Gas–liquid countercurrent integration process for continuous biodiesel production using a microporous solid base KF/CaO as catalyst

Abstract A continuous-flow integration process was developed for biodiesel production using rapeseed oil as feedstock, based on the countercurrent contact reaction between gas and liquid, separation of glycerol on-line and cyclic utilization of methanol. Orthogonal experimental design and response surface methodology were adopted to optimize technological parameters. A second-order polynomial model for the biodiesel yield was established and validated experimentally. The high determination coefficient ( R 2  = 98.98%) and the low probability value (Pr