Direct conversion of glycerol to acrylic acid via integrated dehydration–oxidation bed system

One-step glycerol oxidehydration to acrylic acid on multifunctional zeolite catalysts

“…For instance, an optimal thermal balance could be provided by coupling of the exothermic oxidation reaction with the endothermic dehydration reaction [7]. Furthermore, the combination of both acid and oxidizing sites should make it possible to achieve continuous oxidation of undesired dehydration byproducts.…”

“…The glycerol dehydration step can be performed separately from the oxidation by employing a two-bed reactor approach [7]. However, a potential advantage of bifunctional catalysts contained in a single catalytic bed, in which the different active sites are mixed together, is their better longterm performance.…”

“…In the first step, glycerol is dehydrated to 3-hydroxypropanal, a very reactive intermediate that readily dehydrates to give acrolein [1]. The second step is the selective oxidation of acrolein in the presence of molecular oxygen to yield acrylic acid [3][4][5][6][7].…”

Catalytic routes towards acrylic acid, adipic acid and ε-caprolactam starting from biorenewables

“…In 2011, Witsuthammakul et al 51 described a process using a single reactor with two consecutive reactor beds. First, the complete conversion of glycerol with 81% selectivity to acrolein was recorded over a ZSM-5 reactor bed at 300°C.…”

Sunflower oil methanolisys and glycerol ketalisation: stepwise production of biofuels and additives with 3-methylimidazolium hydrogensulphate as catalyst

“…The efforts to address the first issue have been nicely put into perspective by Sherstyuk and coworkers 1 . On the other hand, the attempts to transform glycerol into value added chemicals have attracted attention all the way down from the production of C3 chemicals from hydrogenolysis or dehydration [2][3][4][5] and glycerol carbonate formation 6 , to the more prosaic etherification 7 and reactions with ketones or aldehydes to produce ketals for fuel additives [8][9] . An up to date account of these later efforts have been summarized by Fan et al, who called the attention to the fact that common inorganic acids used as catalysts for the ketalization reactions pose serious erosion of devices and other environmental problems; to circumvent these drawbacks, heterogeneous acidic catalysts such as cation-exchange resins, heteropolyacids, zeolites, solid superacids and supported metal oxides have been developed 10 .…”