> processes polystyrene material by generating a molten polystyrene material. The temperature of the polystyrene material being processed through reactor <NUM> is controlled by modulating the heat being applied to the polystyrene material by process heaters <NUM>. Temperature sensors <NUM> are provided to measure the temperature of the molten material within reactor <NUM>. Temperature controllers <NUM> are provided to monitor and control the temperature of process heaters <NUM>. Flange heaters <NUM> are also provided to mitigate heat losses through the flanged connections.

The discharged molten polystyrene feed material is conducted through heater <NUM> and reactor <NUM>, in series. While flowing through reactor <NUM>, the reactor-disposed molten polystyrene material is contacted with the catalyst material to affect the depolymerization.

The generated molten product material is cooled within heat exchanger <NUM>, which can be, among other things, water jacketed, air cooled, or cooled by a refrigerant. In some arrangements the waste heat from the cooling molten product can be used to run other processes.

A cooling section heater <NUM> can be provided to melt wax that solidifies in cooling section.

In both System <NUM> and System <NUM> reactors <NUM> and <NUM> include one or more reactor modules. Each reactor modules includes a respective module reaction zone in which the reactor-disposed molten polystyrene material is brought into contact with a catalyst material over a module-defined residence time, thereby causing depolymerization of the flowing reactor-disposed molten polystyrene material. In some of these arrangements, the module-defined residence time of at least two of the reactor modules is the same or substantially the same. In some of these arrangements, as between at least some of the plurality of module-defined residence times are different. In some of these arrangements the catalyst material of at least two of the reactor modules are the same or substantially the same. In some of these arrangements the catalyst material of at least two of the reactor modules are different.

In some arrangements, each of the reactor modules includes a reactor-disposed molten polystyrene material-permeable container that contains the catalyst material. The container is configured to receive molten polystyrene material such that at least partial depolymerization of at least a fraction of the received molten polystyrene 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 polystyrene material and intermediate reaction products, or both). Flowing of the reactor-disposed molten polystyrene material through the reactor-disposed molten polystyrene material-permeable container effects contacting between the catalyst material and the reactor-disposed molten polystyrene material, for effecting the at least partial depolymerization of at least a fraction of the reactor-disposed molten polystyrene material. In this respect, the flowing reactor-disposed molten polystyrene 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 polystyrene material.

In both System <NUM> and System <NUM> a 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 polystyrene material through the respective module reaction zone, such that, flowing of the reactor-disposed molten polystyrene material through the respective module reaction zone brings it into contact with the catalyst material, thereby causing at least partial depolymerization of at least a fraction of the flowing reactor-disposed molten polystyrene 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 polystyrene 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 polystyrene 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 arrangement illustrated in <FIG>, "P" is equal to five, such that reactor <NUM> includes five reactor modules 102a through 102e, the reaction zone consisting of five module reaction zones 104a through 104e, each one respective to a one of the five reactor modules. It is understood that "P" can be more or less than five.

In another arrangement illustrated in <FIG>, "P" is equal to two, such that reactor <NUM> includes two reactor modules: inlet reactor module <NUM> and outlet reactor module <NUM>.

Molten polystyrene material, for supplying to the constructed reactor, is generated by heating a polystyrene material. In some arrangements, the heating is caused by a heater. In <FIG> the heating is caused by a combination of extruder <NUM> and separate heater <NUM>. In <FIG> the heating is caused by a combination of extruder <NUM> and separate heater <NUM>. In such arrangements, the generated molten polystyrene material is forced from the extruder, flowed through a separate heater, and then supplied to the module reaction zone. In some arrangements, the extruders are configured to supply sufficient heat to the polystyrene material such that the generated molten polystyrene material is at a sufficiently high temperature for supply to the reactor, and a separate heater is not required.

In <FIG>, pump <NUM> receives molten polystyrene material from extruder <NUM> and effects transport (or "flowing") of the molten polystyrene material through heater <NUM>, and then through the first reaction zone. In some arrangements, extruder <NUM> is configured to impart sufficient force to affect the desired flow of the generated molten polystyrene material, such that pump <NUM> is optional. <FIG> shows an example without a pump.

In some arrangements, the molten polystyrene material is derived from a polystyrene material feed that is heated to effected generation of the molten polystyrene material. In some arrangements, the polystyrene material feed includes primary virgin granules of polystyrene. The virgin granules can include various molecular weights and melt flows.

In some arrangements, the polystyrene material feed includes waste polystyrene material feed. Suitable waste polystyrene material feeds include mixed polystyrene waste such as expanded or extruded foam, and ridged products. e.g. foam food containers, or packaging products. The mixed polystyrene waste can include various melt flows and molecular weights. In some arrangements, the waste polystyrene material feed includes up to <NUM>% of material that is other than polystyrene material, based on the total weight of the waste polystyrene material feed.

The molten polystyrene material is supplied to the reactor, and the molten polystyrene material is flowed through the first reaction zone (i.e. including the "P" reaction zones) as reactor-disposed molten polystyrene material. The flowing of the reactor-disposed molten polystyrene 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 arrangements, also includes unreacted molten polystyrene material and/or intermediate reaction products). The molten product material is collected.

