“Asphalt is a good example of a medium-scale energy user where the energy requirements of the manufacturing process are not very well understood.”
(The Guardian – UK) — Following a pilot scheme targeting the aggregates industry, among others, a clean tech programme is now being rolled out to bring innovative low-carbon technologies and energy-saving measures to other sectors of UK industry.
When we fill up at the petrol station, we may think about the price of fuel, how far that fuel will take us, and possibly even the carbon our journey will emit. But how often do we consider the carbon footprint of the road that we drive on?
As you pull away from the petrol station, you may not be aware that you are driving on a revolutionary road that will make the asphalt under the tyres as important as the energy efficiency under the bonnet on Britain’s journey to a lowcarbon future.
Britvic, Highland Spring and Tarmac are just some of the household names now in the low-carbon fast lane thanks to the Carbon Trust’s Industrial Energy Efficiency Accelerator (IEEA) scheme. The programme is at the vanguard of the Carbon Trust’s Clean Tech Revolution campaign which aims to help British businesses lead the second industrial revolution in the clean tech sector, which it says could be worth £127bn by 2015.
The IEEA will target British manufacturing with an investment pot of £15m over four years to help innovate low-carbon technologies and energysaving measures. These innovations will ultimately be a vital tool in tackling climate change as they are disseminated across industry to help Britain reduce carbon emissions by 80% by 2050.
Henrietta Stock, technology acceleration manager at the Carbon Trust, says: “Industry is responsible for 25% of the UK’s total CO2 emissions. It’s a big problem and it’s difficult to deal with. In a manufacturing business, the majority of your energy use is in the process of making your particular product. Opportunities like more efficient lighting and heating controls which apply to your typical high street business aren’t as relevant.”
The Carbon Trust selected three manufacturing sectors – aggregates, animal feed and plastic bottle manufacturing – for a pilot scheme that was completed this year. The scheme will now be extended to 20 further sectors which are outside the EU Emission Trading Scheme (ETS) scheme, but still subject to other schemes such as the Carbon Reduction Commitment trading scheme, due to be introduced in April 2010, Climate Change Agreements and Climate Change Levy.
Aggregates, animal feed and plastic bottle manufacturing sectors together produce 3.62m tonnes of CO2 annually.But the Carbon Trust estimates that manufacturers in these three sectors could cut energy costs by £80m and reduce their carbon emissions by nearly half a million tonnes a year. The pilot phase found that up to 90% of energy demand was used in manufacturing, but the carbon output of these processes can be reduced by an average of 28%.
Stock says: “Asphalt is a good example of a medium-scale energy user where the energy requirements of the manufacturing process are not very well understood.”
Hanson Quarry Products is one of the UK’s largest suppliers of asphalt and includes the Highways Agency among its clients. The company spends around £14m on asphalt production a year. Funding from the Carbon Trust’s accelerator programme has enabled the company to continue its work on energy efficiency, says Martin Crow, Hanson’s head of environment.
“As energy becomes more expensive,” Crow says, “we have to find ways of saving money while tackling environmental considerations too, as customers become increasingly interested in the embedded carbon.”
Embedded carbon is becoming of increasing concern with retailers further up the supply chain. This summer Tesco began adding carbon footprint labels on its dairy products, and more recently the supermarket gave the Carbon Trust accelerator scheme its backing.
Stock says: “All three of the sectors we targeted in our pilot phase – aggregates, plastic bottle manufacture and animal feed – impact on the carbon footprint of your pint of milk.
“Animal feed manufacture takes raw materials like wheat and other grains and turns them into a pellet that delivers just the right nutrients to dairy cows to maximise their production of milk. “Plastic bottle manufacture often takes place on the same site as the dairy, filling the bottles immediately with the milk. Transporting bottles of milk to the supermarket wears down roads over time, along with all the other traffic. This creates a demand for asphalt to repair and replace road surfaces.”
The Food and Drink Federation and Dairy UK – both heavy users of plastic bottles and animal feed – have also given the accelerator scheme their backing. Energy consumption for the plastic bottle sector is around 755GWh with carbon emissions of approximately 400,000 tonnes of CO2. The Carbon Trust accelerator pilot found that new heating techniques could make up to 75% energy savings.
