Oregon State University

Greg Rorrer

Professor of Chemical Engineering
School of Chemical, Biological, and Environmental Engineering
Oregon State University
Corvallis, OR 97331
Email:  gregory.rorrer@oregonstate.edu
Phone:  541-737-3370
[link to full CV]

B.S.  Chemical Engineering, University of Michigan, 1983
Ph.D. Chemical Engineering, Michigan State University, 1989

Greg Rorrer is on temporary assignment with the National Science Foundation as Program Director for the “Energy for Sustainability” program, beginning Aug. 24, 2009.

Current Research Group


The Rorrer Laboratory, summer, 2009.  Pictured (right to left), Greg Rorrer, Clayton Jeffryes (Ph.D.), Debra Gale (Ph.D.), Jennifer Rosenburger (M.S.), Aaron Goodwin (Ph.D.), Jeremy Campbell (Ph.D.), Jon Lebsack (undergrad), Chris Neighbor (undergrad).

Research Areas

Current research in the Rorrer Laboratory focuses on two areas: algal biotechnology, and biomass conversion.  In the algal biotechnology area, we are harnessing the unique biosynthetic capacities of photosynthetic marine algae in engineered bioreactor platforms for applications in pharmaceutical production, nanotechnology, bioremediation of toxic compounds, and biofuels production.  Two current projects are highlighted below.

Algal biotechnology for nanostructured semiconductor materials.  Single-celled, biomineralizing algae called “diatoms” consume soluble silicon to make microscopic silica shells which are ornately patterned in the nanoscale (1-100 nm range).  By controlled feeding of alternative substrates such as soluble germanium or titanium to the living diatom cells, we metabolically inserted semiconductor nanophases into the periodic structures of the diatom biosilica.  This process imparted optoelectronic properties to diatom microshell.  

Pictured above (left to right):  illuminated bioreactor, diatom cell suspension culture, micrograph of photosynthetic diatom cells.

Pictured above (left to right):  electron microscope image of nanostructured biosilica from the diatom Pinnularia

Thin films of optoelectronic diatom shells have enabled many device applications with unique performance characteristics, including an immunocomplex biosensor, an electroluminescent display, and a dye-sensitized solar cell.  

Pictured above:  photoluminescent diatom biosilica (top left), antibody-functionalized diatom biosilica with FITC-labeled antigen (bottom left), electroluminescent display material (top right), dye-sensitized solar cell containing diatom-TiO2 thin film (bottom right).

Algal biotechnology for biodiesel production.  There is renewed interest in the potential of algae for biofuels production, particularly where photosynthetic algal cells take up atmospheric CO2 and biotransform it to lipids which can be converted biodiesel.   Many species of diatoms described above are prolific lipid producers, with lipid contents exceeding 40 wt%.  We are developing bioreactor cultivation strategies to intensify and continuously sustain cellular lipid overproduction through controlled feeding of soluble silicon to the cell suspension during the cell division cycle.

Biomass conversion with microchannel reactor technology.  New reactor technologies are needed to efficiently convert renewable plant biomass to fuels.  Water in the “supercritical state” at temperatures greater than 374 C and pressures of greater than 218 atm can reform biomass to a hydrogen-rich gas which can be used in fuel cells.   However, poor heat transfer to the reacting fluid in conventional reactors results in long reaction times and is a barrier to process development.   We have developed a novel “microchannel” reactor to reform water-soluble biomass constituents to hydrogen-rich gas.  The narrow 100 micron channel diameters within the reactor intensify heat flux to the reacting fluid and completely convert carbohydrates to H2 and CO2 within a residence time of about one second.   The microchannel reactor was fabricated by scaleable microfabrication techniques, where a stack of micropatterned metal shims (stainless steel or hastelloy) were fused into a single block by a diffusion bonding process.




Pictured above (left to right):  assembled microchannel reactor and individual shim, cross-section of microreactor showing carbohydrate reforming.

Recent funding sources include the National Science Foundation (NSF, ended July 2009), Air Force Research Laboratory (AFRL), U.S. Office of Naval Research (ONR), Portland General Electric (PGE) Research Foundation, Bend Research Inc., Oregon Sea Grant (NOAA), Oregon BEST, and the Oregon Nanoscience and Microtechnologies Institute (ONAMI) Tactical Energy Systems program.  Current collaborators include Alex Chang (Chemical Engineering, OSU) and Jun Jiao (Physics, Portland State University).


Selected Recent Publications (2008-2009)

Goodwin, A.K., and Rorrer, G.L. “Conversion of Xylose and Xylose-Phenol Mixtures to Hydrogen-Rich Gas by Supercritical Water in an Isothermal Microtube Flow Reactor.”  Energy & Fuels, in press 2009.

Christensen, K.M., and Rorrer, G.L. “Equilibrium Partitioning Behavior of Naphthalene and Phenanthrene with Axenic Microplantlets of the Temperate Green Seaweed Acrosiphonia coalita.”  Chemosphere, 76, 1135-1142, 2009.

Gutu, T., Gale, D.K., Jeffryes, C., Wang, W., Chang, C.-H., Rorrer, G.L., and Jiao, J. “Electron Microscopy Characterization of Nanocrystalline Cadmium Sulphide Deposited on the Patterned Surface of Diatom Biosilica.”  Journal of Nanomaterials, in press 2009.

Wang, W., Gutu, T., Gale, D.K., Jiao, J., Rorrer, G.L, and Chang, C.H.   “Self Assembly of Nanostructured Diatom Microshells into Patterned Arrays Assisted by Polyelectrolyte Multilayer Deposition and Inkjet Printing.”  JACS Communications, 131, 4178-4179, 2009.

