Removal of benzonitrile and carbazole from model green-diesel derived from microalgae using metal-organic frameworks with protonated amines

• MIL-101(Cr) MOF was functionalized, both on metal and linker sites, with amines. • Modified MIL-101, with protonation, showed remarkable performance in denitrogenation. • New material adsorbed 15.6 times of benzonitrile ( Q 0 500 mg/g) that of an activated carbon. • The adsorption results were interpreted with hydrogen bonding/cation-π interactions. • New reusable material might be applied in adsorptive denitrogenation of green-diesel. The utilization of microalgae-derived fuel is very important for our sustainability. Here, adsorptive denitrogenation of model green-diesel (with considerable nitrogen-containing compounds, NCCs) was investigated to check the feasibility of adsorptive purification of fuel, derived from microalgae that is composed of NCCs. A highly porous MIL-101(Cr) (named M101) metal–organic framework was firstly modified to introduce protonated amino groups on both the linker and metallic sites of the MOF. The functionalized MOFs including P-M101-NH 2 -ED (P and ED mean ‘protonated’ and ethylenediamine, respectively), M101-NH 2 -ED, and M101-NH 2 were applied (together with pristine M101 and a conventional activated carbon) in the adsorptive removal of N-containing compounds like benzonitrile (BENZ) and carbazole (CARB) from model green-diesel. The prepared P-M101-NH 2 -ED showed the most effective performances in the adsorption, compared with any other adsorbents known thus far. For instance, P-M101-NH 2 -ED adsorbed 15.6 and 3.6 times of BENZ and CARB, respectively, that of the activated carbon. The observed remarkable performances of P-M101-NH 2 -ED ( Q 0 values for BENZ and CARB are 500 and 455 mg/g, respectively), although with lower porosity than other M101s, for BENZ and CARB adsorption could be explained mainly with hydrogen bonding and hydrogen bonding/cation-π interactions, respectively. Moreover, P-M101-NH 2 -ED was recyclable in several cycles after simple ethanol washing. Therefore, P-M101-NH 2 -ED could be suggested as a plausible adsorbent to remove NCCs from green-diesel, based on remarkable performances and facile reusability.