The animal feed industry, which has a UK carbon footprint of some 620,000 tonnes of CO2 per year, has also embraced the accelerator scheme. Nigel Hillyer, from Carrs Billington, says that the Carbon Trust has provided valuable expertise to give the animal feed manufacturer “a fresh perspective” on potential ways to reduce its annual £2.5m energy costs.
“We already work at 80%-90% operational efficiency. It’s about cost savings, but also from a moral position: customers are going to be asking what is the carbon footprint of what they are buying, and the farmer is then going to ask the feed supplier. It’s a win-win situation with carbon: if you make carbon savings, then you make financial savings from reduced high-cost energy inputs.”
As the government drives the UK towards 80% decarbonisation, industry will have to cut back its emissions by 21% by 2022. Reducing the carbon footprint of everything from the roads we drive on to the pint of milk we buy will all play a part on the revolutionary road to Britain’s lowcarbon future, says Stock of the Carbon Trust.
She says: “The IEEA is a catalyst that brings whole industry sectors together to make step-changes in energy efficiency in a way that individual companies acting alone struggle to make. It also builds capacity and skills in energy management in those industries which help position them better for making long-term deep cuts in emissions.”
Tonnes of advice
The accelerator scheme identifies areas for energy saving in the aggregates industry
Hanson is one of the UK’s largest suppliers of aggregates and construction materials. Its quarry division spends around £30m on energy costs, and up to half of that is spent on the energy-intensive production of asphalt – one of the world’s most versatile building materials that covers around 95% of roads, pavements, car parks and airport runways.
At Hanson, the average energy consumption is 110kWh per tonne of asphalt, but at its most energy-efficient plant in Penderyn, south Wales, just 70kWh is required to make one tonne. Hanson runs 40 plants around the country which produce an average of around 160 tonnes of asphalt an hour, with varying degrees of efficiency.
Heating aggregate accounts for more than 60% of all energy use on an asphalt manufacturing plant. The aggregate is first heated to dry it and allow it to bind with hot bitumen, a product derived from crude oil and traditionally heated to around 175C. The resulting “hot mix” has to be kept at a high te
mperature during transportation and while it is laid on roads and pavements.
Martin Crow, the head of environment at Hanson, says finding ways to increase burner efficiency, improving insulation so that heat is not lost during manufacturing and keeping aggregate dry before the production process, will be key in reducing energy demand across its 40 UK plants.
He says: “The accelerator scheme has provided valuable expertise in identifying areas where we can reduce energy demands. The project was to prove to the industry where we can make energy savings but backed by a bit of science rather than a gut feeling.
“Most of our asphalt goes to the Highways Agency and local authorities, and we’re finding that clients are increasingly asking us about the energy efficiency of a particular site.”
Hanson has also supported the Mineral Products Association in working with the Highways Agency on a database that will enable companies to calculate the carbon footprint of a section of asphalt, to meet this customer demand.
Mat Newton, energy manager, says that energy efficiency is becoming increasingly important industrywide as energy prices increase and environmental policies are enforced. He says: “One of the main aims of joining the accelerator was to raise awareness across the industry of the technology available and finding new uses for technology, sharing information and developing best practice. Sustainability credentials are important in the industry.”
Clean tech spec
Carbon Trust accelerator findings and aims for the aggregates industry There are some 1,300 quarries in the UK producing £3bn aggregate products every year. The aggregates industry annually produces 2.6m tonnes of CO 2, accounting for about 1.7% of UK industry carbon emissions.
Stage one of the accelerator pilot found that in the aggregates industry:
Transport accounts for 35% of CO2 emissions in the sector
Asphalt production is responsible for 25% of emissions.
Stage two will look at:
Development of a market for lower temperature-mixed asphalt. Mixing asphalt at lower temperatures could save 80% of energy required for a traditional hot-asphalt mix.
Heat recovery for preheating combustion air systems. Some 12% of the input energy is wasted as hot air which exits from the stack. This is relatively low-grade heat and hot air which can contain particulates.
Advanced burner control on the asphalt plant. Between 1%-5% of input heat is lost as unburnt or partially burnt fuel. An advanced burner control system with oxygen measurement could control fuel ratio and increase energy efficiency by improving automation.
Evaluating new low-carbon vehicles versus conventional inquarry vehicles. More than 20% of the emissions from the aggregates sector relate to material movement. Vehicle emissions could be reduced through hybrid technologies, suitable for the quarry environment.