Copyright: Maerz Ofenbau AG, Zurich, Switzerland

Simulations of particle assemblies passed by a reacting flow are possible due to the discrete element method (DEM) coupled with computational fluid dynamics. The relevant models required for DEM in terms of particle shape representation, mechanic/thermal interactions, and intraparticle resolution are described. Three systems on very different applications are simulated for an insight of the physical processes.

For the challenging task of modeling shaft furnaces, two techniques were developed: the volume fraction smoother (VFS), where the particle size can be independent of the cell size, and the time scale splitting method (TSSM), which allows separation of the fluid and discrete-element method time scales to speed up the simulation.

Particle-laden turbulent channel flows are simulated using deterministic Lagrangian particle tracking with a stochastic technique to resolve collisions. The implementation of agglomeration in the deterministic approach causes a reduction in the particle collision rate. Modifications are suggested to offer improvements to the stochastic approach while accounting for the repeat collision effect.

By using high-accuracy and robust simulation techniques, the effect of particle Stokes number on particle deposition within a wall-bounded turbulent flow has been investigated using an approach of direct numerical simulation fully coupled with Lagrangian particle tracking. The predictions have been successfully validated through comparison with literature simulations and experimental datasets.

A combined method is developed to locally resolve the flow inside a particle assembly in specific regions only, where strong mixing takes place, thus limiting the computational effort. The result is reviewed for an isothermal mixing of a nitrogen jet in air crossflow. A second case with gas phase chemical reactions is simulated for both static and moving particles.

A dataset from filtered Euler-Lagrange simulations with systematic variations of the cohesion level and filter length was created to develop a machine learning-based drag correction model for liquid bridge-induced cohesive gas-particle flows. Such models afford robust and accurate predictions of drag correction and actual drag force. An anisotropic drag correction model is more accurate than an isotropic model.

Adding particles to a pipe flow affects the properties of the flow. If the particles are small compared to the length scales of the flow, the effects are well. This numerical study focuses, however, on large spherical particles, which means particles that are of the same size as the large scale length scales of the flow and larger. Their impact on flow resistance and on the turbulence is quantified.

The importance of natural gas liquids and their applications are reviewed together with ten different natural gas liquid recovery techniques in terms of their process description with process flow diagrams, comparisons, energy requirements, production processes, operating costs, and propane recoveries. The most efficient technique is evaluated to help researchers for further developments.

Waste plastics are converted into valuable chemicals such as fuel through the pyrolysis process using various catalysts. The physiochemical parameters of the obtained fuels were analyzed. The results were found to be closely similar to those of ordinary fuel, with very low sulfur and nitrogen percentages, proving the potential usage in petrol and diesel engines without upgrading.

Gold nanoparticles (AuNPs) were prepared by a green synthesis from bioreduction of auryl chloride solutions using Pithecellobium dulce leaf extracts. Antibacterial, antifungal, and anticancer tests were successfully performed, confirming the effectivity of the newly developed AuNPs. A promising perspective for future research in the development of potent formulations in patients with cancer is given.

A new and simple method to deduce the capillary pressure from desorption isotherms measurements is proposed. The pressure is presented as a function of the material's level of saturation. A thermodynamic relation between the capillary pressure and the water activity using the Kelvin equation is developed. The results confirm the feasibility of the proposed method to achieve good capillary pressure curves.

The Taguchi experimental design method was used to determine the optimum nanofiltration conditions for the reuse of treated textile wastewater, in a short time and with less cost. With this approach, small and medium-sized enterprises will be able to integrate their facilities into the circular economy model, by the reuse of wastewater in their facilities.

To optimize the flow field in a tubular reactor and solve the problem of catalyst inactivation, flow deflector plates were added by using flow reversal technology. The numerical simulation results met the application requirements. The optimization area of a single asterisk plate was about 5 cm shorter than that of cross plate/porous plate combination and it had better stability in the physical model.

Microalgae have a wide range of applications, but their cultivation is not presently economically feasible. This study sheds light on the advantages of using carbon dioxide from biogas in the cultivation of Chlorella vulgaris in terms of productivity, biomass composition, and cost savings. It also proposes the use of a rotating contacting disk device for separating carbon dioxide from biogas.

Multiple-impeller systems of non-Newtonian fluids were theoretically and experimentally investigated under full flow regime conditions. Their development depends on mixing time, power consumption, and mixing energy. To achieve consistent mixing with optimal mixing energy, the results indicated that axial flow of the 4-pitched-blade turbine is the most effective approach.

Formation of an oil-in-water (O/W) emulsion facilitates pipeline transport of heavy crude oil (HCO) by reducing its viscosity. The flow characteristics of HCO and O/W emulsions thereof through a horizontal pipeline were studied experimentally and simulated in a computational fluid dynamics study. The results of this work may help in designing the pipeline and choosing the operating conditions.

The use of water to transform carbon dioxide into useful products in a sustainable process can address global warming. Herein, oxides of nickel and cobalt supported on ceria facilitate the conversion of carbon dioxide and water to carbon monoxide and hydrogen in a nonthermal plasma process. Parameters such as basicity, carbon dioxide flow rate, plasma input power, and humidity were optimized.

Single-particle comminution of beech wood under impact stress was investigated, analyzing the influence of the moisture content and the particle size. The applicability of existing models to wood, for modeling the breakage probability function for brittle materials, was determined.

Standardized solutions for intelligent process equipment assemblies with own automation promise high potential for chemical and pharmaceutical industries. Different service design approaches for a generic ‘separate' service are investigated on the example of a solvent extraction and a distillation column to show how process development can benefit from the module type package approach and become faster.

Key inspirations for the development of integrated, continuous apparatuses with short changeover times are fast time-to-market, increased efficiency, and flexibility of production processes. Consequently, a modular belt crystallizer was developed and characterized in lab scale. Based on the promising results, a scale-up to pilot size and a first commissioning in an industrial environment was realized.

Simultaneous removal of cutting oils and Cu²⁺ by electrocoagulation was investigated using a cell containing two steel electrodes and a built-in heat transfer facility. The process was modeled and optimized by means of response surface methodology. Reduction in the operating costs and capital costs by simultaneous removal of the oil and Cu²⁺ in the same cell was highlighted.

A temperature-adjustable burner plate was developed and manufactured for investigating the partial oxidation of CH₄/O₂ flames at the laboratory scale under industrially relevant conditions. Chemical etching of thin sheet material and stacking of multiple sheet layouts was used to assemble the layout of the burner.