5 research outputs found
Calcium Looping for Thermochemical Storage: Assessment of Intrinsic Reaction Rate and Estimate of Kinetic/Transport Parameters for Synthetic CaO/Mayenite Particles from TGA Data
Mayenite-supported CaO represents an affordable and safetycompliant candidate material for thermochemical storage processes. We here analyze the thermogravimetric analysis (TGA) performance of synthetic CaO/mayenite micrometric powder under carbonatation/calcination looping and develop a model to interpret and analyze the experimental results. In the experimental campaign, calcination is run at 900 degrees C, while the carbonatation temperature is varied between 600 and 800 degrees C. For the carbonatation reaction, a generalized shrinking core model assuming a thermodynamically consistent first-order kinetic and a conversion-dependent diffusivity of CO2 inside the porous CaCO3 layer is validated through TGA carbonatation tests conducted with CO2/N-2 mixtures at different compositions. Interestingly, the kinetic constant of this reaction is found to be relatively insensitive to the temperature in the interval considered. In contrast, diffusion-limited regimes are never found for the calcination reaction so that this phase of the cycle can be predicted based on a single kinetic constant of the heterogeneous reaction. This constant is found to follow the typical Arrhenius-type dependence on temperature. Sizably different kinetic and transport parameters are obtained in the first carbonation performed on virgin CaO/mayenite particles with respect to those associated with subsequent cycles. When different parameters are afforded for the first and following cycles, the shrinking core model proposed closely predicts the TGA data over five CaO/CaCO3 cycles. The results found constitute an essential preliminary piece of information for designing equipment geometry and operating conditions of industrial-scale reactors. In this respect, knowledge of the parameters defining the intrinsic reaction rates and diffusive transport is essential in defining the optimal conversion of the material associated with minimal looping time
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Industry 4.0: a bibliometric review of its managerial intellectual structure and potential evolution in the service industries
The “industry 4.0” phenomenon is expected to influence almost every aspect of business value chains, and hence it has been increasingly analyzed by management scholars. However, the overarching intellectual structure emerging from this new stream of literature has not yet been synthesized in a framework nor critically discussed. Furthermore, despite being part of the rhetoric in several recent industrial governmental plans, industry 4.0 in service sectors has not been systematically reviewed to date. By leveraging a systematic quantitative literature review, a data-driven approach and a quantitative methodology—embedding both bibliographic coupling and network analysis techniques—this study provides a clear visualization of the emerging intellectual structure of industry 4.0 in management studies. We also develop a framework based on the most recurrent themes emerging from the results of bibliometric and network analyses—the latter could be used by management scholars to understand studies surrounding industry 4.0. As service businesses can create and capture value generated through the 4th Industrial Revolution as well as manufacturing firms, we suggest that scholarly attention should also be directed toward the service industries and provide a research agenda