Glycerol for renewable acrolein production by catalytic dehydration

The significant surge in biodiesel production by transesterification of edible or non-edible oils have caused surplus of glycerol in the market. With its characteristics, unique structure, renewability, and bio-availability, glycerol has tremendous potential to be transformed to higher value-added chemicals. This article provides a comprehensive and critical review of glycerol dehydration to acrolein in both petroleum-and bio-based processes. Acrolein has enormous industrial applications as a significant chemical intermediate for acrylic acid, dl-Methionine and superabsorbent polymer production. The current development of several precursors on suitable support such as heteropoly acids, zeolites, mixed metal oxides, and pyrophosphates in creating superior catalytic properties for both liquid- and gas-phase processes has been discussed. The acidity and textural properties of various catalysts, as significant variables affecting acrolein yield and selectivity, are evaluated separately. Techno-economical evaluation on dehydration of petroleum- and bio-based glycerol to acrolein proved that the bio-based processes are more feasible compared to the conventional petroleum-based process. In addition, various proposed mechanisms for catalytic dehydration of glycerol to acrolein have been examined. Particularly, catalyst coking and few crude glycerol applications have been identified as the main drawbacks for immediate industrialization and commercialization of glycerol dehydration to acrolein.