The concept of the biorefinery is essentially identical to that currently used within the petrochemical industry, i.e., fractionation or conversion of feedstocks into high value products. Instead of using oil as the feedstock to ‘crack’, the idea is to separate or convert biological feedstocks, usually referred to as biomass. In its broadest terms, ‘renewables’ could mean any organic matter that becomes available on a continuous basis. This could include grasses, energy crops such as willow or Miscanthus, agricultural feeds, or organic waste streams from animals and plants. Rather than attempt to encapsulate all these diverse areas, the focus in this article will remain on the applications of plant biomass.