15 Oct 2014
Lucie Pfaltzgraff was awarded an AJ Banks Travel Bursary earlier this year. Lucie was able to present a talk at the 5th IUPAC International Conference on Green Chemistry organised in Durban. Here Lucie shares her experience of participating.
The conference attracted chemists from all over the world: representatives from Brazil, Iraq, India, France, the U.S.A. and Canada, amongst others were present. I was selected to present a talk entitled 'Use of microwave hydrothermal technology for the sequential recovery of chemicals from orange peel residues' as part of the Ultrasounds and Microwaves session. My participation was made possible by SCI, which awarded me with an A. J. Banks travel grant. My talk summarised the biorefinery process developed using microwave technology under acid-less and additive-free conditions for the extraction of D-limonene, flavonoids, sugars and pectin from waste orange peel. I was pleased by the helpful and insightful comments and questions asked following my talk. They represented a rewarding opportunity to discuss my research further following the end of the session. This specific session on microwave technology allowed me to gain further insight into the application of microwaves for the production of MOFs materials for example.
The event offered a great opportunity to understand the different drivers and motivations leading to the implementation of the Green Chemistry principles in each country. Drivers for the implementation of clean technology vary from country to country and the use of Fischer-Tropsch and variety of natural resources (i.e. coal, rare metals) means heterogeneous catalysis and engineering in domains such as liquid and gas fuel production is particularly important for this specific region. Hence there is a world of difference between the American approach focusing on the toxicology of chemical compounds and the European approach which has now moved onto the use of waste as a renewable feedstock, and more specifically food supply chain waste. Interestingly, the later approach is now relayed in developing countries (i.e. India, Tanzania).
The main recurring themes of the conference included the new developments for heterogeneous catalysis in the area of Fischer-Tropsch conversion, a process which is very important for South Africa’s economy since it owns no oil fields for the production of liquid fuels. The heterogeneous catalysis system used for the conversion of syngas obtained from solid fuels (i.e. coal mainly but also biomass and methane) to liquid fuels (i.e. diesel) is at the center of intense academic research to avoid the use of transition metals (use of Cu instead of Co or Fe).
Heterogeneous catalysis for the conversion of water to H2 is another very important research area in South Africa. Research focuses here on proton exchange membrane fuel cell. Using this technology, the organisation HySA of the University of the Western Cape in Cape Town, has for objective to meet 25% of the global fuel cell catalysts demand by 2020.
The use of bio-based materials for energy storage (i.e. MOFs for hydrogen storage), chemical & metal capture (i.e. metal recovery- phytomining) and catalytic support (i.e. bio-derived carbon nanotubes from fly ash, sucrose-derived mesoporous materials development or Fischer-Tropsch) came across as the connecting theme of the different sessions. The increasing popularity of hydraulic fracturing, especially in the U.S.A. is responsible for a renewed academic interest in the chemistry of natural gas.
The chemistry of carbonates was also heavily emphasised at the conference. Prof Michael North from the University of York was awarded the Green Chemistry Award by the Royal Society for Chemistry in this specific area. The talk he gave at this occasion highlighted his work on the synthesis of cyclic carbonates as a route to greener polar aprotic solvents for example, using the amino acid (S)-proline as a catalyst. This example also illustrates the use of alternative catalysts at a time when the systematic use of rare metals such as ruthenium for example is criticised. This area has been highlighted in Prof North’s talk with the use of metals such as Co or Ti for asymmetric catalysis of carbonates.
Being especially interested by a career in industry, I found one talk in particular very interesting: Dr Michel Philippe highlighted the achievements of the French cosmetic company L’Oreal in the area of Green Chemistry. L’Oreal has made a point to implement the Green Chemistry principles in its R&D activities since 2005 and sees it principally as a source of innovation. The company’s concerns for the cradle-to-cradle life cycle of its products has been translated into the development of a tool allowing for the estimation of the footprint of the water necessary to dilute the pollution generated by the use of their products.
One of the company’s most successful anti-ageing ingredients, Pro-Xylan, has been synthesised in 2007 based on the Green Chemistry principles. The sugar Xylose is used as a starting material and is sourced from beech trees. The synthesis of this C-glycoside is based on two steps only, including a condensation reaction with a diketone and a retro-Claisen aldol condensation, avoiding the use of protecting/deprotecting reactants.
One notable sponsor of the event was the Organization for the Prohibition of Chemical Weapons (OPCW). The international NGO, which won the Nobel Peace Prize in 2013, gave several talks to advocate the use of safer, non-toxic chemicals and chemical processes in order to allow easier detection of chemical weapon manufacturing through routine audits under the Chemical Weapons Convention. This particular organisation highlighted its willingness to recruit chemists specialised in Green Chemistry, offering an interesting additional career path for new PhD graduates in this area.
Overall I really enjoyed learning more about Green Chemistry being applied to a different field than mine. This event helped me gain a better understanding of the hurdles Green Chemistry faces in different parts of the world. Understanding the different nature of the challenges the chemical industry faces to become more sustainable in different countries and their drivers is crucial for my future career in industry. Additionally, I have made several interesting contacts in areas not traditionally associated with Green Chemistry.