Catalytic Dehydration of Glycerol to Acrolein in a Two-Zone Fluidized Bed Reactor

Abstract

The gas-phase catalytic dehydration of glycerol to acrolein was carried out in a Two-Zone Fluidized-Bed Reactor (TZFBR) using a 20 wt. % phosphotungstic acid (H3PW12O40) catalyst supported on CARIACT-Q10 commercial silica. In the first step, a hydrodynamic study of the reactor was performed. A quality of fluidization of more than 80% was obtained. In the second step, the mechanical stability of the catalyst was studied. It was found that only the external layer of active phase is eliminated under the conditions of operation whereas the global composition of the catalyst was not significantly affected after 44 h of fluidization. Finally, in a third step, the influence of the main operating parameters on the overall catalytic performances (glycerol/oxygen molar ratio and relative volumes of the reaction and regeneration zones) was investigated, showing notably the importance of the O2/glycerol ratio, resulting in an inverse trend between conversion and selectivity. Increasing O2/glycerol ratio led to higher conversion (lower coke deposit as shown by TGA analysis), but to the detriment of the selectivity to acrolein, supposedly due to the presence of O2 in the reaction zone causing the degradation of glycerol and acrolein.

Valorisation of glycerol through catalytic hydrogenolysis routes for sustainable production of value-added C3 chemicals: current and future trends

“…104 Acrolein, an intermediate for the generation of acrylic acid that can be obtained through dehydration of glycerol, can also be obtained. 105 The overwhelming attention from researchers reflects the significance of glycerol valorisation in the future era.…”

Progress of the Catalytic Deactivation of H‐ZSM‐5 Zeolite in Glycerol Dehydration

“…[6,40] Corma et al [77] developed a system similar to a fluid catalytic cracking process, in which two distinct reactors, in a loop configuration, are used for the reaction and regeneration processes, respectively. On the other hand, Katryniok et al [87] carried out the glycerol dehydration in a fluidized bed reactor using a phosphotungstic acid supported on SiO 2 . In their work, they used simultaneous catalytic and regeneration processes.…”

“…Thus, two zones are formed: the lower one, where the spent catalyst is in contact with the O 2 , and the upper one, where the fresh catalyst is in contact with the glycerol. [87] The knowledge of coke composition, location, and evolution with time is essential for developing novel catalysts and establishing new reactors and regeneration protocols. In this context, this study displays the transformation and chemical composition of coke species formed in the pores and on the outer surface of the crystals of zeolite H-ZSM-5, one of the most studied catalysts in the dehydration of glycerol.…”

Assessment on the Effect of Sulfuric Acid Concentration on Physicochemical Properties of Sulfated-Titania Catalyst and Glycerol Acetylation Performance

“…Several chemical transformation processes have been used for glycerol to improve its commercial availability and biodiesel economics. These processes are known as carboxylation [3], hydrogenolysis [4,5], selective oxidation [6], dehydration [7], oligomerization [8], etherification [9] and esterification or acetylation [10].…”