2.3 Examination of the two-step biodiesel production for simulated oil and waste cooking oil
First, 10 ml mixed oil was reacted with 5 ml MeOH using SrFe2O4/SiO2-SO3H or H2SO4 as a catalyst
at 100oC for 90 minutes. Following that, the reaction mixture were used for next experiments without any
treatment when H2SO4 was used as a catalyst, while for the tests using SrFe2O4/SiO2-SO3H solid catalyst,
a magnetic field was applied to remove the solid catalysts from the reaction mixture prior to the next
experiments.. In the second step, 5 ml MeOH containing 2 wt% NaOH was added into the reaction
mixture resulting from the first step to conduct transesterification at 60oC for 40 min. For comparison, the same procedures were carried out by using waste cooking oil obtained from a fried chicken stallman.