Alessandro Stagni is Assistant Professor of Chemical Plants at Politecnico di Milano since June 2017, entering a 3-year tenure-track in January 2021. He has completed his studies in Chemical Engineering at Politecnico di Milano, also obtaining a double degree in Chemical and Sustainable Process Engineering at Politecnico di Torino. In 2016, he accomplished his PhD summa cum laude in Industrial Chemistry and Chemical Engineering at Politecnico di Milano. Previously, he has been a post doctoral researcher (2016 – 2017) at the same institution, Visiting Student at Stanford University (2015) and Visiting Researcher at Technische Universität Darmstadt (2019).

Alessandro Stagni’s research activity deals with the chemical-kinetic analysis of reacting systems of hydrocarbon and non-hydrocarbon fuels at different levels, i.e. development and reduction of chemical kinetic mechanisms, and their application in CFD computations. The expertise he gained ranges from the pyrolysis and oxidation of hydrocarbon fuels and fuel surrogates to the formation mechanisms of pollutants (NO_x, SO_x), both at a fundamental level and at higher scales (turbulent combustion devices, e.g. furnaces and engines). Within the current energy transition scenario, his research has then expanded to the exploitation of carbon-free energy carriers (ammonia) for the on-demand energy release via either direct combustion or along with conventional fuels.

Abstract

An Insight on Ammonia Chemistry: Experimental and Modelling Challenges

In the recent times, the interest towards ammonia combustion has been significantly increasing for two major reasons: a smarter use of the energy resources to reduce energy waste, and the need to control pollutant emissions. Indeed, the high energy density and ease of transportation (compared to hydrogen, for example) make ammonia an attractive platform molecule for the energy storage from intermittent resources, such that energy can be successively released on demand through combustion. Nevertheless, a fundamental understanding of ammonia chemistry has now been obtained yet, in particular for what concerns low-temperature and diluted conditions.

In order to fulfil such a knowledge gap, experimental measurements were performed at CNRS Nancy in ideal conditions, in order to cover a wide range of operating conditions. In parallel, the most critical reaction pathways were accurately evaluated via an ab initio methodology, and a comprehensive kinetic model was created and included in the CRECK framework. This allowed to understand and interpret the peculiar features of ammonia oxidation at low and intermediate temperatures and in diluted conditions, and to obtain a reference kinetic mechanism which can be applied to predict ammonia combustion properties in the heavier CFD applications.