Breaking with Tradition, Part 2. Cereal Biorefineries

Cereals will necessarily be part of the mix of renewable raw materials for sustainable chemical and energy industries in the 21st century. As well as their immediate contribution to slowing oil depletion and alleviating climate change, cereal biorefineries have a strategic role to play during the next few “transition decades” in leading eventually to lignocellulosic biorefineries that will avoid the current food versus fuel issues. In the meantime, however, oil refining provides both the competition and the model for cereal biorefineries. Oil refining benefits from a relatively cheap and easily processed feedstock. However, since the 1970s oil crisis, oil refineries have increasingly benefitted from the development and extensive application of process integration, in which energy and process streams are recovered and reused to give economic and energetic efficiencies. Obtaining the benefits of process integration requires numerous co-products leading to complex processes that offer scope for effective and extensive application of integration; thus oil refineries gain exceptional efficiencies by being extremely complex and interlinked. By contrast, cereal biorefineries are relatively simple and have limited scope for integration. Emergent cereal biorefineries thus suffer a double disadvantage in competing with oil, limiting their commercial competitiveness and compromising their environmental benefits. In order to achieve complexity, oil refineries operate a fractionation/conversion model which cereal biorefineries must also adopt, drawing on and enhancing the fractionation expertise that operates within traditional flour milling. This paper will present recent work on the application of process integration approaches to cereal biorefineries, and on synergistic opportunities to enhance both the food and non-food uses of cereals together.