Zhiwen Ma

Present to 2017 Syngas Technologies Conference Colorado Spring, CO October 18, 2017

Concentrating Solar Power Technology for Green Syngas and Hydrogen Production

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For more than 40 years, NREL has delivered innovation impact enabling the emergence of the U.S. clean energy industry.

For more information please visit our website at

www.nrel.gov.

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NREL Renewable Research

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Transportation

Photovoltaics (PV) Hydrogen and Fuel Cells

Energy Efficiency

Biomass/Biofuels

Concentrating Solar Power (CSP)

Wind

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H2@Scale Vision

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Solar Technologies

Trough & Linear Fresnel: 200°–500°C Tower: 500°–1,000°C Dish: 800°–1,500°C

Solar Thermochemical/Fuel

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Examples of Recent CSP Plants Built in the U.S.

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390-MWe Ivanpah Solar Electric Generating Plants

110-MWe Crescent Dunes Solar Plant with 10-hour Thermal Energy Storage (TES)

250-MWe Abengoa Solana Plant with 6-hour TES

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Assist hydrocarbon fuel process or production o Solar heat can be used in syngas production, methanation, pyrolysis

process, etc. H2O + CO2 -> H2 + CO o Fischer-Tropsch Reaction: (2n+1)H2 + nCO → H2n+2Cn + nH2O

High-temperature solar thermochemical hydrogen (STCH) o Metal oxide or perovskite o Hybrid electrolysis

CSP can provide heat for high-temperature electrolysis cells. o High-Temperature electrolysis

Photoelectrochemical cell (PEC): o III-V semiconductor photoelectrochemical water splitting o Emerging high-temperature solid electrolyte

Four Types of Solar Fuel and Hydrogen Production

DOE Program targets solar thermochemical cost of 2-3c/kWt, equivalent to pipe delivered natural gas heating cost.

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Multiple Advanced Water Splitting Technologies

Cathode (-)

Anode (+)

Solid oxide electrolyte

𝑶𝑶𝟐𝟐− → 𝟏𝟏𝟐𝟐� 𝑶𝑶𝟐𝟐 + 𝟐𝟐𝒆𝒆−

𝑯𝑯𝟐𝟐𝑶𝑶+ 𝟐𝟐𝒆𝒆− → 𝑯𝑯𝟐𝟐 + 𝑶𝑶𝟐𝟐−

𝑶𝑶𝟐𝟐−

Steam/H2 electrode half-reaction

Oxygen electrode half-reaction

H2O H2

1/2O2 Sweep Gas

Sweep Gas

Power Supply

2e-

Oxygen ion transport SOEC PEM Electrolysis Solid Oxide Electrolysis

Solar Thermochemical Hybrid Sulfur Cycle Photoelectrochemical

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Christos Agrafiotis, DLR

Solar Syngas - Pollution Free and Green

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Agrafiotis, C., From Solar Energy to Green Mobility, in DEMOKRITOS Workshop. 2017: Athens, Greece.

Solar (Fuels) Chemistry

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CSP Thermochemical Processes

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Solar steam methane reforming adding heating value to fuel.

Syngas Production From Solar Thermochemical Process

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Solar thermal energy supports MeO and electrolysis hydrogen production.

Solar Assisted Water-Splitting with Heat and Power

We also provide support to Solid Oxide Electrolysis Cell modeling.

Redox MeO-Based Thermochemical Cycles and High-Temperature Electrolysis

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NREL high-efficiency solar receiver will be used for sulfuric acid decomposition at 800°C or above.

Hybrid Solar Thermal/Electrolysis Technology

A project supported by the DOE HydroGEN Program

Sulfuric acid cycle STCH developed at Savanah River National Laboratory (SRNL)

Team: Greenway Energy, SRNL, NREL, University of South Carolina

HydroGEN Energy Materials Network (EMN) HydroGEN Lab Consortium for Hydrogen Production

HydroGEN fosters cross-cutting innovation using theory-guided applied materials R&D to advance all emerging water-splitting pathways for hydrogen production

Comprising more than 80 unique, world-class capabilities/expertise in materials theory/computation, synthesis, and characterization & analysis:

Materials Theory/Computation Advanced Materials Synthesis Characterization & Analysis

Conformal ultrathin TiO2 ALD coating on bulk nanoporous gold

TAP reactor for extracting quantitative kinetic data

Stagnation flow reactor to evaluate kinetics of redox

material at high-T

LAMMPS classic molecular dynamics modeling relevant to H2O splitting

Bulk and interfacial models of aqueous

electrolytes

High-throughput spray pyrolysis system for

electrode fabrication

Core Labs

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Green syngas production integrated with CSP can achieve economies of scale using power tower technology at a suitable temperature range for thermochemical processes with high-temperature solar heat inputs.

CSP is the only available energy source for renewable thermochemical production of hydrogen and/or syngas from water/carbon dioxide through solar redox processes. The solar thermochemical process has potential to convert syngas into liquid hydrocarbon fuels using only renewable/recoverable resources: solar energy, water and captured/recycled CO2.

CSP-aided reforming of methane-containing gaseous feedstocks with natural gas can offer a viable route for fossil fuel decarbonization and create a transition path towards a “solar hydrogen-solar fuels” path.

CSP systems can generate electricity as an alternative to PVs for electrolysis of steam or steam/CO2 mixtures towards hydrogen/syngas production.

DOE H2@scale aims for widespread production and utilization of hydrogen as an energy carrier across power sources and end uses.

Conclusions

Zhiwen Ma 303-275-3784 zhiwen.ma@nrel.gov

Thank you! Questions?