Interaction of Refractory Dibenzothiophenes and Polymerizable Structures

Jose L Rivera,Enrique Lima,Pedro Navarro-Santos,Roberto Guerra-Gonzalez

doi:10.1155/2014/103945

Jose L Rivera, Enrique Lima + Show 2 more

Open Access

https://doi.org/10.1155/2014/103945

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Abstract

We carried out first principles calculations to show that polymerizable structures containing hydroxyl (alcoholic chain) and amino groups are suitable to form stable complexes with dibenzothiophene (DBT) and its alkyl derivates. These sulfur pollutants are very difficult to eliminate through traditional catalytic processes. Spontaneous and exothermic interactions at 0 K primarily occur through the formation of stable complexes of organosulfur molecules with monomeric structures by hydrogen bonds. The bonds are formed between the sulfur atom and the hydrogen of the hydroxyl group; additional hydrogen bonds are formed between the hydrogen atoms of the organosulfur molecule and the nitrogen atoms of the monomers. We vary the number of methylene groups in the alcoholic chain containing the hydroxyl group of the monomer and find that the monomeric structure with four methylene groups has the best selectivity towards the interaction with the methyl derivates with reference to the interaction with DBT. Even this study does not consider solvent and competitive adsorption effects; our results show that monomeric structures containing amino and hydroxyl groups can be used to develop adsorbents to eliminate organosulfur pollutants from oil and its derivates.

Highlights

The content of sulfur in liquid fuels has been continuously reduced in the past 3 decades through tighter government restrictions in liquid fuel specifications [1,2,3]
An analysis of the global minima of the molecular electrostatic potential (MEP) [58], Vmin, shows the most reactive sites of DBT, which correspond to the π-electron regions of the sulfur atom, as we show in Figure 1(a) and Table 1; the isosurfaces at constant V (−55.79 kJ/mol) contain the positions of the global minima Vmin
We have shown that polymeric materials with structures including amino and hydroxyl functional groups form stable complexes with dibenzothiophene and its alkyl derivates

Summary

Introduction

The content of sulfur in liquid fuels has been continuously reduced in the past 3 decades through tighter government restrictions in liquid fuel specifications [1,2,3]. The sulfur atoms react with hydrogen and the hydrogen sulfide and the corresponding hydrogenated organic compound desorb These processes transform most of the organosulfur compounds, but some alkyl derivates of DBT are very difficult to absorb and transform [11,12,13]. New experimental and theoretical approaches to eliminate DBT and its alkyl derivates (other than catalytic approaches) have been developed in the past decade that include the transformation of organosulfur compounds through digestion by microorganisms [15,16,17], the sonochemical degradation [18,19,20], the formation of charge transfer complexes [21,22,23], and the adsorption on modified surfaces containing metallic cations, that is, zeolites [24,25,26] and silica [27].

Methodology

Electronic Structure of the Monomeric Adsorbent

Conclusions