Chemical Engineering Perspective Research Articles

Continuous process design of the microwave chemical recycling of waste plastics using microwave-absorbing heating elements

Conventional pyrolysis methods to chemically recycle plastic waste require significant energy input owing to inefficient energy transfer from the heat sources to plastics and the generation of excess CO2. Accordingly, there is an urgent need to develop alternative methods for the chemical recycling of waste plastics to limit global warming. In this study, the use of microwaves (MWs) as an efficient energy source for pyrolysis and chemical recycling. However, because plastic is transparent to MW energy, a method that utilizes carbon materials as MW-absorbing heating elements (MWAHEs) was developed. This method directly converted high-density polyethylene (HDPE) into light chemicals in up to 94% yield with 45% ethylene selectivity. A two-stage pyrolysis system incorporating MWAHE-assisted MW pyrolysis was also developed to produce light chemicals in 95% yield with 49% ethylene selectivity. From a chemical engineering perspective, this two-step pyrolysis system is an efficient and feasible method for producing valuable light olefins. This study also demonstrates that MWAHE assisted MW pyrolysis is effective for the chemical recycling of plastic waste. This study offers potential solutions for the environmental problems posed by plastic waste by developing efficient and scalable methods for its chemical recycling.

Chemical engineering perspective of pyrolysis reactor and condenser system for biomass valorisation

The manuscript investigates the design, operating, and economic parameters of components in a biomass pyrolysis system. It covers two key components, the pyrolysis reactor and condenser, with plans to discuss other components in future publications. The study relies on experimental data from a fixed-bed reactor, bio-oil retention experiments using various vials, and computational modeling of the pyrolysis process using a lumped model. The experimental data were thoroughly analysed, considering different types of pyrolysis reactors and heating methods. Dimensionless numbers were employed to predict the impact of changing feed characteristics during pyrolysis. The second part of the study focuses on the operation of conventional condensers and how Bio-oil deposition on their surfaces affects efficiency and cost. Experimental estimation of Bio-oil film thickness on stainless steel and glass surfaces is presented, along with its effects. Finally, a hybrid condenser, combining stainless steel with a glass lining, is proposed to enhance efficiency and reduce costs based on operational requirements.

A Review on the Modeling and Simulation of Shaft Furnace Hydrogen Metallurgy: A Chemical Engineering Perspective

A Review on the Modeling and Simulation of Shaft Furnace Hydrogen Metallurgy: A Chemical Engineering Perspective

Integration of broader impacts and international perspectives into a sustainable energy engineering course

The last 20 years has seen rapid expansion of sustainable energy deployment in the European Union (EU) and the United States (U.S.) that is driving the demand for trained professionals. An engineering degree with coursework in sustainable energy systems is a desirable initial qualification. However, engineering students should also appreciate the societal and environmental impacts of the sustainable energy transition. Furthermore, since the sustainable energy transition is a global endeavor, an international perspective is needed. The sustainable energy engineering course described in this paper taught students the scientific and engineering principles underlying the major types of emerging sustainable energy technologies from a chemical engineering perspective. The technical content served as context for comparing renewable energy deployment in the EU country of Austria with the U.S. The broader impacts (societal and environmental) of renewable energy deployment were then illustrated through student presentations. Survey results showed that students gained understanding of the engineering fundamentals underlying these renewable energy systems and challenges of their deployment in Austria and the U.S. Therefore, a unique outcome of this course was that students gained an international perspective on the expansion of sustainable energy systems needed to secure a low-carbon energy future.

Thermo-fluid dynamics and synergistic enhancement of heat transfer by interaction between Taylor-Couette flow and heat convection.

This study experimentally and numerically investigated the thermo-fluid dynamics of Taylor-Couette flow with an axial temperature gradient from the chemical engineering perspective. A Taylor-Couette apparatus with a jacket vertically divided into two parts was used in the experiments. Based on the flow visualization and temperature measurement for glycerol aqueous solutions with various concentrations, the flow pattern was classified into six modes: heat convection dominant mode (Case I), heat convection-Taylor vortex flow alternate mode (Case II), Taylor vortex flow dominant mode (Case III), fluctuation maintaining Taylor cell structure mode (Case IV), segregation between Couette flow and Taylor vortex flow mode (Case V) and upward motion mode (Case VI). These flow modes weremapped in terms of the Reynolds and Grashof numbers. Cases II, IV, V and VI are regarded as transition flow patterns between Case I and Case III, depending on the concentration. In addition, numerical simulations showed that in Case II, heat transfer was enhanced when the Taylor-Couette flow was altered by heat convection. Moreover, the average Nusselt number with the alternate flow was higher than that with the stable Taylor vortex flow. Thus, the interaction between heat convection and Taylor-Couette flow is an effective tool to enhance heat transfer. This article is part of the theme issue 'Taylor-Couette and related flows on the centennial of Taylor's seminal Philosophical Transactions paper (Part 2)'.

