fulltext.study @t Gmail

Oxidative desulfurization of diesel with oxygen: Reaction pathways on supported metal and metal oxide catalysts

Paper ID Volume ID Publish Year Pages File Format Full-Text
40246 45848 2013 7 PDF Available
Title
Oxidative desulfurization of diesel with oxygen: Reaction pathways on supported metal and metal oxide catalysts
Abstract

•Examined ODS of diesel with O2 for supported Pd, Mo2C, Ti-silicates and homogeneous oxidation catalysts.•Determined product distributions for all reactions of system at <100 °C and ∼1 MPa.•Determined selectivities to sulfur oxidation products typically <20%.•Verified similar behavior with peroxide oxidants.•Showed that oxidation of alkylaromatics in diesel promotes ODS.

We examined oxidative desulfurization (ODS) of a model diesel under conditions where O2 is the oxidant. To help understand the overall reaction pathways, we focused on all oxidation reactions in the system, including those of the alkylaromatic and nitrogen heterocycle components of the diesel. Three catalyst classes were studied in particular: supported Pd (on activated carbons or alumina), supported metal carbides and mesoporous titanium silicates. It is shown that regardless of catalyst the reaction rate for ODS is heavily influenced by the other oxidizable components present, especially the alkylaromatics. These compounds are oxidized to a greater extent than the sulfur heterocycles (by almost an order of magnitude on a molar basis), and temperatures must be kept less than 100 °C in order to minimize co-oxidation. Attaining a measurable rate at these temperatures requires high O2 partial pressures and therefore higher pressure than typically used for peroxide-based oxidations. The products formed from the oxidation of some typical alkylaromatics and nitrogen heterocycles were determined. These products suggest the same reaction pathways are present regardless of oxidant, and over a wide range of catalysts. The results strongly suggest that a key step in the oxidation of sulfur heterocycles with O2 is the generation of hydroperoxides from alkylaromatics and similar oxidizable hydrocarbons; it is these hydroperoxides which in turn oxidize the heterocycles.

Graphical abstractFigure optionsDownload full-size imageDownload high-quality image (109 K)Download as PowerPoint slide

Keywords
Oxidative desulfurization; Alkylaromatic oxidation; Palladium; Molybdenum carbide; Titanium silicate
First Page Preview
Oxidative desulfurization of diesel with oxygen: Reaction pathways on supported metal and metal oxide catalysts
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us
Publisher
Database: Elsevier - ScienceDirect
Journal: Applied Catalysis A: General - Volume 468, 5 November 2013, Pages 143–149
Authors
, , , ,
Subjects
Physical Sciences and Engineering Chemical Engineering Catalysis
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us