An energy, water and food nexus approach aiming to enhance food production systems through CO2 fertilization

As part of the drive for global food security, all nations will need to intensify food production, including those situated in hyper arid climates. The State of Qatar is one such example of a national system that whilst it is presented with environmental challenges, seeks to enhance food security. The energy, water and food (EWF) nexus approach is an effective means to accurately ascertain resource consumption, identify synergies and trade-offs, and quantify environmental burdens in the delivery of products and services. The EWF nexus theory has been uniquely applied to a hypothetical food system in Qatar where sub-system model's representative of EWF systems are developed. It has been suggested that the fertilization of agricultural systems with CO2 can enhance their productivity. The study described in this paper considers the life cycle yield improvements which can be made possible at the faun level by utilizing the captured CO2. This requires a modification of the EWF nexus model to consider the spatial characteristics of the modelled elements. The newly built model is used to investigate the CO2 transport methods (pipeline and truck), and distance that CO2 captured from combined cycle gas turbine (CCGT) and biomass integrated gasification combined cycle (BIGCC) sub-systems which may then be transported for CO2 fertilization, and yield improvements to be justified from an energy utilization perspective. In this regard, an integrated analysis using GIS-based optimization is applied where the sub-systems are represented as geospatial elements together with their design constraints, such as the capacity-related parameters of the fertilization systems, and the energy requirements of the transport network connecting the CO2 sources with the fertilization systems at multiple greenhouse locations in Qatar. These form part of the problem formulation for the determination of optimal locations of food production systems using Non-Linear Programming (NLP) to ensure the feasibility of CO2 fertilization and realize environmental improvements within the overall EWF nexus framework. The results indicate the optimal locations and extents for new greenhouse developments that are constrained by the available farming infrastructures and CO2 transportation options to balance for the net energy and water requirements for food production.