Abstract
Catalysts composed of plurimetallic particles (Cu, Ni and Ru) supported on Keggin type polyanion salts (Cs2.5H0.5PW12O40) are synthesized and characterized by various physicochemical techniques. Several catalysts have been prepared in this view by varying the metal content. The organic yield obtained with CuNi2Ru1@CsPW catalyst (ca. 30wt.%) is two times higher than the one found for the bimetallic CuRu1@CsPW and close to the activity of CuRu2@CsPW material. In the batch reactor, a high yield of good quality biofuel is obtained. However, the catalyst reusability is compromised due to high thermal treatment required for the charcoal removal from the surface of the material which causes catalyst degradation and particles sintering. Moreover, the accumulation of ashes on the catalyst surface decreases the active species accessibility. To avoid the contamination of the catalyst with ashes and charcoal, hydrotreatment process is combined with slow pyrolysis of biomass. Indeed, the pyrolysis oil resulted from thermal decomposition of biomass is treated in a fixed bed reactor containing CuNi2Ru1@CsPW. In this case, the catalytic activity is low, only 15wt.% of biofuel is obtained, but the activity is stable even after four catalytic cycles.
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•CuNiRu trimetallic nanoparticle was supported on cesium heteropolyanion salt.•The conversion of sawdust into biofuel over CuNiRu catalyst was achieved.•The catalyst activity and reusability in batch and fixed bed systems were compared.