(Updated Mar 21st, 2014)
"Conversion of Algal Biomass to Liquid Fuels by Hydrothermal Processing in Continuous-Flow Reactors"
by: Douglas C. Elliott, Pacific Northwest National Laboratory (PNNL)
M.B.A., Operations and Systems Analysis, University of Washington, 1980
B.S., Chemistry (Departmental Honors), Montana State University, 1974
Chemical and Biological Process Development Group
Pacific Northwest National Laboratory (PNNL)
Algae has been identified as a high growth biomass with great potential for fuel production to reduce petroleum imports and reduce greenhouse gas emissions. The standard view for algae utilization has involved growth of oil-producing algae under stressed conditions that maximize lipid production. By this process extractable vegetable oil can be recovered and a lipid-extracted algae (LEA) byproduct is left. Alternatively, hydrothermal conversion (processing in hot, pressurized liquid water) is a valid option that was investigated for use with high-moisture content algae streams.
The utilization of the LEA for energy production is one opportunity investigated at PNNL. Specifically, bench-scale testing of catalytic hydrothermal gasification (CHG) for conversion of LEA to produce a fuel gas product for energy recovery and a clean aqueous byproduct for nutrient recycle was demonstrated.
More importantly, the use of hydrothermal liquefaction (HTL) conditions was demonstrated to process whole algae thereby recovering the inherent lipid but also converting a significant portion of the biomass (LEA) to an oil. Liquefaction of whole algae produced oxygenated viscous bio-oil products. The bio-oil product thus produced was further upgraded to hydrocarbon liquid fuels by catalytic hydroprocessing. Effective hydrodesulfurization and hydrodenitrogenation were demonstrated in addition to hydrodeoxygenation. Subsequent treatment of the aqueous byproduct of the HTL step by CHG was shown to effectively convert the organic material carried in the aqueous byproduct into high yields of medium-Btu fuel gas, composed essentially of methane and carbon dioxide.
Each of these steps was investigated on the bench scale in continuous-flow processing reactor systems at PNNL. Results for each of the processing steps will be presented.
Mr. Elliott has over 39 years of research and project management experience at the Pacific Northwest National Laboratory (PNNL). His work has mainly been directed toward development of fuels and chemicals from biomass and waste. His experience is primarily in high-pressure batch and continuous-flow processing reactor systems. This research has also involved him in extensive study of catalyst systems. Mr. Elliott’s research has involved such subject areas as biomass liquefaction and hydroprocessing of product oils, catalytic hydrothermal gasification of wet biomass and wastewaters, and chemicals production from renewable sources. He has authored or coauthored over 80 peer-reviewed papers and book chapters. He is listed as inventor or coinventor on 21 US patents with numerous foreign filings and was recognized as a Battelle Distinguished inventor in 2004.
Tuesday, April 15, 2014.
Jagerhaus 2525 E Ball Rd., Anaheim, CA
by the 57 Freeway
Local Section Members, $30; Others $35 with a reservation, $40 at the door; Students $10 with reservation, $15 at the door; Unemployed/Retired, $20 with reservation, and $25 at the door.
Please respond by April 11th Noon by
sending an e-mail reservation to
calling Alan Benson at (909) 724-9029.