Bonjour bio-based binders

How can Shell speed the whole road construction sector on its way to decarbonisation? Professor John Read and Richard Taylor have a few ideas.
April 5, 2023
Blacktop Paving Road with Paver and Dump Truck | Photo: Shell
Blacktop Paving Road with Paver and Dump Truck | Photo: Shell

Shell Bitumen has transformed into Shell Construction and Road. It’s not that Shell no longer makes bitumen binders; in fact, it remains one of the industry’s few specialists in this field. It’s more about taking in  the bigger picture: the new business unit, was created to support the decarbonisation of the construction industry across the entire value chain by leveraging its  strong binders business, Shell’s expertise in low-carbon fuels, and its knowledge of cleaner energy solutions.

And so, we now have Shell Construction and Road. By concentrating on harder-to-abate sectors such as aviation, marine, road freight among others– Shell argues that it can have a bigger impact on cutting carbon across the board.

Bitumen, PMB plant, UK, 2015 | Photo: Shell
Bitumen, PMB plant, UK, 2015 | Photo: Shell

“We want to help the entire construction sector to decarbonise,” says Professor John Read, Head of Technology at Shell Construction and Road. “Construction accounts for a very large proportion of global carbon emissions, around 37percent 1, depending on how you measure it.”

As the name suggests, Shell Construction and Road will not be limiting itself to materials for roads, but aims to  also support its partners with decarbonisation solutions for logistics and on-site operations and facilities.

Looking beyond bitumen

Decarbonising bitumen itself is going to be quite a challenge explains Shell Global Product Technology Manager Richard Taylor. “If you look at the carbon footprint of bitumen, we estimate that something like 80percent comes from crude oil extraction, transportation and exploration and the other 20percent comes from the refinery process.”

Shell has a pathway for decarbonising its refineries, says Taylor, and there are also decarbonising pathways for transport and marine shipping in the making.  

“When you start to look at the various levers, it becomes clear that substitution will become quite an important one alongside decarbonising the refinery process for bitumen.”  

Hong Kong-Zhuhai-Macau Bridge | Photo: Shell
Hong Kong-Zhuhai-Macau Bridge | Photo: Shell

By substitution, Taylor means using bio-residues to substitute part - and eventually all - of the bitumen binder. “We used to make roads from tar which was a by-product of the coal energy system. So, as the energy system evolves to include more bio-sourced materials there will be materials arising from that which will be suitable for road construction.”

Shell’s recently launched Shell Bitumen CarbonSink is a step in that direction, says Taylor. CarbonSink contains bio-based binders which lower its embodied carbon and, Shell says, effectively sequestrates some of the carbon taken in by the bio material into the road.

Shell is assessing and evaluating many different bio-residues, looking to identify several solutions for different parts of the world, to avoid adding to their embodied carbon with lengthy journeys. “We do not want to be transporting these bio residues huge distances because that defeats the whole object of using them,” says Read. “You need to have a localized supply.” That’s why Shell has not said what the bio-material based component of CarbonSink is, says Read – it will vary from country to country.

Different biogenic components have very different properties, and take different times to grow. “You have to understand the growing cycle and any land use or land use change implications,” advises Taylor. “You also need to understand the origin of the material, and how that is being managed.”

Bigger picture

Nenthead Image from Drone | Photo: Shell
Nenthead Image from Drone | Photo: Shell

Beyond bitumen and more sustainable binders, Shell is using some of its global research resource to investigate ways to lower the carbon emissions of other solutions for the construction sector and reduce the industry’s reliance on fossil fuels. Last year saw Shell sign separate memoranda of understanding with both Hanson and CRH to work together to decarbonise materials, transport and processes.

For example, with India-based Dalmia Cement, the team are using the physics-based modelling to show how a switch in feedstock would affect both the upstream and downstream production operations and generate insights both into the projected emissions reduction from a change in design or technology. The tools being developed   can even be customised to provide bespoke decarbonisation pathways for other cement plants around the world. Shell is also forging ahead with plans to build Europe’s largest hydrogen plant, Holland Hydrogen I in the port of Rotterdam. Powered by an offshore wind farm, the hydrogen will partially supply the Shell Energy and Chemicals Park Rotterdam, one of Shell’s main industrial sites, grouping a refinery and a chemical manufacturing site.

