Catalytic upgrading of biomass-derived vapors to bio-fuels via modified HZSM-5 coupled with DBD: Effects of different titanium sources

Abstract

Different titanium (Ti) sources modified HZSM-5 coupled with dielectric barrier discharge (DBD) were applied to upgrade biomass-derived vapors to prepare bio-fuels. Four objectives were included: (I) effects of different Ti species on active radicals were investigated, (II) effects of Ti sources on bio-fuel yield and properties were analyzed, (III) the availabilities of bio-fuels were evaluated from different composition angles, and (IV) the catalyst stabilities were characterized on different scales. The results showed that the interaction between low-valent titanium species and DBD could increase radicals. The rutile modification (TiRH5) had no positive effect on bio-fuel production, while the anatase modification (TiAH5) could induce photo-catalysis by coupling with DBD to increase both the yield (17.26%) and high heating value (HHV) (35.56 MJ/kg). The low-valent Ti modification (Ti3H5) further increased the yield to 17.77% and HHV to 36.47 MJ/kg, benefiting from the MAHs increase and the integration of more hydrogen-radicals under multiple interactions, while the conventional titanium dioxide (TiO2) modification (Ti4H5) lacked the catalytic effects. The bio-fuel from TiAH5 catalysis had potential for producing gasoline additives or substitutes, while the bio-fuel from Ti3H5 catalysis tended to become diesel additives or substitutes. The induced photo-catalysis and multiple interactions improved the stabilities of TiAH5 and Ti3H5, respectively.