Dr Gary Leeke, of Birmingham University, thinks he has an answer to a world awash with discarded plastic. He’s working to extract valuable chemicals from plastic waste.
Creative cities
More than half the world’s people already live in cities, with more joining them from the countryside every day.
Steve Rayner, Professor of Science and Civilisation at the University of Oxford, says: “Urban migration is tremendously exciting. You have much more creativity in cities: they give the poor the chance to become rich.”
But he wants cities to be flexible – responsive to technological change and environmental pressure.
He points to the classic top line of a typewriter keyboard – QWERTYUIOP. “It was designed to slow down typists so the keys wouldn’t jam,” he says. “But we still use it. We must avoid socio- technological lock-in.”
That can mean relearning old lessons – building natural cooling systems modelled on the Middle East’s classical wind towers, for example, and not relying on the air conditioners that worsen urban heat islands.
Watch Professor Rayner’s Tomorrows Horizons lecture
A technology called Concentrating Solar Thermal Power can store surplus heat from the solar arrays by day in liquid salt: “At night you use the salt to produce electricity. It’s the only advantage this technology has over photo- voltaics – but it’s an important advantage.”
Looking further ahead, Professor Düren has hopes of producing synthetic fuel: “If you combine sunlight, water and carbon dioxide at high temperatures you end up with liquid fuel and oxygen. It’s already worked in the lab, although not yet on an industrial scale.” High-voltage
power lines that use direct rather than alternating current will drastically cut transmission losses, he says, down to about 10% over 3,000 kilometres – enough to link Africa and Europe.
Professor Düren insists this is a vision that will benefit both continents: “Europe needs a secure energy supply and, even more importantly, a secure neighbourhood. Africa needs energy and, even more importantly, water. The EU-Middle East & North Africa Super Grid will provide jobs and energy – including enough to run seawater desalination plants – and give Africa’s
The trouble with recycling plastic waste is that it comes in so many different forms. The bottles used for soft drinks and milk can normally be recycled, but that still leaves a huge waste mountain.
Dr Leeke and his team had the idea of burning the waste not in an ordinary incinerator but in a dedicated plant that produces the energy needed to run the recycling part of the operation.
This cuts the costs of recycling, avoids the use of fossil fuel and saves the expense of transferring the waste to a landfill. They say the efficiency of converting the chemical energy in the plastic to heat and electricity is much greater than in a typical incineration system.
Watch Dr Leeke’s Tomorrows Horizons lecture
young people the prospect of a stable future.” Supporters of the DESERTEC Industrial Initiative (Dii) include Deutsche Bank.