Gale, D.K, Gutu, T., Jiao, J., Chang, C.-H., and Rorrer, G.L.  “Photoluminescence Detection of Biomolecules by Antibody-Functionalized Diatom Biosilica.”  Advanced Functional Materials, 19, 926-933, 2009.  Cover Image (see below)

Lotufo, G.R., Lydy, M.J., Cruz-Uribe, O., Cheney, D.P., and Rorrer, G.L. “Bioconcentration, Bioaccumulation, and Biotransformation of Explosives and Related Compounds in Aquatic organisms.”  In:  Ecotoxicology of Explosives, G.I. Sunahara, J.A. Hawari, G.R. Lotufo, R.G. Kuperman, Eds., CRC Press, Boca Raton, FL, 2009, pp. 135-155.

Li, H. Jeffryes, C., Gutu, T., Jiao, J., Rorrer, G.L.  “Peptide-Mediated Deposition of Nanostructured TiO2 into the Periodic Structure of Diatom Biosilica and its Integration into the Fabrication of a Dye-Sensitized Solar Cell Device.”  In:  Synthesis of Bioinspired Hierarchical Soft and Hybrid Materials,  F. Meldrum, S. Yang, N. Kotov, C. Li (Eds.),  Materials Research Society (MRS) Symposium Proceedings, 1189E, MM02-05.1-8, 2009.

Gutu, T., Jeffryes, C., Wang, W., Chang, C.-H., Rorrer, G., Jiao, J.   “Structural and Electrical Characterization of Diatom Pinnularia sp. Biosilica Coated with CdS Thin Film.”  In: Structure-Property Relationships in Biomineralized and Biomimetic Composites , D. Kisailus, L. Estroff, W. Landis, P. Zavattieri, H.S. Gupta (Eds.),  Materials Research Society (MRS) Symposium Proceedings, 1187, KK05-20.1-4, 2009.

Jeffryes, C., Gutu, T., Jiao, J., and Rorrer, G.L.  “Metabolic Insertion of Nanostructured TiO2 into the Patterned Biosilica of the Diatom Pinnularia sp. by a Two-Stage Bioreactor Cultivation Process.”  ACS Nano, 2, 2103-2112, 2008.

Jeffryes, C., Gutu, T., Jiao, J., and Rorrer, G.L.  “Peptide-Mediated Deposition of Nanostructured TiO2 into the Periodic Structure of Diatom Biosilica.”  Journal of Materials Research, 23, 3255-3262, 2008.

Lee, D.-H., Wang, W., Gutu, T., Jeffryes, C., Rorrer, G.L., Jiao, J., and Chang, C.-H. “Biogenic Silica Based Zn2SiO4:Mn2+ and Y2SiO5:Eu3+ Phosphor Layers Patterned by Inkjet Printing Process.”  Journal of Materials Chemistry, 18, 3633–3635, 2008.

Qin, T., Gutu, T. Jiao, J., Chang, C.-H., and Rorrer, G.L.  “Biological Fabrication of Photoluminescent Nanocomb Structures by Metabolic Incorporation of Germanium into the Biosilica of the Diatom Nitzschia frustulum.”  ACS Nano, 2, 1296-1304, 2008.

Jeffryes, C., Solanki, R., Rangineni, Wang, W., D.-H., Chang, C.-H., and Rorrer, G.L. “Electroluminescence and Photoluminescence from Nanostructured Diatom Frustules Containing Metabolically Inserted Germanium.”  Advanced Materials, 20, 2633–2637, 2008.

Goodwin, A.K., and Rorrer, G.L.  “Conversion of Glucose to Hydrogen-Rich Gas by Supercritical Water in a Microchannel Reactor.”  Industrial & Engineering Chemistry Research, 47, 4106–4114, 2008.

Qin, T., Gutu, T., Jiao, J., Chang, C.-H., Rorrer, G.L.  “Photoluminescence of Silica Nanostructures from Bioreactor Culture of Marine Diatom Nitzschia frustulum.”  Journal of Nanoscience and Nanotechnology, 8, 2392-2398, 2008.

Jeffryes, C., Gutu, T., Jiao, J., and Rorrer, G.L. “Two-Stage Photobioreactor Process for the Metabolic Insertion of Nanostructured Germanium into the Silica Microstructure of the Diatom Pinnularia sp.”  Materials Science and Engineering C:  Biomimetic and Supramolecular Systems, 28, 107-118, 2008.

Cruz-Uribe, O., and Rorrer, G.L. “Uptake and Transformation of 2,4,6-Trinitrotolune (TNT) from Seawater by Microplantlet Suspension Cultures of the Marine Red Macroalga Portieria hornemannii.”  Biotechnology & Bioengineering, 93, 401-412,2006.

Rorrer Laboratory Highlights

Popular Scientific Media (recent samples)

Chemical & Engineering News, Feb. 28, 2005, Louisa Dalton, Vol. 83(9), p. 14 with photo.  Seaweeds have an Appetite for TNT. (http://pubs.acs.org/cen/news/83/i09/8309notw7.html)

Nature, Research Highlights, Materials Science: Diatomic Power. Vol. 453, 1146, 2008.

Science Channel, Brink, episode 23: Sustainable Technology, broadcast Aug. 3, 2009. (http://science.discovery.com/brink/brink.html, http://science.discovery.com/videos/brink-interviews-how-to-improve-sola...)

Journal Covers

Advanced Functional Materials, inside cover, Vol. 19(6), March 24, 2009



Mass transfer and transport phenomena (CHE 332, CHE 411, CHE 520)

Welty, J.R., Wilson, R.E., Wicks, C.E., Rorrer, G.L.  Fundamentals of Momentum, Heat and Mass Transfer (4th Edition), John Wiley & Sons (2000).