Plastic Pyrolysis & Recycling Patents

Chemical (advanced) plastic recycling patents cover pyrolysis innovations; depolymerization (chemical and enzymatic) innovations; purification and feedstock innovations; and mass-balance and product innovations — with IP held by chemical majors, enzymatic-recycling specialists, and pyrolysis companies (in a field breaking plastics back to molecules to recycle the hard-to-recycle). MAJOR CHEMICAL-RECYCLING PATENT HOLDERS: EASTMAN: 'molecular recycling' at scale — methanolysis (depolymerizing polyester/PET back to monomers DMT/EG) and carbon-renewal/pyrolysis (cracking mixed waste plastic to feedstock), with a large process estate. CARBIOS: ENZYMATIC depolymerization of PET — an engineered enzyme (a PETase/hydrolase) that breaks PET into its monomers under mild conditions (a fundamentally different, low-energy, high-purity route), plus the enzyme and process IP. LOOP INDUSTRIES: low-energy PET/polyester depolymerization (glycolysis/hydrolysis) to virgin-quality monomers. AGILYX: depolymerization of polystyrene back to styrene monomer, and pyrolysis. PLASTIC ENERGY: the TAC (thermal anaerobic conversion) pyrolysis process producing TACOIL. MURA TECHNOLOGY: HydroPRS — hydrothermal (supercritical-water) liquefaction of mixed plastics. OTHERS: Brightmark, Alterra, Encina, Lummus/New Hope, and incumbent petrochemical licensors. Pyrolysis (for mixed/polyolefin waste), depolymerization (chemical and enzymatic, mainly for PET/polyester/PS), and purification are the core chemical-recycling patent domains — and enzymatic and selective depolymerization are the most novel, startup-friendly whitespace.

Pyrolysis-reactor innovations; catalytic-pyrolysis innovations; feedstock and contaminant innovations; and product-upgrading and gasification innovations represent core pyrolysis chemical-recycling patent domains — and pyrolysis is the route for mixed and polyolefin (PE/PP) waste that can't be depolymerized cleanly. PYROLYSIS-REACTOR PATENTS: thermally cracking mixed/polyolefin plastic waste in the absence of oxygen to a pyrolysis oil (which can be re-cracked into naphtha/feedstock for new plastic) — reactor designs (rotary kiln, fluidized bed, screw/auger, molten-media), temperature/residence-time control, heat integration, and continuous operation; hydrothermal/supercritical-water liquefaction (Mura HydroPRS) is a distinct variant. CATALYTIC-PYROLYSIS PATENTS: catalysts (zeolites, etc.) that lower temperature, improve selectivity toward useful fractions, and reduce char/coke. FEEDSTOCK / CONTAMINANT PATENTS: handling contaminated, mixed, multilayer, and food-residue waste, pre-processing/sorting, and removing chlorine (PVC), nitrogen, and other contaminants/poisons (contamination is the central practical problem and yield/quality killer). PRODUCT-UPGRADING PATENTS: upgrading pyrolysis oil (hydrotreating, fractionation) to a clean, drop-in steam-cracker feedstock that petrochemical plants will accept, and removing impurities to meet spec. GASIFICATION PATENTS: gasifying waste plastic to syngas for chemicals/fuels. Continuous, contaminant-tolerant pyrolysis reactors and pyrolysis-oil upgrading to drop-in feedstock are the highest-value pyrolysis IP — because feedstock contamination and product quality determine whether the output is actually recyclable.

Chemical-depolymerization innovations; enzymatic-depolymerization innovations; dissolution/purification innovations; and mass-balance and circularity innovations represent additional chemical-recycling patent domains — and selective depolymerization (back to monomers) gives the highest-quality, most-defensible recycling. CHEMICAL-DEPOLYMERIZATION PATENTS: breaking condensation polymers back to monomers — methanolysis (PET → DMT + EG, Eastman), glycolysis (PET → BHET, Loop), hydrolysis, and aminolysis; catalyst, solvent, conditions, and monomer purification (the recovered monomer must be virgin-quality to re-polymerize), mainly for PET/polyester, polycarbonate, nylon, and PU/PLA. ENZYMATIC-DEPOLYMERIZATION PATENTS: engineered enzymes (PETase/cutinase/hydrolase variants — Carbios) that depolymerize PET under mild aqueous conditions — the ENGINEERED ENZYME (composition-of-matter, a key, novel, defensible asset), enzyme immobilization/recycling, pretreatment (amorphizing crystalline PET for enzyme access), and the bioprocess; enzymatic is low-energy, high-purity, and selective (works on colored/mixed PET). DISSOLUTION / PURIFICATION PATENTS: dissolution recycling (dissolving a target polymer to purify it without depolymerizing — e.g. for polystyrene, polyolefins), and contaminant/additive removal. MASS-BALANCE / CIRCULARITY PATENTS: mass-balance accounting/certification (attributing recycled content through mixed processes — ISCC), and tracking. Engineered depolymerization enzymes and selective chemical depolymerization to virgin-quality monomers are the highest-value chemical-recycling IP because they produce true closed-loop, food-grade recycled plastic.

