INDUSTRIAL APPLICATION OF A REACTION SINTERED MATERIAL

Un procédé de densification par frittage réactif avec ajout de TiO2, mis au point précédemment est utilisé pour produire des composants denses en mullite-zircone. Ces plots de renforcement sont implantés dans des blocs en béton réfractaire pour sole de four à longeron mobile en laminoir d'aciérie. Les propriétés physiques et mécaniques du matériau céramique sont présentées et discutées.A reaction sintering process developed earlier with TiO2 as sintering aid is applied to produce dense mullite zirconia components. These are embedded as reinforcement heads in refractory concrete blocks for walking beam furnace lining in steel rolling-mill. Physical and mechanical properties of the ceramic material are presented and discussed

Characterization of crude oil interfacial material isolated by the wet silica method

COMInternational audienc

Molecular Insight into the Adsorption of H2S in the Flexible MIL-53(Cr) and Rigid MIL-47(V) MOFs: Infrared Spectroscopy Combined to Molecular Simulations

International audienceThe adsorption of the acid gas H2S has been explored in both MIL-47(V) and MIL-53(Cr) porous metal organic frameworks (MOFs) by combining infrared measurements and molecular simulations. It is shown that while the MIL-47(V) structure remains rigid upon H2S adsorption up to a pressure of 1.8 MPa, the MIL-53(Cr) solid initially present in the large pore form (LP) switches to its narrow pore version (NP) at very low pressure before undergoing a second structural transition from the NP to the LP versions at higher pressure. Such structural transitions further explain the different shape of the adsorption isotherms for both MILs. A further step consists of providing some insights into the microscopic arrangements of the adsorbate molecules within the pores of the MILs. At the initial stage of adsorption, the H2S molecules mainly form hydrogen bonded species, either as hydrogen donor (in MIL-47 V) or hydrogen-acceptor (in MIL-53Cr) with the mu(2)-O and mu(2)-OH groups, respectively, present at the MOF surfaces. At higher pressure (1.8 MPa), the adsorbates are preferentially arranged within the channel in order to form dimers with a high orientational disorder. Both experimental and simulated adsorption enthalpies for H2S decrease in the following sequence: MIL-53(Cr) NP > MIL-47(V) > MIL-53(Cr) LP. The conclusions drawn from this work are then discussed considering the use of such materials for the CH4/H2S separation by means of Pressure Swing Adsorption