Cetane improvement of middle distillates from Athabasca syncrudes by catalytic hydroprocessing

Abstract

A series of fuel products was generated experimentally by hydroprocessing synthetic crude middle distillates produced by fluid-bed coking of Athabasca bitumen. Reactions were carried out over a sulfided nickel-tungsten on -alumina catalyst at severe operating pressures. The ignition quality of fuel products was determined by a series of tests using a standard cetane engine. The compositional analyses of the fuels were determined by low-resolution mass spectrometry, and aromatic carbon content was determined by 13C NMR. Fuel Ignition properties were related to the concentrations of aromatics, and comparisons were made of diesel products from fluid and from delayed coking of bitumen. The amount of hydrogen consumed was calculated from mass spectrometry data and correlated with the degree of cetane improvement. Fuel quality enhancement by aromatics saturation is discussed with reference to an alternative upgrading procedure involving ring-opening of naphthenes.

Dearomatization, cetane improvement and deep desulfurization of diesel feedstock in a single-stage reactor

“…For example, the cetane number of n-butylnaphthalene is 6 and that of n-butyltetralin is 18 [9]. This drop of about 15 g/mole due to hydrotreating indicate that the deep desulfurization and aromatic saturation were accompanied by hydrocracking.…”

“…This drop of about 15 g/mole due to hydrotreating indicate that the deep desulfurization and aromatic saturation were accompanied by hydrocracking. 8 and that of n-propyltetralin is only 8 [9]. It is expected that reduction in aromatic carbon by hydrogenation of naphthalenes to form tetralins would result in approximately a 12 point increase in CI.…”

Comparison between refinery processes for heavy oil upgrading: a future fuel demand

“…Estimated capital and operating costs for different process options along with product revenue for three Atmospheric Residue (AR) upgrading options Source:Phillips and Liu (2003) Properties of middle-distillate feedstocks from Athabasca synthetic crudes Source:Wilson et al (1986) …”

“…Typical product composition and its contaminants of upgrading product quality indicating thermal-cracking (a) and hydrocracking (Fuel product compositions from synthetic crude: selectivity after secondary hydrotreating with variation of reaction conditions Source:Wilson et al (1986) …”

Catalytic strategies for improving specific fuel properties

“…In iso-paraffins, the CN decreases as the degree of branching increases. 10 Fig . 1 shows the variation of CN in going from naphthalene to n-decane.…”