Enzymatic Recycling Process for PET Bottles

A method to degrade polyethylene terephthalate (PET) plastic waste using a combined chemical-enzymatic process. The method involves dissolving PET in an organic solvent, adding a small amount of alkali, and pre-degrading the PET in solution at moderate temperature. The pre-degraded PET suspension is then enzymatically hydrolyzed to fully degrade the PET into monomers like terephthalic acid. This two-step process allows efficient bioconversion of high-crystallinity PET waste into valuable monomers using mild conditions and a trace amount of alkali.

Source

A process for degrading plastic products containing polyesters like PET by enzymatic depolymerization at acidic pH without base addition. The process involves two steps: a preliminary step at pH 6.5-10 to reach high terephthalic acid concentration in the reaction medium, followed by main depolymerization at pH 4-6. The high terephthalic acid concentration in the medium allows acidic depolymerization without pH adjustment. Enzymes degrade the polyesters. The acidic depolymerization provides economic benefits by reducing base consumption and salt production.

Source

Chemical-biological integrated method to efficiently recycle PET into high-value products using a catalyst like betaine instead of heavy metal catalysts in the initial glycolysis step. The method involves glycolyzing PET in ethylene glycol with betaine as a catalyst to produce oligomers. These oligomers are then enzymatically hydrolyzed to monomers and platform chemicals. The betaine-catalyzed glycolysis prevents pH drops that inhibit enzymatic hydrolysis. This integrated approach allows efficient recycling of PET into valuable chemicals without adverse impacts on subsequent biological steps.

Source

Enzymatic degradation of polyethylene terephthalate (PET) using lipases from plant and microbial sources along with Yarrowia lipolytica yeast cells. This process provides a less complex, less expensive, and faster alternative for degrading PET into oligomers and monomers. The enzymatic degradation involves using lipases from vegetable and microbial sources, as well as Yarrowia lipolytica yeast cells, to catalyze the breakdown of PET into useful inputs for the petrochemical industry. The process avoids the lengthy biological degradation methods and provides faster enzyme kinetics.

Source

A method to improve the degradation efficiency of polyethylene terephthalate (PET) using bacteria and enzymes. The method involves combining the action of the enzyme cutinase from Humicola insolens with Klebsiella variicola bacteria to jointly degrade PET. This reduces the buildup of inhibitory degradation products like BHET and MHET that can limit the cutinase activity. The combined degradation using bacteria and enzymes allows more complete conversion of PET into monomers.

Source

The disclosure relates to a method for manufacturing a battery cell, and more specifically to a method for manufacturing a battery cell that includes a separator in which a vent hole is formed in an interior region of the separator. A secondary battery includes a positive electrode, a negative electrode, and a separator disposed between the positive electrode and the negative electrode. The separator is disposed between the positive electrode and the negative electrode to prevent a reaction between the positive electrode and the negative electrode. When the secondary battery is overcharged, the secondary battery may generate excessive gas. The excessive gas may be discharged through the vent hole. A method for manufacturing a battery cell according to an aspect of the disclosure includes: providing a separator including a vent hole, the vent hole being formed in an interior region of the separator; stacking the separator with a positive electrode and a negative

Source

Method to improve the efficiency of enzymatic degradation of waste PET bottles by pretreating the bottles before enzymatic degradation. The pretreatment involves cleaning the bottles in pure water for 30 minutes and then drying them in an oven at 65°C. This preprocessing step helps to remove impurities and improve the crystallinity of the PET, making it more susceptible to degradation by enzymes.

Source

A process for degrading polyester containing materials like plastic products using enzymatic depolymerization in acidic conditions. The process involves contacting the polyester material with enzymes like PETase and MHETase at pH 3-6 and temperatures around 60°C. This allows breaking down the polyester into monomers and oligomers without coproduct formation. The low pH and addition of MHETase improves efficiency compared to neutral pH. The process can degrade polyester waste from sources like domestic plastic or textiles.

Source

A chemical pretreatment method to improve the enzymatic degradation and recovery efficiency of waste polyester fabrics. The method involves treating the waste polyester fabrics with a specific chemical pretreatment before enzymatic degradation. The pretreatment involves applying a mixture of sodium hypochlorite and sodium chloride in a certain ratio to the waste polyester fabrics. This pretreatment helps to enhance the enzymatic degradation of the waste polyester fabrics by the enzymes. The specific ratio of sodium hypochlorite and sodium chloride in the pretreatment solution can be optimized for different waste polyester fabrics.

Source

A faster, less complex, and less expensive process for enzymatic degradation of polyethylene terephthalate (PET) using plant lipases and yeast cells. The process involves contacting PET with lipases from vegetable sources and Yarrowia lipolytica cells to degrade PET into useful oligomers and monomers like terephthalic acid. The enzymes are selected for their hydrolysis properties on vegetable oils and aromatic compounds. The process offers faster degradation kinetics compared to traditional fungal degradation processes.

