Transition to sustainable chemistry through digitalization

Modern chemistry is the backbone of our society, but it is also a major contributor to global environmental pollution and the ongoing climate crisis. The transition toward a sustainable future requires a radical transformation of how chemistry is designed, developed, and used. This represents a “break it or make it” challenge for the chemical industry with significant technology lock-in and high entry barriers to radical innovations. We propose that urgently required systemic changes in chemical industry, research and development (R&D), chemicals assessment and management, and education to advance sustainable chemistry are attainable through increased and more rapid adoption of digitalization and new digital tools. This will enable flexible data exchange, increased transparency of information flows along cross-country chemical, material, and product life cycles, and chemistries that are safe and sustainable by design, addressing the complexity of chemicals-environment-health interactions and lowering the costs of entry into chemical R&D and manufacture, and new, more sustainable and collaborative business models

Continuous synthesis of doped layered double hydroxides in a meso-scale flow reactor

Layered double hydroxides are a class of low-cost structured nanomaterials with many potential applica-tions in environmental catalysis and sustainable technologies. Their large-scale use is hindered by the chal-lenge of reproducible synthesis at scale. Here we report a general, readily scalable process for the repro-ducible synthesis of transition metal doped hydrotalcites using a two-step process: co-precipitation in a mm-scale (meso-scale) continuous flow reactor, followed by aging. We have shown that co-precipitation in flow at a residence time close to the micromixing time affords good control of particle formation. Re-producible synthesis allowed us, for the first time, to investigate the formation of the pore morphology of hydrotalcites and their thermal stability as a function of metal doping. The obtained samples exhibited sur-face areas (80-150 m2 g-1) higher than those typically attained in batch syntheses, with very low standard deviation between the samples, a high degree of crystallinity and small crystallite sizes, in the range of 9.5-11.9 nm, depending on composition. A systematic characterization allowed us to elucidate the mechanism of the pore morphology formation: the crystallites were found to agglomerate into disk-like platelets, whereas the pore structure of the hydrotalcites is formed by agglomeration of the platelets.National Research Foundation, Singapor

Scalable Palladium-Catalyzed C(sp3)-H Carbonylation of Alkylamines in Batch and Continuous Flow

Development of scalable processes for C­(sp3)–H oxidative carbonylation of alkylamines is reported to provide convenient access to the β-lactam scaffol d. A study of the kinetics of the process revealed that the reaction is CO-limited even at elevated pressures and that there is an optimal CO concentration for the most effective outcomethis understanding led to an increase in the turnover number from 7 to 420 in the optimized process. Two scalable processes were then developed: a batch process, characterized by a very low catalyst loading, and a continuous process for an oxidative C–H carbonylation reaction that uses a copper-tube-flow reactor as a heterogeneous source of Cu2+ oxidant. The continuous process was tested on oxidative carbonylation of several alkylamines, yielding very good results with virtually no optimization required. This study thereby builds upon the utility of flow chemistry applications to oxidative carbonylations and scalable metal-catalyzed processes more generally

A multi-objective optimisation including results of life cycle assessment in developing bio-renewables-based processes

A decision support tool has been developed, which uses global multi-objective optimisation based on: (i) the environmental impacts, evaluated within the framework of full life cycle assessment, and (ii) process costs, evaluated using rigorous process models. This approach is particularly useful in developing the bio renewable-based energy solutions and chemicals manufacturing, where multiple criteria must be evaluated and where the optimisation-based decision making process is particularly attractive. The framework is demonstrated using a case study of conversion of terpenes derived from bio-waste feedstocks into reactive intermediates. A two-step chemical conversion/separation sequence was implemented as a rigorous process model and combined with a life cycle model. A life cycle inventory for crude sulfate turpentine was developed, as well as a conceptual process of its separation into pure terpene feedstocks. The performed single- and multi-objective optimisations demonstrate the functionality of the optimisation-based process development and illustrate the approach. Most significant advance is the ability to perform multi-objective global optimisation, resulting in identification of a region of Pareto-optimal solutions

Continuous flow Buchwald–Hartwig amination of a pharmaceutical intermediate

A flow process for direct amination of a pharmaceutically relevant substrate using a Pd-NHC based catalyst was demonstrated in a lab-scale mini-plant and in a pilot-scale plant. The lab-scale mini-plant was used to determine catalyst stability under recycling conditions. Results in the mini-plant have shown the maximum space–time yield between the three types of reactor systems: a batch reactor, a mini-plant and a pilot plant. A comprehensive life-cycle assessment study of the synthesis of organometallic catalysts and their impact on the overall LCA of flow vs. batch syntheses was developed. Combined with a simplified economic analysis, the LCA study confirmed the benefits of switching to flow.The research leading to these results has received funding from the European Research Council under the European Union's Seventh Framework Programme (EC FP7) Grant Agreement n. [NMP2-SL-2012-280827].This is the final version of the article. It was first available from RSC via http://dx.doi.org/10.1039/C5RE00048

Evolution of active catalysts for the selective oxidative dehydrogenation of methanol on Fe2O3 surface doped with Mo oxide

Iron molybdate catalysts are used for the selective oxidation of methanol to formaldehyde. In this paper we have attempted to understand what determines high selectivity in this reaction system by doping haematite with surface layers of Mo by incipient wetness impregnation. This works well and the Mo appears to form finely dispersed layers. Even very low loadings of Mo have a marked effect on improving the selectivity to formaldehyde. Haematite itself is a very poor catalyst with high selectivity to combustion products, whereas, when only 0.25 monolayers of Mo are deposited on the surface, formaldehyde and CO selectivities are greatly enhanced and CO2 production is greatly diminished. However, even with as much as seven monolayers of Mo dosed on to the surface, these materials achieve much less selectivity to formaldehyde at high conversion than do the industrial catalysts. The reason for this is that the Mo forms a 'skin' of ferric molybdate on a core of iron oxide, but does not produce a pure Mo oxide monolayer on the surface, a situation which is essential for very high yields of formaldehyde

Facile stoichiometric reductions in flow : an example of artemisinin

Stoichiometric reduction of artemisinin to dihydroartemisinin (DHA) has been successfully transferred from batch to continuous flow conditions with a significant increase in productivity and an increase in selectivity. The DHA space-time-yield of up to 1.6 kg h–1 L–1 was attained which represents a 42 times increase in throughput compared to that of conventional batch process