DBSA-Catalyzed Biodiesel Production From Sewage Sludge In A Micro-Reactor: Box-Behnken Design Optimization

A specially designed microreactor device was used for the testing the process of the production of biodiesel from sewage sludge oil using the Dodecylbenzenesulfonic acid as a catalyst. The effect of co-solvent was investigated in comparison to the process of absence the co-solvent. A mixture of hexane-chloroform were used as the co-solvent in the present study. An experimental design of Box-Behnken method was used for evaluation the optimum conditions for the process. The desirability function showed that the optimum conditions for obtaining the maximum yield of biodiesel (experimental value=97.25, predicted value=97.75) were: reaction temperature (333.15 K), methanol/oil ratio (25:1), residence time (18 min), catalyst loading (7 wt%), co-solvent (16 wt %) for the microreactor system. The physicochemical properties of the sewage sludge biodiesel produced in the microreactor system showed an accepted values in accordance to the biodiesel specifications ASTM D 6751-2 and the properties of the standard diesel oil.