• What is the difference between type1/type2/brim/Hybrim catalysts??

    What is Direct and Indirect desulphurization route in HDS reaction in hydrotreaters, what factors affects the routes or pathways?

    Is there any relation for catalyst selection and route preference for HDS? How does route or pathway makes any difference in final product s specification?



  • Marcio Wagner da Silva, Petrobras, marciows@petrobras.com.br

    This classification is related to the Mo-S2 in hydrotreating catalysts. In Type I structures there is a strong interaction between the active phase and the carrier (Al2O3) mainly the interaction between the Mo and Oxygen from the support.

    In Type II structure there are only weak interactions between the active phase of the catalyst with the carrier, the literature describes that Type II structure tends to present higher catalytic activity than Type I structure once the strong interaction with oxygen raises the required energy to promote the desulfurization reactions in the Type I catalysts.

    The BRIM catalyst family was introduced by Haldor Topsoe company in 2003 and, among other improvements, presents higher dispersion of the active phase over the catalyst carrier leading to higher catalytic activity. The HyBRIM catalysts is a improvement of the BRIM catalyst where the interaction between the active phase and the carrier is optimized leading to a higher catalytic performance according to the licensor.

    Regarding the desulfurization route.
    1 - Direct Desulfurization - The whole atmospheric residue (or the hydrotreating feed) is fed to a hydrodesulfurization unit and the sulphur compounds are treated according to hydrodesulfurization reactions.

    2 - Indirect Desulfurization - The heavier fraction is separated from the atmospheric residue (or another stream which is the goal of the desulfurization process) from a separation process like vacuum distillation unit or through carbon rejection routes like Solvent Deasphalting (SDA). Once the sulphur and other heteroatoms tend to concentrate in the heavier fractions of the crude oil, this process indirectly reduces the sulphur content of the light fractions.