Esterification of acidified oil with methanol by SPES/PES catalytic membrane.
A sulfonated polyethersulfone (SPES)/polyethersulfone (PES) blend catalytic membrane was prepared and used as a heterogeneous catalyst in the esterification of the acidified oil (acid value 153 mg KOH/g) with methanol for producing biodiesel. The results showed that the free fatty acids conversion reached 97.6% using SPES/PES catalytic membrane under the optimal esterification conditions. Meanwhile, the SPES/PES membrane with 20.3% degree of sulfonation showed a good catalytic stability. A pseudo-homogeneous kinetic model was established. The results indicated that the reaction rate constant increased with increasing methanol/acidified oil molar ratio, the loading of catalytic membrane and reaction temperature. The reaction order was 2 and the activation energy decreased from 74.65 to 21.07 kJ/mol with increasing catalytic membrane loading from 0 to 0.135 meq/g(oil). It implies that the esterification is not diffusively controlled but kinetically controlled. The predicted results were in good agreement with the experimental data.
Shi
Wenying
W
State Key Laboratory of Hollow Fiber Membrane Materials and Processes, School of Materials Science and Engineering, Tianjin Polytechnic University, Tianjin 300160, PR China.
He
Benqiao
B
Li
Jianxin
J
D000143:Acids / Q000737:chemistry*; D002384:Catalysis; D004951:Esterification; D005230:Fatty Acids, Nonesterified / Q000138:chemical synthesis; D007700:Kinetics; D008567:Membranes, Artificial; D000432:Methanol / Q000737:chemistry*; D008956:Models, Chemical; D009821:Oils / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*; D013450:Sulfones / Q000737:chemistry*; D013451:Sulfonic Acids / Q000737:chemistry*; D013696:Temperature
D000143:Acids; D005230:Fatty Acids, Nonesterified; D008567:Membranes, Artificial; D009821:Oils; D011108:Polymers; D013450:Sulfones; D013451:Sulfonic Acids; C022840:polyether sulfone; D000432:Methanol