2022 Roadmap on 3D Printing for Energy

This roadmap aims to define the guidelines to maximise the impact of the 3D printing revolution on the next generation of devices for the energy transition. It also outlines the current status, challenges and required advances in Science and Technology for a series of power generation technologies (fuel cells, solar cells, thermoelectric generators and turbomachinery) and energy storage technologies (electrolysers, batteries and supercapacitors). Finally, the roadmap discusses the role of 3D printing in improving the mass and heat transfer to improve the energy efficiency of chemical reactors (CO2 conversion) and novel cooling systems. With this document, the authors intend to provide a valuable tool for researchers, technology developers, and policymakers when defining their strategies for the energy sector's future.

Spectral, Entropy and Bifurcation Analysis of the Dynamics of a Catalyst Chemical Reverse-Flow Tubular Reactor

Oscillations, including chaotic ones, can spontaneously appear in chemical reactors or lean premixed combustors. Such behavior of the system is undesirable and should be identified at the stage of its modeling. This article analyzes the behavior of reverse-flow tubular chemical reactor with longitudinal dispersion in terms of chaotic oscillations. The purpose of using reverse flow is to increase the conversion degree. For the analysis of the reactor, among others, spectral analysis, entropy, and bifurcation analysis were used. The obtained results show the chaotic behavior of the reactor in a wide range of changes in the parameter’s values.

Over-Equilibrium as a Result of Conservatively-Perturbed Equilibrium (Acyclic and Cyclic Mechanisms)

The effect of over-equilibrium, i. e., the effect at which the concentration of some substance is higher than the corresponding equilibrium value, is demonstrated for two types of ideal chemical reactors, continuously stirred tank reactor (CSTR) and plug-flow reactor (PFR), respectively, under conditions of conservatively perturbed-equilibrium (CPE). Two types of complex chemical mechanisms are analyzed, acyclic and cyclic ones. Using numerical experiments and the same residence times, it is shown that for the steady-state PFR this effect is more pronounced that for the steady-state CSTR, and it is true both for acyclic and cyclic reactions. In the studied mechanisms, cyclic and acyclic, the initial concentration of some substance is taken as the equilibrium one, and two other concentrations are the nonequilibrium ones. The greater the difference between the two initially nonequilibrium concentrations, the greater the concentration of the third substance, which was taken initially as the equilibrium one. At the specific values of kinetic parameters considered here, the sensitivity of the occurrence time of the B-concentration extremum for the different reactors (PFR and CSTR) at the fixed mechanism is small, but for the different mechanisms (acyclic and cyclic) at the fixed reactor is significant.

Homotopic Parametric Continuation Method for Determining Stationary States of Chemical Reactors with Dispersion

Physical processes occurring in devices with distributed variables and a turbulent tide with a dispersion of mass and heat are often modeled using systems of nonlinear equations. Solving such a system is sometimes impossible in an analytical manner. The iterative methods, such as Newton’s method, are not always sufficiently effective in such cases. In this article, a combination of the homotopy method and the parametric continuation method was proposed to solve the system of nonlinear differential equations. These methods are symmetrical, i.e., the calculations can be made by increasing or decreasing the value of the parameters. Thanks to this approach, the determination of all roots of the system does not require any iterative method. Moreover, when the solutions of the system are close to each other, the proposed method easily determines all of them. As an example of the method use a mathematical model of a non-adiabatic catalytic pseudohomogeneous tubular chemical reactor with longitudinal dispersion was chosen.

A novel design space concept for design of concrete foundation supporting chemical reactors

PurposeThis paper presents a novel concept for design of concrete support system for chemical reactors used in refineries and petrochemical plants. Graphical method is described that can be used to size the concrete base and piling system. Recommendations are also provided to optimize the parameters required for the design. The procedure is illustrated for design of two reactor models commonly used in gas recovery units.Design/methodology/approachDesign space representation for the foundation system is described for chemical reactors with variable heights. The key points of the design graph are extracted from the numerical finite element models. The reactor load is idealized at discrete points to transfer the loads to the piles. Bilateral spring system is used to model the soil restrains.FindingsThe graphical approach is economical and provides the design engineer the flexibility to select the foundation parameters from wide range of options.Practical implicationsThe concept presented in the paper can be utilized by engineers in the industry for design of chemical reactors. It must be noted that little guidelines are currently available in practice addressing the structural design aspects.Originality/valueA novel concept is presented in this paper based on significant industrial design experience of reactor supports. Using the described method leads to significant cost savings in material quantity and engineering time.

Influence of tab corner geometry on supersonic jets

Purpose The purpose of this study is to evaluate the effect of tabs having different corner geometries on the flow characteristics of a supersonic convergent–divergent (C-D) nozzle. Design/methodology/approach A circular C-D nozzle of Mach 2.0 was used, and the tabs were positioned at the exit of the nozzle in diametrically opposite directions. Three tabs having different corner geometry implemented in the experiments were rectangular tab with triangular top edge, triangular tab with a bell-shaped edge and tapered tab. The pressure profiles across the tabs and the centerline pressure decay along the jets were measured. The shadowgraph technique illustrated the waves present in the center of an oncoming jet. The nozzle pressure ratios (NPR) were varied from 4 to 8, in the steps of one, covering various overexpansion and under expansion levels at the exit of the nozzle. Findings The results showed tapered tabs act as a better mixing promoter than the other tabs used in the study. A reduction of 91.25% in core length for NPR 8 was observed for the tapered tabs. Subsequently, core length reductions generated by triangular tabs with a bell-shaped top edge were 87.5%, and those caused by rectangular tabs with a triangular top edge were 7.5%. Practical implications The research results could be used for designing combustion chambers and chemical reactors that require jets to enhance mixing levels. Originality/value The tabs having three different corners geometries, i.e. sharp or pointed, bell-shaped and straight edge has never been investigated before. The idea of only modifying corners is the innovative step of this research.