100 Years of insulin: A chemical engineering perspective

100 Years of insulin: A chemical engineering perspective

Tackling sustainability challenges in Latin America and Caribbean from the chemical engineering perspective: A literature review in the last 25 years

Although in Latin America there is the presence of many developing countries, the chemical industry is highly competitive in today's globalized world, due to its availability of natural resources and raw materials. The production of highly profitable chemicals, high value-added metals, petroleum and its derivatives, cosmetics, perfumes and pharmaceutical products have placed Latin America as an interesting option for the global chemical industry in the 21st century. However, given the inefficiency of various processes and the growing production of various industrial areas, the daily production of 430,000 tons of waste materials is recorded in the region. In recent years, in Latin America there has been a growing interest in increasing energy efficiency and reducing waste. An example of such a situation is the development in relevant research areas that are reflected in energy, environmental, economic and inherent security aspects; in short, applications of chemical engineering. In a context of growing population, Latin America's chemical and petrochemical industries are well positioned for significant growth, if the logistical and political challenges characteristic of the geographic area can be addressed. The upcoming challenges associated with achieving sustainable operations in conjunction with the dynamics of global trade are key issues that the industry must face, in addition to the particularities of each country in this diverse, multicultural and dynamic part of the world. Consolidation through increased merger and acquisition activity and an increasingly blurred line between logistics service providers and distributors are notable trends across the value chain that suggest competition is intensifying in Latin America. The purpose of this document is to provide a summary of the current status of the application of sustainability tools in chemical processes in research in Latin America and to forecast what additional beneficial contributions might be on the horizon. We present here a brief literature review of the actions that are already being carried out, in Latin America, in the pertinent topics in sustainability where Chemical Engineering is involved, in the last 25 years.

3D printing – Present and future – A Chemical Engineering perspective

3D printing (3DP) has emerged in recent years as a form of processing with many exciting aspects. Today, it finds use in the industrial sector as well as among private individuals and small manufacturers, bringing manufacturing closer to end users and helping to bring a multitude of ideas and innovations to life. In this scenario, Chemical Engineering could play an essential role in 3DP, while it can also receive and benefit from many of the characteristics of this technology. This paper aims to highlight those that we consider the most productive meeting points between Chemical Engineering and 3DP, as well as the new techniques and applications that could benefit from this tandem in the future.

Analysis of Endoscopic Injectability and Post-Ejection Dripping of Yield Stress Fluids: Laponite, Carbopol and Xanthan Gum

Yield stress fluids, which show reversible gel–sol transition and a decrease in viscosity via shear, are expected for endoscopic applications. However, quantitative analyses of such fluids, including pressure drop during endoscopic catheter delivery and post-delivery dripping, have not yet been conducted from a chemical engineering perspective. In this study, we fabricated an equipment setup comprising an endoscopic catheter and a model gastrointestinal (GI) duct to which different concentrations of three model yield stress fluids, specifically, laponite (LAP), Carbopol (CP), and xanthan gum (XG), were applied and compared. We clarified the tradeoff between the pressure drop through the catheter and dripping on the GI duct model. In terms of operability, LAP performed better than CP and XG. The effect of gravity on dripping, which is greatly affected by the position of a patient, was discussed. Finally, the relationship between the operability and rheological properties such as viscosity, yield stress, and restructuring time of the three materials were quantitatively studied.

Perfume and Flavor Engineering: A Chemical Engineering Perspective.

In the last two decades, scientific methodologies for the prediction of the design, performance and classification of fragrance mixtures have been developed at the Laboratory of Separation and Reaction Engineering. This review intends to give an overview of such developments. It all started with the question: what do we smell? The Perfumery Ternary Diagram enables us to determine the dominant odor for each perfume composition. Evaporation and 1D diffusion model is analyzed based on vapor-liquid equilibrium and Fick’s law for diffusion giving access to perfume performance parameters. The effect of matrix and skin is addressed and the trail of perfumes analyzed. Classification of perfumes with the perfumery radar is discussed. The methodology is extended to flavor and taste engineering. Finally, future research directions are suggested.

