Hydrogen Production and Delivery
Most of the hydrogen in the United States is produced by steam reforming of natural gas. For the near term, this production method will continue to dominate. Researchers at NREL are developing advanced processes to produce hydrogen economically from sustainable resources. NREL's hydrogen production and delivery R&D efforts, which are led by Huyen Dinh, focus on the following topics:
- Biological Water Splitting
- Fermentation
- Conversion of Biomass and Wastes
- Photoelectrochemical Water Splitting
- Solar Thermal Water Splitting
- Renewable Electrolysis
- Hydrogen Dispenser Hose Reliability
- Hydrogen Production and Delivery Pathway Analysis.
Biological Water Splitting
Certain photosynthetic microbes use light energy to produce hydrogen from water as part of their metabolic processes. Because oxygen is produced along with the hydrogen, photobiological hydrogen production technology must overcome the inherent oxygen sensitivity of hydrogen-evolving enzyme systems. NREL researchers are addressing this issue by screening for naturally occurring organisms that are more tolerant of oxygen and by creating new genetic forms of the organisms that can sustain hydrogen production in the presence of oxygen. Researchers are also developing a new system that uses a metabolic switch (sulfur deprivation) to cycle algal cells between the photosynthetic growth phase and the hydrogen production phase.
Recent publications:
- Phosphoketolase Pathway Contributes to Carbon Metabolism in Cyanobacteria. Wei Xiong, Tai-Chi Lee, Sarah Rommelfanger, Erica Gjersing, Melissa Cano, Pin-Ching Maness, Maria Ghirardi, and Jianping Yu. Nature Plants. Volume 2. (2015)
- Improving Cyanobacterial O2-Tolerance Using CBS Hydrogenase for H2 Production. Pin-Ching Maness, Carrie Eckert, and Jianping Yu. DOE Annual Progress Report. (2015)
- Improving Cyanobacterial O2-Tolerance Using CBS Hydrogenase for H2 Production. Pin-Ching Maness. DOE Annual Merit Review. (2015)
- Biological Systems for Algal Hydrogen Photoproduction. Maria Ghirardi. DOE Annual Progress Report. (2014)
- Biological Systems for Hydrogen Photoproduction. Maria Ghirardi. DOE Annual Progress Report. (2014)
Contact: Maria Ghirardi
Fermentation
NREL scientists are developing pretreatment technologies to convert lignocellulosic biomass into sugar-rich feedstocks that can be directly fermented to produce hydrogen, ethanol, and high-value chemicals. Researchers are also working to identify a consortium of Clostridium that can directly ferment hemicellulose to hydrogen. Other research areas involve bio-prospecting efficient cellulolytic microbes, such as Clostridium thermocellum, that can ferment crystalline cellulose directly to hydrogen to lower feedstock costs. Once a model cellulolytic bacterium is identified, its potential for genetic manipulations, including sensitivity to antibiotics and ease of genetic transformation, will be determined. NREL's future fermentation projects will focus on developing strategies to generate mutants that are blocked selectively from producing waste acids and solvents to maximize hydrogen yield.
Recent publications:
- Biomass to Hydrogen (B2H2)/Fermentation and Electrohydrogenic Approaches to Hydrogen Production. Pin-Ching Maness and Bruce Logan. DOE Annual Merit Review. (2016)
- Fermentation and Electrohydrogenic Approaches to Hydrogen Production. Pin-Ching Maness, Katherine Chou, and Lauren Magnusson. DOE Annual Progress Report. (2015)
Contact: Pin-Ching Maness
Conversion of Biomass and Wastes
Hydrogen can be produced via pyrolysis or gasification of biomass resources such as agricultural residues like peanut shells; consumer wastes including plastics and waste grease; or biomass specifically grown for energy uses. Biomass pyrolysis produces a liquid product (bio-oil) that contains a wide spectrum of components that can be separated into valuable chemicals and fuels, including hydrogen. NREL researchers are currently focusing on hydrogen production by catalytic reforming of biomass pyrolysis products. Specific research areas include reforming of pyrolysis streams and development and testing of fluidizable catalysts.
