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As global energy demand rose by 2.3% in comparison to the last year rate of 1.2%, fossil fuels, biofuels and natural gas are becoming increasingly important in power generation and production of the liquid fuels. However, the presence of the contaminants, such as H2S and CO2 in the derived products from these fuels is the cause of several operational and technical issues ranging from equipment corrosion, fouling, catalyst deactivation, and environmental pollution. Therefore, it is necessary to remove contaminants from these gaseous mixtures for their effective use for multiple applications. The objective of this review is to explore various experimental, theoretical and simulation approaches which are developed to improve the operation and design of different H2S and CO2 removal technologies. The fundamental thermodynamic and kinetic models for the acid gas removal processes through simulation, design related to their improvements in the absorber and the stripper through experimentation and simulation work and relevant optimization studies based on chemical absorption have been discussed. The simulation and experimental work focusing on physical absorption is also summarized. The experimental and simulation-based studies on blends of different solvents are presented. The comparison of various solvents related to H2S and CO2 removal techniques is demonstrated. Feasibility assessment of various H2S removal techniques via experimentation is presented. The effort for process intensification and new modifications has led to better understanding of acid gas removal techniques. Improvements are eminent in enhancing the efficiency of the absorber and stripper through reduction in the heat requirements. The scope of blends of various solvents for use at commercial scale and optimization of the operating conditions can lead to reduction in capital and operating cost. Finally, the future directions of research to improve the cleaning processes have been indicated. [ABSTRACT FROM AUTHOR]

• Seven integration strategies were identified and grouped into three categories. • A detailed explanation, critical analysis and recommended usage of each strategy is given. • The compartmental model has the best balance between computation time and accuracy. • The fully coupled strategies are very accurate but too computationally expensive. Kinetics and CFD modeling is widely used for the study of biological treatment systems. This work reviews publications from 2006 to 2023 and compares the strategies applied to integrate the fluid dynamics and kinetics modeling. The identified strategies are grouped into three categories: a) the CFD coupled with the kinetics: mostly prohibitive in terms of its computational cost unless severe simplifications are imposed at the expense of the validity of the results; b) the CFD uncoupled from the kinetics: less computationally expensive, nonetheless, not suitable for real-time simulations. In this category, the time-step sub-cycling strategy is recommended for design modeling purposes; and c) the modeling with indirect coupling: using a CFD-based compartmental model, can get an accurate integration of the kinetics and fluid dynamics with the least computational cost. This strategy is a feasible option for real-time applications. [ABSTRACT FROM AUTHOR]

Group-based methodology (SPGM) has been presented as suitable to test for the existence of subpopulations not directly observable. Several criminological studies have used this methodology, and it is fair to say that typological theorizing has been spurred by its development. In particular, much of the empirical support for Moffitt's taxonomy (1993, 2006) is from studies using SPGM. In a small simulation experiment, I investigate whether SPGM is suitable for such tests, and I examine the extent to which similar trajectories might equally well result from mechanisms suggested by general theories. I conclude that, as it is usually applied, SPGM cannot provide evidence either for or against a taxonomy and that the usual findings can be explained by competing theories. I argue that this result is not only because of the methodology characteristics but also because of the modeling strategy applied. [ABSTRACT FROM AUTHOR]

Abstract: This paper investigates the qualities and limitations of a number of modeling strategies for design analysis of composite curved steel I-girder bridges. The strategies range from modified line-girder analysis to 3D finite element approaches. Several key modeling considerations, including girder web distortion, the idealization of the cross-frames, support and load height, and displacement compatibility between the girders and slab, are addressed. Approximate approaches are investigated for the capture of composite I-girder web-distortion effects when modeling the girders using open-section thin-walled beam theory. A representative full-scale composite curved I-girder bridge, tested at the Federal Highway Administration (FHWA) Turner-Fairbank Highway Research Center (TFHRC), is utilized for assessment of the different approaches. The predictions of key lateral and vertical displacements, reactions, cross-frame forces, major-axis bending stresses and flange lateral bending stresses are evaluated using the test bridge. The paper highlights a number of subtle but critical blunders that can occur in the context of the different methods. Engineers need to be aware of these pitfalls in order to avoid potential problems due to inaccurate analysis predictions. The paper closes with a discussion of the efficacy of the various approaches. [Copyright &y& Elsevier]