Chemical Engineering Design Research Articles

PREDICTION OF THE SOLUBILITY OF CAFFEIC ACID IN WATER USING AN ACTIVITY COEFFICIENT MODEL

Solubility of solid compounds is one of the most widely used physicochemical properties in chemical engineering design and experiments. Experimental works for solubility are not always possible because of the small amount of yield available in the phytochemicals extraction. Thus, one interesting perspective is the used of thermodynamic models, which are usually employed for predicting the activity coefficients in the case of solid–liquid equilibria (SLE). Phytochemical compound used in this study is caffeic acid where a comparative study of the MPP-UNIFAC and Pharma Modified UNIFAC were used to predict the solubilities of this phytochemical. The performances of these two activity coefficient models were compared using the experimental solubilities data obtained from the literature in the temperature range of 288 to 323 K and were evaluated by analysing the absolute relative errors (ARE) between the experimental and the predicted values. Moreover, the model errors were also discussed according to the functional groups of the molecules and water as the solvent. In general, the MPP UNIFAC showed better accuracy as compared to the Pharma Modified UNIFAC in predicting the solubility of caffeic acid in water. Nevertheless, both models give very poor qualitative predictions.

Using MD Simulations To Calculate How Solvents Modulate Solubility.

Here, our interest is in predicting solubility in general, and we focus particularly on predicting how the solubility of particular solutes is modulated by the solvent environment. Solubility in general is extremely important, both for theoretical reasons - it provides an important probe of the balance between solute-solute and solute-solvent interactions - and for more practical reasons, such as how to control the solubility of a given solute via modulation of its environment, as in process chemistry and separations. Here, we study how the change of solvent affects the solubility of a given compound. That is, we calculate relative solubilities. We use MD simulations to calculate relative solubility and compare our calculated values with experiment as well as with results from several other methods, SMD and UNIFAC, the latter of which is commonly used in chemical engineering design. We find that straightforward solubility calculations based on molecular simulations using a general small-molecule force field outperform SMD and UNIFAC both in terms of accuracy and coverage of the relevant chemical space.

Characterization of a macrophyte microcosm as a surface water treatment system for antibiotics

Natural water treatment systems provide for a means to manage nutrient (and carbon) cycles while improving water quality. We present chemical engineering design characteristics from an example flow through and model tertiary water treatment microcosm. This research demonstrates that aquatic macrophytes (Pistia stratiotes and Eichhornia crasippes) can degrade concentrations (0–10 mg/L) of oxytetracycline (OTC). First order OTC degradation rate coefficients (0.07–4.5/day) can be adjusted by altering; agitation, pH, temperature, and aeration mass flows in exudate treatment strategies when simulated wastewater was fed at 10 L/day. Further, we suggest that electronic paramagnetic resonance can be used to aid in hypothesis testing that external elicitation with phytohormones can be used to promote biological based oxidative bursts with methyl jasmonate during water treatment. Finally, we suggest there is a lack of research that considers macrophytes in more holistic natural and human use cycles. © 2015 American Institute of Chemical Engineers Environ Prog, 34: 1605–1612, 2015

Improving the solvent-extraction process of rice bran oil

Extracting crude oil from oilseeds is the first step in the production of vegetable oil. Organic solvent-extraction is widely applied. The production of high value rice bran oil is gaining increased interest, and is the subject of the present paper. Field data from a 32T/day pilot plant in Heilongjiang will be compared with engineering simulations. Since these processes are energy-intensive, two strategies for saving energy in the process will be assessed. Field data and simulation results will be shown to be in excellent agreement. Two energy optimization strategies were designed by both energy pinch technology to integrate heat recovery, and by using nitrogen instead of steam in the desolventizer/toaster, subsequently using a solvent recovery unit with gas membrane. As a result, 45.2% of the total energy consumption of the rice bran oil process can be saved whilst maintaining the original production capacity and high purity of the crude rice bran oil. The results confirm the possible energy savings and improvements in the solvent extraction process. It is also noteworthy that simulation techniques, commonly used in gas/liquid chemical engineering design, can be adapted and completed to cover the more complex design of solid/gas/liquid biochemical processes.

