Hydrogenation of Olefins in Bitumen-Derived Naphtha over a Commercial Hydrotreating Catalyst

Instability associated with the presence of olefins in bitumen that is thermally processed during partial upgrading is a major concern for pipeline transportation and downstream refining. A common strategy for stabilizing thermally processed oils is to selectively hydrogenate the olefin-rich fractions, typically, the naphtha fraction (IBP–204 °C). In this paper, olefin hydrogenation was studied with hydrotreated bitumen-derived naphtha spiked with five model olefin compounds under mild hydrotreating conditions. The hydrogenation reactivities of the five model olefin/diolefin compounds are ranked in the order 1,3-hexadiene > allylbenzene > 1-heptene > 2-methyl-2-pentene > 1-methyl-cyclopentene. The reactivity is largely determined by the position of the double bond, and, to a lesser extent, by the molecular structure of the olefin. The conjugated diolefin, 1,3-hexadiene, was the most reactive. The two terminal olefins, 1-heptene and allylbenzene, were observed to be more reactive than the two olefins with internal double bonds: 2-methyl-2-pentene and 1-methyl-cyclopentene. Results also show that temperature has a significant effect on olefin hydrogenation performance, with the pressure and the liquid hourly space velocity having relatively moderate effects. Meanwhile, flash calculations confirmed the presence of vapor–liquid equilibrium under the operation conditions used. When the reactor temperature is 150 °C or less, reactions primarily occur in the liquid phase, whereas at temperatures of 200 °C or higher, the reactions occur in the vapor phase. A hydrogenation kinetics model is proposed that successfully describes the observed trends of olefin hydrogenation in the liquid phase

Development and Application of a Life Cycle-Based Model to Evaluate Greenhouse Gas Emissions of Oil Sands Upgrading Technologies

A life cycle-based model, OSTUM (Oil Sands Technologies for Upgrading Model), which evaluates the energy intensity and greenhouse gas (GHG) emissions of current oil sands upgrading technologies, is developed. Upgrading converts oil sands bitumen into high quality synthetic crude oil (SCO), a refinery feedstock. OSTUM’s novel attributes include the following: the breadth of technologies and upgrading operations options that can be analyzed, energy intensity and GHG emissions being estimated at the process unit level, it not being dependent on a proprietary process simulator, and use of publicly available data. OSTUM is applied to a hypothetical, but realistic, upgrading operation based on delayed coking, the most common upgrading technology, resulting in emissions of 328 kg CO₂e/m³ SCO. The primary contributor to upgrading emissions (45%) is the use of natural gas for hydrogen production through steam methane reforming, followed by the use of natural gas as fuel in the rest of the process units’ heaters (39%). OSTUM’s results are in agreement with those of a process simulation model developed by CanmetENERGY, other literature, and confidential data of a commercial upgrading operation. For the application of the model, emissions are found to be most sensitive to the amount of natural gas utilized as feedstock by the steam methane reformer. OSTUM is capable of evaluating the impact of different technologies, feedstock qualities, operating conditions, and fuel mixes on upgrading emissions, and its life cycle perspective allows easy incorporation of results into well-to-wheel analyses

Implementing Power-to-Gas to provide green hydrogen to a bitumen upgrader

Summary Hydrogen is an important commodity in the processing of intermediate bitumen products into a finished petroleum product and for upgrading bitumen into synthetic crude. With the continued extraction of bitumen-rich material from Alberta's oil sands project, there is an opportunity to reduce the greenhouse gas emissions of upgrading and refining operations by using electrolytically produced hydrogen in place of hydrogen produced by steam methane reformation. Recently, a bitumen upgrading facility had been proposed for the city of Sarnia, Ontario because of its pre-existing petroleum processing infrastructure. Using the Ontario electrical system, which has a lower emissions factor than Alberta, the use of electrolytic hydrogen could result in a significant reduction of greenhouse gasses. In this paper, the objective is to determine an optimal system configuration for reducing greenhouse gas emissions while maintaining a low system cost. The analysis is performed with General Algebraic Modelling System tool, a mixed-integer linear optimization in addition to a simple model in Visual Basic. For each case, an economic and environmental analysis is performed including the use of cap-and-trade values for the price of carbon emissions, which are applied to determine the overall economic impact of the emissions reductions. Copyright © 2016 John Wiley & Sons, Ltd