2004 Folwell Avenue
St. Paul, MN 55108
United States
Areas of Interest
Biography
Dr. Chen is currently an Assistant Professor at the University of Minnesota and previously worked as a senior engineer at the National Renewable Energy Laboratory (NREL). He has more than 20 years of experience in biomass pretreatment, deconstruction, and conversion. Notably, he is the inventor of a patented deacetylation and mechanical refining (DMR) process for converting corn stover to ethanol (U.S. Patent 12,129,342), which has been exclusively licensed to SAFFiRE Renewables, formerly a Southwest Airlines venture-backed company and now part of Conestoga Energy. Conestoga is currently constructing a 10-ton-per-day ethanol pilot facility in Liberal, Kansas, based on Dr. Chen’s DMR technology to demonstrate sustainable aviation fuel (SAF) production.
Teaching
Research
- Advance zero-waste biomass valorization and design chemical recovery process for biorefinery industries
- Generate new biorefinery revenues from value-added chemicals and materials
- Assess process viability through comprehensive techno-economic analysis
Select Publications
- A Simultaneous Depolymerization and Hydrodeoxygenation Process to Produce Lignin-Based Jet Fuel in Continuous Flow Reactor, Fuel Processing Technology 2024,Vol23/Issue 1
- Impact of Mechanical Refining Conditions on the Energy Consumption, Enzymatic Digestibility, and Economics of Sugar Production from Corn Stover, ACS Sustainable Chemistry & Engineering 2023, Vol 11/Issue 44
- Simultaneous Dehydration of Glucose and Xylose Present in a Process-Relevant Biorefinery Hydrolysate to Furfurals Using Heterogeneous Solid Acid Catalysts, Energy & Fuels 2023, Vol 37/Issue 17
- Deacetylation and Mechanical Refining (DMR) and Deacetylation and Dilute Acid (DDA) Pretreatment of Corn Stover, Switchgrass, and a 50:50 Corn Stover/Switchgrass Blend, ACS Sustainable Chemistry & Engineering 2020, 8(17): 6734-6743.
- Electrical decoupling of microbial electrochemical reactions enables spontaneous H2 evolution. Energy & Environmental Science, 2020, 13(2): 495-502.
- Modelling a compressible packed bed flow-through washing and deacetylation reactor for corn stover pretreatment. Chemical Engineering Journal. 2021 10.1016/j.cej.2021.128918.
- Microbial electrochemical treatment of biorefinery black liquor and resource recovery. Green Chemistry, 2019, 21(6): 1258-1266.
- Kinetics and Rheological Behavior of Higher Solid (Solids >20%) Enzymatic Hydrolysis Reactions Using Dilute Acid Pretreated, Deacetylation and Disk Refined, and Deacetylation and Mechanical Refined (DMR) Corn Stover Slurries. ACS Sustainable Chemistry & Engineering, 2019, 7(1): 1633-1641.
- DMR (deacetylation and mechanical refining) processing of corn stover achieves high monomeric sugar concentrations (230 g L-1) during enzymatic hydrolysis and high ethanol concentrations (> 10% v/v) during fermentation without hydrolysate purification or concentration. Energy & Environmental Science. 2016,9,1237-1245
- Development and characterization of a high-solids deacetylation process. Sustainable Chemical Processes, 2016 4:6
- Improving Sugar Yields and Reducing Enzyme Loadings in the Deacetylation and Mechanical Refining (DMR) Process through Multistage Disk and Szego Refining and Corresponding Techno-Economic Analysis, ACS Sustainable Chemistry & Engineering. 2016 4(1), p324-333
- Use of mechanical refining to improve the production of low-cost sugars from lignocellulosic biomass. Bioresources Technology, 2016 v199, p59-67
- Conversion of corn stover hydrolysates to acids: comparison between Clostridium carboxidivorans P7 and microbial communities developed from lake sediment and an anaerobic digester. Biomass Conversion and Biorefinery, 2016 doi:10.1007/s13399-017-0239-9
- Sweet sorghum bagasse and corn stover serving as substrates for producing sophorolipids, Journal of Industrial Microbiology & Biotechnology, 2016 doi:10.1007/s10295-016-1891-y
- A highly efficient dilute alkali deacetylation and mechanical (disc) refining process for the conversion of renewable biomass to lower cost sugars, Biotechnology for Biofuel, 2014, 7:98
- Techno-economic Analysis of the Deacetylation and Disk Refining Process: Characterizing the Effect of Refining Energy and Enzyme Usage on Minimum Sugar Selling Price and Minimum Ethanol Selling Price, Biotechnology for Biofuels. 2015 8:173
- Improved ethanol yield and reduced MESP by modifying low severity dilute acid pretreatment with deacetylation and mechanical refining: 2) Techno-economical analysis, Biotechnology for Biofuels, 5:69
- Heterologous expression of xylanase enzymes in lipogenic yeast yarrowia lipolytica, PloS one, 2014, DOI: 10.1371/journal.pone.0111443
- Noble-metal catalyzed hydrodeoxygenation of biomass-derived lignin to aromatic hydrocarbons, Green Chemistry, 16, 897-910
- Recycling of Dilute Deacetylation Black Liquor to Enable Efficient Recovery and Reuse of Spent Chemicals and Biomass Pretreatment Waste, 2018, Frontiers in Energy Research, Vol. 6
- Deep Eutectic Solvent Extraction of High-Purity Lignin from a Corn Stover Hydrolysate. ChemSusChem 13(17): 4678-4690.
- Characterization and Deconstruction of Oligosaccharides in Black Liquor From Deacetylation Process of Corn Stover, Frontiers in Energy Research 7(54).
- Simultaneous upgrading of biomass-derived sugars to HMF/furfural via enzymatically isomerized ketose intermediates. Biotechnology for Biofuels 12(1): 253.
- Antimicrobial Properties of Corn Stover Lignin Fractions Derived from Catalytic Transfer Hydrogenolysis in Supercritical Ethanol with a Ru/C Catalyst. ACS Sustainable Chemistry & Engineering 8(50): 18455-18467.
Honors and Awards
- NREL’s President Award, 2020, National Renewable Energy Laboratory
- Employee of the Month, January 2013, National Renewable Energy Laboratory NREL outstanding license award
Patents
- Chen X., Himmel ME, Elander RT, Tucker ME, Pretreatment of lignocellulose using two stage alkali and mechanical refining processes, 2024, US Patent 12,129,342
- Odukomaiya A., Aday A., Mendoza N., Rippy K., Himmel M., Chen X., Simpson L., Pecha M., Griffin M., 2024, US Patent US20240294429A1, Thermally Insulative Concrete Made From Biorefinery Byproducts
- Chen X., Himmel ME, Elander RT, Tucker ME, Pretreatment of lignocellulose using two stage alkali and mechanical refining processes, 2025, US Patent App. 18/777,137