1 research outputs found
Continuous Biodiesel Production Catalyzed by Trace-Amount Alkali under Methanol Subcritical Conditions
Biodiesel is a promising alternative
biofuel, but the treatment
of wastewater containing alkali catalyst and glycerol discharged from
the washing unit operation increases the cost significantly. Here
a novel continuous biodiesel production process with trace-amount
alkali as the catalyst under the methanol subcritical condition was
proposed and investigated. The optimal operation conditions of preliminary
batch reaction experiment are temperature of 200 °C, catalyst
concentration of 513 mg/kg, reaction time of 38 min, molar ratio of
methanol to oil of 11.9:1, and system pressure of 1.5 MPa. The one-step
conversion of raw oil in a batch reactor can reach up to 85.5%. The
alkali residue in the biodiesel product can be further reduced by
removing the methanol and washing by glycerol instead of by acid or
water. The optimal weight ratio of glycerol to biodiesel is 1.5:1,
and the residual alkali in the final ester product is about 4.6 mg/kg.
The simulation and bench scale continuous experiment based on the
optimal batch operation parameters confirmed that the biodiesel produced
by the process is qualified well up to the Chinese standard of biodiesel,
and the K<sup>+</sup> concentration in biodiesel was less than 3.0
mg/kg. The economic evaluation showed that this new process is more
economically feasible than the traditional processes