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: a 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 increases the life cycle catalyst. The third stage of regeneration, after the adsorption process for sulfur and nitrogen compounds from real diesel, was assessment using as solvents: acetone (propanone), ethanol, benzene and toluene. For sulphur and nitrogen compounds, ethanol achieved the best performance. The variations of physical and chemical properties of regenerated ecat's in the cycles of adsorption and desorption were evaluated using x-ray diffraction, x-ray fluorescence, nitrogen adsorption-desorption, 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 sulphur 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 ecat to integrate a complete CE model.

Adsorptive Denitrogenation of Coker Diesel over Carbon-Based Adsorbents for Producing Ultralow-Sulfur Diesel

“…The results imply that about 40% of the nitrogen compounds adsorbed on the fresh AC–CC are difficult to remove by using the current toluene washing due to their higher affinity with the adsorption sites on the AC–CC surface. In order to improve the regenerability of the spent adsorbent, more studies need to be conducted on the regeneration methods, such as using different solvents, different temperatures, and ultrasonic extraction …”