17 May 14:00
What does “sustainable” mean in the context of polymers?
Speaker: Prof. Anthony Ryan, OBE
The United Nations defines sustainability as “meeting the needs of the present without compromising the ability of future generations to meet their needs.” A definition that has stood the test of time and comes from the 1987 Brundt Report. IUPAC has a more recent definition of Green Chemistry “the invention, design and application of chemical products and processes to reduce or eliminate the use and the production of harmful substances,” and sees it as a basic element of the UNs’ recent Sustainable Development Goals, in particular SDG 9 “Build resilient infrastructure, promote inclusive & sustainable industrialization, and foster innovation” and SDG 12 “Ensure sustainable consumption and production patterns”.
The 2016 COP21 Paris Agreement (United Nations Framework Convention on Climate Change (UNFCCC) dealing with greenhouse gas emissions, mitigation and adaptation) commits us to reducing our carbon emissions across a whole range of technologies. Chemistry as a whole needs to facilitate the transition from fossil-based energy and feedstocks to renewable energy and feedstocks that are fundamentally based on the use of sunshine in real-time (solar and wind) and in particular to develop scalable means to store that energy.
Polymer production accounts for < 3% of crude-oil consumption and < 1% of the global energy budget and overall has a beneficial (i.e. net negative) effect on global emissions due to light-weight vehicles improving fuel consumption, thermal insulation reducing the need for heating/air-conditioning and sensible food packaging reducing food waste, to give but three examples. Polymers have an important role to play in energy capture (photo-voltaics and wind turbines) and storage (batteries and water splitting). So what we need to do straight away is stop burning the fossil resource and maximize its beneficial use – in making plastics and other petrochemicals.
Life cycle analysis shows that an “eco-bag” made from hessian has to be used 140 times to be less energy intensive per use than taking a new PE bag each time, and if you reuse the PE bag then the effect is compounded. Yet self-identifying green consumers prefer hessian and paper to “nasty” plastics even when the evidence tells them otherwise. Does polymer science suffer from the same problem in the current emphasis on “sustainable”, i.e. renewable, polymers? The feedstocks for sustainable polymers could come from renewable resources, but their production should use less water and energy than the petrochemicals they replace. Currently, commercial “sustainable polymers” are made from plant starch or oils, or more preferably from agricultural waste streams that do not compete with food production. But why use a renewable feedstock to make a plastic if it results in much greater GHG emissions because of all of the processes involved? A full life cycle analysis is needed to make the decisions about whether polymers are sustainable or not – focusing on whether the feedstock is renewable isn’t enough – and it should be done before the laboratory research is underway. And then making polymers from CO2 and putting them into landfill might actually be a great way to sequester carbon!
This lecture will conclude by looking at how crystallization of polyolefins can be manipulated to get the most in terms of their properties. How the most abundant source of biomass (cellulose) could be modified to make engineering materials processed from water. How polymer photovoltaics can produce far more energy from the sun than was need to manufacture them. And how polyurethane foam and polythene films can combine with solar desalination to make deserts fertile and take CO2 out of the atmosphere by using photosynthesis to grow food.
There is enough fossilized carbon to enable all these technologies and more. As long as we stop burning it! And this is the issue polymer scientists should unite behind
17 May 15:00
Level 4 Poster Session
Venue: Richard Roberts Atrium
Contact: Dr Seb Spain
Poster session for level 4 project students to present posters of their research. Refreshments will be provided and poster prizes will be presented at c.a. 4pm.
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