In some arrangements, the catalyst material includes [Fe-Cu-MoP]/Al<NUM>O<NUM>. 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 produces lower molecular weight polymer through thermal degradation.

The generated molten product material is discharged from and collected/recovered from the reactor. In some arrangements, the collection of the molten product material is effected by discharging a flow of the molten product material from the reactor. In those arrangements 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 arrangements, the generated depolymerization product material includes solvent or monomer (Styrene), polyaromatic solvents, oils and/or greases, and/or lower molecular weight functionalized polymer i.e. increased olefin content. 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 arrangements, the polymeric feed material is one of, or a combination of, virgin polystyrene and/or any one of, or combinations of post-industrial and/or post-consumer waste polystyrene. It is desirable to convert such polymeric feed material into a lower molecular weight polymers, with increased melt flow and olefin content using an arrangement of the system disclosed herein. In each case, the conversion is effected by heating the polystyrene feed material so as to generate molten polystyrene material, and then contacting the molten polystyrene material with the catalyst material within a reaction zone disposed at a temperature of between <NUM> degrees Celsius and <NUM> degrees Celsius, preferable <NUM>-<NUM> degrees Celsius. The molecular weight, polydispersity, glass transition, melt flow, and olefin content that is generated depends on the residence time of the molten polystyrene 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 <NUM>-<NUM> minutes, preferably <NUM>-<NUM> minutes, with more than one reactor modules attached in series. In some of these arrangements, the supply and heating of the polystyrene 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 arrangements, extruder <NUM> is a <NUM> HP, <NUM>-inch (<NUM>) Cincinnati Milacron Pedestal Extruder, Model Apex <NUM>, and the pump <NUM> is sized at <NUM> HP for a <NUM>-inch (<NUM>) line.

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

In some arrangements, reactor <NUM> is first reactor <NUM>, and the reaction zone of the first reactor is a first reaction zone, and the flowing of the molten polystyrene 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-<NUM>" 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 <NUM> to "N-<NUM>", such that another reactor is created and includes a total number of "R+<NUM>" reactor modules that are connected to one another, in series, and such that the another reactor includes a second reaction zone including "R+<NUM>" module reaction zones. Another reactor is configured to conduct a flow of molten polystyrene material, such that flowing of the reactor-disposed molten polystyrene material through the second reaction zone effects generation of another depolymerization product material and its discharge from another reactor;.

When "P" is a whole number that is greater than or equal to two, but less than or equal to "N-<NUM>", the modifying includes either one of:.

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-<NUM>", 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 another reactor includes a second reaction zone, including "P-Q" module reaction zones. Another reactor is configured to conduct a flow of molten polystyrene material, such that flowing of the reactor-disposed molten polystyrene material through the second reaction zone effects generation of another depolymerization product material and its discharge from another reactor.

In some arrangements, 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, polystyrene material is heated to generate a molten polystyrene material, and the molten polystyrene 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 arrangements, the same catalyst material is disposed within each one of the "N" reactor modules.

In some arrangements, the reaction zone of each one of the "N" reactor modules is the same or substantially the same.

Referring to <FIG>, in at least some arrangements, each reactor modules <NUM> includes pipe spool <NUM>. In some arrangements, reactor module <NUM> includes pipe spool <NUM> with opposite first and second ends (only one is shown in the illustrated arrangement), with flanges <NUM> at each end, for facilitating connection with other reactor module(s) <NUM>.

Reactor module <NUM> includes inlet 202A at a first end of the spool, outlet 202B at the opposite second end of the spool, and fluid passage <NUM> extending between inlet 202A and outlet 202B. Fluid passage <NUM> includes a catalyst material-containing space that is disposed within the reactor-disposed molten polystyrene material-permeable container, with catalyst material <NUM> disposed within catalyst material-containing space <NUM>. Catalyst material-containing space <NUM> defines module reaction zone <NUM> of reactor module <NUM>.

Reactor module <NUM> is configured for receiving reactor-disposed molten polystyrene material by inlet 202A and conducting the received molten polystyrene material through fluid passage <NUM> such that it is brought into contact with catalyst material <NUM>. This causes at least partial depolymerization of at least a fraction of the molten polystyrene material such that molten product material, including depolymerization reaction products (and, in some arrangements, unreacted molten polystyrene material and/or intermediate reaction products (such as partially depolymerized material)), are produced. Reactor module <NUM> then discharges the molten product material from outlet 202B.

In some arrangements, various monomers and/or copolymers such as, but not limited to, acids, alcohols, acetates, and alkenes such as hexene can be grafted onto the depolymerized product in Reactor module <NUM>. Grating can take place, among other places, in the reactor, in line with the stream after cooling, and/or in a separate vessel.

