Skip to Main Content U.S. Department of Energy
Chemical and Biological Process Development

Gary Neuenschwander

Pacific Northwest National Laboratory
PO Box 999
Richland, WA 99352


Since joining the laboratory in 1984, Gary Neuenschwander has contributed to studies on the gasification, liquefaction, and hydrotreating of biomass feedstocks and the destruction of agricultural and organic chemical wastes. He has also helped develop new technologies such as the Pyroflux, PCB Demo pilot plant, RubberCycle, RTDS, NITREM, MICRO-CATS, and the production of a number of chemicals under the Bioproducts Initative. Most of his work has involved the design, fabrication, and operation of high-temperature, high-pressure continuous feed and batch systems and pilot plants, data acquisition, as well as analytical work such as gas chromatography, solvent extractions, micro-distillations, bomb calorimetry, and elemental analyses. He has also worked on several microbial mechanisms where the process needed to be optimized and scaled up. Mr. Neuenschwander has written many Safe Operating Procedures, Acceptance Test Procedures, Project Test Plans, and was a member of two SBMS subject areas (Pressure Systems and Lock and Tag) development teams. He was also a member of the Lock and Tag committee and has worked extensively with building managers, Facilities Management, ES&H, Operations staff, and many others in support of his responsibilities. Mr. Neuenschwander has received four R&D 100 awards and an FLC award, and has been a co-author on numerous publications.

PNNL Patents

Education and Credentials

  • B.S., Iowa State University, 1976

PNNL Publications


  • Olarte MV, AH Zacher, AB Padmaperuma, SD Burton, HM Job, TL Lemmon, MS Swita, LJ Rotness, Jr, GG Neuenschwander, JG Frye, and DC Elliott. 2016. "Stabilization of Softwood-Derived Pyrolysis Oils for Continuous Bio-oil Hydroprocessing." Topics in Catalysis 59(1):55-64.  doi:10.1007/s11244-015-0505-7


  • Elliott DC, TR Hart, GG Neuenschwander, LJ Rotness, Jr, G Roesijadi, AH Zacher, and JK Magnuson. 2014. "Hydrothermal Processing of Macroalgal Feedstocks in Continuous-Flow Reactors ." ACS Sustainable Chemistry & Engineering 2(2):207-215.  doi:10.1021/sc400251p


  • Elliott DC, GG Neuenschwander, and TR Hart. 2013. "Hydroprocessing Bio-oil and Products Separation for Coke Production." ACS Sustainable Chemistry & Engineering 1(4):389-392.  doi:10.1021/sc300103y
  • Elliott DC, TR Hart, AJ Schmidt, GG Neuenschwander, LJ Rotness, Jr, MV Olarte, AH Zacher, KO Albrecht, RT Hallen, and JE Holladay. 2013. "Process Development for Hydrothermal Liquefaction of Algae Feedstocks in a Continuous-Flow Reactor ." Algal Research 2(4):445-454. 


  • Elliott DC, TR Hart, GG Neuenschwander, LJ Rotness, Jr, MV Olarte, AH Zacher, and Y Solantausta. 2012. "Catalytic Hydroprocessing of Fast Pyrolysis Bio-oil from Pine Sawdust." Energy and Fuels 26(6):3891-3896.  doi:10.1021/ef3004587
  • Elliott DC, TR Hart, GG Neuenschwander, LJ Rotness, Jr, MV Olarte, and AH Zacher. 2012. "Chemical Processing in High-Pressure Aqueous Environments. 9. Process Development for Catalytic Gasification of Algae Feedstocks." Industrial and Engineering Chemistry Research 51(33):10768-10777.  doi:10.1021/ie300933w


  • Elliott DC, GG Neuenschwander, TR Hart, LJ Rotness, Jr, AH Zacher, DM Santosa, C Valkenburt, SB Jones, and SA Tjokro Rahardjo. 2009. Catalytic Hydrothermal Gasification of Lignin-Rich Biorefinery Residues and Algae Final Report PNNL-18944, Pacific Northwest National Laboratory, Richland, WA. 
  • Elliott DC, TR Hart, GG Neuenschwander, LJ Rotness, Jr, and AH Zacher. 2009. "Catalytic Hydroprocessing of Biomass Fast Pyrolysis Bio-oil to Produce Hydrocarbon Products." Environmental Progress & Sustainable Energy 28(3):441-449. 


  • Elliott DC, TR Hart, and GG Neuenschwander. 2008. "CATALYTIC HYDROTHERMAL GASIFICATION OF BIOMASS FOR THE PRODUCTION OF HYDROGEN-CONTAINING FEEDSTOCK (METHANE)." In Petroleum Preprints: Papers Presented at the 235th ACS National Meeting in New Orleans, Louisiana, April 6-10, 2008., vol. 53, no. 1, pp. 73-74.  Division of Petroleum Chemistry, American Chemical Society, Washington DC. 


