Studding the Effects of the Acidic and Alkaline Treatments on the Properties of Atmospheric Residual Crude Oil Desulfurization (RCD) Catalyst Structure

Since residual crude oil has a high content of large molecules such as metal containing and asphaltenes (Nickle Vanadium), the large mesopore structure has been needed for the RCD catalyst. In this research, a specific type of mesopore extrudates gamma alumina which is widely applied as the catalyst support in the atmospheric Residual Crude oil Desulfurization unit (RCD) was prepared. This RCD catalyst support has been prepared by our research team, in which the boehmite powder of Azarshahr Nephlinsinite mine ores for the first time. Then, several RCD catalyst samples have been prepared to perform the ammonia and acetic acid treatments under various operating conditions in order to show the effects of different treatments on the pore volume and diameter in the prepared RCD catalyst during these experiments. Then, nickel and molybdenum as an active metal are impregnated on the catalyst support. In this regard, and in order to compare the acetic acid and ammonia treatments influence on different properties (pore volume and pore diameter) of the prepared RCD catalyst within these experiments, different characterization laboratory method and apparatuses have been used, such as X-ray fluorescence (XRF), N2-adsorption/desorption, microreactory and radial strength techniques. As a result of all aforementioned experiments and characterization tests, it was shown that, the pore volume and pore diameter of the RCD catalyst support became wider and larger by both treatments. But, the effect of acetic acid treatment was better than ammonia treatment on the properties of RCD catalyst. The pore diameter and pore volume of RCD catalyst support which was prepared by acetic acid treatment, were wider and larger than the catalyst which was prepared by ammonia treatment. So, the RCD catalyst which was prepared by acetic acid treatment was applied in demetallization process, and the RCD catalyst which was prepared by ammonia treatment was applied in desulfurization proccess of the RCD unit.