Breakthrough and innovative clean and efficient coal conversion technology from a chemical engineering perspective

To adapt to the needs of a developing global society and provide water and ecological environmental protection, it is necessary to enhance technological innovations for clean coal conversion to achieve the basic requirements of “clean and low carbon, safe and efficient”. This paper puts forward a new idea of the chemical conversion of coal in terms of the material conversion efficiency and energy utilization efficiency of common key technologies, forward leading technologies, modern engineering technologies, and disruptive technologies. In addition, it is pointed out that there are many chemistry and chemical engineering problems restricting the innovation and breakthrough of new clean coal technologies. In view of this problem, we carry out an in-depth study of the main processes used in the coal chemical industry, and find that understanding the structure–activity relationship, designing ideal catalysts, strengthening the main reaction processes, and promoting the integration of processes used in other chemical fields into the coal chemical industry are helpful for realizing the steady development of the modern coal chemical industry. Such approaches can lead to improved economic benefits, and provide means for realizing the clean and efficient transformation of coal.

Concurrent multiresponse multifactorial screening of an electrodialysis process of polluted wastewater using robust non-linear Taguchi profiling

Electrodialysis is an important chemical process that separates pollutants from wastewater pools to produce clean water for consumption and irrigation. Initial wastewater concentration of chemical elements always differs. Chemical components are strongly dependent on the efflux origin and treatment. To optimize an electrodialysis process is congruent to improved key water quality characteristics. To predict optimal electrodialysis performance there will always be a need to conduct a small number of structured experiments. This is because wastewater conditions are usually different in each situation thus requiring reliable evidence-based design decisions to be delivered timely and low-cost. We study a real example from crucial dessert wastewater operations that aim to supply clean water for irrigation. Several issues are scrutinized that are often overlooked when carrying out multi-response multi-factorial statistical optimization in environmental screening. Programming fast-cycle trials with Taguchi-type factorial recipes reaps quick information for new development and improvement projects. But it also introduces phenomena such as saturation, unreplication and non-linearity that could undermine the optimization effort. The showcased paradigm uses popular Taguchi methods to organize a rapid and short round of trials in order to investigate the behavior of four electrodialysis controlling factors: 1) the dilute flow, 2) the cathode flow, 3) the anode flow and 4) the voltage. The three monitored water quality indices are: 1) the percentage of removed sodium cations, 2) the sodium adsorption ratio and 3) the sodium ratio. We discuss the intricacies that emerge from the synthetic type of the electrodialysis data: non-normality, non-linearity and messiness. We propose a robust and agile method to conduct the multi-response multi-factorial optimization for electrodialysis of polluted wastewater. It is based on super-ranking and distribution-free profiling. Comparison with other profiling methods is provided and main advantages are commented from a chemical engineering perspective.

How eyelashes can protect the eye through inhibiting ocular water evaporation: a chemical engineering perspective.

Bionics is a fascinating subject that has inspired many inventions through learning from biological structures and functions. In this work, a coupled multi-physics model has been developed to characterize ocular water evaporation with realistic eyelash structures taken into account. From a chemical engineering perspective, the protective function of human eyelashes in terms of evaporation inhibition has been rationally revealed. Systematic investigations were carried out to elucidate the effects of different eyelash lengths, orientations and inlet air directions on water evaporation on the ocular surface. The results clearly demonstrate that regardless of inlet air directions and eyelash orientations, increasing eyelash length from zero to an optimal length can effectively reduce water evaporation. However, further increase in the eyelash length can lead to enhanced evaporation. For the normal and parallel inlet air directions, the optimal eyelash length is around 15-30% of the eye width and can offer approximately 10-30% evaporation reduction when compared with the cases without eyelashes. These values are independent of the eyelash orientation. This investigation provides valuable data for in-depth understanding of the protective function of the eyelashes, which can be used in the future to improve and optimize bionic designs inspired by human eyelashes.

Application of hybrid RANS-LES models to the prediction of flow behaviour in an industrial crystalliser

Knowledge of the residence time and shear rates in industrial crystallisers is critical for any assessment of the performance of these vessels from a chemical engineering perspective. It is unlikely that the range of expected residence time behaviours, or the shear rates can be predicted accurately with a RANS model. In the current study, a wide range of hybrid RANS-LES models, including Stress-Blended Eddy Simulation (SBES), were used to predict the flow field in a laboratory-scale alumina precipitator with the objectives of both quantifying the accuracy of the models and assessing if the hybrid models provide significant improvement over a previous RANS modelling study. Predicted mean and fluctuating velocities have been compared with Laser Doppler Velocimetry (LDV) data from a laboratory-scale alumina precipitator. The results achieved show that hybrid RANS-LES models can accurately predict both the mean and fluctuating velocities in the precipitator vessel. Importantly, as the mesh is refined, agreement with experimental data improves and differences between model predictions reduce, showing that sensitivity to the sub-grid scale model reduces if all the relevant large-scale turbulence structures are explicitly resolved. Prediction of fluctuating velocities is found to be more accurate than that achieved in a previous RANS modelling study. The SBES results are found to be mesh-independent, and to give closer agreement with experimental data, on a coarser mesh than both the SST-DDES and SST-SAS approaches as the model formulation allows rapid transition to an explicit LES model immediately outside the wall boundary layer. This is an important result for industrial simulation due to the significant reduction in simulation times needed.

