Search Results (3)

In this study, the integration of microwave-assisted technology into fixed-bed configuration processes is explored aiming to characterize and address its challenges with a customized multimodal microwave cavity. This research focuses on evaluating the uncertainty in contactless temperature measurement methods as spectral thermographic cameras and infrared pyrometers, microwave heating performance, and the thermal homogeneity within fixed beds containing microwave–susceptor materials, including the temperature-dependent dielectric characterization of such materials, having different geometry and size (from 120 to 5000 microns). The thermal inhomogeneities along different bed configurations were quantified, assessing the most appropriate fixed-bed arrangement and size limitation at the employed irradiation frequency (2.45 GHz) to tackle microwave-assisted gas–solid chemical conversions. An increased temperature heterogeneity along the axial profile was found for finer susceptor particles, while the higher microwave susceptibility of coarser grades led to increased temperature gradients, ΔT > 300 °C. Moreover, results evidenced that the temperature measurement on the fixed-bed quartz reactor surface by a punctual infrared pyrometer entails a major error regarding the real temperature on the microwave susceptor surface within the tubular quartz reactor (up to 230% deviation). The experimental findings pave the way to assess the characteristics that microwave susceptors and fixed beds must perform to minimize thermal inhomogeneities and optimize the microwave-assisted coupling with solid–gas-phase reactor design and process upscaling using such multimode cavities. Full article

The current climatic and geopolitical situation leads to strong decarbonisation policies in several industries worldwide. Moreover, the European Union is pushing intensive industries to achieve a 55% reduction in CO₂ emissions towards 2030. Among them, the steel manufacturing sector is at the lead of alternative projects that can help achieve this ambitious target. Co-production of syngas and biochar is one potential solution for this sector. Herein, a techno-economic analysis is provided to evaluate the economic feasibility and the effect of the most influential parameters for a successful deployment. A bibliographic review has been carried out to establish a clear baseline for such an analysis in terms of investment costs at several scales for gasification projects. Additionally, the cost evolution for coke, natural gas, and CO₂ emission credits on the profitability of these projects are given. The case scenario processing 20,000 t_biomass/y is the most feasible solution, with a payback of around three years and a net present value (NPV) of around 15 million EUR, showing that biomass gasification can be an up-and-coming alternative in the mid-term. Full article

The present review provides a catalogue of relevant renewable energy (RE) technologies currently available (regarding the 2030 scope) and to be available in the transition towards 2050 for the decarbonisation of Energy Intensive Industries (EIIs). RE solutions have been classified into technologies based on the use of renewable electricity and those used to produce heat for multiple industrial processes. Electrification will be key thanks to the gradual decrease in renewable power prices and the conversion of natural-gas-dependent processes. Industrial processes that are not eligible for electrification will still need a form of renewable heat. Among them, the following have been identified: concentrating solar power, heat pumps, and geothermal energy. These can supply a broad range of needed temperatures. Biomass will be a key element not only in the decarbonisation of conventional combustion systems but also as a biofuel feedstock. Biomethane and green hydrogen are considered essential. Biomethane can allow a straightforward transition from fossil-based natural gas to renewable gas. Green hydrogen production technologies will be required to increase their maturity and availability in Europe (EU). EIIs’ decarbonisation will occur through the progressive use of an energy mix that allows EU industrial sectors to remain competitive on a global scale. Each industrial sector will require specific renewable energy solutions, especially the top greenhouse gas-emitting industries. This analysis has also been conceived as a starting point for discussions with potential decision makers to facilitate a more rapid transition of EIIs to full decarbonisation. Full article