Relatively unobstructed fluid passage portion <NUM> of fluid passage <NUM> extends between inlet 202A and outlet 202B, and is disposed in fluid communication with catalyst material-containing space <NUM> via a wire screen. Wire screen <NUM> is disposed within pipe spool <NUM>, segmenting fluid passage <NUM> into relatively unobstructed fluid passage portion <NUM> and catalyst material comprising space <NUM>. Wire screen <NUM> contains catalyst material <NUM> within catalyst material-containing space <NUM>, and thereby defines molten polystyrene material-permeable container <NUM>.

Wire screen <NUM> is disposed in spaced apart relationship relative to fluid passage-defining internal wall <NUM> of pipe spool <NUM>, and extends longitudinally through the length of pipe spool <NUM>. The space between wire screen <NUM> and internal wall <NUM> defines relatively unobstructed fluid passage portion <NUM> of fluid passage <NUM>. Fluid communication between fluid passage portion <NUM> and catalyst material-containing space <NUM> is made possible via spaces within wire screen <NUM>. Thus wire screen <NUM> permits permeation of the molten polystyrene material from relatively unobstructed fluid passage portion <NUM> to catalyst material-containing space <NUM> (and thereby facilitates contact of the molten polystyrene material with catalyst material <NUM> within the reaction zone), and also from catalyst material-containing space <NUM> to relatively unobstructed fluid passage portion <NUM> (for discharging the molten product material including the depolymerization reaction products and unreacted molten polystyrene material and/or intermediate reaction products), while preventing, or substantially preventing, egress of catalyst material <NUM> from catalyst material-containing space <NUM> to relatively unobstructed fluid passage portion <NUM>.

In some arrangements, pipe spool <NUM> is cylindrical, and wire screen <NUM> is also cylindrical and is nested within pipe spool <NUM>, such that relatively unobstructed fluid passage portion <NUM> is defined within the annular space between internal wall <NUM> of pipe spool <NUM> and wire screen <NUM>, and catalyst material-containing space <NUM> is disposed within wire screen <NUM>. In these arrangements, the catalyst material-containing fluid passage portion <NUM> is radially spaced outwardly, relative to relatively unobstructed fluid passage portion <NUM>, from the axis of pipe spool <NUM>.

In some arrangements, spacer tube <NUM> extends through the space defined by wire screen <NUM> and encourages flow of the reactor-disposed molten polystyrene material to the portions of pipe spool <NUM> that are in close disposition to a heat transfer element (see below). This arrangement helps maintain the reactor-disposed molten polystyrene material at a desired temperature. Also, by occupying space, spacer tube <NUM> effectively reduces the volume of module reaction zone <NUM>, thereby increasing the velocity of the flowing reactor-disposed molten polystyrene material.

In some arrangements, spacer tube <NUM> extends longitudinally through the length of pipe spool <NUM>. In some arrangements, catalyst material-containing space <NUM> is defined within the annular space between spacer tube <NUM> and wire screen <NUM>.

Reactor-disposed molten polystyrene material is received by inlet 202A at the first end of pipe spool <NUM>, and, while traversing pipe spool <NUM>, via fluid passage <NUM>, to the opposite end, is conductible, across wire screen <NUM>, between relatively unobstructed fluid passage portion <NUM> and catalyst material-containing space <NUM>. This produces a molten product material, including depolymerization reaction products (and, in some arrangements, unreacted molten polystyrene material and/or intermediate reaction products), that is discharged via outlet 202B at the opposite second end of pipe spool <NUM>. While being conducted through catalyst-material containing space <NUM>, the reactor-disposed molten polystyrene material is brought into contact with catalyst material <NUM> causing at least partial depolymerization of at least a fraction of the reactor-disposed molten polystyrene material.

Referring to <FIG> and <FIG>, in some arrangements, baffles <NUM>, <NUM> are disposed within relatively unobstructed fluid passage portion <NUM>. In some arrangements, baffle <NUM> is welded to end cap 212a and is in the form of a resilient wire that is wrapped about wire screen <NUM>. In some arrangements, baffle <NUM> is in the form of a resilient wire that is pressed through the space between pipe spool <NUM> and wire screen <NUM>, welded to end cap 212a, and biased against interior wall <NUM> of spool <NUM>.

Baffles <NUM>, <NUM> encourage mixing of the flowing reactor-disposed molten polystyrene material and promote uniform distribution of heat and mitigate charring of the reactor-disposed molten polystyrene material, which could result in depositing of solid organic material on the structures defining fluid passage <NUM> and contribute to fouling. Baffles <NUM>, <NUM> also encourages flow of reactor-disposed molten polystyrene material from the relatively unobstructed fluid passage portion <NUM> towards catalyst material-containing space <NUM> and increase contact between the reactor-disposed molten polystyrene material and catalyst material <NUM>.

Referring to <FIG>, end cap assembly <NUM> is provided, and mounted within the interior space of pipe spool <NUM>. End cap assembly <NUM> includes rigid end caps 212a and 212b, wire screen <NUM>, and spacer tube <NUM>. End cap 212a is disposed proximate to one end of pipe spool <NUM>, and end cap 212b is disposed proximate to an opposite end of pipe spool <NUM>. In some arrangements, end caps 212a and 212b are also permeable to flow of reactor-disposed molten polystyrene material.

