Plastics can be said to be friends that humans love and hate. While bringing convenience, they also cause irreversible damage to the earth. The World Economic Forum once predicted that if plastics recycling or production reduction were not implemented again, marine plastic would be more than fish in 2050. .
According to the Science Advances study, as of 2015, of the approximately 6.3 billion metric tons of plastic waste in the United States, only 9% will be recycled, 12% will remain in the incinerator, and about 79% of the plastic will eventually be disposed of in landfills or discarded at will. In European countries with a strict waste management system, only 31% of plastics are recycled and reused. Therefore, many scholars believe that if plastics cannot be recycled properly, they will try their best to turn plastic into fuel, and at least become another business. power.
The Earth Engineering Center (EEC, CCNY) of the City College of Technology at the City of New York in the United States is working to convert plastics into energy and fuel. The team composed of Marco J. Castaldi and Demetra Tsiamis wants to recycle non-recycled plastic (NRP). For gasification technology, and according to the latest research, if NRP is added to biomass gasification technology, besides helping to reduce greenhouse gas emissions, it can also significantly reduce waste by-product landfill volume, a reduction of up to 76%.
Gasification technology is a kind of energy production method. It places carbonaceous materials such as organic substances, fossil fuels or biomass into a temperature above 700 degrees Celsius, and reacts with water vapor to convert the material into carbon monoxide, carbon dioxide and hydrogen. The gasified gas mixture is called syngas and can be used as gas fuel or processed into liquid fuel such as methanol.
To test the impact of adding NRP, the team also conducted research at the Canadian energy company Enerkem plant. Castaldi said that plastics contain large amounts of carbon and hydrogen, and the energy content is very high. Therefore, gasification technology can be used to convert these plastics into fuels. Chemicals And other products.
The study conducted a gasification reaction of NRP with biomass, and tested 0%, 8%, 15%, and 50% of 4 NRP ratios. It was found that the NRP ratio reached 50% and the best effect. Compared with 100% biomass, Using 50% biomass and 50% NRP can increase the amount of syngas produced by 80%. Adding NRP will not consume much electricity, only 2% more electricity is needed to generate syngas.
The team finally converted the syngas to methanol. An NRP ratio of 50% resulted in a 42% increase in methanol production at the Enerkem plant, which could be said to increase production by 4.2 million gallons annually and reduce 21,000 metric tons of CO2 annually.
Tsiamis pointed out that although plastics still have service life, the team needs to turn plastics from waste into energy, and they also need continuous scientific analysis and research to make decision makers or investors make the best choice for the earth.