Coupling of solvent-free synthesis and reactive extrusion of alumina: an ecologically efficient integration for heterogenous catalyst synthesis

Abstract

Innovating in materials manufacturing processes is a challenge to reduce the environmental impact of the chemical industry in line with sustainable development objectives, such as promote sustainable industrialization, and ensure...

Solvent-free Preparation of Ru/Al2O3 Catalysts for CO2 Methanation: An Example of Frugal Innovation

“…However, from a sustainability point of view, as discussed in our previous article, the synthesis process of the catalysts prepared by direct solvent-free sol–gel synthesis seems to be more efficient in terms of integration of the synthesis process compared to catalysts prepared by impregnation of the active phase on gamma-alumina prepared in the same conditions.…”

“…We made an attempt to compare the production of the Ru(0)/γ-AlOOH catalyst prepared by the solvent-free sol–gel method with the production of a classical Ru(0)/γ-Al 2 O 3 catalyst prepared in a conventional way by precipitation of boehmite, calcination, and postimpregnation (which is representative of industrial reality). , We are aware that both catalysts do not have similar crystalline structures, but references to catalysts Ru(0)/γ-AlOOH are very hard to find in the literature. For the calculation of atoms and energy consumption, this difference has a limited effect (the additional calcination step will be specifically highlighted and discussed in order to avoid possible confusions).…”

“…Two production scenarios were compared. First, a classical batch production method whose parameters have been taken from literature, including calcination steps, was chosen as a standard protocol. ,, It was already used as a reference in a previous article, which contains more details . In this scenario, both acidic and basic aluminum salts are coprecipitated and aged in hot water to form γ-AlOOH.…”

“…Reference Ru/Al 2 O 3 materials were prepared by incipient wetness impregnation of solvent free-sol–gel Al 2 O 3 (prepared according to ref ) with Ruthenium­(III) nitrosyl nitrate solution concentrated at 1.5% (typical). Two Ru loading Ru/Al molar ratios of 1 and 3% (equivalent to wt %Ru 2% Ru/Al 2 O 3 and 6% Ru/Al 2 O 3 ) were prepared.…”

“…In a recent study, we used a continuous reactive extrusion process for the solvent-free production of high-surface-area mesoporous γ-AlOOH and γ-Al 2 O 3 extrudates. The easy scale-up, global low atom and energy consumption, and drastic reduction of the quantity of chemical waste make this synthesis strategy a very realistic method for improving the actual nanoporous alumina catalysts production.…”