Life cycle assessment of integrated seawater agriculture in the Arabian (Persian) Gulf as a potential food and aviation biofuel resource

Abstract

Purpose: Prospective evaluation of the lifecycle impacts of aviation biofuel production in Abu Dhabi, UAE based on a production system that integrates aquaculture, saltwater agriculture, and mangrove silviculture, termed an Integrated Seawater Energy Agriculture System (ISEAS) in order to investigate its energetic and environmental potential compared to conventional fuels. Methods: We compare the hydroprocessed renewable jet fuel (HRJ) produced from ISEAS against fossil jet fuel using a life cycle assessment (LCA) methodology. Based on a detailed description of the production process, we use data from a wide-ranging literature review and experimental results from the specific location to make informed assumptions for the range of the process inputs and yields. We then analyze several process configuration scenarios with different ranges. Results and discussion: ISEAS can produce aviation biofuels, electricity, and food while afforesting coastal desert land, acting as a long-term sink for carbon, minimizing freshwater consumption, and having beneficial land use impacts when compared to fossil jet fuel production. Based on a sensitivity analysis, we show that ISEAS HRJ emits 38 to 68% less greenhouse gases than fossil jet fuel and yields an overall positive net energy balance under all scenarios except one with an extensive use of desalinated water. Conclusions: ISEAS offers a promising pathway for integrating aquaculture and seawater agriculture in arid regions. It is essentially a process to sustainably augment aquaculture-based products by using its waste as a biofuel resource. Achieving positive emissions results depend critically on minimizing freshwater use, maximizing biomass yield and to a lesser extent the performance of biomass gasification.