Biodiesel fuel production from waste cooking oil by the inclusion complex of heteropoly acid with bridged bis-cyclodextrin

•CsPW/B is the inclusion complex of Cs2.5H0.5PW12O40 with bridged bis-cyclodextrin.•CsPW/B is used as a catalyst for the transesterification of waste cooking oil.•The conversion rate of waste cooking oil is up to 94.2%.•The yield of fatty acid methyl esters reaches 96.9% based on the biodiesel product.•The physical properties of produced biodiesel satisfy ASTM D6751 standards. The inclusion complex of Cs2.5H0.5PW12O40 with bridged bis-cyclodextrin (CsPW/B) is prepared as a highly efficient catalyst for the direct production of biodiesel via the transesterification of waste cooking oil. CsPW/B is characterized by X-ray diffraction, and the biodiesel is analyzed by Gas Chromatography–Mass Spectrometer. The conversion rate of waste cooking oil is up to 94.2% under the optimum experimental conditions that are methanol/oil molar ratio of 9:1, catalyst dosage of 3wt%, temperature of 65°C and reaction time of 180min. The physical properties of biodiesel sample satisfy the requirement of ASTM D6751 standards. The novel CsPW/B catalyst used for the transesterification can lead to 96.9% fatty acid methyl esters and 86.5% of the biodiesel product can serve as the ideal substitute for diesel fuel, indicating its excellent potential application in biodiesel production.