Fernando Trejo

The Effect of Solvent Washing on Asphaltenes and Their Characterization

Asphaltenes from an atmospheric residue of heavy crude were precipitated with n-heptane. Part of the isolated asphaltenes was washed under Soxhlet reflux to remove adsorbed maltenes. Comparison among washed and unwashed asphaltenes was carried out and both samples were characterized by atomic absorption, X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy, and differential scanning calorimetry.

Cracking of Maya Crude Asphaltenes

Cracking of Maya crude asphaltenes was carried out in a batch reactor at the following reaction conditions: temperature of 380–410°C, total pressure of 2 MPa, and asphaltenes/catalyst ratio of 5 g/g using NiMo commercial catalyst. n-hexadecane was used to keep asphaltenes dispersed and reaction time ranged from 0 to 60 min. The products were lumped into four fractions: asphaltenes, maltenes, gases, and coke. A kinetic model assuming pseudo–first-order parallel reactions was used to fit the experimental data.

Hydrothermal synthesis of unsupported MoS2 as catalyst for hydrodesulfurization of gas oil

ABSTRACT Hydrothermal synthesis with ammonium heptamolybdate and thiourea as precursors was used to obtain an unsupported MoS2 catalyst. The catalyst was obtained in sulfide state directly at mild reaction conditions (i.e., 180°C during 5 h). After catalyst was obtained, it was characterized through nitrogen physisorption, transmission electron microscopy, energy-dispersive spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. Catalytic evaluation was carried out in a batch reactor at 350°C, 55 bar of hydrogen pressure, 750 rpm, and 3 h of reaction time using straight-run gas oil (SRGO) as feedstock. A commercial CoMo/Al2O3 catalyst was used for comparison of activity. The synthesized catalyst was slightly more active toward SRGO hydrodesulfurization than commercial one keeping constant the sulfur removal after two runs.

Synthesis of Diesel Fuel From Waste Cooking Oil Through Catalytic Hydrotreating

Diesel fuel was synthesized from waste cooking oil using a commercial NiMo/Al2O3 catalyst in a batch reactor under different reaction conditions. The influence of reaction conditions, such as pressure, reaction time, and catalyst-to-oil ratio, were studied during hydrotreating through a response surface methodology and a polynomial model was obtained. The feedstock was characterized to quantify its acid number and density/viscosity. The diesel fuel obtained was characterized to obtain the pour point and density/viscosity. In addition, the yield of diesel fuel was obtained by simulated distillation. The maximum yield of diesel obtained was 91 wt% at the following reaction conditions: 72 bar, 3.6 h, and 3.5 wt%/wt% of catalyst-to-oil ratio.