Decarbonisation Technology - February 2023

Advanced plastics recycling

New chemical recycling technologies will supplement existing mechanical recycling

Marc Yagoub Honeywell UOP

T oday, 6% of oil consumption is used for the production of plastics. The current consumption pattern means that this will grow to 20% by 2040. Ninety per cent of the emissions associated with plastics occur during the production of the plastics, while less than 10% of emissions are associated with end-of- life disposal. Fossil fuels demand for fuel production is declining, with 2050 demand anticipated to be only 30% of 2022 demand. The 30% residual demand is comprised mainly of petrochemicals, but indeed, recycling of plastics will also chip away at that demand. Today the plastics economy is linear. We take crude oil, produce the plastic, then use it, often only once, and then throw it away as waste. Plastic packaging used, for example, as film for food packaging means the life of the plastic is only a few days or months, whereas structural plastics such as PVC tubing can have a usage lifetime of up to 35 years. Plastic packaging is the largest application (30%) but has the shortest life cycle. This means we generate a huge amount of waste, much of which ends up in landfill or incineration. Only 14% is currently collected for recycling, and then only 9% is effectively recycled (OECD, 2022). Ideally, the plastic waste should be collected separately, allowing for efficient re-use. Mechanical recycling Currently, the main way of recycling plastic is mechanical recycling (see Figure 1 ). The plastic has to be high quality and clean before it reaches a processing centre. It then has to be separated and sorted, which further limits the amount that can be recycled. Mechanical recycling, which requires less energy and is more carbon efficient than chemical recycling, is generally the preferred option. Mechanical

recycling works well for items that can be collected separately, such as HDPE and PET. Schemes such as deposit and refund for PET drinks bottles, in place in Germany, are proving to be effective in promoting separate collections for these plastics. However, mechanical recycling has its limitations. Plastic contaminated with organic matter, such as containers used for detergents and other chemicals, cannot be recycled for food contact uses. In Europe, you cannot add more than 5% of non-food recycled material into material for food packaging. As a result, plastic recycled from mixed plastic waste tends to be used in lower-demand applications, such as in school playgrounds and plastic benches. Mechanical recycling is, therefore, not an option Only 14% of plastic waste is currently collected for recycling, and then only 9% is effectively recycled for plastic waste collected as part of mixed municipal solid waste. For these reasons, mechanical recycling will not reduce the demand for virgin plastic on its own. Unfortunately, today, a big part of this waste (22% or 80 million tonnes) is mismanaged, and as many as 22 million tonnes are leaked into the environment. The OECD Global Outlook projects that unless action is taken on plastic waste collection and recycling, the amount of plastic entering the environment will double by 2060 (OECD, 2022). Plastic leakage to the environment, including microplastics, is already a major environmental problem. The Alliance To End Plastic Waste is clear recognition that manufacturers are taking this issue seriously