RePSIM metric for design of sustainable renewable based fuel and power production processes

The sustainability of chemical processes depends on three major pillars, namely, economic performance, environmental and social impacts. To design sustainable processes based on renewable sources and/or to compare fuels and technologies in view of their sustainability, a simple 3-D metric has been developed. It involves production and investment costs, the effect of the facility on the generation of jobs, the emissions of carbon dioxide, due to the consumption of energy and water, and their mitigation, due to the production of renewable based commodities and chemicals. The carbon tax is used to normalize the contribution of the use of resources and the substitution of products by the renewable counterparts into an economic basis. The metric is region specific. It can be used as objective function in process synthesis or as an offline tool for sustainability assessment. In this paper, a large number of biofuels, including several processing paths, and processes for the production of chemicals or power from solar and wind have been evaluated using the metric. The results show that the processes that generate a surplus of energy, like FT fuels, are more sustainable because of their emission mitigation potential. Furthermore, water availability determines the sustainability of solar based facilities.