摘要 : Orange peel waste (OPW), a significant biomass byproduct derived from the juice processing industry, can be used as valuable resource to produce various chemicals, including methyl levulinate (ML) and limonene (LIM). This study in... 展开 Orange peel waste (OPW), a significant biomass byproduct derived from the juice processing industry, can be used as valuable resource to produce various chemicals, including methyl levulinate (ML) and limonene (LIM). This study introduces a tandem catalytic process involving the dehydrogenation of LIM into p-cymene and the (transfer) hydrogenation of ML into gamma-valerolactone (GVL), unlocking the full potential of OPW chemo-catalytic valorisation in the spirit of circular economy. This process is promoted by the heterogeneous Pd/ZrO2 and t-ZrO2 catalysts in the presence of ethanol as hydrogen-donor solvent. Under batch conditions, Pd/ZrO2 not only shows superior performance in the transfer hydrogenation of ML compared to t-ZrO2, but also promotes the conversion of LIM into p-cymene primarily through the hydrogenation/dehydrogenation route. Most important, Pd/ZrO2 exhibits good activity in the simultaneous upgrading of both ML and LIM across various ML:LIM ratios. Continuous gas-flow conditions result in improved outcomes in terms of ML and LIM conversion, as well as GVL and CYM selectivity. Notably, a strong correlation between CYM and H-2 yields has been established providing compelling evidence for the LIM isomerization-dehydrogenation pathway. However, the simultaneous upgrading of LIM and ML was found to be not efficient in the gas-phase due to side oligomerization reactions. 收起