Flexible operation of modular electrochemical CO2 reduction processes

Electrochemical CO2 reduction (eCO2R) is an emerging technology that is capable of producing various organic chemicals from CO2, but its high electricity cost is a big economic obstacle. One solution to reduce the cumulative electricity cost is demand side management, i.e., to adjust the power load based on time-variant electricity prices. However, varying the power load of CO2-electrolyzers often leads to changes in Faraday efficiency towards target components and thereby influences the product composition. Such deviations from the target product composition may be undesired for downstream processes. We tackle this challenge by proposing a flexible operating scheme for a modular eCO2R process. We formulate the economically optimal operation of an eCO2R process with multiple electrolyzer stacks as a parallel-machine scheduling problem. Adjusting the power load of each sub-process properly, we can save electricity costs while the desired product composition is met at any time. We apply an algorithm based on wavelet transform to solve the resulting large-scale nonlinear scheduling problem in tractable time. We solve each optimization problem with a deterministic global optimization software MAiNGO. We examine flexible operation of a modular eCO2R process for syngas production. The case studies show that the modular structure enables savings in the cumulative electricity cost of the eCO2R process via flexible operation while deviations in the syngas composition could be reduced. Also, the maximum ramping speed of the entire process is found to be a key parameter that strongly influences the cost saving.

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Boosting C2 products in electrochemical CO2 reduction over highly dense copper nanoplates

Catalysis Science & Technology ◽

10.1039/d0cy00487a ◽

2020 ◽

Vol 10 (14) ◽

pp. 4562-4570 ◽

Cited By ~ 1

Author(s):

Saira Ajmal ◽

Yang Yang ◽

Muhammad Ali Tahir ◽

Kejian Li ◽

Aziz-Ur-Rahim Bacha ◽

...

Keyword(s):

Renewable Energy ◽

Energy Storage ◽

Carbon Emissions ◽

Large Scale ◽

Co2 Reduction ◽

Electrochemical Co2 Reduction ◽

Renewable Energy Storage

Exclusive C2 selectivity of Cu-Nplates over C1 during electrocatalytic CO2 reduction offers opportunities for large scale, long-term renewable energy storage and lessens carbon emissions.

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Performance of Extended Local Clustering Organization (LCO) for Large Scale Job-Shop Scheduling Problem (JSP)

IEEJ Transactions on Electronics Information and Systems ◽

10.1541/ieejeiss.129.1363 ◽

2009 ◽

Vol 129 (7) ◽

pp. 1363-1370 ◽

Cited By ~ 1

Author(s):

Yohko Konno ◽

Keiji Suzuki

Keyword(s):

Large Scale ◽

Job Shop ◽

Job Shop Scheduling ◽

Scheduling Problem ◽

Job Shop Scheduling Problem ◽

Shop Scheduling ◽

Local Clustering

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An NADH-Inspired Redox Mediator Strategy to Promote Second-Sphere Electron and Proton Transfer for Cooperative Electrochemical CO2 Reduction Catalyzed by Iron Porphyrin

10.26434/chemrxiv.12159207.v1 ◽

2020 ◽

Cited By ~ 1

Author(s):

Peter T. Smith ◽

Sophia Weng ◽

Christopher Chang

Keyword(s):

Proton Transfer ◽

Co2 Reduction ◽

Iron Porphyrin ◽

Redox Mediators ◽

Reservoir Properties ◽

Proton Reduction ◽

Electrochemical Co2 Reduction ◽

Starting Point ◽

Rate Improvement ◽

Molecular Catalysts

We present a bioinspired strategy for enhancing electrochemical carbon dioxide reduction catalysis by cooperative use of base-metal molecular catalysts with intermolecular second-sphere redox mediators that facilitate both electron and proton transfer. Functional synthetic mimics of the biological redox cofactor NADH, which are electrochemically stable and are capable of mediating both electron and proton transfer, can enhance the activity of an iron porphyrin catalyst for electrochemical reduction of CO2 to CO, achieving a 13-fold rate improvement without altering the intrinsic high selectivity of this catalyst platform for CO2 versus proton reduction. Evaluation of a systematic series of NADH analogs and redox-inactive control additives with varying proton and electron reservoir properties reveals that both electron and proton transfer contribute to the observed catalytic enhancements. This work establishes that second-sphere dual control of electron and proton inventories is a viable design strategy for developing more effective electrocatalysts for CO2 reduction, providing a starting point for broader applications of this approach to other multi-electron, multi-proton transformations.

