While traditional resources are becoming scarce, the wastes these resources eventually become are leading to serious pollution problems in the atmosphere, land and seas.  Waste valorization is becoming more popular but it is mostly small scale and with low efficiency. The most chemically interesting of the large volume wastes includes forestry and agricultural by-products, and many industrial wastes.  Current waste valorization is largely limited to simple recycling and anaerobic digestion for bio-wastes.  However, these renewable resources can form the basis of future waste valorisation plants including bio-refineries that can make a wide range of chemical, material and energy products. To fully exploit the concept and make it widely useful while maintaining environmental advantage, we need to use Green Chemistry to ensure that future processes using, and products from waste are genuinely green and sustainable. Green chemical technologies that can convert waste streams into valuable chemicals include low-temperature microwave processing and benign solvent extraction.  The integration of thermo-chemical and bio-chemical technologies will also become increasingly important as we seek to increase the efficiency of biomass conversion and develop efficient chemistry on fermentation broths. In this way we have shown that microwave pre-treatment of biomass substantially increases the yield of fermentable sugars. 

These processes can produce bio-based platform molecules  which in turn can be used to make many new green bio-based products. Countries including the UK are beginning to identify their priority platform molecules that can form the basis of new green and sustainable supply chains. For example the new bio-based solvent cyrene, can easily be made from the platform molecule levoglucosenone which is made in one catalytic step the woody waste in paper and pulp mills.  Cyrene is already commercially available and its invention has led to international awards.  

New solvents and many other new “green” chemicals are becoming essential as increasing legislation adds to pressures to replace hazardous substances.  We need new strategies to find greener replacements including our in silico approaches to help refine the list of potential candidates.  In this way we are able both to identify likely replacements for a toxic chemical and target the most likely applications for new greener chemicals.  Two solvent-related examples will be used to illustrate this strategy: finding a safe alternative for toluene in some polymerisations and selecting the best bio-based solvent for the manufacture of graphene.

          
          Discovering the best green and sustainable solvents for the manufacture of graphene