How can plastic waste fuel a greener future?

Louise Smyth

It may be difficult to imagine that the empty, non-recyclable plastic container you are about to throw away could be turned into car fuel. Yet, this is exactly the idea behind Quantafuel’s latest solution. To succeed in building the revolutionary plant to achieve this, the company chose Sulzer and its advanced separation technologies to deliver vital components for this ground-breaking solution.

While plastic has many valuable uses, not all types of plastic are recyclable, and we currently lack an effective circular economy strategy for these polymers. Most of the commonly used plastics are not biodegradable and need up to 500 – 1,000 years to decompose. Therefore, any solution that has a significant impact on this situation and helps to reduce the volume of plastic waste is being encouraged.

One extremely promising alternative has been recently developed by Quantafuel, a Norwegian start-up whose mission is turning non-recyclable waste into fuel. The company’s innovative feedstock recycling process converts plastic polymers into hydrocarbons, which can then be used by different downstream industrial processes that currently rely on fossil fuels. By using recycled hydrocarbons to produce fuels and other petroleum-based products, including new plastic materials, it is possible to lessen waste whilst reducing the depletion of natural oil and gas resources.

Quantafuel’s Plastic-to-Liquid (PtL) process starts with a thermal depolymerisation, i.e. pyrolysis or gasification, of polyolefin-based plastic, such as polyethylene (PE) and polypropylene (PP). The reaction produces alkanes, which can then be used to distill liquid fuels, as well as secondary products, namely alkenes (or olefins), aromatic compounds and carbon black.

Following this first step, a catalytic process hydrogenates and cracks the secondary products, turning them into useful alkanes. This proprietary catalytic system allows Quantafuel to carefully control the reaction, obtaining over 90 per cent w/w alkanes whilst avoiding any thermal degradation of the substances and production of large volumes of polluting CO2.

The last stage resembles refinery vacuum distillation operations. The alkanes are separated into different hydrocarbon fractions, i.e. diesel (approximately 70 per cent w/w), gasoline (circa 15 per cent w/w) and fuel oil (approximately 5 per cent w/w), that can be used by a number of industries.

The feasibility of this revolutionary process was first tested in a pilot plant located in Mexico under batch conditions and it proved to be successful. Therefore, Quantafuel decided to set up its first of many full-scale plants for continuous processing in Skive, Denmark. To do so, it required a reliable partner that would supply suitable fractionation equipment whilst allowing Quantafuel to focus on other aspects of its business. 

Speed to market was particularly crucial for Quantafuel, therefore Sulzer needed to ensure responsiveness and time efficiency, despite the long manufacturing lead times for different pieces of separation equipment. To succeed in this challenge, Sulzer mobilised its manufacturing sites around the world and adopted a skid-mounted design for the distillation unit. Sulzer has erected over 250 high-quality units globally. The company was able to complete the installation in less than 10 months.



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