Padmesh Venkitasubramanian
Archer Daniels Midland
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Publication
Featured researches published by Padmesh Venkitasubramanian.
Journal of the American Oil Chemists' Society | 2011
Troy D. Haines; Kevin J. Adlaf; Robert M. Pierceall; Inmok Lee; Padmesh Venkitasubramanian; Mark W. Collison
Analysis of MCPD esters and glycidyl esters in vegetable oils using the indirect method proposed by the DGF gave inconsistent results when salting out conditions were varied. Subsequent investigation showed that the method was destroying and reforming MCPD during the analysis. An LC time of flight MS method was developed for direct analysis of both MCPD esters and glycidyl esters in vegetable oils. The results of the LC–TOFMS method were compared with the DGF method. The DGF method consistently gave results that were greater than the LC–TOFMS method. The levels of MCPD esters and glycidyl esters found in a variety of vegetable oils are reported. MCPD monoesters were not found in any oil samples. MCPD diesters were found only in samples containing palm oil, and were not present in all palm oil samples. Glycidyl esters were found in a wide variety of oils. Some processing conditions that influence the concentration of MCPD esters and glycidyl esters are discussed.
Journal of the American Chemical Society | 2016
Junming Sun; Rebecca A. L. Baylon; Chang-jun Liu; Donghai Mei; Kevin Martin; Padmesh Venkitasubramanian; Yong Wang
The effects of surface acidity on the cascade ethanol-to-isobutene conversion were studied using ZnxZryOz catalysts. The ethanol-to-isobutene reaction was found to be limited by the secondary reaction of the key intermediate, acetone, namely the acetone-to-isobutene reaction. Although the catalysts with coexisting Brønsted acidity could catalyze the rate-limiting acetone-to-isobutene reaction, the presence of Brønsted acidity is also detrimental. First, secondary isobutene isomerization is favored, producing a mixture of butene isomers. Second, undesired polymerization and coke formation prevail, leading to rapid catalyst deactivation. Most importantly, both steady-state and kinetic reaction studies as well as FTIR analysis of adsorbed acetone-d6 and D2O unambiguously showed that a highly active and selective nature of balanced Lewis acid-base pairs was masked by the coexisting Brønsted acidity in the aldolization and self-deoxygenation of acetone to isobutene. As a result, ZnxZryOz catalysts with only Lewis acid-base pairs were discovered, on which nearly a theoretical selectivity to isobutene (∼ 88.9%) was successfully achieved, which has never been reported before. Moreover, the absence of Brønsted acidity in such ZnxZryOz catalysts also eliminates the side isobutene isomerization and undesired polymerization/coke reactions, resulting in the production of high purity isobutene with significantly improved catalyst stability (<2% activity loss after 200 h time-on-stream). This work not only demonstrates a balanced Lewis acid-base pair for the highly active and selective cascade ethanol-to-isobutene reaction but also sheds light on the rational design of selective and robust acid-base catalyst for C-C coupling via aldolization reaction.
Journal of the American Oil Chemists' Society | 2011
Michael R. Blumhorst; Padmesh Venkitasubramanian; Mark W. Collison
An LC–MS method using a single quadrupole mass spectrometer was developed for direct analysis of glycidyl esters of fatty acids in vegetable oils. Without any sample clean-up, this method provided acceptable recovery of seven glycidyl esters, comparable results to a previously-published method utilizing two solid-phase extraction steps, and consistent detection parameters after greater than 200 injections without any cleaning operations performed. This method could readily be implemented as a screening assay for glycidyl esters in most oil laboratories.
Archive | 2008
Paul D. Bloom; Padmesh Venkitasubramanian
ACS Sustainable Chemistry & Engineering | 2016
Xiaobin Zuo; Padmesh Venkitasubramanian; Daryle H. Busch; Bala Subramaniam
Chemical Communications | 2016
Rebecca A. L. Baylon; Junming Sun; Kevin Martin; Padmesh Venkitasubramanian; Yong Wang
Archive | 2012
Padmesh Venkitasubramanian
Archive | 2012
Bala Subramaniam; Xiaobin Zuo; Daryle Busch; Padmesh Venkitasubramanian
Archive | 2013
Kenneth Stensrud; Padmesh Venkitasubramanian
Archive | 2015
Kenneth Stensrud; Padmesh Venkitasubramanian