http://hdl.handle.net/2268.2/16576 Fri, 27 Mar 2026 08:15:52 GMT 2026-03-27T08:15:52Z http://hdl.handle.net/2268.2/25223 Title: Heat and Mass Balance on a Curing Oven Abstract: Glass wool manufacturing requires simultaneous drying and curing of an impregnated glass wool mat in a multi-zone conveyor oven. This work develops a lumped-capacity model that couples heat and mass transfer mechanisms with curing kinetics to predict the temperature profile and conversion level throughout the process. The model uses a Number of Transfer Units formulation to model the cross-flow drying process and implements an isoconversional kinetic model using Differential Scanning Calorimetry data. Heat transfer coefficients were computed from two years of production data and show discrepancies that reflect the physical configuration of the oven. Simulations on 60 production runs showed that the model captures the global temperature profile of the product by identifying three main periods: preheating, constant-rate drying, and falling-rate periods where curing predominantly occurs. Additionally, a sensitivity analysis of the most important parameters was performed to assess and understand their impact on the drying process and the temperature profile of the mat. When the outlet gas temperature is fixed from process data, the model achieves good agreement with experimental observations. The conversion profile also shows physically consistent behaviour as the final conversion increases with residence time under favourable temperature conditions. Several limitations were encountered, including the estimation of initial and critical moisture content, the inability to capture internal diffusion that leads to thermal and material gradients along the mat thickness, and uncertainty regarding the accuracy of the computed heat transfer coefficients. To tackle one of these limitations, the critical moisture content was defined to produce a transition between the constant drying rate period and the falling rate period that matches the measured temperature profile. Future work should focus on experimental determination of characteristic drying curves and development of appropriate correlations that will enable accurate computation of transport properties. Validation experiments in controlled pilot-scale equipment would also strengthen model predictions. Finally, the lumped assumption can be relaxed by taking into account both heat and mass transfer limitations along the mat thickness. Sun, 25 Jan 2026 23:00:00 GMT http://hdl.handle.net/2268.2/25223 2026-01-25T23:00:00Z http://hdl.handle.net/2268.2/24913 Title: Contributions to the electrification project of multiple hearth furnaces: evaluation of the economic and environmental impacts of the electrical heating technology on CRM pilot facilities Abstract: Climate change poses a critical challenge for energy-intensive industries, which rely heavily on fossil fuels for high-temperature processes. This thesis investigates the electrification of multiple hearth furnaces (MHFs) as a pathway to decarbonize industrial thermal operations, focusing on two processes: the regeneration of spent activated carbon (AC) and the calcination of hydromagnesite (HM). The study is based on experimental trials conducted on a batch furnace replicating the operating conditions of a single hearth of the MHF, allowing for a controlled comparison between natural gas and electric heating. Experimental results reveal that AC regeneration under electrical heating achieves comparable product quality with 2.5-3 times lower energy consumption than gas-fired operations, highlighting significant efficiency gains and a substantial reduction in direct carbon dioxide emissions. In contrast, HM calcination exhibits technical limitations under the electric configuration, where incomplete gas sweeping leads to carbon dioxide accumulation and partial decomposition, indicating the need for further process adaptation. Environmental and economic assessments, including direct and indirect emissions and operating expenditures under 2023 Belgian conditions, demonstrate clear advantages for electrification. AC regeneration achieves a 75% reduction in total carbon dioxide emissions and a 50% decrease in operating costs, while HM calcination shows reductions of 60% and 45% respectively, albeit with unsatisfying product quality. Sensitivity analyses across European contexts, considering variations in electricity and natural gas prices, carbon prices, and emission factors indicate that electrification benefits are robust for AC regeneration, whereas HM calcination requires specific low-carbon and cost-competitive conditions compared to NG to ensure net benefits. Looking ahead, structural trends in European energy markets, such as declining electricity prices due to renewable expansion and rising carbon costs, are expected to progressively strengthen the competitiveness of electrified heating technologies. Overall, this thesis confirms that electrifying MHFs can deliver substantial environmental and economic benefits, with process-specific adaptations critical for certain applications, thereby supporting the transition of industrial thermal technologies toward a low-carbon economy. Sun, 07 Sep 2025 22:00:00 GMT http://hdl.handle.net/2268.2/24913 2025-09-07T22:00:00Z http://hdl.handle.net/2268.2/24909 Title: Modelling of Hybrid Carbon Capture via Membrane and Potassium Carbonate Process Abstract: This thesis presents a techno-economic assessment of three post-combustion CO₂ capture technologies applied to the flue gas of the Luminus-Seraing natural gas combined-cycle (NGCC) plant. The flue gas, characterized by a low CO₂ concentration (4.5%) and high flowrate (1069 kg/s), corresponding to a capture scale of 246 tCO₂/h, represents a particularly challenging case for post-combustion capture. Three configurations were evaluated: a two-stage membrane system, a potassium carbonate absorption process, and a hybrid membrane–solvent integration. The membrane process achieved the lowest capital cost (280 M€) but only moderate CO₂ purity (≈70%), insufficient for transport or storage. The potassium carbonate process delivered high-purity CO₂ (>96%) but incurred high energy penalties (5.4 GJ_work/tCO₂, 3.2 GJ_heat/tCO₂) and capture costs (≈295 €/tCO₂). By contrast, the hybrid configuration enriched the absorber feed to 30% CO₂, reducing equipment size and energy demand, and lowering the capture cost to ≈152 €/tCO₂. Although still above pilot-scale benchmarks (70–90 €/tCO₂), the study demonstrates that hybridization can substantially reduce the cost and energy intensity of capturing CO₂ from dilute NGCC flue gases. Future work should focus on global optimization, thermal integration, and embedding the models into the decision-support tool for large-scale deployment developed by PhD researcher So-Mang Kim. Sun, 07 Sep 2025 22:00:00 GMT http://hdl.handle.net/2268.2/24909 2025-09-07T22:00:00Z http://hdl.handle.net/2268.2/24840 Title: Study of the impacts of lime-based products in beet sugar purification process Abstract: The purification of sugar is studied in this master's thesis. Sugar factories usually use quicklime and carbon dioxide for their purification. In order to reduce the greenhouse gas emissions associated with it and provide a better product to sugar factories, a patented product is investigated in which a part of the quicklime is substituted with milled limestone. The purification process is carried out on a laboratory scale using raw materials from sugar factories such as raw juice and sweetwater where different ratios [CaO]/[CaCO\textsubscript{3}] are tested in the form of a milk of lime. Analysis on the milk of lime shows that the theoretical ratio is not a fit parameter to observe for the interpretation of results. The principal analysis techniques employed are the CaO available and neutralizing value analysis. It is less precise for limed juices. The carbonation had not been well controlled and may have impacted the quality of the thin juice. The quality of the final product of the purification process, the thin juice is investigated. The parameters evaluated on the thin juice are the absorbance and the residual calcium ions. The absorbance seems to be constant regardless of the concentration of limestone in the thin juice. The residual calcium ions found in the thin juice might be due to some ions seeping through the filter during filtration. It is found that the protocol needs some improvements and the analysis technique on the limed juice needs to be modified. Once these modifications are implemented, different types of quicklime and milled limestone mix can be tested. From that, different process parameters such as the alkalinity of the limed juice and the flow rate of CO2 can be varied to find the best operating conditions for the best quality of the thin juice. Sun, 07 Sep 2025 22:00:00 GMT http://hdl.handle.net/2268.2/24840 2025-09-07T22:00:00Z