摘要：
After activated at 850oC under air condition, calcium hydroxide and calcium carbonate in carbide slag are transformed into calcium oxide. The prepared transesterification catalyst, labeled as CS–850, gains surface area of 8.00 m2∙g–1, functional groups of vanishing O–C–O and O–H bonds, surface morphology of tenuous branch and porous structure and basic strength of 9.8<H_<15.0. From aspects of the molar ratio of methanol to oil (γ), the catalyst added amount (ζ) and the reaction temperature (Tr), transesterification catalyzed by CS–850 is optimized through the Box–Behnken design of the response surface methodology (BBD–RSM). A quadratic polynomial model is preferred for transesterification efficiency prediction with coefficient of determination (R2) of 0.9815. The optimal parameters are predicted to be γ=13.8, ζ=6.7 % and Tr=60 oC with efficiency of 94.70 % and validated by experimental value of 93.83 %. Meanwhile, γ is demonstrated to be the most significant variable for the minimum p–value. Besides, CS–850 performs acceptable reusability and for the fifth time reusage, efficiency of 82.61 % could still be supplied. Physicochemical properties of the purified biodiesel meet American Society for Testing and Material (ASTM) standard.