Approaching energy saving from another angle, Shell’s MachineMax digital platform for off-highway fleets aims to use artificial intelligence (AI) to minimise fuel use and better manage tasks. “By monitoring the vibrations of the machines, we can work out whether they're idling or working, see where their location is, and then help to optimise the entire system, for instance by reducing the number of machines being used,” explains Read.

Procurement must change

When it comes to more sustainable roads, there’s no silver bullet, says Taylor. And actually, there is no need for one.

“We already know how to meet the majority of the challenges for a net zero asphalt  pavement,” he says. “We have already started looking at the main levers: substitution with bio-residues, biofuels at the burner, electrification of transport. Most of these technologies are reasonably well developed. It is really a question of having the will to implement them.”

Penrith | Photo: Shell
Penrith | Photo: Shell

A big barrier to implementation- and to decarbonisation - is the way that roads are procured. Specifications need to be changed to prescribe performance and contracts need to look at the distribution of risk differently to enable new technologies to be deployed without just one party shouldering all the risk of failure.

“If we had performance-based specifications, we could determine whether or not something was going to perform in the application in which you want to use it, and therefore you would be able to take it forward,” says Read. Instead, any contractor or client wishing to deviate from standard specifications has to jump through so many bureaucratic hoops that the additional time and cost required makes deviation from the norm unviable.

What this has meant in practice is that new technologies which could have cut the carbon footprints of our roads long ago have not spread. Warm mix for example has been around for 25 years  but is not well established in most countries around the world. The technology behind polymer modified bitumen (PMB) has been around for 50 years, says Taylor, but based on data from EAPA (European Asphalt Pavement Association) it is still only used in roads in 15-to-20% of the global market.

A contemporary example of the time it takes to get new technology to market is Shell’s Cariphalte AgeSafe bitumen binder designed to slow the aging of bitumen, and hence extend the life of a pavement. Over ten years in the making, based on extensive research and with multiple trials completed, it is being commercially launched later this year.

STCB (Shell Technology Centre Bangalore) 2018 | Photo: Shell
STCB (Shell Technology Centre Bangalore) 2018 | Photo: Shell

“There is a real big disconnect between the speed of adoption of innovation, the speed of change in the road market, and the net zero plans that are being laid out by the highways authorities,” says Taylor. “Some net zero plans have target dates of 2040 or even 2035.”

Although Shell won’t be extending its services to procurement advice, it is aiming to be a strong advocate in this area. Together with Deloitte, Shell is currently working on an extensive market research looking into the barriers and opportunities for decarbonising construction, with findings due later this year. Barriers identified are likely to include procurement and specifications, as well as tools and skill requirements.

Hard road ahead

One of the challenges for road authorities, given the tools they currently have at their disposal, is how to properly measure carbon emissions over the whole life of the road. “We have to move away from the cradle-to-gate view – which is most carbon  emissions calculators – for asphalt,” says Taylor. “We need to move to whole life carbon  emisions, known as cradle-to-grave, which requires an understanding of service life.”

The perennial problem of capital cost versus whole life cost – and now whole life carbon cost – are another hurdle for road owners who want to make the case for new technologies. Until carbon pricing, and a global trading scheme for carbon are established, this will remain an issue, says Read.

STCB (Shell Technology Centre Bangalore) 2017 | Photo: Shell
STCB (Shell Technology Centre Bangalore) 2017 | Photo: Shell

“We are also looking at the environmental product declarations (EPDs) that we are starting to generate for all of our products, and working out how we can make them as informative as possible,” adds Read.

But even working out what a carbon  emissions baseline is can be demanding, given that carbon calculation is an emerging specialism in most markets, with the possible exception of some Nordic countries .

Read’s advice to road authorities is to start somewhere. “Whether it is baselining, understanding exactly what is in the materials that are in your road, or evaluating low-carbon technology, they are all good first steps,” he says.

Like Shell itself, road authorities are being forced to look more closely into their supply chains and to consider their carbon emissions withing the bigger picture of regional or national net zero goals. “Sometimes starting is the hardest thing,” says Read. “But if we do not start somewhere, we will never get to where we need to go. We just need to start, and we will learn the rest as we go along.”

Content produced in association with Shell

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