El hidroprocesamiento de crudos pesados (HPR) se ha visto limitado por la disponibilidad del hidrógeno como la materia prima para llevar a cabo las transformaciones de las diferentes fracciones presentes en éstos, es decir, los crudos pesados no convencionales requieren una mayor relación de hidrógeno/hidrocarburo. El agua tiene el potencial de introducir el hidrógeno y la energía por otra ruta hidrotérmica, mientras que las altas presiones y altas temperaturas favorecen los cambios de las estructuras químicas de los compuestos de crudos pesados. En este trabajo se presenta un enfoque teórico-experimental de la reacción química de hidroprocesamiento de un crudo pesado usando agua supercrítica. Se explora el efecto de las propiedades del agua bidestilada y agua congénita, respectivamente, y utilizando nitrógeno como gas inerte para conseguir una presión elevada en todo el sistema reactivo. Después de esto, los nuevos experimentos de hidroprocesamiento incluyen un catalizador de CoMo comercial, con las siguientes especificaciones: área superficial de 250 m2/g (mínimo), volumen de poro de 0.5cm3/g, contenido de molibdeno de 12.5%peso, y contenido de cobalto de 3.8%peso. Los experimentos de hidroprocesamiento de crudo pesado se llevaron a cabo en un reactor por lotes (batch) con capacidad de 1000 ml. En cada ensayo se usaron 180g de aceite pesado con 20g de agua y 1g de catalizador (

Hydrotreatment of heavy crude oil has been limited by the available hydrogen for the raw material and the residual transformations, i.e. the unconventional heavy crude requires hydrogen/hydrocarbon higher ratios. Water has the potential to introduce hydrogen and energy to another route, while high pressures and high temperatures favor changes in the chemical structures of heavier crude compounds. This work presents a theoretical and experimental approach to the chemical reaction of hydroprocessing a heavy crude oil using supercritical water. The effect of distilled water and connate water, respectively, and using nitrogen as the inert gas is explored to achieve high pressure throughout the reactive system. Thereafter, the novel hydroprocessing experiments include a commercial CoMo catalyst (IMP-DSD14), with the following specifications: surface area of 250 m2/g (minimum), pore volume of 0.5cm3/g, molybdenum content of 12.5 wt%, and cobalt content of 3.8 wt%. Heavy crude hydroprocessing experiments were carried out in a 1000 ml batch reactor. In each test 180g of heavy oil were used with 20g of water and 1g of catalyst (<1mm particle size). Nitrogen gas was introduced at ambient temperature to achieve a starting pressure of 70.3 kg/cm2, then the system was subjected to heating, the total pressure was adjusted to approximately 210 kg/cm2. The stability of the reaction system was monitored for four hours. Changes in system pressure and reactor temperature were recorded in all scheduled experimental trials. The combination of different systems: N2-oil-H2O and N2-oil-H2O-catalyst was determinant in changes in physical properties, such as viscosity and API gravity of the processed crude. The composition of the crude oil was determined by quantitative analysis in the final products applying material balances and simulated distillation curves. For the reaction the HPR, a kinetic model of lumps was used in which the hydrocracking reaction of heavy crude oil included five pseudocomponentes: residue (538+), vacuum gas oil (343-537 °C), intermediate distillates (204-342 °C), Naphtha (IBP-203 °C), and gases (IBP), with ten kinetic rate constants. The results of the simulation in the GAMS software of the mathematical model show a good agreement with the experimental results obtained from the HPR of a heavy crude. The values of the constants are within the range reported in the literature with conditions close to those raised in this study. The proposed model is capable of predicting the production of residue, vacuum gas oils, intermediate distillates, naphtha and gases.

Consejo Nacional de Ciencia y Tecnología (México).

111 páginas. Maestría en Ingeniería de Procesos.