Recent publications:
- Distributed Production of Hydrogen by Auto-Thermal Reforming of Fast Pyrolysis Bio-Oil. Stefan Czernik and Richard French. International Journal of Hydrogen Energy. Volume 39. (2014)
- Evaluate Impact of Catalyst Type on Oil Yield and Hydrogen Consumption from Mild Hydrotreating. Richard French, James Stunkel, Stuart Black, Michele Myers, Matthew Yung, and Kristiina Iisa. Energy and Fuels. Volume 28. (2014)
- Distributed Bio-Oil Reforming. Stefan Czernik, Richard French, and Michael Penev. DOE Annual Progress Report. (2013)
- Distributed Bio-Oil Reforming. Stefan Czernik. DOE Annual Merit Review. (2013)
Contact: Richard French
Photoelectrochemical Water Splitting
The cleanest way to produce hydrogen is by using sunlight to directly split water into hydrogen and oxygen. Multijunction cell technology developed by the photovoltaic industry is being used for photoelectrochemical (PEC) light harvesting systems that generate sufficient voltage to split water and are stable in a water/electrolyte environment. The NREL-developed PEC system produces hydrogen from sunlight without the expense and complication of electrolyzers, at a solar-to-hydrogen conversion efficiency of 12.4% lower heating value using captured light. Research is underway to identify more efficient, lower cost materials and systems that are durable and stable against corrosion in an aqueous environment.
Recent publications:
- High-Efficiency Tandem Absorbers for Economical Solar Hydrogen Production. Todd Deutsch. DOE Annual Merit Review. (2016)
- Solar to Hydrogen Efficiency: Shining Light on Phoelectrochemical Device Performance. Henning Döscher, James Young, John Geisz, John Turner, and Todd Deutsch. Energy and Environmental Science. Volume 9. (2016)
- Remarkable Stability of Unmodified GaAs Photocathodes during Hydrogen Evolution in Acidic Electrolyte. John Young, Xerxes Steirer, Michael Dzara, John Turner, and Todd Deutsch. Journal of Materials Chemistry A. Volume 4. (2016)
- Reversible GaInP2 Surface Passivation by Water Adsorption: A Model System for Ambient-Dependent Photoluminescence. James Young, Henning Döscher, John Turner, and Todd Deutsch. Journal of Physical Chemistry C. Volume 120. (2016))
- High-Efficiency Tandem Absorbers for Economical Solar Hydrogen Production. Todd Deutsch, John Turner, James Young, Henning Döscher, and Heli Wang. DOE Annual Progress Report. (2015)
- Semiconductor Materials for Photoelectrolysis. Todd Deutsch, John Turner, Heli Wang, and Huyen Dinh. DOE Annual Progress Report. (2014)
- Semiconductor Materials for Photoelectrolysis. Todd Deutsch and John Turner. DOE Annual Merit Review. (2014)
Contact: John Turner or Todd Deutsch
Solar Thermal Water Splitting
NREL researchers use the High-Flux Solar Furnace reactor to concentrate solar energy and generate temperatures between 1,000 and 2,000 degrees Celsius. Ultra-high temperatures are required for thermochemical reaction cycles to produce hydrogen. Such high-temperature, high-flux, solar-driven thermochemical processes offer a novel approach for the environmentally benign production of hydrogen. Very high reaction rates at these elevated temperatures give rise to very fast reaction rates, which significantly enhance production rates and more than compensate for the intermittent nature of the solar resource.
Recent publications:
- Flowing Particle Bed Solarthermal RedOx Process to Split Water. Alan Weimer, Brian Ehrhart, Ibraheam Al-Shankiti, Samantha Miller, Amanda Hoskins, Arto Groehn, Ryan Trottier, and Charles Mus. DOE Annual Merit Review. (2016)
- Flowing Particle Bed Solarthermal Redox Process to Split Water. Alan Weimer, Charles Musgrave, Brian Ehrhart, Ibraheam Al-Shankiti, Christopher Muhich, Amanda Hoskins, Samantha Miller, and Barbara Ward. DOE Annual Progress Report. (2015)
Contact: Judy Netter
Renewable Electrolysis
Renewable energy sources such as photovoltaics, wind, biomass, hydro, and geothermal can provide clean and sustainable electricity for our nation. However, renewable energy sources are naturally variable, requiring energy storage or a hybrid system to accommodate daily and seasonal changes. One solution is to produce hydrogen through the electrolysis—splitting with an electric current—of water and to use that hydrogen in a fuel cell to produce electricity during times of low power production or peak demand, or to use the hydrogen in fuel cell vehicles.
