Development of a Life Cycle Assessment Tool for the Analysis of Food Production Systems within the Energy, Water and Food Nexus

As the demand for services and products continues to increase in light of rapid population growth, it is vital to ensure the sustainability of the natural resources. Critical to this growth is the question of energy, water and food security. The systems representing these three resources are intrinsically interdependent where impact on any one of them will have a simultaneous impact in the remaining two. As such, there is a need to develop assessment tools that consider the interdependencies of energy, water and food (EWF) systems in order to ensure that system dynamics are understood and disturbances are avoided where possible. For instance, when evaluating the environmental performance of a food production system, aggregating the system in terms of its agriculture, water and energy components is critical to develop a lifecycle blueprint of the system. The EWF Nexus tool has been used to describe food security in Qatar from a local environment perspective. The tool is a culmination of well-established theories related to system design and analysis such as Industrial Ecology and LCA with emphasis on EWF inter-linkages. The modularity of the nexus model enables the integration of a variety of different technologies which promote the de-materialization of the system and the subsequent evaluation of different configurations. The basis of which is to identify and achieve maximum emission reduction. This paper reports recent work expanding the LCA modelling tool of the EWF Nexus developed by the authors (Al Ansari et al, 2015). Through the integration of greenhouse gas control technologies, sub-system analsysis and scenario development, the objective is to enhance the environmental performance of Qatar's food production system. Using de-materilization and waste minimisaiton strategies promoted by Industrial Ecology, the objective of EWF Nexus tool is to reduce environmental degradation in business as usual scenarios. This includes the integration of waste management strategies and technologies to reduce the overall life cycle environmental impact of the Qatar Food system. Waste management strategies and greenhouse gas control technologies are represented by additional sub-systems which convert waste material to energy and capture of CO2 from power generation. As part of the LCA, sub-system LCI models representing the EWF systems have been developed. The food portion of the nexus is represented by the production of fertilizers and agricultural activities such as the application of fertilizers and the raising of livestock. The livestock under management include broilers, dairy, beef, sheep and camels. The water portion of the nexus includes Multi-Stage Flash (MSF) and Reverse Osmosis (RO) for the production of water. Finally, the energy sub-system considers power generation from a combined cycle gas turbine plant (CCGT) and renewable energy from solar Photovoltaics (PV). Furthermore, a biomass integrated gasification combined cycle (BIGCC) is integrated to recycle solid waste into useful forms of energy to be re-used within the nexus. Finally, carbon capture (CC) technology is integrated to capture and recycle CO2 from both the CCGT and the BIGCC. The integration of CC with the BIGCC transforms the carbon neutral BIGCC process to a negative GHG emission technology with carbon capture and storage (BECCS). For the different scenarios and subsystem configurations considered, the global warming potential can be theoretically balanced (i.e. eliminated) through the integration of PV's, BIGCC and CC technology. The peak GWP, i.e. a fully fossil fuel dependent system, is recorded at 1.73 × 107 kg CO2 eq./year whilst the lowest achievable GWP is 2.18 × 107 when utilising a combination of PV, CC integrated with CCGT in addition to BECCS technology. The natural gas consumption to − 7.8 × 107 kg/year in the best case configuration achieving a credit. In the same scenario, the PV land footprint required is calculated to a maximum of 660 ha. The maximum theoretical achievable negative emission is 1.09 × 109 kg CO2/year.