Narasi Sridhar

Bio: Narasi Sridhar is an academic researcher from DNV GL. The author has contributed to research in topics: Corrosion & Stress corrosion cracking. The author has an hindex of 27, co-authored 202 publications receiving 3017 citations. Previous affiliations of Narasi Sridhar include Southwest Research Institute & Ohio State University.

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

Abstract: 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.

Effects of Water and Gas Compositions on the Internal Corrosion of Gas Pipelines—Modeling and Experimental Studies

Abstract: Results of a laboratory study of internal corrosion in wet gas pipelines under conditions involving a stagnant or slowly flowing aqueous phase indicate that the corrosion rate is not affected by calcium and magnesium scale-forming tendency of the test solutions, provided that they are buffered. It is possible that the scales formed are sufficiently porous to permit electrolyte contact with steel. However, an increase in pH and decrease in oxygen resulted in significant corrosion rate reduction. Thermodynamic analyses indicate that the formation of metastable iron sulfide (FeS) precipitates is promoted by higher pH and higher dissolved iron concentration, and hindered by the presence of carbon dioxide (CO2). The presence of oxygen on corrosion may lead to the transformation of a metastable FeS phase, mackinawite (Fe1+xS), to another metastable phase, greigite (Fe3S4). Electrochemical polarization data indicate that the steel behaves in an active manner symptomatic of a nonprotective corrosion prod...

Applicability of Repassivation Potential for Long-Term Prediction of Localized Corrosion of Alloy 825 and Type 316L Stainless Steel

Abstract: Repassivation potential (Erp) was investigated for use as a parameter in the long-term prediction of pitting resistance of two Fe-Ni-Cr-Mo alloys that are candidate materials for high-level nuclear waste containers. This potential was found to be independent of the extent of prior pit growth for alloy 825 (UNS N08825) and type 316L (UNS S31603) stainless steel (SS). Repassivation potential decreased by an increase in backward scan rate after pits were grown under potentiostatic conditions. This was related to the effect of potential on repassivation time. The corrosion potential (Ecorr) in simulated pit-crevice solutions increased with a decrease in pH and was independent of chloride (Cl−) concentration even to the point of depassivation. The depassivation pH (pHD) was independent of Cl− concentration and increased slightly with an increase in temperature. The relationship between repassivation potential and Ecorr in simulated pit solutions was discussed. It was hypothesized that the repassivatio...

A review of catalysts for the electroreduction of carbon dioxide to produce low-carbon fuels

Abstract: This paper reviews recent progress made in identifying electrocatalysts for carbon dioxide (CO2) reduction to produce low-carbon fuels, including CO, HCOOH/HCOO−, CH2O, CH4, H2C2O4/HC2O4−, C2H4, CH3OH, CH3CH2OH and others. The electrocatalysts are classified into several categories, including metals, metal alloys, metal oxides, metal complexes, polymers/clusters, enzymes and organic molecules. The catalyts' activity, product selectivity, Faradaic efficiency, catalytic stability and reduction mechanisms during CO2 electroreduction have received detailed treatment. In particular, we review the effects of electrode potential, solution–electrolyte type and composition, temperature, pressure, and other conditions on these catalyst properties. The challenges in achieving highly active and stable CO2 reduction electrocatalysts are analyzed, and several research directions for practical applications are proposed, with the aim of mitigating performance degradation, overcoming additional challenges, and facilitating research and development in this area.

Light-Driven Heterogeneous Reduction of Carbon Dioxide: Photocatalysts and Photoelectrodes

Abstract: Photocatalysts and Photoelectrodes James L. White,† Maor F. Baruch,† James E. Pander III,† Yuan Hu,† Ivy C. Fortmeyer,† James Eujin Park,† Tao Zhang,† Kuo Liao,† Jing Gu,‡ Yong Yan,‡ Travis W. Shaw,† Esta Abelev,† and Andrew B. Bocarsly*,† †Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States ‡Chemical and Materials Science Center, National Renewable Energy Laboratory, Golden, Colorado 80401, United States

Recent Advances in Inorganic Heterogeneous Electrocatalysts for Reduction of Carbon Dioxide

Abstract: In view of the climate changes caused by the continuously rising levels of atmospheric CO2 , advanced technologies associated with CO2 conversion are highly desirable. In recent decades, electrochemical reduction of CO2 has been extensively studied since it can reduce CO2 to value-added chemicals and fuels. Considering the sluggish reaction kinetics of the CO2 molecule, efficient and robust electrocatalysts are required to promote this conversion reaction. Here, recent progress and opportunities in inorganic heterogeneous electrocatalysts for CO2 reduction are discussed, from the viewpoint of both experimental and computational aspects. Based on elemental composition, the inorganic catalysts presented here are classified into four groups: metals, transition-metal oxides, transition-metal chalcogenides, and carbon-based materials. However, despite encouraging accomplishments made in this area, substantial advances in CO2 electrolysis are still needed to meet the criteria for practical applications. Therefore, in the last part, several promising strategies, including surface engineering, chemical modification, nanostructured catalysts, and composite materials, are proposed to facilitate the future development of CO2 electroreduction.

Handbook of Corrosion Engineering

Abstract: Introduction 1. Aqueous Corrosion 2. Environments and Application Examples 3. high-Temperature Corrosion 4. Modeling, Life Prediction, and Computer Applications 5. Corrosion Failures 6. Corrosion Maintenance Through Inspection And Monitoring 7. Acceleration and Amplification of Corrosion Damage 8. Materials Selection 9. Protective Coatings 10. Corrosion Inhibitors 11. Cathodic Protection 12. Anodic Protection

Catalysis for CO2 conversion: a key technology for rapid introduction of renewable energy in the value chain of chemical industries

Abstract: Replacement of part of the fossil fuel consumption by renewable energy, in particular in the chemical industry, is a central strategy for resource and energy efficiency. This perspective will show that CO2 is the key molecule to proceed effectively in this direction. The routes, opportunities and barriers in increasing the share of renewable energy by using CO2 reaction and their impact on the chemical and energy value chains are discussed after introducing the general aspects of this topic evidencing the tight integration between the CO2 use and renewable energy insertion in the value chain of the process industry. The focus of this perspective article is on the catalytic aspects of the chemistries involved, with an analysis of the state-of-the-art, perspectives and targets to be developed. The reactions discussed are the production of short-chain olefins (ethylene, propylene) from CO2, and the conversion of carbon dioxide to syngas, formic acid, methanol and dimethyl ether, hydrocarbons via Fischer–Tropsch synthesis and methane. The relevance of availability, cost and environmental footprints of H2 production routes using renewable energies is addressed. The final part discusses the possible scenario for CO2 as an intermediary for the incorporation of renewable energy in the process industry, with a concise roadmap for catalysis needs and barriers to reach this goal.