Design Engineering as an Interdisciplinary Graduate Course1

Design Engineering as an Interdisciplinary Graduate Course W. I. Jose, Ph.D. Abstract This paper presents the circumstances behind the proposal to institute a design engineering option in the graduate program at the University of the Philippines at Diliman (UPD). Originally, the UPD Department of Chemical Engineering proposed a chemical engineering design option in its graduate program. However, the implementation of the proposal did not push through. A similar proposal several years later suffered the same fate. The reason for the failure of implementation was not clear. The problem was resolved through the use of “probing paradigms”, developed by this author. The technique enlightened us in identifying the necessary information and components of the option. One was the apparent influence of the undergraduate design course that serves as a capstone course. A paradigm shift was necessary. The interdisciplinary nature of the option became a major consideration. Design engineering subjects are necessary in all fields of engineering. Thus, the subjects are suitable to all engineering disciplines. The design courses would give the necessary background to graduate students whose research requires some aspects in design. The core subjects are: Principles of Design Engineering, Innovation and Creativity in Design, and Design for Environment and Sustainability. Specialized courses from each discipline are to be offered. Full Text: PDF DOI: 10.15640/jea.v3n2a10

Call for applications: graduate student researcher (PhD student) and postdoctoral associates on LCA research

Modern societies generate and mobilize chemicals of enormous diversity and quantity. However, our understanding of the life cycle environmental impacts of chemicals and materials has not kept pace with new discoveries or with the production scale of chemicals. Development of a rapid, early stage tool to evaluate life cycle impacts has a broad relevance to industry, government, and academic communities. We have received a significant amount of funding to develop the science, data, and the tool that will enable an open-access, online platform, the Chemical Life-Cycle Builder (CLB) for early stage life cycle environmental evaluation of chemicals and materials. We have 12 industrial, governmental, and academic partners throughout the world that will collaborate under this project. The project will be conducted by a multidisciplinary team of experts, representing life cycle assessment (LCA); database development; fate, transport, and toxicity modeling; chemical engineering and chemical process design; sustainable chemistry; and materials science. The project will be a crystallization of cutting-edge approaches from each of these fields and offers a fertile ground for world-class research. The PhD researchers and postdoctoral associates recruited for this project will be given the opportunity to participate in the research program, collaborate with our partners, and join our rich training and internship programs. Depending on the qualifications, we will provide tuition, fees, stipend, travel funds, and other benefits for the PhD researchers and postdoctoral associates. For postdoctoral associates, we will offer a competitive salary commensurate with experience.

3-D printing for CO2 capture and chemical engineering design

3-D printing for CO2 capture and chemical engineering design

3D printing for CO2 capture and chemical engineering design

Three-dimensional printing is a form of additive manufacturing that allows the fabrication of items directly from digital files, allowing the user to virtually produce any solid object on demand. Three-dimensional printing is already a frequently discussed topic in the mainstream media and is beginning to find a number of applications in research laboratories. The authors have recognized that 3D printing can have many roles in the design of chemical engineering processes as a means of fabricating parts or perhaps entire unit operations. The authors foresee many opportunities for 3D printing as a means of producing novel and advanced components and entire devices for gas treating. Gas treating (i.e. the removal of one or more contaminants from a gaseous mixture) plays a crucial role in many existing and emerging energy-related processes including natural gas sweetening, flue gas desulfurization and pre- and post-combustion carbon dioxide capture. These processes are typically carried out in absorption columns containing trays or packing that provide interfaces for gas–liquid contacting. New devices such as membrane contactors are also emerging as alternative mechanisms for achieving separation of gases with potential cost and energy-saving benefits derived from having smaller footprints, being of lighter weight and having much larger interfacial areas. Yet in all cases, the design, cost and ability to optimize gas–liquid contactors may be limited by conventional manufacturing techniques. In this respect, 3D printing could be a mechanism by which to achieve improvements on existing technologies and more rapidly deploy novel devices. Here, the authors describe their efforts to date in the application of 3D printing for the fabrication of components and devices for carbon dioxide–capture applications and provide perspective on design strategies, opportunities and challenges.

