Investigation of the Process of Catalytic Steam Cracking of Heavy Oil in the Presence of Disperse Catalysts. Part 2. Studies of the Influence Concentration of the Ni-Containing Catalyst on the Product Yield and Properties

Abstract

The process of steam cracking of heavy oil (HO) was studied under static conditions at 425 °C in the presence of a nanodisperse Ni-containing catalyst (0,3–2,0 wt.% of Ni). This catalyst was established to promote upgrading of the semi synthetic oil produced from HO: the H : O ratio increases (against noncatalytic steam cracking) but the sulfur content and viscosity decreases. An increase in the catalyst loading results only in a minor increase in the H : O ration, while the yield of the liquid products decreases from 81 to 76 % at an increase in the yield of coke and gas products (from 8 to 13 and from 2 to 4 wt.%, respectively). X-ray phase analysis and transmission electron spectroscopic techniques were used for characterization of the catalyst-containing coke residue. The formation of Ni 9 S 8 nanoparticles (15–40 nm in size) from the catalyst precursor (Ni(NO 3 ) 2 ·6H 2 O) under the process conditions was shown. To improve efficiency of the upgrading process needs further choice and studies of catalytic systems for cracking of heavy oil feedstock in the presence of overheated steam and optimization of the process conditions.