Wire screen <NUM> is disposed between end caps 212a and 212b, and its axial positioning within pipe spool <NUM>, relative to pipe spool <NUM>, is determined by end caps 212a and 212b. One end of wire screen <NUM> is welded to end cap 212a, while the opposite end of wire screen <NUM> is disposed within a recess formed in end cap 212b, such that catalyst material-containing space <NUM>, within which catalyst material <NUM> is contained, is defined within the space bounded by wire screen <NUM> and end caps 212a and 212b.

Spacer tube <NUM> is disposed between end caps 212a and 212b. One end of spacer tube <NUM> is welded to end cap 212a, while the opposite end of spacer tube <NUM> is disposed within a recess formed in end cap 212b.

Referring to <FIG>, end cap 212a is welded to pipe spool <NUM>, for effecting connection of end cap assembly <NUM> to pipe spool <NUM>. In this respect, end cap 212a includes a plurality of rigid end cap spacers 2120a to 2120c, projecting radially outwardly from end cap integrator <NUM> (to which wire screen <NUM> and spacer tube <NUM> are welded). End cap spacers 2120a to c are received within corresponding recess provided within end cap integrator <NUM>. End cap spacers 2120a to 2120c are spaced-apart from one another such that fluid communication allowed between reactor modules <NUM> that are connected to one another, and, specifically between reaction zones of connected reactor modules <NUM>. End cap spacers 2120a to 2120c can be welded to the interior of pipe spool <NUM>, thereby determining the position of end cap 212a relative to pipe spool <NUM>, and also determining the axial position of spacer tube <NUM> relative to pipe spool <NUM> (which is welded to end cap 212a).

Referring to <FIG>, positioning of end cap 212b relative to pipe spool <NUM> is determined by disposing of end cap 212b in contact engagement with pipe spool <NUM>, spacer tube <NUM> and by an adjacent piping structure, such as welded end cap 212a of another reactor module <NUM>, or a conduit. Each one of spacer tube <NUM>, and the adjacent piping structure are relatively rigid structures, such that the substantially fixed axial positioning of each one of spacer tube <NUM> and the adjacent piping structure, relative to pipe spool <NUM>, determines the axial positioning of end cap 212b relative to pipe spool <NUM>. When reactor module <NUM> is assembled, end cap 212b is pressed between spacer tube <NUM> and the adjacent piping structure (in the arrangement illustrated in <FIG>, the adjacent piping structure is end cap 212b of another reactor module <NUM>), such that axial positioning of end cap 212b, relative to pipe spool <NUM> (and, therefore, end cap 212a is determined by spacer tube <NUM> and the adjacent piping structure.

End cap 212b also includes rigid end cap spacers 2124a to 2124c, disposed within corresponding recesses within an end cap integrator <NUM>. The end cap integrator includes recesses which receive spacer tube <NUM> and wire screen <NUM>. End cap spacers 2124a to 2124c are disposed in contact engagement with the interior wall of pipe spool <NUM>. End cap spacers 2124a to 2124c project radially outwardly from end cap integrator <NUM>. End cap spacers 2124a to 2124c are spaced apart from one another such that fluid can flow between reactor modules <NUM> that are connected to one another, and, specifically between reaction zones of connected reactor modules <NUM>. When disposed in contact engagement with the interior wall of pipe spool <NUM>, and in co-operation with spacer tube <NUM> and the adjacent piping structure, end cap spacers 2124a to 2124c function to substantially fix vertical positioning of end cap 212b relative to pipe spool <NUM>.

By configuring end cap 212b such that end cap 212b is removable from end cap assembly <NUM>, repairs and maintenance within the reaction zone including the replacement of catalyst material <NUM>, is made easier.

Heaters <NUM> are disposed in heat transfer communication with fluid passage <NUM> so as to effect heating of the reactor-disposed molten polystyrene material that is flowing through fluid passage <NUM>. Maintaining the flowing reactor-disposed molten polystyrene material at a sufficient temperature leads to at least partial depolymerization. In some arrangements, heaters <NUM> include electric heating bands that are mounted to the external wall of pipe spool <NUM> and are configured to supply heat to fluid passage <NUM> by heat transfer through pipe spool <NUM>.

Referring to <FIG>, in some arrangements, reactor includes inlet reactor module <NUM>, outlet reactor module <NUM>, and, optionally, one or more intermediate reactor modules <NUM>.

In some arrangements, inlet reactor module <NUM> includes pipe spool <NUM>, having opposite ends, with respective flange 330A, 330B provided at each one of the opposite ends, for facilitating connection with an outlet reactor module <NUM>, and, in some arrangements, an intermediate reactor module <NUM>.

Inlet reactor module <NUM> includes inlet 302A at a first end of pipe spool <NUM>, outlet 302B at the opposite second end of the spool, and fluid passage <NUM> extending between inlet 302A and outlet 302B. Fluid passage <NUM> includes catalyst material-containing space <NUM> that is disposed within reactor-disposed molten polystyrene material-permeable container <NUM>, with catalyst material <NUM> disposed within catalyst material-containing space <NUM>. Catalyst material-containing space <NUM> defines module reaction zone <NUM> of reactor module <NUM>.

