CATALYTIC STEAM CRACKING OF VACUUM RESIDUE IN PRESENCE OF DISPERSED CATALYSTS BASED ON MO, NI, FE, CO, AL METALS

Abstract

The relevance of the research is caused by need in developing alternative hydrogen-free technologies for processing heavy oil feedstocks to involve the latter in oil refining and increase the depth of processing of residues (atmospheric and vacuum residues) to minimize yield of by-products. The main aim of the research is to investigate catalytic steam cracking of vacuum residue of West-Siberian oil in the presence of dispersed catalysts based on various metals. Objects: catalytic steam cracking – thermocatalytic process of heavy oil feedstock upgrading in the presence of water. Methods. To assess the efficacy of catalysts based on various metals, a complex of physicochemical parameters: fractional composition of catalytic steam cracking liquid products (ASTM D7169–11), S content, H: C ratio (HCNS-O analysis), density and kinematic viscosity (ASTM D7042) of liquid products, was used. Results. The authors have determined the main features of steam catalytic cracking of vacuum residue at 450 °C in the presence of dispersed catalysts based on various metals (at a metal concentration in the initial emulsion of 0,5 wt. %). It was revealed that the use of a Mo­based dispersed catalyst leads to an increase of the H: C ratio (to 1,56) in liquid products comparing to steam cracking without a catalyst (1,32), also the sulfur content in liquid products decreases (by 0,22 wt. %), these facts indicate the enhancement of interaction between water and heavy feedstocks using this type of dispersed catalyst. The use of a dispersed catalyst based on iron, an increase in the yield of light fractions (29,3 wt. %) was noted, since this catalyst is characterized by high activity in oxidative cracking. The remaining dispersed catalysts based on Ni, Al, and Co do not exceed Mo- and Fe-based catalysts in the yield and quality of liquid products. The viscosity of liquid products is reduced by about 90 times compared with the original vacuum residue.

Keywords

• Catalytic steam cracking
• heavy oil feedstocks
• dispersed catalyst
• slurry-reactor
• molybdenum
• iron