Mexican Institute of Petroleum

About: Mexican Institute of Petroleum is a government organization based out in Mexico City, Mexico. It is known for research contribution in the topics: Catalysis & Asphaltene. The organization has 3273 authors who have published 4170 publications receiving 87269 citations.

Molecular View of the Asphaltene Aggregation Behavior in Asphaltene−Resin Mixtures

Abstract: The aggregation behavior of asphaltenes in asphaltene−resin mixtures within different host media is studied on the basis of the asphaltene/resin molecular structures and considering the embedding medium as a uniform background field. The approach employs models of molecular structures for both asphaltenes and resins (as derived from characterization data), and uses Molecular Mechanics (MM)/Molecular Dynamics (MD) calculations to predict the effect of the intermolecular interactions on the aggregation process as a function of composition and embedding medium. The peptizing behavior of resins is analyzed as a function of the ratio of resin to asphaltene molecules in each host medium by constructing the corresponding MD-generated radial distribution functions as well as the associated potentials of mean force (PMF). In all cases, the PMF presents repulsive barriers characteristic of aggregate systems showing a strong aggregation effect in a highly precipitant medium such as heptane. For an intermediate preci...

Experimental and Theoretical Study of the 3-Amino-1,2,4-triazole and 2-Aminothiazole Corrosion Inhibitors in Carbon Steel

Abstract: The corrosion inhibitor properties of the 3-amino-1,2,4-triazole (ATR) and 2-aminothiazole (ATH) molecule were studied by means of polarization curves and electrochemical impedance spectroscopy techniques. The experimental results indicate that ATH is a bad or dangerous inhibitor at low concentrations while ATR behaves as an efficient inhibitor at all concentrations. The rationalization of this behavior was achieved by means of first principles theoretical calculations, of the all-electron type, performed with the Gaussian-98 program, at the HF, MP2, B3LYP, and BLYP levels of theory, in concert with 6-31G** orbital basis sets. The reactivity of ATR and ATH was addressed in terms of the computed frontier molecular orbitals, highest occupied molecular orbital and lowest unoccupied molecular orbital, charge distributions, reactivity indices, and electrostatic potentials (EPs). These theoretical parameters indicate that the ATR moiety has much greater inhibitor efficiency than ATH, since, for instance the EP of the former displays two maximums on the nitrogen centers, favorable for the coordination with the metallic centers, while the latter has only one maximum. Analysis of the coordination modes of these two molecules with iron atoms indicates that in ATR-Fe, ATR is bonded to Fe through two nitrogen atoms of the ring yielding a highly stahle ATR-Fe system. However, in ATH-Fe, ATH is bonded to Fe only through one N atom, because the S center experiences a repulsive effect with the metal atom. These experimental results suggest that derivatives based on the triazole rings are good candidates for the design of high performance corrosion inhibitors.

Modeling residue hydroprocessing in a multi-fixed-bed reactor system

Abstract: A three-phase heterogeneous plug-flow reactor model was developed to describe the behavior of residue hydroprocessing in a multi-fixed-bed reactor system. The model considers gas–liquid and liquid–solid mass-transfer phenomena and incorporates reactions such as hydrodesulfurization (HDS), hydrodenitrogenation (HDN), hydrodemetallization (HDM), hydrodeasphaltenization (HDAs) and hydrocracking (HCR) as well as hydrogen consumption. HDS reaction was described by Langmuir–Hinshelwood kinetics while the rest of the reactions were modeled with power law kinetics. To estimate kinetic parameters, experiments were carried out in a multi-reactor pilot plant loaded with a triple catalyst system under the following operating conditions: 380–420 °C temperature and 0.25–1.0 h −1 liquid hourly space velocity (LHSV), keeping constant hydrogen-to-oil (H 2 /oil) ratio at 891 std m 3 /m 3 and pressure at 9.81 MPa. Model predictions showed good agreement with experimental data in the range of the studied operating conditions. The model was also applied for simulating an industrial scale residue hydroprocessing unit with multi-bed adiabatic reactors and hydrogen quenching.