6 New Technologies Which Could Improve Urban Air Quality

May 5, 2016

It’s fair to say there is now a growing sense of urgency about the need to clean up air pollution in the UK, in particular in London. Policy Exchange recently published reports setting out both the scale of the air pollution challenge in London, and a range of policy solutions. The High Court recently granted permission for lawyers ClientEarth to take Defra back to court to challenge the adequacy of the Government’s latest air pollution plans. The EFRA select committee released a report criticising the Government’s plans, and 29 MPs have signed an Early Day Motion calling for action on diesel emissions in urban centres. Air pollution has also become one of the key issues in the London Mayoral race, with all of the main candidates focusing heavily on the issue in their manifestos (see our analysis here)..

Our most recent report on air pollution considered many of the key technologies to tackle air pollution, including lower emission vehicles (including electric, hybrid and LPG), car sharing, and lower emission sources of heat and power. Whilst the role of these technologies in reducing air pollution is generally accepted, there are also numerous other emerging technologies which could also play a role in the future.

Here is a selection of technologies I have been reading about recently:

Gas to Liquids: one solution to tackle emissions from diesel vehicles is to switch to alternative fuels. Whilst electric and LPG offer completely separate fuel systems, there are also other options which offer the potential to clean up existing diesels. For example, Shell has developed a new synthetic “gas to liquid” (GTL) fuel derived from natural gas which is a “drop in” replacement for diesel (i.e. the engine requires no modification). Testing has shown that the use of GTL in heavy duty vehicles such as trucks, buses and ships could reduce Nitrogen Oxide (NOx) emissions by 5-37%, and Particulate Matter (PM) emissions by 10-38%, depending on the vehicle age. GTL fuel is already being produced in significant quantities globally, and is available commercially in the Netherlands, but its use is currently very limited in the UK. Similarly, natural gas can also be converted into dimethyl ether (DME) – another potential alternative to diesel. It is thought that the use of DME reduces NOx emissions by around 25% (compared to a standard diesel), and virtually eliminates PM emissions.  DME is less straightforward to implement than GTL in the sense that it requires some engine modification, although manufacturers such as Ford and Volvo are apparently investigating the potential to bring vehicles to market which use DME as a fuel.

Hydrogen Fuel Additives: reductions in emissions can also be achieved by improving the fuel combustion cycle in existing vehicles through the use of additives. The ezero1 technology produced by UK developer CGON does this by feeding small amounts of hydrogen into the vehicle air intake such that it creates a more efficient burn. Independent tests show that this increases fuel efficiency, whilst reducing emissions of NOx, PM, Hydrocarbons and Carbon Monoxide. The technology can be retrofitted to existing cars and vans (petrol or diesel) and is available commercially, although to date has only been sold in relatively small numbers.

Autonomous vehicles: one of the mega-trends in the automotive sector is the move towards autonomous vehicles or “self-driving cars”.This could fundamentally change the way that vehicles use the road network, reducing the stop-start nature of traffic (which is partly caused by the way that we humans drive cars), and opening up the possibility of “vehicle platooning” on motorways. A range of studies have estimated that autonomous vehicles could improve fuel efficiency by 15-40%, reducing emissions of local pollutants as well as greenhouse gases, not to mention the benefits in terms of safety and congestion. Volvo has launched plans to trial driverless cars in London by 2017, whilst the 2016 Budget also contained a number of measures to promote connected and autonomous vehicles.

Liquid air: New technologies are also being developed to address very specific sources of pollution. For example, a growing source of pollution in cities comes from refrigerated vans and trucks. It has been estimated that there are around 84,000 transport refrigeration unitson the road in the UK, each of which emits 29 times as much PM and six times as much NOx as a modern truck. Whilst trucks are subject to emissions standards, the auxiliary engines used to power refrigeration units are largely unregulated and are highly polluting. Technology company Dearman is developing an alternative system based on the use of “liquid air”, which produces zero emissions on the road.

Photo-catalytic materials: An alternative to cleaning up emissions from vehicles directly could be to deploy technologies which remove pollution from the ambient air. For example, a number of companies are developing photo-catalytic treatments which remove pollutants from the air in the presence of sunlight. These treatments can be applied to a range of surfaces, for example roofing tiles, roofing felt or even the surface or roads. A recent report by the Environmental Industries Commission suggested that applying photo-catalytic treatment to roads is amongst the cheapest options to reduce PM and NOx pollution, although it acknowledged that further trials of the technology would be required to understand its potential. However, contrary to this, a recent report for Defra found “no compelling evidence” that the use of these treatments would actually reduce NOx pollution.

Air purification: Developers are also looking at other ways of cleaning air in urban environments. Studio Roosegarde, a Dutch design company, has developed the “Smog Free Tower” – an air purifying tower which sucks in pollution and expels clean air. The extracted pollution is, somewhat bizarrely, turned into pieces of jewellery. The first tower has been installed in Rotterdam (paid for by a kickstartercampaign), and the designers claim that a single tower could clean 3.5 million cubic metres of air per day. They plan to roll out the smog free towers across other global cities.

These are but a few examples of the many technologies out there to reduce pollution. The challenge for policymakers will be how to support new technologies from research through to commercialisation, whilst avoiding “picking winners” and ensuring that technologies do deliver claimed improvements in air quality. Some of these technologies (such as the fuel additives mentioned above) offer fuel savings, which may help to drive their adoption by vehicle manufacturers and owners. Other technologies face policy barriers which could be removed – for example the uptake of gas-to-liquid fuels has been hampered by fuel standards, although this is changing. A key question for Government is around where to focus its limited research budget.  Considerable UK research funding is going in to next generation Ultra Low Emission Vehicles. However, given the overwhelming contribution of existing diesel vehicles to urban air pollution, there is arguably a need for more research into retrofit technologies. The European Commission recently launched a €1.5 million research prize for diesel retrofit technologies, but given the scale of the challenge the Government could do more to support innovation in this space.

We’d love to hear about other technologies to improve air quality. Email me at richard.howard@policyexchange.org.uk.


Richard Howard

Richard Howard
Director of Development & Head of Environment & Energy Read Full Bio

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