Application of cyanated asphaltenes in gas-phase adsorption processes for removal of volatile organic compounds

Abstract

The paper presents an innovative, chemically modified (methylcyanated) asphaltene-based adsorbent that can be an interesting low-cost alternative for traditional adsorbents. Adsorption properties of adsorbents were examined by inverse gas chromatography technique, adsorption isotherms, and breakthrough curves. A significant increase in retention volume for pyridine, 2-pentanone, nitropropane, toluene, and 1-butanol was observed. Rohrschneider–McReynolds constants revealed an increase in strength of interactions as a result of the modification, especially in strong proton–acceptor interaction (by a factor of 4.6). The surface-free energy of asphaltene adsorbents increased from 136.71 to 169.95 mJ m−2 after modification. It is similar to the surface-free energy of silica or alumina. Moreover, modified adsorbent shows very high adsorption potential for pyridine. Adsorption isotherms revealed that monolayer adsorption capacity for pyridine increased 1.5 times after modification. Breakthrough curves of pyridine indicate that chemical modification increased the adsorption capacity, removal efficiency, and throughput. Scale-up calculations revealed that adsorption column packed with modified asphaltene adsorbent would be almost two times smaller compared to a column packed with unmodified one. Graphic abstract

The Asphaltenes: State-of-the-Art Applications and Future Perspectives in Materials Science

“…Furthermore, structurally modified asphaltene shows a very high monolayer adsorption capacity for pyridine. 94 Phosphopropoxylated asphaltenes are a new class of functionalized Mexican asphaltenes prepared by reacting phosphorus trichloride followed by different poly(propylene oxide)s. 95 These functionalized asphaltenes were found to be effective inhibitors, and the mechanism of asphaltene inhibition is linked to the capability of these molecules to interrupt the π−π interactions between the asphaltenes containing polyaromatic structural units to prevent the assembling of asphaltenes. 95 Recently, asphaltene-based ionic liquids were synthesized by connecting imidazolium cations with asphaltene carboxylate anions, and their properties were assessed.…”

“…Methylcyanated asphaltene-based adsorbent is a low-cost alternative to traditional adsorbents for removing volatile organic compounds, such as pyridine, 2-pentanone, nitropropane, toluene, and 1-butanol. Furthermore, structurally modified asphaltene shows a very high monolayer adsorption capacity for pyridine . Phosphopropoxylated asphaltenes are a new class of functionalized Mexican asphaltenes prepared by reacting phosphorus trichloride followed by different poly­(propylene oxide)­s .…”

Asphaltenes from Ethylene Tar as a Potential Raw Material to Obtain High Value-Added Products

“…Preparation of effective acidic carbocatalysts and sorbents based on modified petroleum asphaltenes has been extensively investigated in recent years [13][14][15][16][17][18][19]31,32]. A rigid carbon framework and facile modification of the polyaromatic core with reactive functional groups could improve the catalytic and sorption ability of modified asphaltenes and allow for their use as effective catalysts in some acid-catalyzed reactions, as well as adsorbents of heavy metals and other ecotoxicants.…”

“…Many works are devoted to the modification of petroleum asphaltenes. Modified asphaltenes can be used in the production of sorbents and catalysts [13][14][15][16][17][18][19], precursors of carbon materials [20][21][22][23][24][25], components for energy storage and conversion in alternative energetics [26][27][28][29], and for other purposes [30]. Production of such materials is possible due to the high reactivity of asphaltenes molecules, which easily undergo sulfonation [30][31][32], nitration, and other reactions [13][14][15][16]33], as a result of which various functional groups are added to the polycondensed aromatic core.…”