Arun S. Agarwal

The Electrochemical Reduction of Carbon Dioxide to Formate/Formic Acid: Engineering and Economic Feasibility

The engineering and economic feasibility of large-scale electrochemical reduction of carbon dioxide to formate salts and formic acid is the focus of this Full Paper. In our study we investigated the long-term performance of tin and other proprietary catalysts in the reduction of carbon dioxide to formate/formic acid at a gas/solid/liquid interface, using a flow-through reactor. The overall economics and energy consumption of the process are evaluated through a value chain analysis. The sensitivity of the net present value of the process to various process parameters is examined.

Cathodic degradation mechanisms of pure Sn electrocatalyst in a nitrogen atmosphere

The application of electrocatalysts used at high cathodic overpotentials for the electrochemical reduction of pollutant species such as CO2 has revealed a lack of understanding of the cathodic degradation mechanisms of those materials. Pure Sn is one of the most relevant candidate materials mainly because of its high selectivity for the reduction of CO2 to formic acid and formate salts. Degradation of the electrocatalyst can arise from a combination of cathodic polarization and induced changes to the surface by CO2 reduction products. In this study, the cathodic degradation mechanisms of pure Sn were studied as a function of rotation rate, time, current density, electrolyte concentration, grain size, and orientation in a nitrogen-saturated atmosphere using a rotating disk electrode. Several degradation morphologies were observed, but three were dominant. In the first type, electrochemical alterations of grains with specific orientations produced substantial weight changes, both losses and gains. The second type resulted in an alkali-rich deposit that had a high coverage but produced small weight changes. The third type consisted of carbon-rich stains that typically had a small coverage.

On the modelling of multidisciplinary electrochemical systems with application on the electrochemical conversion of CO2 to formate/formic acid

Abstract This paper presents a model-based approach on the analysis of complex multidisciplinary electrochemical processes, with implementation on a reactor for the electrochemical conversion of CO2 to formate/formic acid. The process is regarded as a system of interacting physical and electrochemical mechanisms. A process model is developed by combining individual mathematical sub-models of the mechanisms, organised at groups of compartments following the physical process structure. This approach results in a generic reconfigurable model that can be used as a part of integrated systems, and to test design modifications. The approach is demonstrated on an electrochemical cell, where CO2 is converted to formate/formic acid. The model captures the molar transportation under electric field, the two-phase flow effects, and the key electrochemical reactions. The model is calibrated and validated against experimental data obtained from a continuous flow cell. The key parameters affecting the process performance are discussed through scale-up analysis.

A Review of Engineering and Safety Considerations for Hybrid-Power (Lithium-Ion) Systems in Offshore Applications

topside and subsea systems enjoy the same benefits (increased efficiency and reduced costs), yet for different reasons. Oil and gas stakeholders must determine when and where hybrid-power systems provide the most value for operations, how they should be implemented, what technologies are acceptable, what safety considerations there may be, system suitability for extreme environments, and how these technologies can improve the bottom line. There is a wealth of information on Li-ion batteries, though it is not all consistent—cost data are unclear, lifetime and energy density considerations vary under different conditions, and ruggedness and application to harsh environments constitute a large uncertainty. In the following sections, we will address these issues to help provide clarification for the oil and gas operator.

Energy Storage Via Electrochemical Conversion of CO2 Into Specialty Chemicals

There is significant interest in technologies that reduce or mitigate greenhouse gases in the atmosphere because of their contribution to climate change. In addition, concerns for energy security are linked to political, environmental, and economic factors that threaten supply of hydrocarbon sources for fuels and the petrochemical feedstock that support the production of plastics, fertilizers, and chemical supply chains. With these climate and energy security concerns, there is a need for technologies that can economically address both issues. In addition, with increased integration of renewable energy systems into the grid, there are major concerns about grid instability and the need for energy storage. Significant research is being done on both topics, but there is a need to more efficiently transmit and use energy (which is the focus of the Smart Grid initiatives) as well as store energy for future use. Electrochemical conversion of CO2 to useful products will be discussed including analyses of the energy and carbon balances required for the process, the value of the end use chemicals as energy storage media, and the energy density of the end use chemicals compared to other energy storage technologies.Copyright