Inhibiting effect of decan-1-ol on the transformation of n-hexadecane over a Pt/SiO2–Al2O3 catalyst

Inhibiting effect of decanoic acid and its by-products on the transformation of n-hexadecane over a Pt/SiO2-Al2O3 catalyst

“…Moreover, the catalyst acidic and metallic functions were characterized before and after the introduction of the oxygenates in order to understand the modification of the catalyst induced by their presence. These results are compared to those previously obtained by Guedes et al [22] in the same operating conditions for the impact of decan-1-ol and water for the hydroconversion of n-hexadecane.…”

“…The overall rate constants for each step were determined and the theoretical curves obtained using these values have allowed to report correctly the experimental results. This behavior is not typical of an ideal hydrocracking catalyst where the n-alkane is transformed successively into monobranched isomers, multibranched isomers and cracked products, as already discussed in [22]. Decanoic acid is totally converted under hydrocracking conditions only on the metallic function and not on the acidic function of the catalyst.…”

“…Alcohols would adsorb preferentially on the acid sites, increasing the metal-to-acid sites ratio while carboxylic acid would decrease this ratio by adsorbing preferentially on the metallic sites. Guedes et al [22], in the same way, showed that the presence of decan-1-ol inhibited the transformation of n-hexadecane, a model molecule representative of the long chain paraffins produced from LT F-T and also the selectivities towards isomerization and cracking in favour of isomerization over a Pt/silicated alumina catalyst. The authors explained these results by an irreversible modification of the catalyst by water which was found to be the real contaminant.…”

“…As described previously [22], catalytic activity measurements were carried out in a fixed-bed reactor at 608 K under a total pressure of 5 MPa, which was typically loaded with 1 g of catalyst. First of all, the catalyst was dried in situ at 423 K for 1 h in nitrogen flow (6 NL g catalyst -1 h −1 ) and then reduced under atmospheric pressure in H 2 flow (6 NL g catalyst -1 h −1 ) at 723 K for 2.5 h. The desired reaction conditions were adjusted (608 K, 5 MPa) and then the model feed was injected into the reactor.…”

“…Decanoic acid was chosen as a model molecule representative of the carboxylic acid and n-hexadecane as the model molecule representative of the long chain paraffin as reported in literature [15,22]. The decanoic acid and its oxygenated by-products (CO, CO 2 ) impact on the hydroconversion of n-hexadecane performed over a con- ventional Pt/silicated alumina hydrocracking catalyst was studied under typical hydrocracking conditions.…”