Multiphase reactions

In our laboratories, we conduct catalytic activity tests on powders, pellets, and monoliths, using a wide range of sizes, flow rates (< 2 NL/min), temperatures (< 1000°C), and pressures (< 30 bar). We employ tubular flow reactors and autoclaves (in both batch and CSTR modes), along with customized protocols for accelerated aging and catalyst poisoning monitoring.

Online analyses are performed using GC, MS, and FTIR. Our experiments are carried out both in steady-state and in transient conditions.

To complete the experimental activities, we also add the modeling, processing the collected data to develop advanced simulation models. These models integrate the data obtained in the laboratory, and provide clients with effective tools for optimizing their processes and products, as well as the basis for the scale-up/down.

Case Studies

Papers

• Investigation of thermal effects on heterogeneous exothermic reactions and their impact on kinetics studies.
  Chemical Engineering Journal

  Investigation of thermal effects on heterogeneous exothermic reactions and their impact on kinetics studies.

  Chemical Engineering Journal

  Abstract

  Experiments and modelling were performed to investigate CO oxidation over a Pd-Rh monolith. We focused on thermal effects and hysteresis, to validate by modelling a thermal explanation of the results. Different feed composition (0.07–4% vol. CO) and heating rates (0.5–5 °C/min) have been used to reproduce both ignition and extinction stages, up to 300 °C, thus measuring the catalyst activity under transient conditions.

  The heating rate plays a marginal role in producing hysteresis, whereas the reactants concentration appears the real cause, because of its effect on the rate of heat production. The local overheating of the catalyst surface explains the hysteresis observed.

  A model accounting for the thermal dynamics of the solid predicts the hysteresis and supports the thermal explanation. The estimated activation energy is quite reasonable; preexponential factors accommodate for the weakening of the adiabatic channel critical assumption, less and less realistic as the reaction heat increases. The local temperature can vary widely, in time and space, and any kinetic study not accounting for a precise knowledge of that will inevitably produce poorly representative parameter estimates.

  Full article
• Is fighting against pollutants possible with critical raw material free perovskites?
  Catalysis Today

  Is fighting against pollutants possible with critical raw material free perovskites?

  Catalysis Today

  Abstract

  Perovskites free of critical raw materials (noble metals and rare earths) of the type Ba_1-ySr_yMn_1−0.2-xMg_0.2Cu_xO₃ (y = 0.1, 0.5; x = 0.1, 0.2, 0.3) are developed for the abatement of pollutants in automotive exhaust, both gaseous (CO, NOx and HCs) and solid (carbon soot). The reactivity in oxidation and reduction is tuned through ad-hoc induced surface segregation phenomena and the promotion of specific Mn(III)/Mn(IV) and Cu/Mn atomic ratios. The insertion of Cu into the perovskitic cell, moves the crystalline structure from 2H-type toward a Mn-deficient one, in which Mn(III) is prevalent. The catalytic capability in abatement of pollutants was studied comparing the activity in the following reactions: CO oxidation, CO assisted NO reduction, and with a complex mixture simulating the composition of automotive exhausts in stoichiometric and rich conditions. CO oxidation is favored by surface segregation of Mn, Mg may play a role in CO coordination. Copper enhances the NO reduction activity of the catalysts in the CO + NO reaction and Ba_0.9Sr_0.1Mn_0.5Mg_0.2Cu_0.3O₃ is the more active, whereas in the complex mixture Ba_0.9Sr_0.1Mn_0.7Mg_0.2Cu_0.1O₃ and Ba_0.9Sr_0.1Mn_0.6Mg_0.2Cu_0.2O₃ are the more active suggesting a less relevant role of surface composition and a more active contribution of bulk ion mobility.

  Full article