Producing next-generation biofuels from filamentous cyanobacteria: An economic feasibility analysis

The need for renewable, sustainable sources of biofuels continues to increase as the world's population continues to grow. Using microorganisms as biofuel producers is one area that is being researched extensively for this purpose. Anabaena sp. PCC 7120 is a filamentous strain of cyanobacteria capable of fixing atmospheric nitrogen, and has been genetically engineered to produce limonene, a cyclic hydrocarbon which has potential as a next-generation biofuel. This study analyzed the economic feasibility of a theoretical next-generation production facility that uses genetically engineered Anabaena 7120 to produce limonene. The economic feasibility of a limonene production facility was analyzed using the Farm-level Algae Risk Model (FARM). This model is an integrated systems compilation of numerous technoeconomic models that has been used previously in several algal production scenarios. FARM simulated 10 years of operation for the production facility for two scenarios. The 1st scenario used actual limonene productivity data (0.018 mg/L/d) from a genetically engineered strain of filamentous cyanobacteria, while the 2nd scenario used a 'best case' assumption that limonene productivity can be increased 100-fold (1.8 mg/L/d). It was determined that the average probability of economic success of the 1st scenario at year 5 was 0%, while the average probability of success of the 2nd scenario was 100%. Assuming no fractional reductions in OPEX and CAPEX, the average net present value (NPV) at year 5 of the 1st scenario was -$588 million, compared to $392 million for the 2nd scenario. Further analysis determined that a limonene productivity of 1.02 mg/L/d is needed to yield an NPV of 0 dollars at year 5. This study shows strong evidence that a next-generation biofuel production facility utilizing genetically engineered strains of filamentous cyanobacteria could become economically feasible in the future if strains are developed with increased biofuel productivities. (C) 2016 Elsevier B.V. All rights reserved.