Regeneration study of ecat-R as adsorbent for denitrogenation and desulfurization of diesel fuels

Abstract

The purpose of this paper is to present the third stage of regeneration for ecat: deactivated or equilibrium catalysts which are waste from fluidized catalytic cracking (FCC) units. This stage is going to compose a complete circular economy (CE) model and increase the life cycle of the catalyst. The third stage of regeneration, after the adsorption process for sulfur and nitrogen compounds from real diesel, was assessed using as solvents: acetone (propanone), ethanol, benzene and toluene. For sulfur and nitrogen compounds, ethanol achieved the best performance. The variations of physical and chemical properties of regenerated ecats in the cycles of adsorption and desorption were evaluated using x-ray diffraction, x-ray fluorescence, nitrogen adsorptiondesorpion, thermogravimetric and differential thermal analysis, scanning electron microscopy and Fourier-transform infrared spectroscopy. The recovery rate over four cycles is superior for sulfur compounds. After all cycles, ecat-R- -SA exhibited 5.09% reduction in the recovery for sulfur and 24.58% reduction in the recovery for nitrogen. The nitrogen adsorption-desorption analysis suggests the adsorption of compounds by ecat-R may be more correlated with the adsorption sites than with specific area. Overall, the results of this work are promising and allows for ecat to integrate a complete CE model.

Keywords

• circular economy
• equilibrium catalyst (ecat)
• nitrogen compounds
• regeneration
• solvents
• sulfur compounds