Deep Desulfurization of Gasoline by Selective Adsorption over Nickel-Based Adsorbent for Fuel Cell Applications

Abstract

Adsorptive desulfurization of model gasoline fuels and a real gasoline over a nickel-based adsorbent Ni−Al was conducted in a flowing adsorption system at a temperature range of 25−200 °C under ambient pressure without using H2 gas in order to evaluate the desulfurization performance of the adsorbent for producing ultra-low-sulfur gasoline for fuel cell applications. Adsorptive capacity and selectivity of the Ni−Al adsorbent for various sulfur compounds and the effects of coexisting olefin in gasoline as well as adsorptive conditions on the adsorptive performance were examined. It was found that the nickel-based adsorbent shows high capacity and selectivity for the adsorptive desulfurization of gasoline. Olefins in gasoline have a strong inhibiting effect on the desulfurization performance of the nickel-based adsorbent at room temperature. Increasing the temperature to 200 °C can significantly improve the desulfurization performance of the nickel-based adsorbent for real gasoline. The adsorption mechanism and selectivity are discussed on the basis of the experimental results and computational analysis. The adsorption of sulfur compounds on the nickel surface involves C−S bond cleavage, as evidenced by the formation of ethylbenzene from benzothiophene in the absence of H2 gas in the flow adsorption system.

Adsorption of Thiophenic Compounds from Model Diesel Fuel Using Copper and Nickel Impregnated Activated Carbons

“…However, for mesoporous ACH carbons a linear trend for the isotherms is observed, suggesting a similar adsorption affinity over the tested concentration range. While the microporous carbons appear to reach their maximum TC capacities at equilibrium concentration of ~ 200 mg S/L, two tested mesoporous carbons are expected to have much higher capacities at higher concentrations (>>200 mg S/L).In agreement with the previous reports [14,16,[19][20][21]49], our results show that copper or nickel impregnation improves the TC uptake onto activated carbon adsorbents. However, this study quantifies the importance of different individual metal species on the TC adsorption.…”

“…Adsorption processes are some of the most economically attractive methods because of the straightforward operating conditions and availability of inexpensive and re-generable adsorbents including zeolites, metal-based adsorbents, silica, alumina, and activated carbon [8][9][10][11][12][13][14][15][16][17][18][19]. Adsorbents are modified by different treatment methods, including metal impregnation and oxidation, to enhance their affinities for the removal of TC from liquid fuels [20][21][22][23][24][25][26][27][28][29][30].…”

“…Adsorbents are modified by different treatment methods, including metal impregnation and oxidation, to enhance their affinities for the removal of TC from liquid fuels [20][21][22][23][24][25][26][27][28][29][30]. Zeolites, alumina, silica and activated carbon are impregnated with various transition metals such as Cu; Ni; Ag; Zn; Fe; and Pd, to prepare adsorbents with higher capacities for TC removal from commercial and model fuels [8,11,14,16,[20][21][22][23][24][25][26]. Enhanced TC adsorption of several metal-impregnated adsorbents is explained by specific interactions (i.e., chemical interactions) between the metals and thiophenic molecules [8,12,14,20,21,[31][32][33].…”

“…Zeolites, alumina, silica and activated carbon are impregnated with various transition metals such as Cu; Ni; Ag; Zn; Fe; and Pd, to prepare adsorbents with higher capacities for TC removal from commercial and model fuels [8,11,14,16,[20][21][22][23][24][25][26]. Enhanced TC adsorption of several metal-impregnated adsorbents is explained by specific interactions (i.e., chemical interactions) between the metals and thiophenic molecules [8,12,14,20,21,[31][32][33]. Adsorbent pore geometry is also an important factor in TC adsorption.…”

Adsorption Process of Sulfur Removal from Diesel Oil Using Sorbent Materials

“…The adsorptive desulphurization of gasoline over nickel based adsorbent, showed high capacity and selectivity for the adsorptive desulfurization of gasoline. The adsorption involves C-S bond cleavage as evidenced by the formation of ethyl benzene from benzothiophene in the absence of hydrogen gas [5].…”