Tailoring of surface oxygen‐containing functional groups and their effect on adsorptive denitrogenation of liquid hydrocarbons over activated carbon

Abstract

The objective of this study is to get a fundamental understanding of role of surface oxygen-contained functional groups (OCFG) in adsorptive denitrogenation (ADN) of liquid hydrocarbons over activated carbon, and thus to improve the ADN performance of activated carbon through modification of surface chemistry of activated carbon. A set of activated carbon samples with different amount and distribution of OCFG was prepared by oxidative modification and thermal treatment of a commercial activated carbon. The prepared activated carbons were characterized by the temperature-programmed desorption coupled with mass spectrometry for the concentration of various OCFG, and evaluated in a fixed-bed adsorption system using a model fuel containing aniline, indole, quinoline, carbazole, and ethyl-carbazole. The results indicate that OCFG, especially the strong carboxyls, weak carboxyls and anhydrides, play a crucial role in determining the adsorptive performance of activated carbon for selective removal of nitrogen compounds from liquid hydrocarbons. The adsorption mechanism of the nitrogen compounds over activated carbon was discussed on the basis of the structure-performance correlation and the molecular simulation.

Adsorption of quinoline from liquid hydrocarbons on graphite oxide and activated carbons

“…24 The modified sample was collected by filtration and washed with abundant deionized water till reaching neutral. 24 The modified sample was collected by filtration and washed with abundant deionized water till reaching neutral.…”

“…This deconvolution method has been widely used for different carbon materials, such as the activated carbon, 44 carbon nanofibers, 47 carbon nanotubes, and carbon xerogels. 24 The deconvolution results of CO 2 and CO for OAC are shown in Figures 3c and 3d. 24 The deconvolution results of CO 2 and CO for OAC are shown in Figures 3c and 3d.…”

“…6,[14][15][16][17] An efficient adsorbent plays a crucial role in the adsorption approach. 24 The commercially available ACs and their modified versions used in the previous studies showed different chemical properties and physical structures, which make it difficult to discern their individual effects on their adsorption performances. Therefore, a wide range of adsorbents have been developed and tested for ADN, such as metal oxides, activated carbon, ion-exchange resins, and supported metal (Ni/SiO 2 -Al 2 O 3 ), activated alumina, zeolites, metal organic frameworks (MOFs) and others.…”

Adsorptive denitrogenation and desulfurization of diesel using activated carbons oxidized by (NH4)2S2O8 under mild conditions

“…The dibenzothiophene (DBT) capacity of a (NH 4 ) 2 S 2 O 8 oxidized AC was found to increase by 74 %, compared to that of the original AC . Li et al also reported that the adsorption capacities of a carbon sorbent for N compounds, especially the basic N compounds, were effectively enhanced after (NH 4 ) 2 S 2 O 8 oxidation . However, in these studies, the model diesels only contained singular type of species, i.e., either N or S compounds.…”

“…Our previous study showed (NH 4 ) 2 S 2 O 8 performed better than HNO 3 and H 2 SO 4 in the denitrogenation of light cycled oil (LCO) for the studied carbon . The performance of (NH 4 ) 2 S 2 O 8 oxidized AC in the adsorptive removal of N or S compounds from model diesel fuels has been tested . The dibenzothiophene (DBT) capacity of a (NH 4 ) 2 S 2 O 8 oxidized AC was found to increase by 74 %, compared to that of the original AC .…”