Mathematical models for water vapor absorption on catalyst and adsorbent in atmosphere detritiation and correlation of oxidation rate of hydrogen

Establishment of tritium recovery system is necessary to prevent its leakage to the working area. The catalytic oxidation and adsorption process is the most valid method to recover tritium into the working area of those facilities. Therefore, there is a necessity that the tritium recovery system with large-scale and higher integrity is developed and constructed. For this purpose, it is required to obtain and accumulate updated database for chemical engineering design based on most recently commercial and available catalysts and adsorbents. In this work, we selected an adsorbent and catalysts, and examined their adsorption characteristics for water vapor. Adsorption isotherms were studied with a volumetric gas adsorption instrument. Various adsorption models were tested to correlate the experimental isotherms. For the catalyst, catalytic activity for oxidation of hydrogen was investigated in wet gas conditions. The experimental isotherms were successfully correlated using multi-site Langmuir–Freundlich equations. The catalytic activity was found to be influenced by the amount of water vapor adsorbed on the catalyst substrate.

Proposed vertical integration of prior learning to support students undertaking Chemical Engineering Design

During academic session 2008–2009, the Department of Chemical Engineering, University of Strathclyde, changed Year 4 Chemical Engineering Design project teaching to include mixed groups from Bachelors and Masters programmes; team delivery and two separate components of design. This paper presents data for 408 students studying Chemical Engineering at the University of Strathclyde pre and post change; exploring the impact of these changes and highlighting potential for supported, vertically integrated learning programmes, across the first four years of teaching, to provide a framework fostering student confidence and autonomy. The impact of course restructuring indicates that Bachelors students’ aspirations are increased, with no detriment to Masters performance. Early years performance over this period is unchanged, allowing separate investigation of the changes made in 2008–2009. Gender basis analysis shows that male students’ performance is little affected, although the whole cohort fit shows a marked change due to the improved performance of low attaining female students. Post 2009 final performance shows direct correlation with Chemical Engineering Design mark, suggesting the latter may indicate final expected grades for given students. The study reveals widely applicable benefits for increased student motivation, managing expectation, and facilitating students’ utilisation and integration of knowledge gained during their studies.

Simple and accurate correlations for diffusion coefficients of solutes in liquids and supercritical fluids over wide ranges of temperature and density

The binary diffusion coefficients at infinite dilution, D12, are fundamental properties in chemical engineering simulation and design. In this work, very simple and accurate expressions involving two parameters are proposed/analyzed for their estimation. They depend only on temperature and/or solvent density and/or solvent viscosity. Their correlation and prediction abilities are tested with the largest database ever compiled, composed of 539 binary systems and 8219 data points, where polar/non-polar, symmetrical/asymmetrical, small/large, and light/heavy molecules are included without exception. It is shown that only two experimental D12 values are sufficient to get good parameters for the subsequent estimation of reliable diffusivities far away from the conditions of the experimental data utilized to fit them. Globally, Eqs. (2)–(4) and (9) are recommended for D12 calculation, due to the excellent results achieved for both correlation (average errors between 2.78% and 3.05%) and prediction (average errors between 4.21% and 4.44%). A comparison with models from the literature is also accomplished.

Model-based design of synthetic, biological systems

Synthetic biology brings engineering tools and perspectives to the design of living systems. In contrast to classical cell engineering approaches, synthetic biology enables cellular networks to be understood as a combination of modular elements in much the same way as unit operations combine to describe a chemical plant. Consequently, models for the behavior of these designed systems are inspired by frameworks developed for traditional chemical engineering design. There are direct analogies between cellular metabolism and reaction networks in a chemical process. As examples, thermodynamic and kinetic models of chemical reaction networks have been used to simulate fluxes within living systems and predict the performance of synthetic parts. Concepts from process control have been brought to bear on the design of transcriptional and translational regulatory networks. Such engineering frameworks have greatly aided the design and understanding of living systems and have enabled the design of cells exhibiting complex dynamic behavior and high productivity of desirable compounds. This review summarizes efforts to quantitatively model cellular behavior (both endogenous and synthetic), especially as related to the design of living systems.

