Lowering the Energy Demand and Broadening the Scope of Renewable Polymer Manufacture

Our society is completely dependent upon polymers (plastics) in every facet of our lives; from clothes to computers to novel composites and cosmetics. But this brings problems. In 2010 every citizen of the USA discarded 140 kg of plastic into land-fill; and those figures are rising across the globe. As more of the World's economies move towards Western levels, we simply will not be able to continue to use polymers in the same way, nor will our oil reserves provide sufficient raw materials with security of supply.

There are alternatives, derived from renewable resources, and these can also lead to degradable polymers that could have a significant positive impact and could help solve the issues of landfill. But despite all the hype and expectation, renewables currently account for less than 5% of all polymers. One of the major routes to achieving better market penetration of renewable polymers is to lower the price, and one of the biggest fixed costs is in the energy required to carry out the polymerisation reactions that make these polymers on the commercial scale. Our industry partners have told us clearly that lowering the energy costs and shaving off a just a few pence per kg of the overall cost of the polymer would have a dramatic effect on their ability to sell more renewable polymers into the marketplace.

Our project addresses this issue directly and focuses on new energy efficient polymerisations. Our approach is novel, using high pressure carbon dioxide as a processing aid to enhance polymerisations at lower temperatures. If successful we will achieve not only significant energy savings, but also, by using lower temperatures, we will open up a completely new range of polymer properties, such as increased heat resistance and enhanced mechanical properties that have not been easily accessible before, and certainly cannot be achieved through the traditional high temperature commercial processes.

This project will tackle both the technical and engineering aspects around the use of high pressure carbon dioxide in polymerisation reactions and will provide new approaches to overcoming the key hurdles that are currently preventing larger scale manufacture of renewable polymers. Our project will also produce valuable life cycle and energy consumption data on our new process. These data will be useful in helping our industry partners to build a credible business case for utilising high pressure carbon dioxide to improve their processes and polymer products.

The chemistry using industries have set out stringent requirements to lower their impact on our planet. Initial targets were set over ten years ago, to be delivered by 2020 and included goals such as: lowering of feedstock wastes and by-products by 90%, reductions in energy intensity by 30%, reducing emissions by 30%, shrinking time to market by 30% and slashing production costs by 25%. Although great progress has been made, the goals have not been achieved across the sector, and there is still much to be done. The EU has recently looked carefully at these through the SPIRE 2030 Roadmap (Dec 2013) (www.spire2030.eu) which reinforces many of the same targets.

As well as being more sustainable, it is also vital that the UK chemistry using industries grow. This has been formalised through the Chemistry Growth Strategy Group which has initiated key discussions at UK government level with the aim of pushing forward strategies to grow the UK chemicals industry and its contribution to our economy. A key statement in their report is that "By 2030, the UK chemical industry will have further reinforced its position as the country's leading manufacturing exporter and enabled the chemistry-using industries to increase their Gross Value Added contribution to the UK economy by 50%" with "smart manufacturing" being one of the three priorities highlighted to achieve their vision.1

This tightly focused project addresses a key issue around smart manufacturing for one of the major chemistry using sectors - the polymer industry. Ours is a completely new approach to a long standing problem. As polymers grow in the melt, the viscosity increases and control of the polymerisation is lost. To overcome this, the temperature is raised and viscosity is lowered. However, raising the process temperature brings severe issues of energy usage in melt polymerisations and this is currently the limitation on pricing, and is preventing the market penetration of the valuable renewable polymers that our society needs. We have now understood how to use high pressure CO2 to dramatically lower the viscosity of the reaction process, and hence operate at much lower temperatures. This saves energy, and also as a consequence allows us access to new polymer structures through well-controlled, stereoselective polymerisations that would not otherwise be possible.

We focus on one particular polymer system, and our Impact Plan is designed around using the proof of concept data we will obtain to demonstrate the commercial viability of the technique. We will work closely with a committed industry partner with decades of expertise in this polymer system and we will show that our new approach has the potential to save energy, reduce costs and broaden the product portfolio.

The methods we develop will be transferable to other polymer systems across the sector. So a key aspect of our approach will be to disseminate the major outputs obtained during this 18 month feasibility study to a wider industry grouping. An important aspect of our impact plan is to put in place these dissemination routes using both our own internal Business Science Fellows and to work closely with skilled industry professionals who have written strongly supportive letters to demonstrate their engagement.

Our proposal is timely, there are stringent demands upon the sector, and there is a strong industry pull to develop new technologies that can deliver. This means we will be implementing our pathways to impact and manufacture to a very receptive commercial audience.

1. http://www.cia.org.uk/Portals/0/Documents/Growth%20Strategy%20FINAL.PDF