Transformation of raw lignocellulosic biomass into glycols and amino derivatives: catalysts design, reactivity, modeling – CatReMo

The catalysts will have to possess various properties (acid, metallic) to allow the target transformations.
Studies from benchmark catalysts will be realised then original catalysts will be developed upon obtained results.

Partner 1 started the study in november 2019 with a PhD student.
Catalysts like Ni-WxC/AC (AC = activated carbon, WC = tungsten carbide) have been prepared and studied for cellulose, hemicellulose then pine wood transformation.
Globally good yields were obtained up to 60% in ethylene and propylene glycol, whatever the substrate. We noted the influence of the composition of the substrate on the selectivity. Cellulose and pine wood, formed mainly of C6 sugars will preferentially form ethylene glycol. Hemicelluloe, composed of C5 sugars will give propylene glycol.
The characterisation of the catalysts has shown the influence of the preparation mode on the selectivity. It seems that it plays on acid catalytic species WxC (x = 1 or 2) present on the catalyst, giving a different reactivity of the substrate.

Partner 2 started in pctober 2020 with a PhD student. The first stage was to validate and extrapolate the synthesis of the reference catalyst. Many synthesis have been performed on the base of an established protocal, and the variability on the main parameters (specific surface area, pore volume, pore size, crystalline structure, elemental composition) have beed determined. This stage was followed by an exhaustive literature study on the synthesis ways allowing preparations for catalytic applications for the route 1. Three directions have been identified (hydrothermal synthesis, chemical activation, surface post-functionalization with oxygen and nitrogen).

Partner 1. Studies on acidity determination with parner 2 are in progress to determine the influence on the selectivity.
Studies on glycol amination have started with the amination of intermediates. An internship has developped the adequate analytical method.

Partner 2 has designed and ordered an autoclave system to study the stability of catalysts simulating the reaction conditions. Studies are planned by the end of the year for Task 2 of the project.

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The CatReMo project aims at studying the solvothermal conversion of non-fractionated LC in the presence of heterogeneous catalysts, in order to produce glycols (ethylene and propylene) and glycol-derived amines. Despite the relative robustness of LC, its chemical valorization is expected thanks to the highly functionalized structure of its constituting biopolymers. The three LC principal components are sources of 5 to 6 carbon molecules and substituted aromatics, which can be further transformed into a wide variety of useful chemicals. For such valorization, heterogeneous catalysis will definitively play a crucial role besides other types of catalysis due to several advantages related to durability, recovery, use in different types of reactors including continuous flow reactors. In the project, the target molecules are glycol-derived amines, value-added chemicals, of great interest considering their potential industrial uses like in the polymer industry. To date, these compounds are produced from fossil resources and CatReMo project aims at studying in details alternative routes, starting from LC. The possibility of obtaining usual short chain (di)amines at a large scale from renewable biomass, especially from wood LC, is therefore attractive in the context of the biorefineries development. Glycol-derived amines production will be studied following two configurations of reaction during the project. In a first configuration, involving sequential reactions, the first step is the production of glycols from LC (in water), that is followed by a second reaction between produced glycols with amines to produce glycol-derived amines. This route then involves independent steps, and different catalysts, and the challenge here is to perform the reactions in a sequential way in order to avoid an isolation step of glycols issued from the LC transformation. In a second configuration, the one-pot formation of such amines through a direct catalytic reductive aminolysis of LC (reaction of LC with amines) will be studied. This strategy appears much more challenging and corresponds to a very innovative approach considering that only one step is needed to reach short chain glycol-derived amines. The two approaches will include: (i) a detailed study of the reactivity of LC over catalysts in hydrothermal conditions; (ii) the evaluation of the benchmark catalysts and novel catalytic formulations stabilities, and elucidation of physical and chemical deterioration mechanisms; (iii) a reaction mechanism and process modeling to evaluate the robustness of the integrated process, and including the measure of 2L scale LC transformation. For the study purpose, the constituted consortium regroups three major laboratories in France. Each laboratory bears specific expertise that will be shared to reach the objectives : Institut de Recherches sur la Catalyse et l’Environnement de Lyon (IRCELYON) is recognized for its knowledge of biomass reactivity using heterogeneous catalysis and leads the LC reactivity activities; Unité de Catalyse et Chimie du Solide (UCCS) has strong expertise in the preparation and characterization of tailored solid catalysts and leads activities on heterogeneous catalyst optimization and characterization; Laboratoire de Génie Chimique et Procédés (LGPC), expert in the field of reactor and process engineering, leads the activities devoted to the modeling of reaction mechanism and process integration. To reach these challenging objectives CatReMo will involve two PhD students (IRCELYON and UCCS) and a post-doctoral associate (LGPC). CatReMo will implement and consolidate research collaboration, contributing to the acquisition of knowledge of material sciences and catalyst formulations, reaction mechanisms and kinetics, and biomass catalytic transformation, towards the formation of partly biosourced amines. In the long term, CatReMo will contribute to the acquisition of fundamental knowledge necessary for the development of biorefineries.