Cool asphalt to cut carbon emissions?

UK industry leaders start trials to wipe over a third off asphalt carbon footprint by 2020

The UK is set to slash the carbon emissions of road works and cut traffic delays following the announcement today by the Carbon Trust of pilot projects to develop the market for low temperature asphalt.

Companies including Tarmac, United Asphalt and Aggregate Industries have partnered with the Carbon Trust to invest in projects that could cut energy bills and wipe a combined 339,000 tonnes of carbon off the asphalt industry's annual footprint by 2020, equivalent to 39% of current emissions.

The majority of UK asphalt is currently produced at around 170 degrees Centigrade but lower temperature ‘cold mix' and ‘warm mix' asphalt uses less energy to produce and can be ready to drive on much sooner. With cold mix this can reduce road works by anything up to 12 hours, cutting congestion and disruption.  Using cooler asphalt also reduces many health and safety risks associated with higher temperature materials.

The trials will also test heat recovery technology to reduce the carbon emissions from the burner that heats and dries the aggregates: the main energy consumer in the hot asphalt manufacturing process.

Dr Mark Williamson, director of innovations at the Carbon Trust, said:

"There are huge carbon savings to be gained from using cooler asphalt. We are partnering with the leaders in the UK industry to prove the benefits so that more cooler asphalt will hit our roads soon.

"The Carbon Trust has already launched a carbon-reduction strategy to help the aggregates industry reduce its carbon footprint by 20% and shave some £45million a year off its energy bills. We are now targeting the next level of carbon savings by demonstrating innovative technologies and solutions that could cut carbon across the industry and help cut the UK's carbon footprint."

The Carbon Trust is providing funding for the projects through its £15m Industrial Energy Efficiency Accelerator.  Following a call for proposals in September last year the Carbon Trust has so far selected three consortia to take forward projects, each of which will take around two years to complete:

• Tarmac, Nynas, Atkins and MIRO will demonstrate semi warm and cold mix asphalt with the aim of securing approval from highways operators at a local and national level for colder types of road surface. This approval is needed for wider industry uptake.  The Carbon Trust is contributing £275,000 of funding for the project with the consortium providing £410,000.  The technology could save 118,000 tonnes of carbon per year across the industry by 2020.
• United Asphalt, Shell Bitumen and Berkshire Engineering will seek to maximise the amount of reclaimed asphalt which can be used in road resurfacing by combining warm mix asphalt and an innovative new aggregate dryer.  West Berkshire Council will seek to utilise this innovative material within the district of West Berkshire as soon it becomes available.  The technologies could reduce an asphalt plant's carbon emissions by up to 22% and by 2020 could be saving over 188,000 tonnes of carbon across the industry each year.  The Carbon Trust is contributing £237,000 of funding.  The project team is providing £358,000.
• Aggregate Industries will install an innovative heat recovery system at its Haughmond Hill site in Shrewsbury.  Developed by Econotherm, it will cut energy use by using waste heat to pre-heat the air combusted in the asphalt burner.  Trials will tackle issues including moisture and dust in the recovered hot air.  By 2020 the technology could be saving 33,000 tonnes of carbon a year.  The Carbon Trust is contributing £195,000 of funding.  The project team is providing £219,000.

The Carbon Trust has been working closely with the aggregates sector over the past two years to identify opportunities to improve energy efficiency and has now published a report of it findings called ‘Industrial Energy Efficiency Accelerator - Guide to the asphalt sector'.  

The Carbon Trust has a dedicated manager, David Pratt, to ensure that opportunities for energy saving and emissions reduction are maximised within the sector.

Dr Nizar Ghazireh, the project director from Tarmac, said: "Working to continuously improve the sustainability and carbon efficiency of road materials is of key importance to Tarmac, Nynas and Atkins, and we are delighted to be working with the Carbon Trust on this project. The team will be running trials using semi-warm and cold temperature asphalts, designing mixes that can help to speed up road works and creating industry-standard design specifications that can easily be adopted by highways operators. The ultimate aim is to create wider market acceptance of these lower temperature, lower carbon materials and evaluate their whole-life carbon impact. By making the critical step from technical development to commercial uptake, the team hopes to unlock the significant environmental and practical benefits that these materials can deliver, and create more carbon efficient roads."

Ross Snape, managing director of United Asphalt said: "This pioneering project has the potential to fundamentally change the asphalt industry in the UK, producing sustainable low carbon products.   We are delighted to be working with the Carbon Trust, our innovative technology partners and a forward thinking supply chain and client, who are committed to making a step change in the performance of the industry.   In these times it is unacceptable to continue to ignore the sustainable resource and new technologies we have available to re-use recycled asphalt pavement and produce low energy products that have the same performance as hot mix asphalt.  With this innovative project we will be able to manufacture products that could halve the carbon footprint of traditional asphalt products"

Paul Taylor, UK carbon manager of Aggregate Industries, said: "As a key part of the supply chain for construction materials, Aggregate Industries has long recognised the part it can play in the UK's transition to a low carbon economy. Innovations like this are needed and we are pleased to have been selected to participate in the IEEA programme."

Technical manager at MPA (Mineral Products Association) Asphalt, Malcolm Simms, welcomed the announcement by the Carbon Trust, noting: "As responsible operators, MPA Asphalt members support the Government policy of reducing emissions of greenhouse gases.  For those companies involved, the assistance provided by Carbon Trust with investment for innovative products and processes will clearly be a significant boost, particularly in the current challenging economic climate.

"I hope that the projects will identify and enable the adoption of practical, value-driven and transferable means by which the whole of the sector can make a contribution to UK emissions reduction targets."

The Carbon Trust's Industrial Energy Efficiency Accelerator aims to transform the traditional sector-specific processes that underpin British manufacturing. In partnership with industry leaders, the organisation is identifying and demonstrating new, lower-carbon solutions that can be replicated widely across each sector, saving an average of 28% on energy costs and carbon emissions.  The Carbon Trust is currently working with the asphalt, animal feed, plastic blow-moulding, dairy, bakery, confectionery, paper and brick-making industries and plans to engage a total of around 25 sectors.