Green and Sustainable Chemistry approaches have a major role in maximising agricultural productivity, while also preserving the environment and protecting human health. The growing need for diverse food sources, more effective fertilisers, pesticides and herbicides with no detrimental human and environmental effects, greener surfactants and greener polymers for agriculture, all require an emphasis on green chemistry approaches.
Agricultural endeavours world-wide are primarily focused on food production. Globally, one third of food produced for human consumption is categorised as lost or waste, which equates to 1.3 billion tonnes per annum. This loss represents the waste of potentially valuable materials such as proteins, simple and complex carbohydrates and lignin (collectively termed lignocellulose), oils and secondary metabolite extractives. In this presentation, several topics and relevant examples for valorising this by-product or discarded biomass will be presented.
A systematic approach first involves determining the chemical composition of the biomass by a variety of standard methods to identify what is valuable1. Following the identification of the more highly valued and accessible components (eg pectin, pomegranate oil and other extractives) a number of strategies for the extraction and purification of selected components are described2.
Other examples of green chemistry applications in agriculture will be covered including: development of an organic based fertiliser for more efficient nitrogen delivery3 and the application of lignocellulose and protein extracts for hydrogels and films for food preservation and water retention in soils4.
In all cases, Green and Sustainable Chemistry approaches were applied to give valuable products such as pectin, pomegranate oil and nanocellulose. In addition, a more effective nitrogen fertiliser was achieved as well as the use of by-product lignocellulose for the preparation of a sprayable mulch that could replace current plastic mulches used in the field.
1. NREL Biomass Compositional Analysis Laboratory Procedures
https://www.nrel.gov/bioenery/biomass-compositional-analysis.html