A study of sulfur functionalities in fossil fuels using destructive- (ASTM and Py–GC–MS) and non-destructive- (SEM–EDX, XANES and XPS) techniques

Abstract

A set of Spanish coals and oil shales were studied using destructive and non-destructive techniques to identify the functionalities of the sulfur compounds. The selected samples included organic-sulfur-rich Spanish lignites mined in the Mequinenza, Utrillas and Calaf basins; calcareous source-rocks from Organya Á and sulfur-rich oil shales from Ribesalbes. Using analytical pyrolysis coupled to gas chromatography±mass spectrometry, we estimated the ratio S org /C in these coals and oil shales, and compared them with those obtained by the ASTM method D2492. Also, a scanning electron microscope (SEM) coupled to an energy-dispersive X-ray spectrometer (EDX) allowed the direct determination of organic sulfur content in coals. Two major non-destructive techniques, XANES and XPS, were used to investigate sulfur functionalities, such as pyritic, sul®dic, thiophenic, sulfoxide, sulfone, sulfonate and sulfate forms. The study shows that sulfur characterization in coal is not without dif®culties and no method is exempt from problems and the introduction of possible artifacts. q

Probing the oxidation–reduction properties of terrestrially and microbially derived dissolved organic matter

“…(1) sulfur 2p electrons with binding energies <165 eV are characteristic of ''reduced'' functional groups (158.7-159.6 eV pyritic, 161.2-162.5 eV sulfidic, 163.7-164.0 eV thiophenes, thioesters, and mercaptans) (2) sulfur 2p electrons with binding energies >165 eV are characteristic of ''oxidized'' functional groups (166.0 eV sulfoxides, 168.0 eV sulfones, 169.2 eV sulfonates, and 174.8-175.8 eV sulfates) and (3) nitrogen 1s electrons with binding energies at $399-400 eV are characteristic of peptidic and amide forms, while forms at higher binding energies (401-402 eV) can be attributed to primary amines including protonated amines, and forms with lower binding energies (398 eV) are characterized as non-peptidic nitrogen (pyrroles, imines, anilines and pyridines) (George et al, 1991;Kelemen et al, 1995;Olivella et al, 2002;Abe and Watanabe, 2004;Abe et al, 2005 and references therein).…”

Surface Chemical Composition of Size-Fractionated Urban Walkway Aerosols Determined by X-Ray Photoelectron Spectroscopy

“…The concentration of elements can be determined with an accuracy of up to 0.1 atm%. Chemical states of elements can also be determined by peak synthesis (Briggs and Seah 1990;Monteil-Rivera et al 2000;Olivella et al 2002;Paoletti et al 2003).…”

Bench-Scale Experimental Study on the Effect of the Fluidized Bed Combustion Off-Gas Composition on the Reduction of Nitrous Oxide by Propane over an Fe-Zeolite Monolith

“…[53][54][55] The formation of RSO x species was also evidenced by the appearance of different peaks in the S 2p 3/2 level (at approximately 165.0, 166.0, 167.0, 168.0, and 169.8 eV) associated with the presence of RSO x (sulfonate) species on the catalyst surface. [55][56][57][58][59][60] The decomposition or reduction by the hydrocarbon (or surface carbonaceous deposits 61 ) of the produced iron sulfates and RSO x species, at high temperature, seems to be confirmed by the SO 2 , CO 2 , and CO emissions observed during the heating of the tested catalyst samples in nitrogen up to 550°C. In fact, according to the literature, 53 the decomposition temperature ranges for FeSO 4 and Fe 2 (SO 4 ) 3 are similar.…”