Georgina C. Laredo

Nitrogen compounds characterization in atmospheric gas oil and light cycle oil from a blend of Mexican crudes

The distribution of basic and non-basic nitrogen compounds along the distillation curves of the middle distillates atmospheric gas oil (AGO) and light cycle oil (LCO), used as feedstocks for diesel fuel production, is presented in this paper. For this purpose, the total and basic nitrogen content of true boiling point distillation fractions of AGO and LCO were obtained, followed by nitrogen compounds identification by a GC–MS technique. The ratio of quinoline, indole and carbazole derivatives was determined as 1/0.75/2.5 in AGO. In LCO, a 1/2.3/12.2 ratio of aniline, indole and carbazole derivatives was found. A complete physical and chemical characterization of both AGO and LCO is also presented.

Kinetics of hydrodesulfurization of dimethyldibenzothiophenes in a gas oil narrow-cut fraction and solvent effects

Abstract The hydrodesulfurization kinetics of the dimethyldibenzothiophenes lump (DMDBTs) presented in a narrow-cut gas oil fraction at conditions commonly used in the hydrotreating of diesel feedstocks, has been experimentally determined. In order to obtain experimental data at different DMDBTs concentrations, octadecane was used as a solvent. During the mathematical treatment of the data, an inhibiting matrix effect due to the sulfur compounds themselves and octadecane was observed. These inhibitory effects were quantitatively represented by introducing the apparent adsorption constants K D [ D ] and K sol [ S ] 2 into the denominator of a modified Langmuir–Hinshelwood type rate equation.

Adsorption of nitrogen compounds from diesel fuels over alumina-based adsorbent towards ULSD production

ABSTRACT The aim of this work is to estimate some nitrogen (N)-adsorption properties and the N-adsorption capacity (q) required for commercial application in the ultra-low sulfur diesel production. Hydroxyl (OH) groups and interactions among the commercial adsorbent Selexsorb® CDX (CDX) and pyridine and indole were studied by means of Fourier transform infrared spectroscopy. The adsorption of N-compounds from three diesel fuels over CDX was estimated at CDX/fuel ratio: 0.01–0.09 g/g, Contact time: 1–60 m, 303 K, and 0.078 MPa in a batch setup. It was concluded that an appropriate N-adsorbent should have high densities of suface OH groups and Lewis and Brønsted strong-acid sites and a q ≥ 0.70 mmol/g.

Study of the Adsorption of Nitrogen Compounds for Diesel Fuel Production Using Three Commercial Materials

The aim of this work was to study the removal of nitrogen (N-) compounds for ultra-low sulfur diesel (ULSD) production purposes by using three commercial materials: selexsorb® CDX (CDX), silica gel (SG), and activated carbon VG-077 (VG-077). The experiments were conducted in three steps: (1) Adsorption of quinoline, indole, or carbazole from model fuels (300wppm in a 1:1g/g nhexadecane:toluene mixture) in a batch setup; adsorption of N- compounds from straight run gas oil (SRGO): (2) in a batch setup, and (3) in a fixed-bed column (FBC). Langmuir and Freundlich models were considered for modeling the adsorption isotherms of quinoline, indole, carbazole from model fuels and N-compounds from SRGO. Clark and Thomas models were employed for fitting the FBC