Removal of Thiophene From Fuels by Reactive Adsorption Catalyzed by Solid Phosphoric Acid

Abstract

This article presents a new reactive adsorbent used to effectively remove thiophenic compounds from transportation fuels. This reactive adsorbent was composed of 33.3 wt% SBA-15, 56.7 wt% solid phosphoric acid, and 10.0 wt% formaldehyde. This work was based on condensation reaction of thiophenic compounds with formaldehyde using solid phosphoric acid as the catalyst in pore spaces. In the breakthrough experiment, four model transportation fuels containing 1,500 μg/g thiophene were pumped through a fixed-bed reactor packed with reactive adsorbent at 70°C, respectively. The results showed that ultra-low sulfur model fuels were obtained despite the presence of aromatics. Nitrogen-containing compounds can poison the catalysts or competitively adsorb on the catalyst sites prior to refractory sulfur compounds. The reliability of this approach was also demonstrated by fluid catalytic cracking gas oil after hydrodesulfurization. The sulfur capacity of regenerated reactive adsorbent was almost totally recovered.