TY - JOUR

T1 - Microwave-assisted transesterification of industrial grade crude glycerol for the production of glycerol carbonate

AU - Teng, Wai Keng

AU - Ngoh, Gek Cheng

AU - Yusoff, Rozita

AU - Aroua, Mohamed Kheireddine

PY - 2016/1/15

Y1 - 2016/1/15

N2 - This study is the first of its kind to report on the transesterification of industrial grade crude glycerol (GLY) to glycerol carbonate (GC) using microwave processing. Pure and two grades of crude GLY at 70% and 86% purity were transesterified with dimethyl carbonate (DMC) using calcium oxide (CaO) as catalyst. A comparison study was made of the conventional and microwave-assisted transesterification process. It was found that 70% purity of crude GLY gave higher yield in both conventional and microwave-assisted transesterification processes with the latter technique showing better energy efficiency. The highest GC yield of 93.4% was obtained from GLY with purity of 70% under microwave irradiation system with 1. wt% of catalyst, 2:1. M ratio of DMC:GLY at 65. °C in five minutes reaction time. The yield of GC was observed to increase with temperature, time and molar ratio but not the catalyst loading. The impurities such as methanol (MeOH) and sodium methylate (NaOMe) in the crude GLY were found to increase GC yield by four times. This indicates that the impurities which might not be desirable for the transesterification process under normal circumstances have unconventionally demonstrated positive effects on the performance of transesterification under microwave irradiation.

AB - This study is the first of its kind to report on the transesterification of industrial grade crude glycerol (GLY) to glycerol carbonate (GC) using microwave processing. Pure and two grades of crude GLY at 70% and 86% purity were transesterified with dimethyl carbonate (DMC) using calcium oxide (CaO) as catalyst. A comparison study was made of the conventional and microwave-assisted transesterification process. It was found that 70% purity of crude GLY gave higher yield in both conventional and microwave-assisted transesterification processes with the latter technique showing better energy efficiency. The highest GC yield of 93.4% was obtained from GLY with purity of 70% under microwave irradiation system with 1. wt% of catalyst, 2:1. M ratio of DMC:GLY at 65. °C in five minutes reaction time. The yield of GC was observed to increase with temperature, time and molar ratio but not the catalyst loading. The impurities such as methanol (MeOH) and sodium methylate (NaOMe) in the crude GLY were found to increase GC yield by four times. This indicates that the impurities which might not be desirable for the transesterification process under normal circumstances have unconventionally demonstrated positive effects on the performance of transesterification under microwave irradiation.

KW - Biodiesel

KW - Crude glycerol

KW - Glycerol carbonate

KW - Impurities

KW - Microwave irradiation

KW - Transesterification

U2 - 10.1016/j.cej.2015.08.108

DO - 10.1016/j.cej.2015.08.108

M3 - Journal article

AN - SCOPUS:84941991943

VL - 284

SP - 469

EP - 477

JO - Chemical Engineering Journal

JF - Chemical Engineering Journal

SN - 1385-8947

ER -