Pyrolysis for PET Bottle Chemical Recycling

A method and apparatus for converting plastics into hydrocarbon products using pyrolysis in a dual fluidized bed reactor. The method involves preheating and shearing the plastic feed in an extruder to reduce viscosity for atomization and dispersion in the reactor. The plastic feed is then injected into the reactor where it pyrolyzes into hydrocarbons. The reactor has a cyclonic separator to remove the hydrocarbon vapors from the char and heat carrier. The char is combusted in a separate bed to regenerate the heat carrier. This prevents hydrocarbon loss and allows higher throughput. The cyclone, stripper, and regenerator are all designed to handle corrosive plastic contaminants.

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Continuous pyrolysis system for recycling waste plastics that avoids issues like sticking, coking, and low yields. The system uses a stirring assembly inside the pyrolysis reactor with a rotating shaft and stirring rods to prevent plastic from accumulating. The stirring breaks up and removes molten plastic before it adheres to the reactor walls. The system also has multiple connected pyrolysis units that allow continuous operation without stopping for material changes. The final unit has a separation unit to separate the pyrolysis products into oil, gas, and solid fractions.

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Thermochemical conversion of waste plastics into useful products like petrochemicals, fuels, and asphalt. The process involves melting the waste plastic in a tank and then pyrolyzing it in a reactor. The melting step removes water and oxygen to prevent coking. The pyrolysis is done at lower temperatures to produce pitch instead of tar. This allows higher oil yield. The pyrolysis oil is separated into gases, light oil, medium oil, and heavy oil fractions. The system uses controlled heating and stirring to optimize conversion and prevent coking.

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Chemical recycling of waste plastics with lower carbon footprint by using waste heat integration. The process involves liquefying the waste plastics, pyrolyzing them, separating the pyrolysis products, and then feeding some of the separated pyrolysis oil back into the pyrolysis zone. This closes the loop and reduces the need for external fuel to heat the plastics. The pyrolysis effluent is also used to indirectly heat the pyrolysis oil, further reducing external fuel. The process can be operated at high pressures (>200 psig) to enable efficient heat transfer.

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Chemical recycling of waste plastics with lower carbon footprint by integrating heat recovery from the pyrolysis flue gas to liquefy and further heat the waste plastics. The process involves pyrolyzing liquefied waste plastics, recovering heat from the pyrolysis flue gas to liquefy the waste plastics, and further heating the liquefied plastics using flue gas heat. This reduces the need for fossil fuel combustion to provide heating.

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A chemical recycling process with lower carbon footprint by integrating heat recovery and utilization across the recycling steps. The process involves liquefying waste plastic, pyrolyzing it, cracking the pyrolysis oil, and generating steam. Heat from pyrolysis flue gas, cracker flue gas, quench fluid, residual steam, and combustion flue gas is used to preheat the initial feed streams like the waste plastic, combustion fuel, and combustion air. This reduces the need for external fossil fuel combustion for heating, thereby lowering CO2 emissions.

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Two-step plastic recycling process to convert waste plastics into monomers like ethylene and propylene. The process involves pyrolyzing the plastics at 300-600°C in a first stage to produce low-temperature pyrolysis products. Then, a portion of those products is heated to 600-1100°C in a second stage to further pyrolyze into monomers. This two-step process allows converting plastics into monomers with higher yields compared to single-stage high-temperature pyrolysis.

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A process for converting plastic waste into liquid hydrocarbons with improved yield and efficiency compared to existing methods. The process involves two steps: 1) thermocatalytic degradation of the plastic in a reactor at high temperatures to produce a mixture of gases and liquids, and 2) condensation of the gases to separate and collect the liquid hydrocarbons. A key feature is recycling a portion of the liquid slurry from the reactor back into it, rather than discharging the entire slurry. This improves hydrocarbon yield and reduces the amount of solid charcoal that forms. The process can be scaled up to commercial levels for converting large amounts of plastic waste into valuable liquid hydrocarbons.

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Waste plastic pyrolysis apparatus that improves efficiency and productivity of low-boiling pyrolysis oil production. The apparatus has a melting section, thermal decomposition section, and reactive distillation column. Waste plastic is melted, rapidly pyrolyzed, and decomposed using recycled high-temperature gases. Uncondensed gases separate and recirculate to maximize thermal contact, increase reaction rates, and further decompose unreacted materials. This avoids carbonization and reduces energy consumption compared to separate units.

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A containerized plastic waste pyrolysis plant that can efficiently convert plastic waste into hydrocarbon fuels like diesel. The plant is designed to be modular, portable, and scalable for deploying in various locations. It uses containerized units with pyrolysis reactors, flash distillation, fractionation, and scrubbing steps to convert plastic waste into hydrocarbon fuels. The plant can handle smaller feed sizes than fixed plants, making it suitable for mobile deployment. The containerized design allows easy shipping and assembly, while the modular units can be combined in series or parallel to scale output. The plant can also generate electricity from the pyrolysis gas byproducts.

