The blast furnace hearth plays an important role in the operational stability and lifetime of the reactor. The quasi-stagnant bed of coke particles termed the deadman undergoes complex interaction with the flowing hot metal, and remains largely ill-understood. In this work, a cold model blast furnace hearth is presented, and studied using both numerical and experimental techniques. Magnetic Particle Tracking (MPT) is used to investigate the individual particle behaviour within the cylindrical, opaque bed. At high liquid holdup, the particle bed was found to alternate between floating and sitting states, following the liquid level during the tapping and filling cycle. This bed motion was found to induce a migration of particles, thereby slowly renewing the deadman. The rate of horizontal migration increases with the vertical bed amplitude, and the renewal of particles is concentrated around the opening of the tap hole. No direct influence of the coke-free space on the tapping rate was found in these experiments. Instead, the disturbance of the packing in front of the tap hole was observed to lead to a higher tapping rate. Additionally, a coupled numerical framework is presented, in which Computational Fluid Dynamics (CFD), the Volume of Fluid (VOF) method and the Discrete Element Method (DEM) are combined. A simulation set-up is presented which closely replicates the experimental conditions. The position and movement of the floating bed are found to be well-predicted by the VOF/CFD-DEM model. Particle trajectories are presented, and migration of particles within the deadman is observed. Alongside the particle motion, the liquid flow pattern during draining of the vessel is visualised. It is concluded that a coke-free space underneath the deadman significantly impacts the shape of the liquid flow pattern, which affects the erosion processes within the blast furnace hearth.

Countercurrent membrane supported reactive extraction (MSRE) was studied for removal of carboxylic acids from aqueous streams with a PTFE capillary membrane. Analysis of the mass transfer rates was performed to support modeling of the process. Total mass transfer coefficients ranging from 2.0·10-7 to 4.0·10-7 m/s were obtained when extracting lactic acid with 20 wt% tri-N-octyl amine in 1-decanol with membrane thicknesses of 260 µm and 80 µm. The limiting mass transfer resistance in all experiments was in the membrane phase. The developed model based on mass transfer and reaction in parallel allows to predict countercurrent extraction. Experimental validation with 5, 7 and 12 m long membrane modules showed excellent accordance for two acids, validating the model simulations. Simulated membrane contactor lengths required for single, two and three countercurrent stages varied between 10 and 39 m/stage for lactic, mandelic, succinic, itaconic and citric acid, depending on acid, membrane, and diluent.

This study aimed to systematically investigate the effect of elevated hydrogen partial pressure on mixed culture homoacetogenesis in the range of 1–25 bar. Seven batch experiments were performed at different initial headspace pressures, i.e., 1, 3, 5, 10, 15, 20, and 25 bar. The 15 bar batch showed the highest gas uptake rate (6.22 mol h−1L−1) and volatile fatty acids synthesis (3.55 g L−1) by a final microbial consortium that was found to be largely reduced in complexity compared to the original inoculum culture and dominated by members of the Pseudomonadaceae and Clostridiaceae. Product distribution shifted from acetate to C3-C5 acids at a pressure above 15 bar. 15 bar was found to be the optimum elevated pressure for the used mixed culture fermentation medium and biodiversity used in this study, and pressure above 15 bar inhibited the microbial consortia and resulted in lowered gas uptake rate and product synthesis.

Visualization and analysis of size and shape of fluid particles breakage in turbulent flow have been studied using high speed cameras and an image processing technique. The focus of this experimental research was set to investigate and discuss the accuracy and uncertainties of the different measurements obtained through image processing. The discussion presented shows different aspects in which image processing can affect the accuracy of the measurements obtained, with particular emphasis on the effects of the sizes determination of fluid particles. A novel approach for image segmentation is also presented and compared. We found that a higher accuracy can be achieved when this method is used.

Entrained flow gasification is an established technology for coal and petroleum coke particles. The technology is being investigated extensively for biomass gasification to meet the requirement of the green energy targets. A three-dimensional computational particle fluid dynamics (CPFD) model is developed to simulate an Entrained Flow (EF) gasification reactor. The model is validated against experimental gas composition and process temperature reported from an experiment published in the literature. The interdependence between reactor hydrodynamics, thermal and reaction chemistry is demonstrated and described for an EF reactor. Simulations show zones of high and low temperatures suggesting different reaction zones, such as a partial combustion zone near the fuel injector followed by a gasification zone. Particles in the central region show high carbon conversion compared to the particles in the other zones. Char- O₂ and char-H₂O are significant in the gasifier entrance region, whereas the char-CO₂ reaction is prevalent throughout the reactor elevation. The optimal gasification performance (higher mole fraction of CO and H₂) is in the range of equivalence ratio 0.3 to 0.44.

Single octanol droplet fragmentations in channel flow have been investigated by use of high speed imaging. The resulting raw data have been analyzed, interpreted and used to elucidate the fluid particle breakage phenomena, enabling improved understanding and motivating development of more universal population balance equation closures. The breakage kernel functions considered are the breakage time, the breakage probability, the average number of daughters and the daughter size distribution. These functions have been determined from the same set of data ensure consistency. The impact of the drop size and the turbulent energy dissipation rate on the different kernel functions were investigated. The breakage probability and average number of daughters functions correlate reasonably with the Weber number. Similarly, the breakage time correlates adequately with known model concepts. However, the correlations may not be considered universal as the parameter values obtained are not in agreement with values reported in the literature.