Researchers at NREL's Energy Systems Integration Facility and Distributed Energy Resources Test Facility are examining the issues related to using renewable energy sources for producing hydrogen via the electrolysis of water. NREL tests integrated electrolysis systems and investigates design options to lower capital costs and enhance performance.
Learn more about NREL's hydrogen production cost analysis, renewable electrolysis research, and the wind-to-hydrogen project, which uses electricity from wind turbines and solar panels to produce hydrogen.
Recent publications:
- Renewable Electrolysis Integrated System Development and Testing. Mike Peters, Kevin Harrison, Huyen Dinh, Danny Terlip, Jennifer Kurtz, and Josh Martin. DOE Annual Merit Review. (2016)
- Dynamic Modeling and Validation of Electrolyzers in Real-Time Grid Simulation. Jennifer Kurtz, Kevin Harrison, Rob Hovsapian, and Manish Mohanpurkar. DOE Annual Merit Review. (2016)
- Overview of an Integrated Research Facility for Advancing Hydrogen Infrastructure. Kevin Harrison, Josh Martin, Mike Peters, Owen Smith, and Danny Terlip. DOE Annual Merit Review. (2016)
- Renewable Electrolysis Integrated Systems Development and Testing. Mike Peters, Kevin Harrison, and Huyen Dinh. DOE Annual Progress Report. (2015)
- FCTO INTEGRATE Stack Test Bed and Grid Interoperability. Kevin Harrison, Owen Smith, Mike Peters, Danny Terlip, Paul Denholm, and Marc Mann. DOE Annual Progress Report. (2015)
- Dynamic Modeling and Validation of Electrolyzers in Real-Time Grid Simulation. Rob Hovsapian. DOE Annual Progress Report. (2015)
- FCTO INTEGRATE Stack Test Bed and Grid Interoperability. Kevin Harrison, Owen Smith, Mike Peters, Danny Terlip, Paul Denholm, and Marc Mann. DOE Annual Merit Review. (2015)
Contact: Kevin Harrison
Hydrogen Dispenser Hose Reliability
With a focus on reducing costs and increasing reliability and safety, NREL performs accelerated testing and cycling of 700 bar hydrogen dispensing hoses at the Energy Systems Integration Facility using automated robotics to simulate field conditions. View the video of the robot, which mimics the repetitive stress of a person bending and twisting a hose to dispense hydrogen into a fuel cell vehicle's onboard storage tank. Researchers perform mechanical, thermal, and pressure stress tests on new and used hydrogen dispensing hoses. The hose material is analyzed to identify hydrogen infiltration, embrittlement, and crack initiation/propagation.
Recent publications:
- 700 bar Hydrogen Dispenser Hose Reliability Improvement. Kevin Harrison and Owen Smith. DOE Annual Merit Review. (2016)
- 700-Bar Hydrogen Dispenser Hose Reliability Improvement. Kevin Harrison, Owen Smith, Michael Peters, Krista Isham, Huyen Dinh, and Svitlana Pylypenko. DOE Annual Progress Report. (2015)
Contact: Kevin Harrison
Hydrogen Production and Delivery Pathway Analysis
NREL performs systems-level analyses on a variety of sustainable hydrogen production and delivery pathways. These efforts focus on determining status improvements resulting from technology advancements, cost as a function of production volume, and the potential for cost reductions. Results help identify barriers to the success of these pathways, primary cost drivers, and remaining R&D challenges. NREL-developed hydrogen analysis case studies provide transparent projections of current and future hydrogen production costs. Learn more about NREL's systems analysis work.
Recent publications:
- Analysis of Advanced H2 Production Pathways. Brian James, Daniel DeSantis, Jennie Huya-Kouadio, Cassidy Houchins, and Genevieve Saur. DOE Annual Merit Review. (2016)
- Hydrogen Pathways Analysis for Solid Oxide Fuel Cell (SOFC) and Dark Fermentation. Brian James, Daniel DeSantis, Jennie Moton, and Cassidy Houchins. DOE Annual Progress Report. (2015)
Contact: Genevieve Saur