RESUMO
Understanding the viability of the RWGS from a thermodynamic and techno-economic angle opens new horizons within CO2 conversion technologies. Unfortunately, profitability studies of this technology are scarce in literature and mainly focused on overall conversion and selectivity trends with tangential remarks on energy demands and process costs. To address this research gap, herein we present a comprehensive techno-economic study of the RWGS reaction when coupling with Fischer-Tropsch synthesis is envisaged to produced fuels and chemicals using CO2 as building block. We showcase a remarkable impact of operating conditions in the final syngas product and both CAPEX and OPEX. From a capital investment perspective, optimal situations involve RWGS unit running at low temperatures and high pressures as evidenced by our results. However, from the running cost angle, operating at 4 bar is the most favorable alternative within the studied scenarios. Our findings showcase that, no matter the selected temperature the RWGS unit should be preferentially run at intermediate pressures. Ultimately, our work maps out multiple operating scenarios in terms of energy demand and process cost serving as guideline to set optimal reaction conditions to unlock the potential of the RWGS for chemical CO2 recycling.
Assuntos
Dióxido de Carbono , Temperatura Baixa , Pressão , Reciclagem , TecnologiaRESUMO
The exponential growth of greenhouse gas emissions and their associated climate change problems have motivated the development of strategies to reduce CO2 levels via CO2 capture and conversion. Reverse water gas shift (RWGS) reaction has been targeted as a promising pathway to convert CO2 into syngas which is the primary reactive in several reactions to obtain high-value chemicals. Among the different catalysts reported for RWGS, the nickel-based catalyst has been proposed as an alternative to the expensive noble metal catalyst. However, Ni-based catalysts tend to be less active in RWGS reaction conditions due to preference to CO2 methanation reaction and to the sintering and coke formation. Due to this, the aim of this work is to study the effect of the potassium (K) in Ni/CeO2 catalyst seeking the optimal catalyst for low-temperature RWGS reaction. We synthesised Ni-based catalyst with different amounts of K:Ni ratio (0.5:10, 1:10, and 2:10) and fully characterised using different physicochemical techniques where was observed the modification on the surface characteristics as a function of the amount of K. Furthermore, it was observed an improvement in the CO selectivity at a lower temperature as a result of the K-Ni-support interactions but also a decrease on the CO2 conversion. The 1K catalyst presented the best compromise between CO2 conversion, suppression of CO2 methanation and enhancing CO selectivity. Finally, the experimental results were contrasted with the trends obtained from the thermodynamics process modelling observing that the result follows in good agreement with the modelling trends giving evidence of the promising behaviour of the designed catalysts in CO2 high-scale units.
RESUMO
Las técnicas de cirugía mínimamente invasiva son cada vez más frecuentes. Sin embargo, estas técnicas son procedimientos costosos, complejos y difíciles de dominar. Los actuales métodos de aprendizaje presentan limitaciones y son susceptibles de ser complementados por soluciones de alta tecnología como el presente simulador de realidad virtual. El entrenamiento mediante simuladores mejora la destreza de los cirujanos en el uso del instrumental artroscópico, reduciendo el tiempo de la intervención, aumentando la seguridad y confianza del cirujano, disminuyendo el posible daño al paciente y permitiendo obtener experiencia en una gran variedad de patologías (AU)
Minimal Invasive Surgery (MIS) techniques are becoming more and more frequent. However these techniques are complex and expensive procedures difficult to master. Current learning methods have a number of limitations that can be compensated for and complemented by our virtual reality simulator. Training with simulators considerably improves surgeons dexterities with the arthroscopic instruments, reduces surgery times, increases surgery confidence and procedures safety, reducing the morbidity of real interventions and allowing obtaining experience in a large variety of pathologies (AU)
