Studies of Thermochemical Heat Recovery of Exhaust Gases of Furnaces

The review of schemes and methods of thermochemical heat recovery (TCR) of exhaust flue gas for different power plants operating on hydrocarbon fuels have been performed. The essence of the heat of flue gases TCR is to use their physical endothermic heat for pre-processing the original hydrocarbon fuel, which thus receives a greater supply of chemically bound energy in the form of increased heat of combustion. If the traditional VTU, energy of fuel is converted into heat in one stage by direct incineration, in plants with TCR the process of transformation of the fuel energy is divided into two stages. The first stage is the heating of the reaction mixture and carrying out endothermic reactions of the initial fuel conversion, resulting in an increase in its calorific value. The second stage is burning of the reaction products, i.e., reformed gas having a large heat of combustion compared to the original fuel

Is There a Negative Thermal Expansion in Supported Metal Nanoparticles? An In-Situ X-ray Absorption Study Coupled with Neural Network Analysis

Interactions with their support, adsorbates and unique structural motifs are responsible for the many intriguing properties and potential applications of supported metal nanoparticles (NPs). At the same time, they complicate the interpretation of experimental data. In fact, the methods and approaches that work well for the ex situ analysis of bulk materials may be inaccurate or introduce artifacts in the in situ analysis of nanomaterials. Here we revisit the controversial topic of negative thermal expansion and anomalies in the Debye temperature reported for oxide-supported metal NPs. In situ X-ray absorption experimental data collected for Pt NPs in ultrahigh vacuum and an advanced data analysis approach based on an artificial neural network demonstrate that Pt NPs do not exhibit intrinsic negative thermal expansion. Similarly as for bulk materials, in the absence of adsorbates the bond lengths in metal NPs increase with temperature. The previously reported anomalies in particle size-dependent Debye temperatures can also be linked to the artifacts in the interpretation of conventional X-ray absorption data of disordered materials such as NPs