Inlet reactor module <NUM> is configured for receiving reactor-disposed molten polystyrene material by inlet 302A, conducting the received molten polystyrene material through fluid passage <NUM>, and while such conducting is being effected, contacting the molten polystyrene material being conducted with catalyst material <NUM> such that at least partial depolymerization of at least a fraction of the molten polystyrene material is effected and such that a molten product material is produced that includes depolymerization reaction products (and, in some arrangements, includes unreacted molten polystyrene material and intermediate reaction products, or both), and discharging the molten product material from outlet 302B.

In some arrangements, various monomers and/or copolymers such as, but not limited to, acids, alcohols, acetates, and alkenes such as hexene can be grafted onto the depolymerized product in inlet reactor module <NUM>.

Fluid passage <NUM> includes relatively unobstructed fluid passage portion <NUM> and catalyst material-containing fluid passage portion <NUM> that includes catalyst material-containing space <NUM>. Relatively unobstructed fluid passage portion <NUM> extends form inlet 302A, and is disposed in fluid communication with catalyst material-containing fluid passage portion <NUM> via wire screen <NUM>. Catalyst material-containing fluid passage portion <NUM> extends into outlet 302B.

Wire screen <NUM> is disposed within pipe spool <NUM>, segmenting fluid passage <NUM> into relatively unobstructed fluid passage portion <NUM> and catalyst material-containing fluid passage portion <NUM>. Wire screen <NUM> is mounted at one end to, and extends from, the first end of pipe spool <NUM> and, in some arrangements, is mounted at an opposite end to spacer tube <NUM> (see below). Wire screen <NUM> contains catalyst material <NUM> within catalyst material-containing space <NUM>. Wire screen <NUM> is disposed in spaced apart relationship relative to fluid passage-defining internal wall <NUM> of pipe spool <NUM>, and extends longitudinally through a portion of pipe spool <NUM>. The space between wire screen <NUM> and internal wall <NUM> defines a portion of catalyst material-containing fluid passage portion <NUM> and extends longitudinally across a portion of pipe spool <NUM> to define a portion of catalyst material-containing space <NUM>. In this respect, the relatively unobstructed fluid passage portion <NUM> extends longitudinally along, or proximate to, an axis of pipe spool <NUM>.

In some arrangements, wire screen <NUM> is cylindrical in shape, and is nested within pipe spool <NUM>. In this respect, in some arrangements, catalyst material-containing fluid passage portion <NUM> is radially spaced outwardly, relative to relatively unobstructed fluid passage portion <NUM>, from the axis of pipe spool <NUM>.

Fluid communication between relatively unobstructed fluid passage portion <NUM> and catalyst material-containing fluid passage portion <NUM> is effected via spaces within the wire screen. In this respect, wire screen <NUM> is configured to permit permeation of the molten polystyrene material from relatively unobstructed fluid passage portion <NUM> to catalyst material-containing fluid passage portion <NUM> (and thereby facilitate contact of the molten polystyrene material with catalyst material <NUM> within the reaction zone), while preventing, or substantially preventing, egress of catalyst material <NUM> from catalyst material-containing space <NUM> to relatively unobstructed fluid passage portion <NUM>.

In some arrangements, at a downstream end of relatively unobstructed fluid passage portion <NUM>, an end wall is tapered to encourage flow of the molten polystyrene material towards the catalyst-material containing space via wire screen <NUM>, thereby mitigating pooling of the molten polystyrene material.

The catalyst material-containing fluid passage portion <NUM> extends into an annular space defined between spacer tube <NUM>, which is mounted within pipe spool <NUM>, and internal wall <NUM> of pipe spool <NUM>. By occupying this space, spacer tube <NUM> encourages flow of the reactor-disposed molten polystyrene material within catalyst material-containing fluid passage portion <NUM> to the portions of pipe spool <NUM> that are in close disposition to a heat transfer element, and thereby maintaining the reactor-disposed molten polystyrene material at a desired temperature. Also, by occupying space, spacer tube <NUM> effectively reduces the volume of module reaction zone <NUM>, thereby increasing the velocity of the flowing reactor-disposed molten polystyrene material.

Reactor-disposed molten polystyrene material is received within relatively unobstructed fluid passage portion <NUM> via inlet 302A at the first end of pipe spool <NUM>, and conducted across wire screen <NUM> to catalyst material-containing space <NUM> of catalyst material-containing fluid passage portion <NUM> (see directional arrows <NUM>). While being conducted through catalyst material-containing fluid passage portion <NUM> (see directional arrows <NUM>), the molten polystyrene material becomes contacted with catalyst material <NUM> such 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 portion <NUM> (and, in some arrangements, also includes unreacted molten polystyrene material and intermediate reaction products, or both), is then subsequently discharged via outlet 302B at the second opposite end of pipe spool <NUM>.

In some arrangements, various monomers and/or copolymers such as, but not limited to, acids, alcohols, acetates, and alkenes such as hexene can be grafted onto the depolymerized product in catalyst material-containing fluid passage portion <NUM>.