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Facet Dependent Reactivity of Copper Nanocrystals for Electrochemical CO2 Reduction to Valuable Products

10.29363/nanoge.ngfm.2019.093 ◽

2019 ◽

Author(s):

Pranit Iyengar ◽

Gian Luca De Gregorio ◽

Raffaella Buonsanti

Keyword(s):

Co2 Reduction ◽

Electrochemical Co2 Reduction

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Mechanistic Studies of the Electrochemical CO2 Reduction on Single Site, Metallic and Hybrid Electrocatalysts

10.29363/nanoge.ngfm.2019.037 ◽

2019 ◽

Author(s):

Peter Strasser

Keyword(s):

Co2 Reduction ◽

Single Site ◽

Mechanistic Studies ◽

Electrochemical Co2 Reduction

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The Effect of the Electrolyte on Electrochemical CO2 Reduction

10.29363/nanoge.ngfm.2019.255 ◽

2019 ◽

Author(s):

Karen Chan

Keyword(s):

Co2 Reduction ◽

Electrochemical Co2 Reduction

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Nanoporous Au-Sn with solute strain for simultaneously enhanced selectivity and durability during electrochemical CO2 reduction

Journal of Material Science and Technology ◽

10.1016/j.jmst.2019.11.007 ◽

2020 ◽

Vol 43 ◽

pp. 154-160 ◽

Cited By ~ 2

Author(s):

Xianglong Lu ◽

Tianshui Yu ◽

Hailing Wang ◽

Lihua Qian ◽

Ruichun Luo ◽

...

Keyword(s):

Co2 Reduction ◽

Electrochemical Co2 Reduction ◽

Enhanced Selectivity

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Investigation of Gas Diffusion Electrode Systems for the Electrochemical CO2 Conversion

Catalysts ◽

10.3390/catal11040482 ◽

2021 ◽

Vol 11 (4) ◽

pp. 482

Author(s):

Hilmar Guzmán ◽

Federica Zammillo ◽

Daniela Roldán ◽

Camilla Galletti ◽

Nunzio Russo ◽

...

Keyword(s):

Carbon Capture ◽

Active Sites ◽

Co2 Reduction ◽

Gas Diffusion ◽

Gas Diffusion Electrode ◽

Catalyst Loading ◽

Co2 Conversion ◽

Atmospheric Conditions ◽

Electrochemical Co2 Reduction ◽

Liquid Products

Electrochemical CO2 reduction is a promising carbon capture and utilisation technology. Herein, a continuous flow gas diffusion electrode (GDE)-cell configuration has been studied to convert CO2 via electrochemical reduction under atmospheric conditions. To this purpose, Cu-based electrocatalysts immobilised on a porous and conductive GDE have been tested. Many system variables have been evaluated to find the most promising conditions able to lead to increased production of CO2 reduction liquid products, specifically: applied potentials, catalyst loading, Nafion content, KHCO3 electrolyte concentration, and the presence of metal oxides, like ZnO or/and Al2O3. In particular, the CO productivity increased at the lowest Nafion content of 15%, leading to syngas with an H2/CO ratio of ~1. Meanwhile, at the highest Nafion content (45%), C2+ products formation has been increased, and the CO selectivity has been decreased by 80%. The reported results revealed that the liquid crossover through the GDE highly impacts CO2 diffusion to the catalyst active sites, thus reducing the CO2 conversion efficiency. Through mathematical modelling, it has been confirmed that the increase of the local pH, coupled to the electrode-wetting, promotes the formation of bicarbonate species that deactivate the catalysts surface, hindering the mechanisms for the C2+ liquid products generation. These results want to shine the spotlight on kinetics and transport limitations, shifting the focus from catalytic activity of materials to other involved factors.

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