Research
Process Intensification
The defining paradigm of chemical engineering is the unit operations approach, in which a process is broken down into individual unit operations (hence the name!), such as mixing, preheating, reacting, and separating, and an individual apparatus is devoted to each of these operations.
More recently, a new approach has emerged in which several unit operations are integrated into one apparatus--which thus becomes multifunctional--with the aim of achieving a process with reduced energy, environmental, and/or physical foot-print - typically referred to as 'process intensification'. Well-established examples are heat-exchange reactors (combination of heat exchanger with a chemical reactor), membrane reactors (mixing/separation and reaction) and reactive distillation (separation and reaction).
We have been exploring heat-integrated reactors (so-called 'reverse-flow reactors') and 'chemical looping' as a means to exploit periodic reactor operation to achieve such process intensification. Our current focus is on application of chemical looping to reactions beyond combustion reactions (i.e. beyond oxygen carrying).
In parallel, we are exploring the transition of specialty chemicals production from the traditional batch processing to continuous processing in a close collaboration with an industry partner. Here the focus is again on exploiting the various efficiency advantages offered by continuous reactors towards processes with drastically reduced physical, energy, and environmental footprints and much improved process safety.
Novel Catalysts
Catalysis is the lifeblood of the chemical industry. It is widely estimated that more than 90% of all chemical manufacturing processes use a catalyst in at least one processing step. Catalysts enable industry to lower energy consumption, increase product yield and selectivity, reduce waste (and hence reduce environmental impact while improving process economics), to name just a few key advantages of catalysts.
In this context, the engineering of materials properties on the molecular scale has enabled tailoring of physical and chemical - and hence: functional - properties of catalysts with unprecedented precision, opening a vast array of exciting novel opportunities.
Beyond the investigation of structure-property relationships (such as impact of size, shape, and composition of materials on their reactive properties) in catalysis and related reactive applications, our research has previously focused on the development of cost-effective and scalable synthesis pathways which result in robust nanomaterials that can survive the conditions of typical industrial applications. Current work (collaborative with the Jacobs group in our Materials Science Department at the Swanson School) is now focused on characterizing metal-support interactions as a key descriptor for catalyst stability. This research extends our joint recent work in which we developed the first method to directly measure these interactions for supported bimetallic nanoparticles.
In parallel, a major focus of our current work (in collaboration with the Masnadi group in our department) is on exploring liquid metals as a novel catalytic reaction media. Liquid metals – i.e. low-melting metals, operated above their melting point – are a recently emerging novel class of catalytic materials which offer many potential advantages for catalytic processing of a wide range of feedstocks. However, to-date, this class of catalysts is only little studied and hence poorly understood. We are exploring liquid metals for processes ranging from fossil fuel conversion, over biomass pyrolysis, to (circular) processing of plastic wastes.