Sweden’s Enviro, a company developing, building and operating industrial plants for material recovery from End of Life Tyres (ELT), has formulated pyrolysis oil that can be used as fuel. That is the conclusion reached by RISE (Research Institute of Sweden) together with Enviro and Ragn-Sells in their research project, which was kicked off in October 2017.
“We’re currently at a stage where we’ve demonstrated that fuel can be produced from tyres and that pyrolysis oil is a feasible way for the petrochemical industries to reduce their consumption of fossil oil,” says Linda Sandström, project manager at RISE.
The project set out to evaluate three different approaches for upgrading pyrolysis oil to higher grade products, with a special focus on co-upgrading to fuels together with fossil raw materials in refinery processes.
“For the project, we characterised and upgraded pyrolysis oil through various refinery technologies. At RISE Energy Technology Centre’s laboratory in Piteå, we conducted pilot-scale experiments where we compared upgrading pure fossil oil to oil with 20% pyrolysis oil. The findings showed that that there were no significant differences between the two, and that pyrolysis oil is excellently suited to fuels.”
The next stage is to arrange for a continuation of the project in order to verify the findings as well as to prepare to commercialise the concept with pyrolysis oil in fuel.
“We’re looking for a refinery that’s willing to accept pyrolysis oil as a raw material for production and thereby start reducing its consumption of fossil oil. Once we’ve shown that the concept can be commercialised and that it’s profitable, the general hope is for the industry to be willing to participate and develop it further,” says Sandström.
For Enviro, the goal of its development efforts with RISE and Ragn-Sells is for pyrolysis oil to be priced on the basis of its value to the petrochemical industry as a fuel as well as from the perspective of sustainability.
“We’re extracting about 500 kilos pyrolysis oil from 1 tonne of tyres by means of Enviro’s patented technology. With a plant that processes 30,000 tonnes of tyres annually, that’s approx. 14,000 tonnes of oil per year available for the market. In other words, the financial potential is substantial. We’re looking forward to continuing the project and to explore the environmental and commercial benefits further,” says Thomas Sörensson, CEO of Enviro.
Recycling of end-of-life tyres represents both a big challenge and a great opportunity. Ragn-Sells has the task of collecting and recycling discarded tyres in Sweden, and today the tyres are used, for example, for its energy content and for making granules used as fillings in, for example, artificial turf. However, the tyres have potential for more high value recycling than direct combustion, and globally a large number of tyres are deposited every year, especially in developing countries.
At Enviro Systems’ recycling plant in Åsensbruk, discarded tyres are recovered in a pyrolysis process, where carbon black, pyrolysis oil, steel and gas are obtained as products. The carbon black, which is today the main product of the process, is of high quality and is sold to the rubber industry. The pyrolysis oil has great similarities with fossil oil, and therefore has potential to be used instead of fossil oil for the production of, for example, transportation fuels. Natural rubber in the tyre also makes the pyrolysis oil partially bio based. The pyrolysis oil from Scandinavian Enviro Systems consists of 48% of bio-oil.
Enviro says it has developed a process, based on a patented technology, where gas generated in the process is heating the tyres in absence of oxygen. This enables the materials in the tyres to decompose and be recovered instead of incinerated. Thus, a sustainable recovery of the resources carbon black, oil, steel and gas is obtained. Enviro was founded in 2001, has its head office in Gothenburg and runs its own plant for ELT tyres in Åsensbruk, Sweden.