Techno-Economic Assessment of Producing Refinery Feedstock From High Impact Algae Feedstock

Microalgae, derived from sunlight, carbon dioxide, water and inorganic salts through photosynthetic process can be a future renewable source of biomass to produce liquid biofuels. Algae slurry with 15-20% solid content, produced by Raceway cultivation and centrifugation can be a direct feedstock to produce refinery ready biocrude using thermochemical liquefaction (TCL) and hydrodeoxygenation (HDO) technologies. However, high concentrations of nitrogen and water in the algae biocrude are the key challenges to generate refinery ready biocrude. Two stage TCL process was proposed to limit nitrogen content in the biocrude followed by catalytic HDO technology. The main objective of this study was to investigate a techno-economic assessment (TEA) of algae to refinery feedstock conversion platform for its commercial viability and economic competitiveness with petroleum crude oil.  A discounted cash flow model was developed using the commercial process simulation platform to estimate the capital and operating cost of producing refinery ready algae biocrude. Microalgae to biocrude system consists of raceway with primary harvesting by algal floway technology followed by centrifuging, two state liquefaction, hydrodeoxygenation and distillation processes.  Bench scale performance data for each unit operation were used to generate 100 barrels per day plant capacity. A sensitivity analysis on algae productivity, liquefaction yield and catalytic HDO yield on the final cost of producing refinery feedstock was conducted and compared with crude oil price. The developed TEA model can be used to optimize various parameters for each unit operations to produce low cost algae biocrude.