Power to Chemicals
The P2C project seeks to investigate how ammonia can be produced on the basis of renewable electricity instead of the CO2-intensive production processes that exist today.
Project type: cSBO in MOT3 Electrification & Radical Process Transformation
Approved on: 12/12/2019
Start date: 01/01/2020 (expected duration of 18 months)
PublicationsEnergy-Efficient Ammonia Production from Air and Water Using Electrocatalysts with Limited Faradaic Efficiency
ACS Energy Lett. 2020, 5, 4, 1124-1127 – DOI: 10.1021/acsenergylett.0c00455
Ammonia is an industrial large-volume chemical. It is used in fertilizers and many chemical products and materials, and it pops up as a candidate green energy vector. Today, the industrial production of ammonia is dominated by the Haber–Bosch process departing from natural gas or other fossil fuels. This process is responsible for about 1.6% of global man-made CO2 emissions.
Electrochemical ammonia production is a promising alternative, only using water, wind and solar energy without intrinsic CO2 emissions. Yet, electrochemical ammonia production is currently characterized by limited selectivity, losing lots of energy to the production of hydrogen gas as a byproduct. Over the last few years, electrocatalysts with steadily increasing Faradaic efficiency are being reported, but there seems to be a trade-off between ammonia selectivity and catalytic activity.
The new SECAM process (Solar ElectroChemical AMonnia synthesis) enables energy-efficient ammonia production, using electrocatalysts with a limited selectivity of 30%. This is possible because the process uses the fluctuating energy availability associated with renewable energy sources like wind and solar energy. During periods of high energy availability, the process converts water and air into ammonia, with hydrogen gas as a byproduct. During periods of more limited energy availability, the process converts air and the previously produced excess hydrogen byproduct into ammonia, with a much lower energy cost. This technology makes it possible to produce green ammonia with an overall energy efficiency similar to that of the Haber–Bosch process, but without intrinsic CO2 emissions.
The full publication can be accessed for free at https://pubs.acs.org/doi/full/10.1021/acsenergylett.0c00455.
Angewandte Chemie, 2020 – DOI: 10.1002/anie.202011676
Ammonia is an industrial large volume chemical, with its main application in fertilizer production. It also attracts increasing attention as a green energy vector. Over the past century, ammonia production has been dominated by the Haber‐Bosch process, in which a mixture of nitrogen and hydrogen gas is converted to ammonia at high temperatures and pressures. Haber‐Bosch processes with natural gas as source of hydrogen are responsible for a significant share of the global CO2 emissions. Processes involving plasma are currently investigated as an alternative for decentralized ammonia production powered by renewable energy sources. In this work, we present the PNOCRA process (Plasma Nitrogen Oxidation and Catalytic Reduction to Ammonia), combining plasma‐assisted nitrogen oxidation and Lean NOx Trap technology, adopted from diesel engine exhaust gas aftertreatment technology. PNOCRA achieves an energy requirement of 4.6 MJ/mol NH3, which is an over 4‐fold energy reduction compared to the state‐of‐the‐art plasma‐enabled ammonia synthesis from N2 and H2 with reasonable yield (>1%).
More information can be found at https://onlinelibrary.wiley.com/doi/abs/10.1002/anie.202011676.