Distributed marine biorefineries for developing economies

In the coming decades, developing countries will be responsible for significant increases in liquid fuel demand. There is an urgent need to develop alternative, preferably carbon-neutral, transportation fuels to supplement limited fossil fuel resources and minimize undesirable climatic change. While biofuels present a promising alternative to fossil fuels, sustainable biorefinery process design remains challenging. Efficiencies of scale realized by large centralized facilities are offset by increased feedstock collection and fuel distribution logistical costs. In this work, we use a thermodynamic balance approach to derive the optimal serviced territory size for a single biorefinery. We find that the optimal size decreases with increasing population density and per capita fuel consumption. We propose a modular, scalable, and sustainable biorefinery design based on the marine macro algae Ulva sp. To demonstrate the design principal, we provide an example marine biorefinery design for a coastal town of 20,000 inhabitants in rural India. Beyond basic biorefinery design, we consider biorefinery integration into distributed power sources and environmental impacts.