Development of an efficient downstream process for product separation and catalyst recycling of a homogeneous polyoxometalate catalyst by means of nanofiltration membranes and design of experiments

H8[PV5Mo7O40] – A Unique Polyoxometalate for Acid and RedOx Catalysis: Synthesis, Characterization, and Modern Applications in Green Chemical Processes

“…In another recent study by Esser et al [128] . in 2022, an efficient downstream process could be developed to separate and recover the HPA‐5 catalyst from the reaction mixture using nanofiltration membranes.…”

“…The desulfurization of iso ‐octane solutions containing benzothiophene was used as a model experiment, in which the solution is completely desulfurized via six cycles. Thus, the ECODS process in combination with nanofiltration could be brought to a level relevant for industrial application [128] …”

Extractive Catalytic Oxidative Deoxygenation of Model Fuels Catalyzed by a Vanadium-Substituted Heteropolyacid and Molecular Oxygen

“…16,17 An efficient recycling of the catalyst has already been established via membrane filtration. 23 Other methods for the removal of sulfur are the use of Ti oxoclusters in ionic liquids with an extractant, such as alcohols and glycol derivatives, 24 or the application of heterogeneous nanohybrid POMs with magnetic properties to ease the purification of the reaction medium. 21,22 While the removal of sulfuric compounds is achieved to a high degree and under mild conditions, the synthesis strategies are far more complex and money-consuming than the comparably simple and cheap HPA-5 Keggin-type synthesis.…”

“…This approach is called extractive catalytic oxidative desulfurization (ECODS) and denitrogenation (ECODN). , The reaction mixture consists of a gas phase, that is air or pure oxygen, an aqueous phase in which the catalyst is dissolved, and the crude oil containing the impurities . The oxidized waste products are either gaseous or polar liquids, whereby the latter are separated from the oil directly into the aqueous phase. , An efficient recycling of the catalyst has already been established via membrane filtration …”

Revealing the nitrogen reaction pathway for the catalytic oxidative denitrification of fuels

“…In addition, part of the aqueous phase was removed after six hours to prevent further reaction of the nitrate formed. The HPA-5 catalyst was removed by membrane separation 39 and the permeate was measured by IC.…”