Termination Mechanisms of Turing Patterns in Growing Systems

The question of the termination of a periodic spatial structure of Turing type in a growing system is addressed in a chemical engineering perspective and a biomimetic approach. The effects of the dynamical parameters on the stability and the wavelength of the structure are analytically studied and used to propose experimental conditions for which a Turing pattern stops by itself with a decreasing wavelength. The proposed mechanism is successfully checked by the numerical integration of the equations governing the dynamics of the activator and the inhibitor. We conclude that a local increase of the concentration of the reservoir which controls the injection rate of the inhibitor into the system can be used to achieve the appropriate termination of a Turing pattern.

Horseradish Peroxidase Catalyzed Hydrogelation for Biomedical, Biopharmaceutical, and Biofabrication Applications.

Horseradish peroxidase (HRP)-catalyzed hydrogelation has attracted much attention owing to the ease of handling, high biocompatibility, and processability. This review summarizes recent developments, including cutting-edge research into the use of HRP-mediated hydrogelation toward biomedical, biopharmaceutical, and biofabrication applications. From the viewpoint of polymer chemistry, the basic chemistry behind hydrogelation, the structure-property relationship, and hybridization of multiple materials by using HRP-catalyzed hydrogelation are summarized. From the chemical engineering perspective, strategies for controlling hydrogelation kinetics, hydrogel characteristics, and hydrogelation processes are summarized and discussed in detail. Strategies for obtaining biomaterials for medical and pharmaceutical use, and biofabrication for tissue engineering and regenerative medicine emerge by unifying the aspects of HRP-mediated hydrogelation.

WITHDRAWN: Editorial overview: Process systems engineering: A chemical engineering perspective of the food–energy–water nexus

WITHDRAWN: Editorial overview: Process systems engineering: A chemical engineering perspective of the food–energy–water nexus

Tools and concepts for environmental sustainability in the food‐energy‐water nexus: Chemical engineering perspective

This work primarily deals with environmental sustainability and/or sustainable development, and with methodologies to design or redesign sustainable chemical and allied processes and products using sustainability concepts and LCA thinking. The overall approach is illustrated with two case studies involve: (1) an eco‐sugar complex producing sugar, ethanol, and paper using water and energy as inputs to the process, and (2) the leather industry in Tamil Nadu, India which requires substantial amounts of water and energy to process leather from cattle—a food source. Also, this work focuses on what chemists, chemical engineers, and other disciplines can further contribute to fully visualize, establish and implement environmental sustainability and sustainable development. Sustainability has traditionally had three underlying bases: (1) economic viability—cost and business aspects; (2) social concern—human health and social welfare; and (3) natural or ecological issues—depletion of natural capital and environment. Sustainable development has become a major driving initiative in engineering throughout the world today. Here, our focus is on various aspects of sustainability or sustainable development including environmental, industrial, business, economical, ethical, and social sustainability. The work concludes with some summary thoughts on available tools and the nature of sustainability. © 2017 American Institute of Chemical Engineers Environ Prog, 37: 73–81, 2018

A chemical engineering perspective of nanoparticle‐based targeted drug delivery: A unit process approach

A chemical engineering perspective of nanoparticle‐based targeted drug delivery: A unit process approach

A Chemical Engineering Perspective on the Origins of Life

Atoms and molecules assemble into materials, with the material structure determining the properties and ultimate function. Human-made materials and systems have achieved great complexity, such as the integrated circuit and the modern airplane. However, they still do not rival the adaptivity and robustness of biological systems. Understanding the reaction and assembly of molecules on the early Earth is a scientific grand challenge, and also can elucidate the design principles underlying biological materials and systems. This research requires understanding of chemical reactions, thermodynamics, fluid mechanics, heat and mass transfer, optimization, and control. Thus, the discipline of chemical engineering can play a central role in advancing the field. In this paper, an overview of research in the origins field is given, with particular emphasis on the origin of biopolymers and the role of chemical engineering phenomena. A case study is presented to highlight the importance of the environment and its coupling to the chemistry.