In some arrangements, outlet reactor module <NUM> includes pipe spool <NUM>, having opposite ends, with flanges provided at each one of the opposite ends, for facilitating connection with an inlet reactor module <NUM>, and, in some arrangements, one an intermediate reactor module disposed between inlet and outlet reactor modules <NUM>, <NUM>.

The outlet reactor module <NUM> includes an inlet 402A at a first end of pipe spool <NUM>, an outlet 402B at the opposite second end of the spool, and fluid passage <NUM> extending between inlet 402A and outlet 402B. Fluid passage <NUM> includes catalyst material-containing space <NUM> that is disposed within reactor-disposed molten polystyrene material-permeable container <NUM>, with catalyst material <NUM> disposed within catalyst material-containing space <NUM>. Catalyst material-containing space <NUM> defines module reaction zone <NUM> of reactor module <NUM>.

The outlet reactor module <NUM> is configured for receiving reactor-disposed molten polystyrene material by inlet 402A, conducting the received molten polystyrene material through fluid passage <NUM>, and while such conducting is being effected, contacting the molten polystyrene material being conducted with catalyst material <NUM> such that at least partial depolymerization of at least a fraction of the molten polystyrene material is effected and such that a molten product material is produced that includes depolymerization reaction products (and, in some arrangements, also includes unreacted molten polystyrene material and intermediate reaction products, or both), and discharging the molten product material from outlet 402B.

In some arrangements, various monomers and/or copolymers such as, but not limited to, acids, alcohols, acetates, and alkenes such as hexene can be grafted onto the depolymerized product in outlet reactor module <NUM>.

The fluid passage <NUM> includes catalyst material-containing fluid passage portion <NUM>, which includes catalyst material-containing space <NUM>, and a relatively unobstructed fluid passage portion <NUM>. Catalyst material-containing fluid passage portion <NUM> extends from inlet 402A, and is disposed in fluid communication with the relatively unobstructed fluid passage portion <NUM> via wire screen <NUM>. The relatively unobstructed fluid passage portion <NUM> extends into outlet 402B.

In some arrangements, spacer tube <NUM> is mounted within pipe spool <NUM> at a first end of pipe spool <NUM>, such that the space (such as, for example, the annulus) between pipe spool <NUM> and spacer tube <NUM> defines a portion of catalyst material-containing fluid passage portion <NUM> that is extending from inlet 402A. By occupying this space, spacer tube <NUM> encourages flow of the reactor-disposed molten polystyrene material within the catalyst material-containing fluid passage portion <NUM> to the portions of pipe spool <NUM> that are in close disposition to a heat transfer element (see below), and thereby maintaining the reactor-disposed molten polystyrene material at a desired temperature. Also, by occupying space, spacer tube <NUM> effectively reduces the volume of module reaction zone <NUM>, thereby increasing the velocity of the flowing reactor-disposed molten polystyrene material.

The catalyst material-containing fluid passage portion <NUM> extends into an annular space defined between internal wall <NUM> of pipe spool <NUM> and wire screen <NUM>. Wire screen <NUM> is disposed within pipe spool <NUM>, segmenting fluid passage <NUM> into catalyst material-containing fluid passage portion <NUM> and the relatively unobstructed fluid passage portion <NUM>. Wire screen <NUM> is mounted at one end to, and extends from, the second end of pipe spool <NUM> and is mounted at an opposite end to spacer tube <NUM>. Wire screen <NUM> contains catalyst material <NUM> within catalyst material-containing space <NUM>. Wire screen <NUM> is disposed in spaced apart relationship relative to fluid passage-defining internal wall <NUM> of pipe spool <NUM>, and extends longitudinally through a portion of pipe spool <NUM>. The space between wire screen <NUM> and internal wall <NUM> defines a portion of catalyst material-containing fluid passage portion <NUM> and extends longitudinally across a portion of pipe spool <NUM>. In this respect, the relatively unobstructed fluid passage portion <NUM> extends longitudinally along, or proximate to, an axis of pipe spool <NUM>, and into outlet 402B.

In some arrangements, wire screen <NUM> is cylindrical in shape, and is nested within pipe spool <NUM>. In this respect, in some arrangements, catalyst material-containing fluid passage portion <NUM> is radially spaced outwardly, relative to the relatively unobstructed fluid passage portion <NUM>, from the axis of pipe spool <NUM>.

Fluid communication between catalyst material-containing fluid passage portion <NUM> and the relatively unobstructed fluid passage portion <NUM> is effected via spaces within the wire screen. In this respect, wire screen <NUM> is configured to permit permeation of the molten polystyrene material from the relatively unobstructed fluid passage portion <NUM> to catalyst material-containing fluid passage portion <NUM> (and thereby facilitate the contacting of the molten polystyrene material with catalyst material <NUM> within the reaction zone), while preventing, or substantially preventing, egress of catalyst material <NUM> from catalyst material-containing space <NUM> to the relatively unobstructed fluid passage portion <NUM>.