  • Elliott DC, TR Hart, and GG Neuenschwander. 2006. "Chemical Processing in High-Pressure Aqueous Environments. 8. Improved Catalysts for Hydrothermal Gasification." Industrial and Engineering Chemistry Research 45(11):3776-81. 
  • Elliott DC, GG Neuenschwander, TR Hart, J Hu, AE Solana, and C Cao. 2006. "Hydrogenation of Bio-oil for Chemicals and Fuels Production." In Science in Thermal and Chemical Biomass Conversion, vol. 2, ed. AV Bridgwater and DGB Boocock, pp. 1536-1546.  CPL Press, Speen, United Kingdom. 


  • Matsumura Y, T Minowa, B Potic, SR Kersten, W Prins, WP van Swaaij, B van de Beld, DC Elliott, GG Neuenschwander, A Kruse, and MJ Antal. 2005. "Biomass Gasification in Near- and Super-critical Water: Status and Prospectus ." Biomass & Bioenergy 29(4):269-292.  doi:10.1016/j.biombioe.2005.04.006


  • Elliott DC, GG Neuenschwander, TR Hart, and RS Butner. 2004. "Low-Temperature Catalytic Gasification of Wet Biomass Residues." In Second World Biomass Conference, Biomass for Energy, Industry, and Climate Protection, vol. I, ed. Van Swaaij, W.P.M. et al., pp. 746-749.  ETA-Florence and WIP-Munich, Florence, Italy. 
  • Elliott DC, GG Neuenschwander, TR Hart, RS Butner, AH Zacher, MH Engelhard, JS Young, and DE McCready. 2004. "Chemical Processing in High-Pressure Aqueous Environments. 7. Process Development for Catalytic Gasification of Wet Biomass Feedstocks." Industrial and Engineering Chemistry Research 43(9):1999-2004. 
  • Elliott DC, KL Peterson, DS Muzatko, EV Alderson, TR Hart, and GG Neuenschwander. 2004. "The Effects of Trace Contaminants on Catalytic Processing of Biomass-Derived Feedstocks ." Applied Biochemistry and Biotechnology 115(1-3):807-825. 


  • Elliott DC, GG Neuenschwander, TR Hart, AH Zacher, and RS Butner. 2003. "Low-Temperature Catalytic Gasification of Wet Biomass." Chapter TH-Envisioning the Bioref in AIChE 2003 Annual Meeting Conference Proceedings, p. n/a.  AIChE, New York, NY. 


  • Elliott DC, RJ Orth, J Gao, TA Werpy, DE Eakin, AJ Schmidt, and GG Neuenschwander. 2002. "Biorefinery Concept Development Based On Wheat Flour Milling." In Fuel Chemistry Division Preprints American Chemical Society National Meeting, April 2002, vol. 47, no. 1, pp. 361-362.  American Chemical Society, Washington, DC. 
  • Elliott DC, RJ Orth, TA Werpy, J Gao, DE Eakin, AJ Schmidt, GG Neuenschwander, J Murry, A Flagg, L Lahman, D Mennel, CJ Lin, and R Landucci. 2002. "Biorefinery Concept Development Based on Wheat Flour Milling." In Bioenergy 2002, ed. John Crockett and Charles L. Peterson, p. 35.  Pacific Regional Biomass Energy Program, Boise, ID. 


  • Elliott DC, SW Fitzpatrick, JJ Bozell, JL Jarnefeld, RJ Bilski, L Moens, JG Frye, Y Wang, and GG Neuenschwander. 2000. "Production of Levulinic Acid and Use as a Platform Chemical for Derived Products." In Biomass, a Growth of Opportunity in Green Energy and Value-Added Products: Proceedings of the 4th Biomass Conference of the Americas, vol. 1, pp. 595-600.  Elsevier Science, Oxford, United Kingdom. 


  • Darab JG, GG Neuenschwander, DC Elliott, and JG Frye. 1999. "Production, Consolidation, Sintering, and Stability of Novel Nanocrystalline Zirconia Catalyst Support Powders." In Advanced Catalytic Materials-1998; Materials Research Society Symposium Proceedings , vol. 549, pp. 67-72.  Materials Research Society, Warrendale, PA. 
  • Elliott DC, GG Neuenschwander, MR Phelps, TR Hart, AH Zacher, and LJ Silva. 1999. "Chemical Processing in High-Pressure Aqueous Environments. 6. Demonstration of Catalytic Gasification for Chemical Manufacturing Wastewater Cleanup in Industrial Plants." Industrial and Engineering Chemistry Research 38(3):879-883. 

Chemical and Biological Process Development

Additional Information