1.2.1 Defining biorefineries and bio-processing

In addition to the definition of green chemistry given previously in Section 1.1.1, two additional definitions need to be highlighted in this chapter: the term ‘biorefinery’ and the term ‘bioprocessing’.

A biorefinery is an analogue to the current petro-refinery, in the sense it produces energy and chemicals. The major difference lies in the raw material it will use, ranging from biomass to waste. The use of clean technology is another imperative for the biorefinery, ensuring its output(s) are truly sustainable. The IEA Bioenergy Task 42 defines biorefining as ‘the sustainable processing of biomass into a spectrum of bio-based products (food, feed, chemicals and/or materials) and bioenergy (biofuels, power and/or heat)’ (IEA, 2009). Various biorefinery designs of varying size and output number will emerge commercially in the future (Cherubini, 2010), taking advantage of flexible technology, helping the concept of a biorefinery to process locally available biomass to its fullest in an integrated fuel — chemical-material-power cycle, improving cost-efficiency, the quality of life of the local population and lowering the environmental impact governed by the three dimensions of sustainability (environmental protection, social progress and economic development; see Fig. 1.4). Networks of biorefineries are to be considered too, for maximum resource efficiency.

Bio-refining should not be confused with bioprocessing. A bioprocess is any process which uses biological organisms (e. g., enzymes) to carry out targeted chemical or physical transformations. A bioprocess can be used as part of the conversion process in a biorefinery along with other low environmental impact technologies such as microwave chemistry or aqueous phase catalysis processing. This illustrates how important it is to interconnect different disciplines such as chemistry, chemical engineering, biotechnology and biology together with techno-economic and sustainability assessment, as they are crucial for the development of a successful fully integrated biorefinery. Biomass is a term applied which includes a great variety of different and often complex plant components embedded in a matrix that differs according to the origin of the biomass used. A multi-disciplinary approach is therefore necessary to maximize the value of the products obtained while using green chemistry technology.