Source

A novel plastic degrading enzyme that can decompose plastics like PET in an environmentally friendly manner. The enzyme is a protein derived from the bacteria Rhizobacter gumiphilus. It has higher activity compared to existing PET degrading enzymes like PETase from Ideonella saciensis. The enzyme can degrade PET, MHET, and BHET plastics. The enzyme can be produced using recombinant DNA techniques and used in compositions and methods for decomposing plastics.

Source

Process for depolymerizing resistant PET waste from oil and gas industry using enzymes to improve recycling and reduce environmental impact. The process involves pre-treatments to reduce PET recalcitrance before enzymatic depolymerization. Pre-treatments include microwave, ultrasound, and surfactant treatments to reduce PET crystallinity, making it more susceptible to enzymatic degradation. Enzymatic depolymerization uses sea water as the solvent instead of organic solvents. This allows using lower enzyme concentrations and reduces the energy required for solvent removal. The sea water also facilitates PET dissolution.

Source

Producing glycolic acid from ethylene glycol using wild yeast strains for applications like biodegradable packaging, adhesives, and textiles. The process involves depolymerizing poly(ethylene terephthalate) (PET) into ethylene glycol using enzymes from Yarrowia lipolytica yeast. Then, the yeast biotransforms the ethylene glycol into glycolic acid. This avoids chemical synthesis and reduces costs and pollution compared to traditional methods. The yeast strain can selectively oxidize hydroxyl groups on ethylene glycol to make glycolic acid.

Source

Enzymatic depolymerization of polyethylene terephthalate (PET) at temperatures close to the glass transition temperature of PET. This allows accessibility of the enzyme to the PET chains as they become more mobile at those temperatures. The depolymerization time is shorter than the crystallization time to prevent recrystallization. The PET has an initial crystallinity of 25% or less. The enzyme used can depolymerize PET faster than it crystallizes. The method involves contacting amorphous or semi-crystalline PET with the enzyme at temperatures between Tg-10°C and Tg+10°C.

Source

Degrading PET plastic using a synergistic combination of two enzymes, PETase and MHETase, to rapidly break down PET into its constituent monomers. The enzymes are used in a 3:1 ratio at 30°C for 48 hours. This method improves upon using each enzyme separately to degrade PET, as it allows faster and more complete breakdown into terephthalic acid and ethylene glycol. The synergistic effect is achieved by mixing the enzymes in optimized ratios to degrade PET into its monomers.

Source

Enzymatic recycling of post-consumer PET plastic waste into new PET using glycolysis. The process involves breaking down the polyester structure of PET into bis-hydroxyethylene terephthalate (BHET) monomers using enzymes. The enzymatic glycolysis reaction is carried out on pretreated PET waste, such as ground-up bottles, to enrich the BHET content. The BHET-rich stream can then be repolymerized into new PET. The enzymatic recycling avoids using catalysts that could contaminate the recycled PET.

Source

A method for recycling and degrading PETG (polyethylene terephthalate glycol) plastic waste, which involves crushing, degradation, and reuse programs to convert degraded PETG into new usable substances without generating waste. The method involves breaking down the PETG into smaller pieces, then degrading the PETG further using chemicals or enzymes. The degraded PETG can then be reused in new applications, such as making coatings or adhesives. The method aims to provide a closed-loop recycling solution for PETG plastic that avoids waste generation.

Source

A pretreatment method to improve the enzymatic degradation of waste polyester fabrics by melting and quenching the fabric. The method involves melting clean, dry polyester waste at temperatures between 280-300°C, then immediately quenching it in water. This reduces the crystallinity of the polyester, making it more susceptible to enzymatic degradation. The lower crystallinity enables enzymes to more easily break down the polyester molecules during biodegradation.

Source

A heat-resistant enzyme that can degrade polyester plastics like PET at temperatures close to the plastic's glass transition temperature (65-75°C). This enzyme allows efficient biodegradation of high-temperature polyester plastics without requiring lower temperatures. It can degrade PET with >70% efficiency at 65°C in 8 days. The enzyme is encoded by a gene with a specific amino acid sequence.

Source

Enzymatic process for recycling used PET plastic containers by depolymerizing them into monomers using enzymes. The process involves mixing PET and ethylene glycol in a reactor, adding enzymes, and heating to decompose the PET into terephthalic acid, monohydroxyethylene terephthalate, and bishydroxyethylene terephthalate. The bishydroxyethylene terephthalate can then be used to make new PET, closing the recycling loop. The enzymatic process allows higher bishydroxyethylene terephthalate yields compared to hydrolysis, simplifies separation, and reduces water needs.

Source