Intensified Reactor Structures for Intrinsically Secure processes. – IRSIS

To develop their industrial capability in a sustainable way, the European countries have to invest in new production methods and tools. A breakthrough in chemical production could be achieved by adapting technologies for the production of key chemicals to new markets using Process Intensification (PI). For many catalytic processes the reactor is often the limiting unit operation since several physical phenomena - mass and heat transfer - may limit the intrinsic chemical properties. Furthermore, such limitations can strongly impact the products distribution thus calling for larger downstream treatments units. Also, oxidation reactions performed with dioxygen are most often conducted at very low oxygen content in order to lower runaway and explosion issues. Thus, the current reactor technologies for gas-liquid or gas-solid processes require new inputs to lower capital costs as well as to increase compactness and safety. Recently, Open Cell Foam Reactors (OCFR) have emerged as possible gas-liquid-solid catalytic reactors to solve such issues. These materials are available in large quantities and with quite a large diversity considering dimensions and nature. Solid open-cell foams are highly porous (from 60 to 97 %) monolithic media with a continuous cross-linked strut network resulting in a quite irregular structure. These structures enable a considerable reduction of pressure drop combined to a very high geometrical specific surface areas. Fluid flow can proceed in all the directions resulting in a good radial mixing. Thus, efficient heat and mass transfer performances are expected.

The project IRSIS is thus targeting two main objectives: Firstly, to characterize OCFR performances (heat transfer, hydrodynamics) for G/L reactions. Secondly, to evaluate the use of OCFR for G/L and G/S demanding, exothermic and potentially explosive oxidation reactions. The target reaction, the oxidation of aldehydes (AL) into acids, is also of strong industrial interest. The choice was dictated by the fact that this reaction is also very challenging - it is exothermic (ca. – 250 kJ.mol-1), it presents selectivity issues, and the AL/O2 reaction mixture is potentially explosive – and also because it could be readily performed without a solid catalyst thus leading to easier experimentations.

To run the project, a consortium involving two academic teams, LGPC (UMR5285 CNRS-CPE Lyon-Université Claude Bernard Lyon 1) and ICARE (UPR 3021 CNRS, Orléans), has been set with the aim at using advanced gas-solid and gas-liquid-solid reactor technologies. The objective is both to extend the fundamental knowledge on advanced reactors but also to demonstrate a generic solution to operate oxidation processes safely with oxygen rich gases. Dissemination of PI to the public and to the Higher Education is foreseen with a lab kit for teaching PI in practice courses. The work program is divided in 6 tasks. Task 1 concerns the project management. Task 6 deals with dissemination. Task 2 to 5 are concerned respectively with heat transfer measurements (G/L, G/L/S) in OCF, flame & detonation propagation properties in open-cell foam materials and the validation with reactive media in lab scale devices.