Reactor-disposed molten polystyrene material is received within catalyst material-containing fluid passage portion <NUM> via inlet 402A at the first end of pipe spool <NUM> (such as, for example, from outlet 302B of reactor module <NUM>, or such as, for example, from the outlet of intermediate reactor module <NUM>, see below), conducted through catalyst material-containing fluid passage portion <NUM> (see directional arrows <NUM>). While being conducted through catalyst material-containing fluid passage portion <NUM>, the molten polystyrene material becomes contacted with catalyst material <NUM> such that a molten product material, that includes depolymerization reaction products (and, in some arrangements, also includes unreacted molten polystyrene 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 portion <NUM>, are conducted across wire screen <NUM> to relatively unobstructed fluid passage portion <NUM> (see directional arrows <NUM>) and subsequently discharged via outlet 402B at the second opposite end of pipe spool <NUM>.

In some arrangements, the reactor includes one or more intermediate reactor modules <NUM> disposed between inlet and outlet reactor modules <NUM>, <NUM>.

In some arrangements, intermediate reactor module <NUM> includes pipe spool <NUM>, having opposite ends, with flanges 530A, 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 module <NUM>, or another intermediate reactor module <NUM>. The flange at the second end is provided for facilitating connect with either one of outlet reactor module <NUM> or another intermediate reactor module <NUM>.

Pipe spool <NUM> includes inlet 502A at a first end of pipe spool <NUM>, outlet 502B at an opposite second end of pipe spool <NUM>, and fluid passage <NUM> extending between inlet 502A and outlet 502B. Fluid passage <NUM> includes catalyst material-containing space <NUM>. Catalyst material-containing space <NUM> is disposed within reactor-disposed molten polystyrene material-permeable container <NUM>, and catalyst material <NUM> is disposed within catalyst material-containing space <NUM>. Catalyst material-containing space <NUM> defines module reaction zone <NUM> of reactor module <NUM>.

Intermediate reactor module <NUM> is configured for receiving reactor-disposed molten polystyrene material by inlet 502A, conducting the received molten polystyrene material through fluid passage <NUM>, and while such conducting is being effected, contacting the molten polystyrene material being conducted with catalyst material <NUM> such that at least partial depolymerization of at least a fraction of the molten polystyrene material is effected and such that a molten product material is produced that includes depolymerization reaction products (and, in some arrangements, also includes unreacted molten polystyrene material and intermediate reaction products, or both), and discharging the molten product material from outlet 502B.

In some arrangements, various monomers and/or copolymers such as, but not limited to, acids, alcohols, acetates, and alkenes such as hexene can be grafted onto the depolymerized product in intermediate reactor module <NUM>.

Fluid passage <NUM> includes catalyst material-containing fluid passage portion <NUM> that includes catalyst material-containing space <NUM>.

In some arrangements, spacer tube <NUM> is mounted within pipe spool <NUM> at a first end of pipe spool <NUM>, such that the space between pipe spool <NUM> and spacer tube <NUM> defines catalyst material-containing space <NUM>. By occupying this space, the spacer tube encourages flow of the reactor-disposed molten polystyrene material within catalyst material-containing fluid passage portion <NUM> to the portions of pipe spool <NUM> that are in close disposition to a heat transfer element (see below), and thereby maintaining the reactor-disposed molten polystyrene material at a desired temperature. Also, by occupying space, spacer tube <NUM> effectively reduces the volume of module reaction zone <NUM>, thereby increasing the velocity of the flowing reactor-disposed molten polystyrene material.

<FIG> shows a cross-section side-elevation view of catalytic reactor 700a with removable static mixer <NUM> configured to be heated via thermal fluid and/or molten salt. Static mixer <NUM> provides greater mixing in catalytic reactor 700a and can result in the need of a lower operating temperature. In some arrangements static mixer <NUM> is removable which allows for easier cleaning and maintenance of reactor 700a. Removable static mixer <NUM> also 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 arrangements thermal fluid and/or molten salt reduces the costs of having to use electric.

The tubular configuration of catalytic reactor 700a offers 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 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 (see <FIG>) 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 arrangements the inner faces of the tubular sections are made of <NUM> or <NUM> steel.

The thermal fluid and/or molten salt can enter jacket <NUM> via inlet/outlets <NUM>. In some arrangements catalytic reactor 700a is configured to be mounted with a thermocouple/pressure transducer (not shown) and includes relevant notches <NUM>. Notches <NUM> are used to bring the thermocouple/pressure transducer in physical contact with the fluid. In some arrangements the thermocouple/pressure transducer will be mounted in a well, which reduces the material in-between the fluid and the sensor.

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

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

<FIG> is a cross-section side-elevation view of catalytic reactor 700b with removable static mixer <NUM> configured to use electric heating. In some arrangements 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 arrangements, reduce of electric heating reduces the overall footprint of the system. In some arrangements catalytic reactor 700b is configured to be mounted with a thermocouple/pressure transducer (not shown) and includes relevant notches <NUM>.

