Separation and Characterization of Vanadyl Porphyrins in Venezuela Orinoco Heavy Crude Oil

Xu Zhao, Yu Liu, Chunming Xu,^* Yuanyuan Yan, Yahe Zhang, Qingyu Zhang, Suoqi Zhao, Keng Chung, Murray R. Gray, and Quan Shi^*

State Key Laboratory of Heavy Oil Processing, China University of Petroleum, Beijing 102249, People’s Republic of China 

Well Resources Incorporated, 3919-149A Street, Edmonton, Alberta T6R 1J8, Canada

Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta T6G 2V4, Canada

^*Corresponding Author: E-mail: xcm@cup.edu.cn; sq@cup.edu.cn

DOI: 10.1021/ed400161p

Keywords: Anions; Carbon; Petrochemicals; Pyrroles; Vanadium

Abstract: Venezuela Orinoco heavy crude oil was sequentially separated into several subfractions to determine the contents and types of vanadyl porphyrins contained in the products. Vanadium contents in each subfraction were detected using an atomic absorption spectrometer (AAS) combined with the characterization of vanadyl porphyrins by ultraviolet−visible (UV−vis) spectroscopy and positive-ion electrospray ionization (ESI) Fourier transform-ion cyclotron resonance mass spectrometry (FT-ICR MS). Six types of petroleum vanadyl porphyrins, which have been identified previously, were well-characterized with the detailed fractionation. Three new series of vanadyl porphyrins corresponding to molecules of C_nH_mN₄VO₂, C_nH_mN₄VO₃, and C_nH_mN₄VO₄, respectively, were identified in addition to the six known types of vanadyl porphyrins.