(455d) High Value Products from a Photobioreactor-Based Biorefinery

Authors: 
Chance, R. R., Georgia Institute of Technology and ExxonMobil Research and Engineering
Fishbeck, T., Algenol Biofuels
Yuan, Y., Georgia Institute of Technology
Fiato, R., Accelergy Corporation
Though Algenol continues research and development activities aimed at biofuels (ethanol and biocrude), increasing emphasis is being placed on high value products and co-products that can both provide sustainable income and serve as a market entry/risk reduction strategy for eventual development of biofuels. Algenol has successfully built and operated a large pilot scale (2 acre) integrated biorefinery (IBR) based on its proprietary photobioreactors (PBRs) and genetically modified cyanobacteria to produce fuel grade ethanol via an EPA approved pathway (70% carbon footprint reduction compared to gasoline). Ethanol productivities in the range of 4000-5000 gal/acre-yr (annualized) have been achieved. However, the system is not economic under current market conditions. The IBR and R&D support infrastructures are now being applied to higher value products, including a biocrude co-product. Though several products are under active consideration, algae based soil amendment is one application that is well advanced in our product development pipline. The soil amendment contains nitrogen-fixing cyanobacteria as the active component (based on Anabaena and/or Nostoc strains). The formulated product provides enhanced yields as a biofertilizer, can be used as a soil amendment for reclamation of degraded soil, and can result in high carbon storage levels in the soil.1,2 This talk will use the soil amendment application as an example and provide a description of the selection process for product development (e.g., techno-economics, life cycle impacts, compatibility with PBR growth systems) and the development process from the lab, through outdoor testing, and then to pilot scale deployment. In particular, the alignment of indoor and outdoor performance will be demonstrated for several strains relevant to the above application, along with a modeling system that has been developed for productivity prediction for any rational position on the earth’s surface, and for various configurations for Algenol’s vertically-oriented PBR arrays. Harvesting and downstream processing will be described and experimentally demonstrated for several cyanobacterial strains, including strains designed for biocrude production. A comparison of the relative productivities and economics of PBR systems versus open pond systems will be discussed.

1Accelergy Corporation, “Montana Integrated Carbon to Liquids Study,” US DOE Award Number: DE‐FE0003595, December 2013.

2US Patent2014/0345341, November 27, 2014; “Integrated Process for Producing Fuels and BioFertilizers from Biomass and Products Produced.”