Effect of Nitrogen Compounds on Reactive Adsorption Desulfurization over NiO/ZnO-Al₂O₃-SiO₂ Adsorbents

Abstract

The effect of nitrogen compounds in FCC gasoline on reactive adsorption desulfurization (RADS)­was investigated over NiO/ZnO-Al2O3–SiO2 adsorbents. On the basis of ammonia temperature-programmed desorption (TPD), pyridine infrared radiation (Py-IR), and X-ray diffraction (XRD), adsorbents calcinated at 500 °C exhibit weak acidity and strong acidity, high Brδnsted acidity, and good dispersion of the active components. High Brδnsted acidity adsorbent presents the best RADS ability, contributing to adsorption and removal of nitrogen compounds. The results show that the basic nitrogen quinoline and pyridine inhibit significantly RADS, but the nonbasic nitrogen carbazole only affects RADS mildly. The order of inhibition is quinoline > pyridine > carbazole.

High Adsorption Performance of Bimetal Ag,Ti-Doped SiO2 Aerogel Composites for the Removal of Thiophenic Compounds from Model Fuels

“…For Ag 2 O/SiO 2 –TiO 2 -50, the peak at 1445 cm –1 shifted to a higher wavenumber (1448 cm –1 ), which was attributed to Lewis acid center-bonded pyridine, and another peak at 1489 cm –1 appeared, which was assigned to either the Lewis acid center or the Brönsted acid center. However, no peak at around 1540 cm –1 was observed. , The case indicated that the incorporation of Ti into Ag 2 O/SiO 2 -50 led to the appearance of Lewis acid sites. As displayed in Figure b, the NH 3 -TPD profile of Ag 2 O/SiO 2 -50 showed no evident peak, indicative of the negligible acidity and the weak interaction of NH 3 with Ag + , which was desorbed by purging at a temperature of 393 K. Ag 2 O/SiO 2 –TiO 2 -50 showed a broad NH 3 desorption peak spanning 385–560 K, centered at around 495 K, which was attributed to the desorption of NH 3 adsorbed on weak acid centers according to the literature .…”

“…However, no peak at around 1540 cm −1 was observed. 39,40 The case indicated that the incorporation of Ti into Ag In other words, the incorporation of Ti into Ag 2 O/SiO 2 -50 led to an increase in the actual incorporation rate of Ag species and the appearance of weak Lewis acid sites on the surface; simultaneously, the mesoporous structure and the larger S BET were also sustained. interaction, where thiophene acted as a Lewis base.…”

Adsorption of Dibenzothiophene in Gasoline by Si-MCM-41/Sodium Alginate Porous Hybrid Membrane

“…It has large pore size (1.5-10 nm), high specific surface area (over 700m 2 /g) and high adsorption capacity, which has the properties required for the adsorption material [21]. Moreover, the removal of the template exposed some active sites, which provided binding sites for the sulfide and improved the removal efficiency of the sulfide [22]. Its pore size is similar to that of DBT, and it can be stabilized in water and in simulated oil (n-heptane-DBT).…”

High-Efficiency Separation of Aromatic Sulfide from Liquid Hydrocarbon Fuel in Conjugated Porous Organic Framework with Polycarbazole Unit

“…Desulfurization of liquid hydrocarbon fuels has attracted wide attention due to the severe atmospheric pollution caused by sulfur-containing fuel consumption. − Governments have imposed more and more pressure on petroleum refineries to produce ultralow sulfur level fuel in view of environmental sustainability. − Catalytic hydro-desulfurization technology is for now the most mainstream technique for the industrialization of removing mercaptans and thioether, but it is unreliable for eliminating aromatic sulfur compounds. − Furthermore, catalytic hydro-desulfurization is conducted at high temperatures and pressures (>300 °C, hydrogen pressure of 20–100 atm), which require high energy consumption and come the side-effects of large octane loss. , One alternative technology, adsorptive desulfurization, has attracted enormous attention by virtue of its high efficiency, low consumption, and ultradeep desulfurization without changing the characteristics of gasoline . More importantly, liquid fuels with an ultralow sulfur content of less than 10 ppm can be achieved by adsorption desulfurization, which can meet the increasingly stringent vehicle exhaust regulations worldwide. − …”

“…8−10 Furthermore, catalytic hydro-desulfurization is conducted at high temperatures and pressures (>300 °C, hydrogen pressure of 20−100 atm), which require high energy consumption and come the side-effects of large octane loss. 6,11 One alternative technology, adsorptive desulfurization, has attracted enormous attention by virtue of its high efficiency, low consumption, and ultradeep desulfurization without changing the characteristics of gasoline. 12 More importantly, liquid fuels with an ultralow sulfur content of less than 10 ppm can be achieved by adsorption desulfurization, which can meet the increasingly stringent vehicle exhaust regulations worldwide.…”