AN EMPIRICAL EQUATION TO DIRECTLY CALCULATE PARAMETER B 4 OF THE MARTIN-HOU EQUATION OF STATE

The Martin-Hou (MH) equation is a widely used equation of state in chemical engineering, mechanical engineering, and refrigeration technology design. It has pronounced advantages in calculations of liquid volume and enthalpy-entropy of high pressure gases and polar liquids. However, the determination of parameter B4 of the MH equation by using the conventional method is very time- and computation-consuming, which significantly restricts the application of the MH equation in engineering calculations. This article proposes an empirical equation to conveniently calculate B4 at different temperatures according to B4(0.7) (B4 at reduced temperature = 0.7). The accuracy of the MH equation to calculate volume of pure liquids by using the proposed equation was verified by comparing tcalculated data with literature data. The proposed equation can remarkably decrease the time to determine parameter B4, which would boost the application of the MH equation in engineering calculations.

A controlled biochemical release device with embedded nanofluidic channels

A controlled release device is developed by embedding nanofluidic biomolecule reservoirs into a polymer network of a stimuli-responsive hydrogel. The reservoirs are made of liquid core-polymer shell nanofibers using co-electrospinning. The mechanism of controlled release is based on buckling instability of the polymer shell under combined axial and radial compression, caused by volume changes of hydrogel responding to a specific stimulus. The device decouples releasable biomolecules from a hydrogel polymer matrix, avoiding chemical interactions between biomolecules and hydrogel polymer chains, and thus, alleviating nontrivial chemical and biological engineering design of hydrogel formulations. Temperature-sensitive hydrogel is used as a model hydrogel.

Auxiliary of ChemCAD in Chemical Engineering Design

ChemCAD was applied to the simulation of distillation, and SCDS was used as a platform. to simulate distillation of benzene rectifying, obtaining the simulation result and the impact of operating parameters were analyzed to select the appropriate distillation conditions. Providing theoretical instructions for engineering design, and optimizing operations.

11-111 プラント模型作りを組み込んだ化学設計製図((12)エンジニアリング・デザイン-II,口頭発表論文)

11-111 プラント模型作りを組み込んだ化学設計製図((12)エンジニアリング・デザイン-II,口頭発表論文)

DESIGN IN CHEMICAL ENGINEERING: WHAT ARE THE PERSPECTIVES

Design in chemical engineering should aim at reaching a balance between theory and practice in engineering education in order to have students better prepared for their future endeavors. As students progress through the curriculum they learn more fundamental engineering science, more design components are introduced into courses and the complexity of the design problems increases. Elements of design are introduced in many courses and culminate in a capstone design course. Current practices in Chemical Engineering at McGill University are described here and general perspectives are discussed.

INTRODUCING DESIGN IN FIRST YEAR CHEMICAL ENGINEERING AT UNIVERSITY OF WATERLOO

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Development of an internal reforming alcohol fuel cell: Concept, challenges and opportunities

The complexity of the balance of plant of a fuel cell-fuel processor unit challenges the design and development of compact and user friendly fuel cell systems. Many of these drawbacks could be alleviated by incorporation of a methanol reforming catalyst into the anodic compartment (bi-functional anode) of a high-temperature, polymer electrolyte fuel cell (HT-PEMFC), so that methanol reforming takes place inside the fuel cell stack (internal reforming). The development of an internal reforming alcohol fuel cell (IRAFC) poses an ambitious technological and research challenge, which requires the effective combination of various technological approaches as regards materials development, chemical reaction engineering and stack design. It aims at opening new scientific and engineering prospects, which may allow easier penetration of the fuel cell system in the energy market. This paper particularly emphasizes technological aspects of the IRAFC unit and reports on preliminary results obtained from single-cell laboratory prototypes.

Teaching “operability” in undergraduate chemical engineering design education

This paper presents a proposal for increased emphasis on operability in the Chemical Engineering capstone design courses. Operability becomes a natural aspect of the process design courses for a project that is properly defined with variation in operations and model uncertainty. Key topics in operability are operating window, flexibility, reliability, safety, efficiency, operation during transitions, dynamic performance, and monitoring and diagnosis. The key barrier to improved teaching and learning of operability is identified as easily accessed and low-cost educational materials, and a proposal is offered to establish a portal open to all educators.