Chemical recycling startup IP strategy must navigate Eastman methanolysis/pyrolysis patents, Carbios enzymatic patents, Loop/Agilyx depolymerization patents, decades of pyrolysis and depolymerization prior art (cracking and glycolysis are old chemistry), the central practical problems (feedstock contamination, product quality/yield, energy/cost, and the scrutiny of whether 'advanced recycling' is genuinely circular), petrochemical-buyer acceptance and mass-balance certification, regulatory/recycled-content policy, and a landscape where the route (pyrolysis vs depolymerization vs enzymatic) shapes the IP; understand that basic pyrolysis and glycolysis are prior art, so the durable IP is in contaminant-tolerant continuous reactors, pyrolysis-oil upgrading, selective/efficient depolymerization, and especially ENGINEERED ENZYMES (composition-of-matter), and that feedstock and product-quality economics matter as much as patents; identify whitespace in enzymatic depolymerization, selective depolymerization, contaminant tolerance, and product upgrading. CHEMICAL-RECYCLING STARTUP IP STRATEGY: BASIC PYROLYSIS/GLYCOLYSIS ARE PRIOR ART — CONTAMINANT TOLERANCE, UPGRADING, AND ENGINEERED ENZYMES ARE THE IP: patent contaminant-tolerant continuous reactors, pyrolysis-oil upgrading to drop-in feedstock, selective/efficient depolymerization, and (highest-value) engineered depolymerization enzymes; ENGINEERED ENZYMES ARE COMPOSITION-OF-MATTER — THE STRONGEST DEPOLYMERIZATION IP: a novel PETase/hydrolase enzyme (Carbios-style) that depolymerizes PET under mild conditions is durable composition-of-matter and a low-energy, high-purity advantage — the most defensible, novel route; SELECTIVE DEPOLYMERIZATION TO VIRGIN-QUALITY MONOMER IS HIGHEST-VALUE FOR CLOSED-LOOP: producing food-grade, virgin-quality recycled monomer (vs lower-value pyrolysis oil) commands a premium and is patentable; CONTAMINANT TOLERANCE AND PRODUCT UPGRADING DECIDE PYROLYSIS VIABILITY: handling real, dirty, mixed waste and upgrading the oil to a spec petrochemical plants accept are the make-or-break, patentable problems; MASS-BALANCE CERTIFICATION AND BUYER ACCEPTANCE ARE PARALLEL MOATS: ISCC mass-balance certification and petrochemical/brand offtake gate the business; ADDRESS THE CIRCULARITY SCRUTINY: 'advanced recycling' faces criticism (energy use, fuel vs feedstock) — genuine closed-loop, low-energy processes (enzymatic) are both better IP and better positioned; WHEN TO PATENT: NOVEL PROCESS/ENZYME WITH MEASURED PERFORMANCE: file once a system shows measured results (monomer/oil yield + product purity (virgin-quality?) + feedstock contamination tolerance + energy intensity + enzyme activity/recyclability + cost) vs. mechanical-recycling or incumbent baselines — measured yield/purity, contaminant tolerance, energy, and (for enzymatic) enzyme activity are the critical chemical-recycling IP metrics; KEY FTO CHECKLIST: Eastman methanolysis PET→DMT/EG + carbon-renewal pyrolysis; Carbios engineered PETase/hydrolase enzymatic depolymerization (composition-of-matter); Loop glycolysis/hydrolysis PET→virgin monomer; Agilyx polystyrene→styrene depolymerization + pyrolysis; Plastic Energy TAC pyrolysis; Mura HydroPRS hydrothermal supercritical-water; pyrolysis reactor (rotary/fluidized/auger) + catalytic; contaminant (PVC chlorine) handling; pyrolysis-oil hydrotreating/upgrading drop-in feedstock; dissolution recycling; ISCC mass-balance certification.