Food, Energy, Fuels and Chemical Feedstocks from Rice Crops: Multi-Objective Optimisation of Multi-Product Value Chains for the Philippines

Rice is an important staple food in the Philippines such that its 20 M metric tons annual production places the country rank 8th among the rice producers in the world. However, there are many improvements in the efficiency and sustainability of the Philippines rice value chains that could be made by addressing various constraints related to technological, environmental, economic and socio-political factors [1]. Consequently, the Philippine government is striving to achieve Philippine rice competitiveness and to transform its value chains to be more profitable, resilient and sustainable; they recognise the importance of research and development as basis for such a laudable goal [2]. From a recent analysis of the Philippine rice value chain commissioned by the government, by-products like rice straw, rice hull and rice bran can be important sources of raw material for other industry sectors. Ninety-five percent of the rice bran is being used as animal feed component while seventy percent of the of the rice hull is being used as an alternative source of energy and fuel. Moreover, the silica-rich rice hull ash is being used as additive in the cement industry [3]. These could not only provide affordable renewable energy, fuels and materials but also much-needed rural development and employment opportunities. However, there are complex issues that need to be addressed: rice production is a water- and energy-intensive activity. The global water footprint from rice production is 1308 Mm3/year with irrigated rice cultivation consuming the most water. Energy is required for the production of fertilisers, electricity for pumping water and heat for parboiling, drying and other milling activities [4]. Furthermore, the limited land for rice cultivation is being threatened by the rapid and unregulated conversion of agricultural land to other uses [1]. In this project, a comprehensive optimisation model, based on mixed-integer programming [5-6], is being developed that can support complex decision-making related to multi-product rice value chains and can capture the trade-offs between water, energy and land utilisation. The model is used to identify promising rice value chains for sustainable and efficient production of food, energy, fuels and chemical feedstocks. In this conference, we will present the optimisation model and the key findings from the case studies.