Article pubs.acs.org/EF
High Temperature Simulated Distillation of Bitumen Fractions with Open Tubular Capillary Columns Depleted in Silicone/Siloxane Stationary Phases Lante Carbognani,* Josune Carbognani Arambarri, Hebert Molero, and Pedro Pereira-Almao Chemical and Petroleum Engineering Department, Schulich School of Engineering, University of Calgary, Calgary, Alberta T2N 1N4, Canada ABSTRACT: High Temperature Simulated Distillation (HTSD) is routinely carried out in petroleum laboratories for characterization of heavy hydrocarbon fractions. However, thermal cracking from HTSD high operating temperatures (up to 430 °C) has been reported to affect analytes during the chromatographic process. This work showed the feasibility of using silicone/ siloxane depleted stationary phase wide bore capillary columns for HTSD carried out under lower setup temperatures to avoid cracking. Sequential low temperature elution for analysis followed by high temperature oven cycles for injector cleaning were found mandatory for successful operation. Depleted stationary phase metal capillary columns were determined as a feasible interesting alternative, advantageous from the point of view of column life span and retention times constancy. Present findings suggest that these columns can have useful life in the greater than or equal to a year span. Heavy hydrocarbon upgrading monitoring with standard and depleted stationary phase metal columns was found equivalent, further supporting the feasibility of using the latter for routine applications. X-ray photoelectron spectroscopy (XPS) analysis of the internal wall of metal columns highlighted differences brought by stationary phase depletion, particularly on the silicone/siloxane groups. Finally, preliminary results indicated that one further alternative to avoid “on column” thermal cracking is to elute standard columns to temperature limits
