Microporous activated carbon catalyst for an efficient and deactivation resistive supercritical water upgrading process of sour crude oil

Exploiting unconventional heavy crude oil is a fascinating and crucial strategy for meeting the rapidly rising need for energy and the dramatic depletion of conventional crude oil. Supercritical water upgrading (SCWU) of heavy oils reduces sulfur content and decreases average molecular weight, without rejecting carbon as coke products. In this article, we describe a technique for upgrading unconventional crude oils, highly sour crude oil, using a supercritical water process catalyzed by 6 % Co/Activated carbon (AC) biowaste catalysts. The catalysts were prepared by conventional and microwave calcination of the active Co oxide. Also, a sample of the prepared catalyst was coated with TiO2 to prolong the lifetime of the catalyst. The surface area of the Co/AC and Ti-Co/Ac catalysts were 504.65 m2/g and 443.54 m2/g respectively for conventional heating and 589.775 m2/g and 480.165 m2/g for microwave heating and the AC was found to be majorly microporous. Scanning electron microscopy-energy dispersive spectroscopy (SEM-EDX) and X-ray diffraction (XDR) were used to demonstrate the impregnation of catalytic Co particles onto AC. Also, Transmission Electron Microscope (TEM) for examining the coating layer. Different operational parameters (temperature, time of reaction, type of catalyst) were applied in supercritical water upgrading in a hydrothermal autoclave reactor. It was found that the sulfur content of the Co/ AC catalysts are outstanding upgrading catalyst for the sour feedstock as sulfur content was reduced to 94 % and the Ti-coated catalyst sustain its activity against upgrading reaction time. Also, the API gravity was raised to 28.6 at 390 degrees C as well as the viscosity of the petroleum-upgraded light fraction was reduced to 117 mPa.s. The results of this work help establish the role of biowaste microporous catalysts in the SCWU process; demonstrate that modest upgrading can be achieved in the absence of an external hydrogen source and provide guidelines for catalyst preparation at high quality and stability.

Automated summary

Upgrading unconventional heavy crude oil using supercritical water process catalyzed by biowaste catalysts can reduce sulfur content and molecular weight, improve API gravity and reduce viscosity of the upgraded petroleum light fraction, without the need for an external hydrogen source.