In some arrangements catalytic reactor 700b includes removable screen <NUM> that can hold the catalyst. In other or the same arrangements, catalytic reactor 700b can include removable adaptor <NUM> with cut-outs for static mixer supports. Catalytic reactor 700b can include flanges <NUM> on one or both ends to connect catalytic reactor 700b to other reactors, extruders or the like.

<FIG> is a cross-section side-elevation view of catalytic reactor 700c with removable annular insert <NUM> configured to be heated via thermal fluid and/or molten salt. Annular insert <NUM> can 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 jacket <NUM> via inlet/outlets <NUM>. In some arrangements catalytic reactor 700c is configured to be mounted with a thermocouple/pressure transducer (not shown) and includes relevant notches <NUM>.

In some arrangements catalytic reactor 700c includes removable screen <NUM> that can hold the catalyst. In other or the same arrangements, catalytic reactor 700c can include removable adaptor <NUM> with cut-outs for removable annular and screen support. Catalytic reactor 700c can include flanges <NUM> on one or both ends to connect catalytic reactor 700c to other reactors, extruders or the like.

<FIG> is a cross-section side-elevation view of catalytic reactor 700d with removable annular <NUM> insert configured to use electric heating. In some arrangements catalytic reactor 700d is configured to be mounted with a thermocouple/pressure transducer (not shown) and includes relevant notches <NUM>.

In some arrangements catalytic reactor 700d includes removable screen <NUM> that can hold the catalyst. In other or the same arrangements, catalytic reactor 700d can include removable adaptor <NUM> with cut-outs for removable annular and screen support. Catalytic reactor 700d can include flanges <NUM> on one or both ends to connect catalytic reactor 700d to other reactors, extruders or the like.

<FIG> is a cross-section side-elevation view of a catalytic reactor 700e with 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 reactor 700e which 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 jacket <NUM> via inlet/outlets <NUM>. In some arrangements catalytic reactor 700e is configured to be mounted with a thermocouple/pressure transducer (not shown) and includes relevant notches <NUM>.

In some arrangements catalytic reactor 700e includes removable screen <NUM> that can hold the catalyst. In other or the same arrangements, catalytic reactor 700e can include removable adaptor <NUM> with cut-outs for removable screen support. Catalytic reactor 700e can include flanges <NUM> on one or both ends to connect catalytic reactor 700e to other reactors, extruders or the like.

<FIG> is a cross-section side-elevation view of catalytic 700f reactor with empty internals configured to use electric heating. In some arrangements catalytic reactor 700f is configured to be mounted with a thermocouple/pressure transducer (not shown) and includes relevant notches <NUM>.

In some arrangements catalytic reactor 700f includes removable screen <NUM> that can hold the catalyst. In other or the same arrangements, catalytic reactor 700f can include removable adaptor <NUM> with cut-outs for screen support. Catalytic reactor 700f can include flanges <NUM> on one or both ends to connect catalytic reactor 700f to other reactors, extruders or the like.

<FIG> is a cross-section front-elevation view of a group of catalytic reactors <NUM> like the one shown in <FIG> arranged in parallel. Parallel arrangements such as that shown in <FIG> 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 depolymerisation to occur at once.

Housing <NUM> allows catalytic reactors <NUM> to be bathed in thermal oil/ molten salt which is often more effective than electric. The thermal oil/molten salt is held in chamber <NUM>. In some arrangements flange <NUM> allows for multiple housings to be joined together.

<FIG> is a cross-section side-elevation view of the parallel catalytic reactor arrangement of <FIG> show 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 single tube arrangements. Horizontal configurations are often more convenient to operate/maintain.

<FIG> is a cross-section side-elevation view of the parallel catalytic reactor arrangement of <FIG> show in a vertical configuration. Vertical configurations can reduce stratification of liquid/gas products, and can eliminate need for static mixers.

<FIG> is a cross-section side-elevation view of vertical helical internal catalytic reactor arrangement 900A with two reactors 700a like the one shown in <FIG> connected in series. Horizontal helical mixer pre-heat section <NUM> is connected to one reactor 700a. Helical mixers can lead to better mixing by avoiding stagnancies and hot spots.

Helical mixer cooling segment <NUM> is shown connected to the other reactor 700a at a <NUM>-degree decline. The decline allows for the product to flow via a gravity, while the <NUM>-degree angle allows for sufficient contact between the cooling medium and the product.

In the arrangements shown, vertical helical internal catalytic reactor arrangement 900A 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> is a cross-section side-elevation view of a vertical annular catalytic reactor arrangement 900B with two reactors 700c like the one shown in <FIG> connected in series.

Claim 1:
A method for continuously treating polystyrene material comprising:
(a) selecting a solid polystyrene material;
(b) heating said solid polystyrene material in an extruder to create a molten polystyrene material;
(c) filtering said molten polystyrene material;
(d) placing said molten polystyrene material through a chemical depolymerization process in a reactor to create a depolymerized polystyrene material;
(e) cooling said depolymerized polystyrene material;
(f) purifying said depolymerized polystyrene material, and
(g) grafting a copolymer/monomer onto said molten depolymerized polystyrene material.