Catalyst design informed by product and process requirements

Each year, thousands of academic papers are published on catalyst design, while there are only around 300 commercial catalysts available currently. To a certain extent this is due to the traditional approach of catalyst design, which starts with identifying a useful candidate catalyst for the desired chemical transformation, then iteratively synthesizing, modifying, and testing to improve the activity, selectivity and breadth of application. If the product is known, a catalyst(s) with the required attributes could be designed to manufacture it. Even the ā€œbestā€ catalyst might never find its way to industrial practice, as the processes that use it can employ solvents, reagents, and conditions that may be partially or fully incompatible. A change in the catalyst might alter the design of separation units completely. This work aims to develop a digital methodology, which is founded on the integration of catalyst and process design,Ā Ā to find optimal ranges of catalyst attributes (e.g. activity, selectivity, operating temperature) and optimal process selection (reaction, separation, purification, telescoping) to guide the chemist more directly to a commercially viable catalyst. As a proof of concept, we simulated a reaction being evaluated in another Catalysis Hub project4: the gas-phase dehydration of bio n-butanol to butenes, producing dibutyl ether as co-product. Considering two catalysts from the literature5,6, our results have shown that a lower reactor temperature is not the most economic option, as the process with a Zn-Mn-Co modified Ī³-Al2O3 catalyst with 96% selectivity to 1-butene (at 400 Ā°C) outperforms GdPO4 that has a lower selectivity (85%) despite its lower energy demand (300 Ā°C) for the same 1000 kg/h butanol feed and 97% molar purity of 1-butene as the product. This demonstrates the need to consider not only safe operating conditions, but also reactant feed, catalyst attributes, product price and purity, and a whole process view to select a suitable catalyst.

Reza Abbasi (UCL)

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