Bitumen partial upgrading over Mo/ZSM-5 under methane environment: Methane participation investigation

- A novel catalytic methanotreating process is developed to partially upgrade bitumen.
- Mo/ZSM-5 facilitates bitumen partial upgrading under methane.
- Methane involvement into bitumen upgrading is evidenced via model compound study.
- Active metal dispersion and oxidation state influence the catalytic performance.

Bitumen extracted from oil sands which is abundant in Canada needs to be partially upgraded in order to meet pipeline specifications before being sent to downstream refineries. Hydrotreating where expensive hydrogen is involved at high pressure (15 ∼ 20 MPa) is commonly employed as the technique to satisfy the upgrading requirement. In this study it is reported that a partially upgraded crude oil can be readily produced from bitumen under methane environment at mild conditions (400 °C and 3 MPa) without H2 engagement under the facilitation of 5%Mo/ZSM-5 (SiO2/Al2O3 = 23:1). The methane participation into the upgrading process was evidenced by analyzing the products obtained from the methanotreating of styrene and n-butylbenzene, the model compounds to represent heavy oil, as well as the heat effect during upgrading. Direct evidence of methane incorporation into the product molecules is observed on 1H, 2D and 13C NMR spectra, revealing that the carbon and hydrogen from methane occupy the phenyl carbon sites and aromatic and benzylic hydrogen sites, respectively, in the product molecules. Through extensive catalyst characterizations using TEM, XRD, and XPS, the excellent catalytic upgrading performance might be closely related to the highly dispersed molybdenum oxide particles on the zeolite support at partially reduced oxidation state for better methane activation. The outcomes from this research could not only create an innovative route for more profitable natural gas utilization, but also benefit bitumen partial upgrading in a more economical and environmentally friendly way.

A novel catalytic methanotreating process is developed to partially upgrade bitumen at mild conditions (400 °C and 3 MPa) for pipeline transportation with reduced cost and minimized carbon footprint and methane involvement into bitumen upgrading is evidenced via model compound study.204