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Process for making recycled content hydrocarbon products from waste plastic pyrolysis vapor. The process involves co-locating waste plastic pyrolysis and cracking facilities. The pyrolysis vapor is withdrawn from the pyrolysis facility at a certain temperature, then introduced into the cross-over pipe between the cracker furnace sections. This prevents condensation since the vapor temperature is higher than the cracker furnace sections. By combining and cracking the vapor with the cracker feed, it enhances energy efficiency and reduces waste heat losses compared to separate facilities. The vapor introduction rate is adjusted as cracker feed rate changes to maintain furnace heat balance.

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Simultaneous pyrolysis of mixed plastics containing PET (polyethylene terephthalate) and polyolefin plastics like PP and PE to efficiently recycle complex plastic waste streams. The method involves pyrolyzing the mixed plastic feed at high temperatures in the presence of steam and nitrogen. The pyrolysis converts the mixed plastics into terephthalic acid (TPA) and olefin monomers like ethylene and propylene. The high H/C ratio of PET and the acid catalytic effect of TPA in the mixed plastic feed synergistically enhance the pyrolysis yield of TPA and olefins compared to pyrolyzing the plastics separately.

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Process for recycling waste plastic into hydrocarbons and a plant for implementing it. The process involves depolymerizing waste plastic in a heated reactor filled with molten salt to break down the polymer chains into gaseous hydrocarbons. The plant has features like scraper blades to prevent floating of plastic, mixing to dissolve, and jacket heating with salt circulation. The hydrocarbons are fractionated into fuels and gases. The plant also has steps to prepare the plastic feed, remove contaminants, and reduce size. This allows recycling of difficult-to-recycle waste plastics into valuable products.

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Converting waste plastics into high-value hydrocarbon products through steam cracking of the pyrolysis effluent. The process involves pyrolyzing plastics at high temperatures around 450°C to obtain a pyrolysis effluent stream. This stream is then steam cracked to separate out C5 and C4 hydrocarbon streams. Quenching the pyrolysis effluent stream before steam cracking reduces oligomerization and preserves valuable light olefins. The steam cracking can be done in parallel with plastic feed steam cracking to utilize the furnace capacity.

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Recycling composite plastics like packaging materials, batteries, and fiber-reinforced plastics by pyrolysis in a system using molten metal as the pyrolysis medium. The feedstock is charged onto a molten metal surface maintained at 160-650°C in an oxygen-free atmosphere. Vapors are removed while keeping the pressure above atmospheric, and solids are removed from the metal surface. This allows fast, efficient pyrolysis with direct heat transfer to the plastic. The molten metal prevents contamination of the products. The waxes and oils are condensed from the vapors.

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Recycling waste plastics through pyrolysis and partial oxidation gasification to produce recovery component syngas. The process involves pyrolyzing waste plastics to form a pyrolysis effluent with a high carbon content residue. This residue is then gasified in a partial oxidation process using oxygen to produce syngas. The syngas can be further processed into useful chemicals and fuels. This closed-loop recycling of waste plastics reduces environmental impact compared to incineration or landfilling.

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A continuous waste plastic pyrolysis system that efficiently extracts oil and gas from waste plastic. The system uses a multi-stage pyrolysis process with automated adjustment of operating conditions based on waste plastic quality. It involves a waste input unit, pyrolysis reactor, residue treatment, oil/gas separation, and storage. The multi-stage pyrolysis allows gradual heating to prevent explosion. Automatic stop/start based on waste quality prevents overheating. The multi-stage separation efficiently extracts oil and gas.

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Large-scale production of recycled content feedstocks and products using pyrolysis of waste plastics and industrial waste. The system involves shredding recycled plastics, blending with industrial waste, and pyrolyzing in stages at increasing temperatures. This improves flowability and homogenization. The pyrolysis oil can be further processed into valuable chemicals like ethylene oxide. Recovered components from pyrolysis and other sources can be added to products like ethylene oxide to increase recycled content.

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A method to prepare terephthalic acid (TPA) from waste polyethylene terephthalate (PET) using water-assisted pyrolysis that reduces carbon black formation compared to traditional methods. The process involves pyrolyzing PET in the presence of water vapor instead of oxygen or air. This water-assisted pyrolysis step converts PET into TPA, benzoic acid, and carbon black. The carbon black yield is significantly lower compared to pyrolysis without water. The water-assisted pyrolysis conditions include using a mixed carrier gas containing water vapor, and a fixed bed reactor. The lower carbon black formation enables higher TPA yields from PET waste.

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A method to recycle waste plastics into useful products through pyrolysis. The method involves treating the waste plastic feedstock before pyrolysis to address issues like heterogeneity and contaminants. Steps like shredding, separating, mixing, and co-feeding with liquids improve pyrolysis efficiency for variable waste streams. This allows recycling of post-consumer and post-industrial plastics together without sorting. The recycled pyrolysis oil can be used to make new plastics or chemicals like ethylene oxide. The process enables scalable closed-loop recycling of mixed waste plastics.

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