Mechanistic and adsorption equilibrium studies of dibenzothiophene‐rich‐diesel on MnO₂‐loaded‐activated carbon: Surface characterization

Abstract

In this work, the preparation and characterization of MnO2‐modified‐activated carbon for selective removal of organosulfur compounds including dibenzothiophene were outlined. The deposited particles of the modifier were entrapped within the micropores and the resulting adsorbent was efficient to desulfurize in diesel with rich‐sulfur (7055 mgS kg−1). Removal of organosulfur compounds was positively correlated with the deposited MnO2 and the best efficiency was observed at surface loading 30.6%Mn. The comprehensive characterization tests indicated drastic changes in the physicochemical properties of the modified adsorbents. The main findings were: (a) particles of α‐MnO2 were accumulated within the microspores and (b) less acidic surface compared to activated carbon was created in all modifications. Scanning electron microscope pictures indicated the filling of the pores by particles of MnO2. The mechanisms of S‐compounds removal by the modified adsorbent were elucidated with the aid of Infrared spectral analysis. Adsorption isotherms of dibenzothiophene were measured and the data were presented by different models. Dubinin‐Radushkevich model confirmed that adsorption of dibenzothiophene was exothermic and both Jovanović and Langmuir models indicated the homogeneity of the modified surface. Jovanović model gave the best prediction of the maximum adsorption capacity. Combustion qualities of deeply desulfurized diesel were found within the regulated limits. © 2017 American Institute of Chemical Engineers Environ Prog, 36: 903–913, 2017

A detailed investigation of MnO2 nanorods to be grown onto activated carbon. High efficiency towards aqueous methyl orange adsorption/degradation

“…Indeed, manganese dioxide can grow in more than 20 different polymorphs (having layered or tunneled structures) characterized by multivalent nature and nonstoichiometric compositions, which can lead to both high adsorption degree and great oxidative degradation power [9,29]. However, manganese oxides suffer from the low electron transfer performance and the small surface area [30]; hence, in order to overcome these issues, a MnO 2 growth onto Activated Carbon (AC) support could be performed, achieving composites characterized by enlarged surface area and great adsorption capabilities [31][32][33]. Indeed, the possibility to combine different materials to produce innovative composite with enhanced performances with respect to the precursors has brought important results in many research fields [34][35][36].…”