Feasibility of Bitumen Production from Unconverted Vacuum Tower Bottom from H-Oil Ebullated Bed Residue Hydrocracking

Abstract

In relation to the constant requirement for reduction of sulfur level and low demand for fuel oil, this study presents an approach for utilization of unconverted vacuum tower bottom (UVTB) from the ebullated bed hydrocracking process, H-Oil technology, in bitumen production. The kinetic study shows a slower softening point increase for crude blend 70% Urals and 30% Middle Eastern than other feeds in the air-blowing process. Also, penetration values for straight run vacuum residue feeds decrease quicker than the increase in their softening point values. UVTB softening point increase at high temperature is faster and penetration decrease is slower than LNB SRVR. Air blowing is shown to improve the penetration index of UVTB to a greater extent than the SRVR one. The bottleneck of this new application of UVTB is its low resistance to hardening, determined by using a rolling thin film oven (RTFO), which limits its quantity up to 20−30% in blends.

Commercial Investigation of the Ebullated-Bed Vacuum Residue Hydrocracking in the Conversion Range of 55–93%

“…These data indicate that both the softening point and the Fraass breaking point linearly decrease with the hydrocracked VTB cut point reduction, whereas the penetration exponentially decreases with hydrocracked VTB cut point reduction. The oxidative aging that is measured by ΔSP (the increase of the softening point after oxidation at 163 °C for 24 h in a rolling thin-film oven (RTFO)) shows that, as known from our earlier studies, 51 − 54 the hydrocracked VTB has poor resistance to oxidative aging (higher ΔSP). The undercutting while improving the softening point, Fraass breaking point, and penetration seems to deteriorate the hydrocracked VTB resistance to hardening.…”

“…The very high values of the softening point and the Fraass breaking point embarrass the increasing amount of the hydrocracked VTB in the feed for the production of road asphalt. Our recent study 51 showed that by the addition of fluid catalytic cracking slurry oil (FCC SLO) to the hydrocracked VTB, the rheological properties can be improved. However, the FCC SLO impairs the oxidative aging characteristics of the hydrocracked VTB.…”

“…50 − 54 It turned out, however, that the hydrocracked VR, designated as vacuum tower bottom (VTB), altered its properties from study to study. 51 − 54 Initially, it was found that the hydrocracked VTB can be used as a feedstock for the production of road asphalt in concentrations of about 15–20% of the total road asphalt feed. 51 Later, by modification of the road asphalt feed blend by addition of sulfur, the share of hydrocracked VTB in the road asphalt feed blend was increased to 70%.…”

“… 51 − 54 Initially, it was found that the hydrocracked VTB can be used as a feedstock for the production of road asphalt in concentrations of about 15–20% of the total road asphalt feed. 51 Later, by modification of the road asphalt feed blend by addition of sulfur, the share of hydrocracked VTB in the road asphalt feed blend was increased to 70%. 53 − 55 However, on further increase of the VR conversion, a consequence of the use of the nanodispersed catalyst 56 was found to affect the hydrocracked VTB quality as a feedstock for the production of road asphalt.…”

Crude Slate, FCC Slurry Oil, Recycle, and Operating Conditions Effects on H-Oil® Product Quality

“…The VTB, is blended with cutter stocks (FCC cycle oils) to produce heavy fuel oil and it is also used as a feed component for production of road asphalt [5,6]. It was found that the properties of the VTB also varied in a wide range, depending on the crude blend processing and on the H-Oil ® feed structure and operation severity [1].…”