Nov-2022

Creating value from wastes to help achieve net zero

Transport fuels and circular economy products from wastes are essential ingredients in the energy transition journey towards net zero.

Mark Whittle
Greenergy

Article Summary

As part of the UK Government's roadmap to net zero, the sale of new petrol and diesel cars and vans will be banned from 2030. Hybrids and some heavy goods vehicles (HGVs) will follow in 2035, with all conventional vehicles banned from 2040. UK consumers are taking note of this legislative change. In 2021 alone, 190,000 electric vehicles (EVs) were sold, more than the combined sales of EVs in the previous five years (SMMT, 2022). Today, one in eight new cars sold are EV (SMMT, 2022) and the figure will progressively rise in the coming years, but will it be at a rate to meet the fast-approaching net-zero deadline? Are battery-powered vehicles going to be the solution to transition to net zero?

EVs can only be part of the solution. HGVs are one of the most difficult transport sectors to decarbonise, with electrification and hydrogen solutions only possible in some applications in the mid to long term. We cannot ignore the huge challenges in electrifying larger and HGVs and the constraints in power generation, distribution infrastructure, and the raw materials needed to produce EVs. Also, with the average lifespan of a passenger car of scrappage at around 14 years (SMMT, 2022), it is important we acknowledge that vehicles powered by gasoline and diesel will be on the road for some time following the ban.

So, the question is, what more can be done during the transition period to accelerate decarbonisation?

One answer is biofuels. Biofuels have played an important and increasing role in the decarbonisation of vehicle emissions. Given their success in reducing greenhouse gas (GHG)emissions from road transport, there is an increased focus on how biofuels can be deployed into other modes of transport, including maritime and aviation as well as road.

For some time, biofuels will remain one of the most readily deployable, scalable, and renewable options available; however, current biofuel production is not enough to achieve net zero. New approaches and new advanced biofuels will be needed to meet the demand for low-carbon fuels during the transition period.

Background
For 30 years Greenergy has been working on cleaner road fuels and producing biofuels. We have become an industry leader in the development of waste-based fuel solutions for transport, producing biodiesel from used cooking oil.

Greenergy's original low-sulphur fuel changed the standard for diesel fuel products for road transport in the 1990s, reducing harmful air pollutants and driving real carbon emission reductions. Today, we are Europe's largest manufacturer of waste-based biodiesel and are now applying our expertise to the broader waste-to-renewables sector through projects that support decarbonisation and enable net zero. The challenge is to continue to innovate and produce low- and no-carbon fuels and renewables that can be supplied at scale.

Our current focus is on broadening the range of waste feedstocks, and how best to bring them into the circular economy and repurpose wastes such as used cooking oil, tyres, household waste, and plastics to create next-generation renewables, transitioning from waste to energy to waste to X.

Utilising waste feedstocks, we can make a significant positive environmental impact and contribution to the circular economy by creating value through developing solutions to reduce carbon emissions and waste overall. Repurposing waste products also reduces our reliance on the current approaches of adding to landfill, exporting wastes, or using waste to generate electricity. Our experience in efficiently delivering products of this kind ensures that these potential renewable solutions can be adopted at scale with security of supply and domestic production.

Renewables from waste tyres
One of the projects we are actively developing utilises the traditionally environmentally troublesome waste stream of end-of-life tyres as a feedstock.

Every year, some 1.5 billion tyres worldwide come to the end of their useful lives (Williams, 2017), and this will not change with the switch to electric vehicles. Tyres are difficult to recycle and are non-biodegradable. As such, a new approach is required to deal with the waste tyres thrown away and in need of disposal each year. In the UK, some 55 million waste tyres are disposed of annually, either by burning them here in the UK or exporting them, and this is not a sustainable or responsible solution when considering the valuable products that are intrinsically held in this waste stream (Hartnell, 2022).

With a site in Teesside under development and the engineering FEED phase underway, Greenergy's Green Tyre Technology (GTT) project is integrating conventional, commercially proven processes and technologies to transform tyres into transport fuels such as lower carbon diesel as well as carbon black that can be reused in tyre production. This large-scale project will create a significant environmental improvement compared to the current disposal of waste tyres. The plant will utilise existing and proven technologies from world-renowned partners to produce a waste-to-value solution based on years of development and testing to prove each aspect and the process as a whole.

The GTT project will recycle waste tyres from the UK market and create valuable end-use materials, including advanced diesel, naphtha for advanced gasoline blending or as a petrochemical feedstock, low-sulphur marine fuel for blending, and at the same time producing a recovered carbon black (rCB) for reuse in the tyre manufacturing process, creating a circular economy. Supplying the naphtha to petrochemicals to make new tyres or green plastics also supports a circular economy.

The planned facility will be capable of processing up to 155,000 tonnes of tyres per year, using five pyrolysis reactor trains, making it the largest tyre pyrolysis facility in the UK.

To help deliver the project, Petrofac, a leading international engineering and construction (EPC)service provider, is undertaking the engineering FEED contract to design the plant and develop a turn-key engineering, procurement and construction contract. Having previously delivered pyrolysis plants at scale, thyssenkrupp* has been engaged to deliver the pyrolysis technology and brings extensive experience in the oil and gas sector.

The process
At the facility, tyres will be shredded and mulched, and the tyre mulch is then fed into the thyssenkrupp pyrolysis system. This process heats the feedstock in an oxygen-free atmosphere, so there is no combustion, thermally decomposing the mulch into solid, liquid, and gas phases.

Tyre-derived oil (TDO) is separated and extensively treated using proprietary technology to remove solids and other contaminants before being treated in a dedicated on-site hydroprocessing plant to refine and enhance the properties of the oil products, enabling the diesel product to meet UK diesel standards. Testing calculations show 85% savings in GHG emissions compared to fossil diesel, easily surpassing the 65% GHG threshold required for development fuels under UK legislation (UK Gov, 2007).

The hydroprocessing removes sulphur and other contaminants from the oil before it is separated into various product streams. This process will produce diesel, naphtha, and marine fuel, each containing significant biogenic fractions derived from the natural rubber used in tyre production.