1,722,205 research outputs found
Process intensification and energy transition: A necessary coupling?
No full textThe energy transition requires an extensive employment of gas-solid catalytic chemical reactors to support the long-term energy storage. Many renewable resources are decentralised, so that the feedstock for the energy conversion facilities is limited. New reactor technologies will be needed to ensure the efficient conversion of renewable resources in smaller scale than the state-of-the-art processes. Process intensification is a key in this direction, fulfilling the desired conversion efficiency, miniaturization of the process units and integration with the existent facilities. This paper analyses the key aspects of process intensification to be considered and implemented in the development of chemical reactors for the energy transition. The intensification strategies should follow three main directions: miniaturization of the process units, enhanced process efficiency and high reactor flexibility. An effective tackling of these directions is challenging for the standard packed-bed reaction technology, but many alternative and promising options are available. An efficient utilization of reaction engineering principles in the design of the new processes can successfully open the way to the optimal equipment selection for each specific application. Hence, a rationally based, but creative selection of the available technologies will be an essential step in the successful implementation of chemical technology in the energy transition
Trendbericht Technische Chemie 2023
No full textDie Energiewende stellt neue Forderungen an die Verfügbarkeit von Rohstoffen – das verändert das Aufgabengebiet der technischen Chemie. Gefragt sind neue Methoden, um lastflexible Reaktoren zu optimieren, und Prozesse, die sich an die Verfügbarkeit von Ressourcen anpassen
The rate-based modelling of CO2 removal from the flue gases of power plants
No full textRecently global warming has become a topic of great interest, involving social, economic and industrial issues. Many efforts are being made in order to limit emissions of CO2, a powerful greenhouse gas, whose massive presence in the atmosphere is increasing more and more. Industrially the most commonly used process for CO2 capture is absorption by alkanolamines, widely applied to the removal of exhaust gases from power plants. The design of the absorber is still difficult, due to the different phenomena involved. Commercially, several process simulators can be found, based on different assumptions, both for thermodynamics and for diffusion with reaction. Thermodynamics, kinetics and mass transfer greatly influence the chemical absorption process. Acid gases and amines are weak electrolytes, which partially dissociate in the aqueous phase: the high non-ideality of the liquid phase must be properly taken into account, usually with a / method. Kinetics and mass transfer can be described using two different approaches: the “equilibrium-based stage efficiency” or the “rate-based” one. This latter, if based on a proper mass transfer theory, can be used to correctly describe the phenomenon of diffusion with reaction occurring from the vapor phase to the liquid phase.
This paper focuses on modelling the absorption of CO2 by means of a piperazine solution, performed by properly modifying ASPEN Plus® with a homemade subroutine linked to the simulator. Experimental data of a pilot plant for cleaning flue gases from power plants have been used to validate the model, which well represents the absorption phenomeno
Design of the process of CO2 removal in NGCC by potassium taurate solvent
No full textOne of the most mature technologies for removal of carbon dioxide from gaseous streams is chemical absorption and aqueous solutions of alkanolamines are employed, with Monoethanolamine (MEA) considered the benchmark solvent. However, its volatility and toxicity and the need for a lot of energy for regeneration made research focus on possible solvents that can perform the desired treatment of gaseous streams while reducing production and operating costs and the environmental impact, to be considered as substitutes. The process based on amino acid aqueous solutions, one type of these new solvents, has the advantage of an improved sustainability and, as the one employing aqueous solutions of potassium taurate, can also benefit of the enhancement due to the reaction of precipitation. In this work a rigorous rate-based model, built in the commercial process simulator ASPEN Plus®, properly customized for the representation of the system, is used to carry out a detailed process design for the CO2 removal section of a NGCC plant by an aqueous solutions of potassium taurate, for which no previous papers on the topics have been found in the literature. The scheme is optimized and the performances of the process are evaluated for different targets of CO2 removal
La Storia Economica come Impegno. Saggi in onore di Ange Moioli
No full textIl volume raccoglie i contributi di studiosi italiani legati alla storia economica nazionale ed europea. I saggi vengono così offerti in onore della carriera accademica di Angelo Moioli
Enhancement of Power-to-Gas via Multi-catalyst Reactors Tailoring Reaction Rate and Heat Exchange
No full textThe Sabatier reaction is a key element of power-to-gas development. For this reason, even though the process is known since more than one century, the Sabatier reaction is currently the object of important research efforts towards the development of new catalysts for performance improvement. However, the industrial exploitation of the Sabatier reaction depends on the development of reactors that match the best catalyst with an appropriate heat management. For this reason, this paper develops a methodology for the contemporary optimization of the reactor concept and the catalysts. It is observed that the reactor can be divided into three sections with contrasting requirements. In the first section, the main requirement concerns the reach of the reaction activation conditions. Hence, an adequate match between catalyst and reactor is needed, for example with an appropriate pre-heater. Once the reaction is activated, a reaction hotspot is formed, so that the cooling becomes determining and the main requirement for the catalyst is the resistance to poisoning and sintering. In the last section of the reactor, the low temperature activity of the catalyst is determining, so that a high-performing catalyst is needed. This paper indicates a strategy for the rational design of this catalyst, based on mechanistic evidences
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