Roger Hilten


Roger Hilten


Research Engineer II


College of Engineering






Driftmier Engineering Center
University of Georgia
Athens, Georgia 30602



Ph.D., Agricultural and Biological Engineering, University of Georgia (2012)
M.S., Biological Engineering, University of Georgia (2005)
B.S., Ecology, University of Georgia (2002)


Algae, Biomass, Bioenergy, Biofuels, Bioproducts, Biodiesel, Thermochemical and catalytic processing

Roger Hilten


Roger Hilten is a Research Engineer II in the University of Georgia's Biorefining and Carbon Cycling Program. For over eight years, Roger Hilten has managed the Biorefinery's thermochemical analytical laboratory and equipment and has coordinated industrially-, state-, and federally-funded projects involving research and development of biofuels and bio-based products. He has worked to develop novel ways to test the properties of bio-based products using state-of-the-art analytical tools including thermal analysis, mass spectrometry, and FT-IR.

Hilten's research has focused on producing better biofuels and bio-based products from widely-available terrestrial feedstocks and waste oils in Georgia and from algae using thermochemical bioconversion processes including pyrolysis, gasification, and high-pressure liquefaction. Methods of producing of high quality end products that have been explored include pre-processing of biomass feedstock, use of novel catalysts during primary processing, and a number of post-processing techniques to optimize characteristics.


Hilten, R., Kastner, J.R., Das, K.C., Bibens, B. 2009. Production higher quality bio-oils by in-line esterification of pyrolysis vapor. Patent Pending. Provisional Patent application serial No.: 61/154,863. University of Georgia.


Hilten, R., R. Speir, J. Kastner, K.C. Das.  Modeling oleic acid conversion over a fixed-bed of HZSM-5 in both diffusion and reaction rate-limited regimes with experimental validation.  To be submitted to the Applied Catalysis, 2013.

Vandenbrink, J., Hammonds, R., Hilten, R., Das, K.C., Henson, J.M., Paterson, A.H., Feltus, F.A. Tissue specific analysis of bioconversion traits in the bioenergy grass Sorghum bicolor. Industrial Crops and Products, accepted for publication.

Vandenbrink, J., Hilten, R., Das, K.C., Paterson, A., Feltus, F.A. Quantitative models of hydrolysis conversion efficiency and biomass crystallinity index for plant breeding. Plant Breeding, published online 7 Apr 2013, DOI: 10.1111/pbr.12066.

Hilten, R., Speir, R., Kastner, J., Mani, S., Das, K.C. 2013. Effect of torrefaction on bio-oil upgrading over HZSM-5. Part 1. Product yield, product quality, and catalyst effectiveness for benzene, toluene, ethylbenzene, and xylene production. Energy and Fuels, 27(2): 830-843, DOI: 10.1021/ef301694x.

Hilten, R., Speir, R., Kastner, J., Mani, S., Das, K.C. 2013. Effect of torrefaction on bio-oil upgrading over HZSM-5.  Part 2: Byproduct formation and catalyst properties and function.  Energy and Fuels, 27(2): 844-856, DOI: 10.1021/ef301695c.

Jarvis, J., A. McKenna, R. Hilten, K.C. Das, R. Rodgers, A. Marshall.  2012.  Characterization of pine pellet and peanut hull pyrolysis bio-oils by negative-ion electrospray ionization Fourier Transform Ion Cyclotron Resonance Mass Spectrometry. Energy and Fuels, 26: 3810-3815. (1)

Vandenbrink, J., R. Hilten, K. C. Das, A. Paterson, F.A. Feltus.  2012.  Analysis of crystallinity index and hydrolysis rates in the bioenergy crop Sorghum bicolor.  Bioenergy Resources, 5(5): 387-397.

Hilten, R., R. Speir, K. Kastner, K.C. Das.  2011.  Production of aromatic green gasoline additives via catalytic pyrolysis of acidulated peanut oil soap stock.  Bioresource Technology, 102: 8288-8294.  (1)

Das, K.C., K. Singh, B. Bibens, R. Hilten, S. Baker, D. Greene, J. Peterson.  2010.  Pyrolysis characteristics of forest residues obtained from different harvesting methods.  Applied Engineering in Agriculture, 27(1): 107-113.

Hilten, R., K.C. Das.  2010.  Comparison of three accelerated aging procedures to assess bio-oil stability.  Fuel, 89: 2741-2749. (10)

Hilten, R., B. Bibens, J. Kastner, K.C. Das.  2010.  In-Line esterification of pyrolysis vapor with ethanol improves bio-oil quality.  Energy and Fuels, 24: 673-682. (18)

Hilten, R., R. Speir, J. Kastner, K.C. Das.  2010.  Production of fuel from the catalytic cracking of pyrolyzed poultry DAF skimmings.  Journal of Analytical and Applied Pyrolysis, 88: 30-38. (3)

Hilten, R., T. Lawrence, E. Tollner.  2008.  Modeling stormwater runoff from green roofs with HYDRUS-1D.  Journal of Hydrology 358(3): 288-293. (22)

Hilten, R., T. Lawrence.  2007.  Using Green Roof and Other Technologies for Reducing the Need for Stormwater Retention Capacity.  Low Impact Development: New and Continuing Applications.  Second National Low Impact Development Conference, March 12-14, 2007, Wilmington, NC.  ASCE Conf. Proc. 331, 21 (2007), DOI: 10.1061/41007(331)21, pp. 226-239.


Sudahagar Mani, Jim Kastner, Roger Hilten, Gerry Lindo, and KC Das.   Integrating Biomass Torrefaction with Pyrolysis for Improved Bio-Crude Oil Production.  ASABE Annual International Meeting, June 21-24, 2009: Reno, Nevada

Hilten, R.., T.M. Lawrence. Greenroofing as a stormwater management tool.  Joint Southeastern Stormwater Management and Erosion and Sediment Control Conference, 2005:  Peachtree City, GA.

Hilten, R., T.M. Lawrence. Using Green Roof and Other Technologies for Reducing the Need for Stormwater Retention Capacity. Oral presentation at the 2007 2nd National Low Impact Development Conference. Wilmington, NC.

Hilten, R., T.M. Lawrence, E.W. Tollner, and D. Gattie. Predicting building energy use and stormwater runoff associated with greenroofs. Oral presentation at the 2006 annual meeting of the American Ecological Engineering Society.

Hilten, R., T.M. Lawrence. Greenroofing as a stormwater management tool. Oral presentation at the 2005 Joint Southeastern Stormwater Management and Erosion and Sediment Control Conference.

Hilten, R., T.M. Lawrence, and E.W. Tollner. An analysis of the energetics and stormwater mediation potential of greenroofs. Poster presentation at the 2005 annual meeting of the UGA Biological and Agricultural Engineering Department.