Coolbrook cracks pyrolysis oil using renewable electricity

Coolbrook

RENEWABLE process heat developer Coolbrook has successfully cracked pyrolysis oil made entirely from waste plastic using an electrically powered steam cracker.

A pilot cracker in the Netherlands used Coolbrook’s RotoDynamic Reactor (RDR) to generate the heat needed to break down pyrolysis oil – made entirely from waste plastic – into ethylene and propylene. The oil was produced by Pryme using an electrically heated reactor.

Developed with the universities of Oxford, Cambridge and Ghent along with Neste Engineering and Mitsubishi Heavy Industries, the RDR uses a renewable electricity-powered motor to drive high velocity rotor blades. Combined with steam, the heat produced from the rotor blades then breaks down long-chain hydrocarbons into olefins and polyolefins which can then be processed into new plastics.

Conventional steam cracking relies on fossil heat and is responsible for 300m t/y of greenhouse gas emissions, amounting to 30% of global chemical and petrochemical emissions. Coolbrook says its process is more efficient because it generates heat directly within the reaction zone, unlike conventional methods that rely on heat transfer through pipe walls. This approach yields a higher volume of olefins, helping to reduce overall feedstock demand.

Cracking pyrolysis oil has long been challenging due to impurities such as oxygen, nitrogen and sulphur, often introduced through contamination from residual waste. Coolbrook’s latest testing formed part of the European Union-funded eLECTRO project, which integrates plastic waste pre-treatment, electrical pyrolysis and steam cracking.

Coolbrook’s latest achievement follows tests last year in which the company demonstrated successful cracking of naphtha. Coolbrook says testing has shown it is on a “technical pathway” to becoming the only technology capable of achieving 1,700°C heat using electricity, and that it can deliver this at scale.

Tuomas Ouni, head of process development at Coolbrook, said: “Cracking 100% pyrolysis oil directly without the need for dilution with conventional feedstock simplifies operations and enhances traceability of circular materials.

“Using Coolbrook’s RDR also delivers benefits in terms of ethylene and propylene yields compared to conventional furnaces, without any noticeable increase in coking. These results confirm the potential of Coolbrook’s RDR to play a central role in both decarbonisation and circularity in the petrochemical industry.”

Closed loops

The eLECTRO project aims to tackle hard-to-recycle plastics by converting them into light olefins using renewable energy. Coolbrook says that pyrolysis oil derived entirely from waste plastic is the “essential building block in closing the loop for plastics recycling”.

A recent study published in Communications Earth & Environment found that, of the more than 250m t of plastic waste produced in 2022, 39% was sent to landfill and 34% was incinerated, while only 9% of primary plastics were recycled. A 2019 report from the Center for International Environmental Law found that plastic production and incineration release more than 850m tCO2e/y into the atmosphere.

The eLECTRO project says initial life cycle analyses show the overall process could reduce greenhouse gas emissions by 90% compared to today’s best available technology.