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Research Interests

James D. McMillan works to advance lignocellulose and algal biorefining science and technology. His primary research and development focus is on lignocellulosic biomass conversion process technology development, integration, and scale up. He has more than 25 years of research experience on biochemical and sugar platform approaches to biomass conversion and integrating the key processing steps of pretreatment, enzymatic hydrolysis, and fermentation/microbial conversion to efficiently and cost-effectively produce biofuels and bio-based chemicals from cellulosic feedstocks.

McMillan currently leads the National Renewable Energy Laboratory (NREL's) Biomass Program's Separations Development and Applications task. Previously, he also led NREL's Integrated Biochemical Process Improvements Validation and Enzyme Validation tasks, supporting the U.S. Department of Energy (DOE) by auditing and verifying performance and cost improvements being achieved in DOE cost-shared projects in these technical areas. Additional research interests include:

  • Lignocellulosic biomass compositional analysis

  • Biomass deconstruction via pretreatment and enzymatic hydrolysis

  • Submerged enzyme production, particularly on biomass-derived carbon sources

  • Mixed sugar fermentation to fuels and chemicals, including hydrolysate toxicity issues

  • Biorefinery process development and integration, including in-process and product recovery separations

  • Monitoring and control of biochemical conversion processes, including mass balancing

  • Conversion process performance measurement and validation

Affiliated Research Programs

McMillan also coleads the International Energy Agency's Bioenergy Task 39 focused on accelerating technology development and commercialization of liquid biofuels, and he cochairs the annual Symposium on Biotechnology for Fuels and Chemicals. In addition, he is a section editor for the open-access journal Biotechnology for Biofuels and a reviewer for several other journals and U.S. and international funding agencies. McMillan is a member of the American Chemical Society and the American Institute of Chemical Engineers (AIChE), where as a former elected director of the Food, Pharmaceutical, and Bioengineering Division he helped to grow AIChE's biorefinery-related programming (which has since become part of AIChE's Sustainable Engineering Forum). He has served on numerous doctoral and master's students' theses committees, and he is or has been an adjunct faculty member in the Colorado State University, University of Colorado, and University of Puerto Rico chemical engineering departments.


  • Ph.D., Biochemical Engineering, Massachusetts Institute of Technology (MIT), 1990

  • M.S., Chemical Engineering Practice, MIT, 1985

  • B.S., Chemical Engineering, Colorado State University, 1982 (with distinction)

Professional Experience

  • Chief Engineer, NREL, National Bioenergy Center (NBC), 2014–present

  • Group Manager, NREL, NBC, Biochemical Process Science & Engineering, 20072013

  • Co-Leader, IEA Bioenergy Task 39 ("Liquid Biofuels"), International Energy Agency, 20042006

  • Senior II Group Manager, NREL NBC, Biochemical Refining Process R&D, 20042006

  • Senior Biochemical Engineer II, NREL NBC, 19982004

  • Senior Biochemical Engineer I, NREL Biotechnology Center, 19941998

  • Staff Biochemical Engineer, Solar Energy Research Institute/NREL Alternative Fuels Division, 19901994

Featured Publications

  1. "The Potential and Challenges of Drop-In Biofuels," IEA Technical Report (2014)

  2. "Comparative Performance of Pre-commercial Cellulases Hydrolyzing Pretreated Corn Stover," Biotechnology for Biofuels (2011)

  3. "Calculating sugar yields in high solids hydrolysis of biomass," Bioresource Technol. (2010)

  4. "Comparative Study of Corn Stover Pretreated by Dilute Acid and Cellulose Solvent-Based Lignocellulose Fractionation: Enzymatic Hydrolysis, Supramolecular Structure, and Substrate Accessibility," Biotechnol. Bioeng. (2009)

  5. "Rheology of corn stover slurries at high solids concentrations—Effects of saccharification and particle size," Bioresource Technol. (2009)

  6. "Soluble and insoluble solids contribution to high-solids enzymatic hydrolysis of lignocellulose," Bioresource Technol. (2008)

  7. "Methodological Analysis for Determination of Enzymatic Digestibility of Cellulosic Materials," Biotech. Bioeng. (2007)

  8. "Kinetic modeling to optimize pentose fermentation in Zymomonas mobilis," Biotechnol. Bioeng. (2006)

  9. "Measurement and Analysis of Intracellular ATP Levels in Metabolically Engineered Zymomonas mobilis Fermenting Glucose and Xylose Mixtures," Biotechnol. Prog. (2006)

  10. "Dilute Sulfuric Acid Pretreatment of Corn Stover in a Pilot-Scale Reactor: Investigation of Yields, Kinetics, and Solids Enzymatic Digestibilities," Appl. Biochem. Biotechnol. (2003)

  11. "Simultaneous Saccharification and Cofermentation of Dilute-acid Pretreated Yellow Poplar Hardwood to Ethanol Using Xylose-fermenting Zymomonas mobilis," Appl. Biochem. Biotechnol. (1999)

View all NREL Publications for James D. McMillan.

Awards and Honors

McMillan is a coinventor on two issued patents, corecipient of two R&D 100 awards, and author or coauthor of 8 book chapters, 45 peer-reviewed publications, more than three dozen nonpublished technical reports, and more than 150 posters and presentations.