Comprehensive GC×GC Characterization of the Catalytic Alkylation of Thiophenic Compounds in a FCC Gasoline

Comprehensive GC×GC analysis with MS and FPD detection was performed to follow the alkylation of thiophenic compounds with olefins in a FCC gasoline over a supported phosphotungstic acid catalyst, under continuous flow at 120 °C and 0.5 MPa. Doping with 3-methylthiophene (3MT) or benzothiophene (BT) was used to enhance the response of each type of S compounds after alkylation. The combination of the two detectors allowed to isolate different families of products: alkyl-3MT, alkenyl-3MT, alkyl-BT as well as undesired dimerized olefins or alkylated aromatics. Quantification of the families and the calculation of conversion of initial S compounds, aromatics and olefins and their respective distributions were also performed. This work illustrates that GC×GX technique can provide a unique comprehensive understanding of the various catalytic reactions involved in a complex matrix such as an FCC gasoline during its conversion on an acidic catalyst.