A significant amount of plastic waste is difficult to recycle due to contamination, mixing with other types of plastic and the use of multi-layer packaging. Chemical recycling is a promising method that can convert difficult to recycle plastics into fuel, carbon or petrochemical feedstocks in a cost-effective manner.
The technology owner has developed a proprietary catalyst that can convert grinded mixture of food and polyolefin-based plastic waste into carbon coke within 24 hours. The catalyst enables carbonisation reaction to occur at lower temperature and pressure than other processes, e.g. hydrothermal carbonisation. It promotes radical reactions that eventually produces carbon coke, nitrogen gas and water vapor.
The technology owner has also developed a semi-automatic mixer system with a processing capacity of 100 kg/day to 24 ton/day. The system can accept up to 10% volume of polyolefin plastics for it to work efficiently. The mixer will blend the powder catalyst with the waste feed at specific ratio. The amount of catalyst will be adjusted depending on the feed characteristic, moisture content and treatment duration. The system uses electric heater to maintain the reaction temperature at 150-200°C at atmospheric pressure. The system can handle feed with higher moisture content, e.g. up to 80%. Preferably, the moisture content of the feed should be below 60%.
The spent catalyst will be discharged together with the carbon coke as the product. On a trial with a food manufacturer, the carbon coke produced was analysed to have 99.5% carbon content with a calorific value of 5,300 kcal/kg, suited for use as biofuel.
The technology owner is seeking potential partners to perform trial on organic waste mixed with plastic. They are also open to license the existing technology to interested partners.
In a separate development, the technology owner is developing another type of catalyst (TRL 5) to depolymerise PET, nylon and ABS plastics into their monomers, which can be further refined into feedstock chemicals for the petrochemical industry. The reaction occurs at 120°C, 0.2 MPa. They are seeking collaboration with partners who possess the technical know-how in refining the monomer mixture into valuable feedstock chemicals.
- For a 10 ton/day system, it requires approximately 15 kW of input power for the mixer and electric heater. Based on trial data, the system consumes approximately 360 kWh for every batch of feed processed in 24 hours.
- Depending on the requirement, optional equipment such as fully automated waste and catalyst feeders, waste shredder and a container for carbon coke storage can be integrated to minimise manpower requirement. A fully integrated 10 ton/day system is estimated to fit in a 40-ft container.
- The feed should be shredded into a size of 10x10 mm.
- The catalyst can potentially handle some amount of PVC given that emission control systems are installed to reduce toxic gas emissions to a safe level.
- Municipal waste management
- Food establishments
- Island and off-grid areas
- Reduced logistic cost and tipping fee at landfills or waste incineration plants as the waste can be treated on-site.
- Use of the carbon coke as a biofuel.