The global population’s increasing appetite for consumer goods is placing enormous strain on the resources needed by the world’s manufacturing industries. Meanwhile, our consumer society also produces vast quantities of waste. In this seminar, Professor James Clark explores how green chemistry can help us to address both these problems by extracting valuable chemicals, metals and other materials from waste.
Abstract
Increasing demand for consumer goods from an increasing world population is placing enormous strain on the resources needed by the world’s manufacturing industries. Traditional resources have often been from non-renewable sources but these are finite, their exploitation non-sustainable and they are becoming scarce. At the same time, the wastes from the consumer society have been allowed to accumulate in landfill sites which are now filling up in many developed countries leading to the export of waste to developing countries. This “out-of-sight, out-of-mind” reaction to the problem can create serious health and safety problems and is completely non-sustainable.
Industrial symbiosis seeks a closed loop approach to the twin problems of resource and waste by making the latter the solution to the former. To fully exploit this idea and make it widely useful to both inter- and intra-sector industry transfer while maintaining environmental advantage, we need to use Green Chemistry. Food wastes are especially useful as sources of organic chemicals for a variety of processes and products; examples include the physical modification of polysaccharide wastes as novel Starbon materials which have excellent metal-binding properties – metal-rich waste streams can become invaluable future sources of metals as traditional sources decline and the environmental an economic costs of new mines goes up.
Chemically modified polysaccharide wastes can also be converted to switchable and flame resistant adhesives and the ashes from burning biomass can act as a source of silicate binders. One very interesting large volume food waste that is chemically rich, is citrus peel – we grow over 100 million tons of oranges every year and a high proportion of these are juiced leading to millions of tons of chemically rich peel all over the globe – we can extract valuable chemicals and materials from this peel. New, energy efficient conversion technologies that can convert a wide variety of waste streams into valuable chemicals include low-temperature microwave processing, supercritical carbon dioxide extractive fractionation, green solvents, mesoporous bio-materials and phytomining. Examples will be given from all of these areas.
Biography
James Clark leads about 100 people as Professor of Chemistry and Director of the Green Chemistry Centre of Excellence and the Biorenewables Development Centre. James has been at the forefront of green chemistry worldwide for 20 years: he was founding scientific editor of the journal Green Chemistry, and is senior editor for the RSC Green Chemistry book series, and President of the Green Chemistry Network. He has numerous recent awards including the RSC Environment Prize, the SCI Chemistry for Industry award, and an honorary doctorate from Ghent University. He has over 400 articles and written or edited over 20 books.