Chemical Engineering Commons^™

Dem-Cfd Modelling Of A Fluidized Bed Spray Granulator, Lennart Fries, Sergiy Antonyuk, Stefan Heinrich, Stefan Palzer

The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering

Coupled DEM-CFD simulations have been performed to study the hydrodynamics of a Wurster granulator on the scale of individual particles. Based on extensive material tests, the collision behaviour of dry "Gamma"-Al2O3 particles is identified and incorporated into the model. The effect of process parameters like air flow rate and geometry details like the Wurster position is studied. Based on a physical description of the material properties, an effective tool for design and scale-up of a Wurster granulator is obtained.

Computational Study Of Layer Inversion In Two-Component Liquid-Fluidized Beds By Dem-Cfd, Alberto Di Renzo, Fernando Cello, Francesco Paolo Di Maio

The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering

In the present work the layer inversion phenomenon observed in experiments from the literature is reproduced via discrete element simulations, in which a novel drag force model valid for bi- and poly-disperse particle systems is used. The simulations serve both as validation of the drag model and as a tool to analyze the dynamics of the phenomenon. The comparison with published data is carried out in terms of bed height and component distributions as functions of the liquid velocity, showing very good agreement.

Zero-Dimensional Modeling Of Indirect Fluidized Bed Gasification, Anton Larsson, David Pallarés, Daniel Neves, Martin Seemann, Henrik Thunman

The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering

Zero-dimensional models has been developed to investigate mass balance and fuel (biomass) Chalmers a 2-4MW indirect fluidized bed gasifier. The result from this work is that more than 95%(Mass) of the tars is converted in the gasifier and that the water gas shift reaction is far from equilibrium.

Dem Fluidization Of Smart Particles, Amit Suri, Masayuki Horio

The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering

Numerical simulations using DEM for smart particles/bodies having a capability to induce a repulsive force on the particle based on the cognition were simulated. A particle-particle interaction type repulsive force was used to induce self fluidization and it was found that if the repulsive force is sufficiently high, fluidization of particles can be achieved.

Inside Photo, Sang Done Kim

The 13th International Conference on Fluidization - New Paradigm in Fluidization Engineering

Inside Photo

High Temperature Water Gas Shift Catalysts With Alumina, Morris D. Argyle, Tiberiu Popa, Guoqing Xu, Thomas F. Barton

Faculty Publications

Alumina (Al2O3) was added as a component of conventional iron oxide based high temperature water gas shift (WGS) catalysts. The catalysts contained Fe-Al-Cr-Cu-O and were synthesized by coprecipitation. A series of catalysts were prepared with 5 to 50 wt% Al2O3, 8 wt% Cr2O3, 4 wt% CuO, and the balance Fe2O3. One catalyst was prepared in which the chromia was replaced by alumina. All of the catalysts were compared to a reference WGS catalyst (88 wt% FeOX, 8 wt% Cr2O3, and 4 wt% CuO) with no alumina. The catalysts were characterized using temperature programmed reduction (TPR), surface area analysis using nitrogen …

The Impact Of Thermal Coupling On Catalyst Behavior In Wall-Coated Heat-Exchanger Microreactors, Gregory S. Honda

Honors Scholar Theses

This thesis presents a numerical study of reaction and diffusion phenomena in wall-coated heat-exchanger microreactors. Specifically, the interactions between an endothermic and exothermic catalyst layer separated by an impermeable wall is studied to understand the inherent behavior of the system. Two modeling approaches are presented, the first under the assumption of a constant thermal gradient and neglecting heat of reaction and the second considering both catalyst layers and reaction heat. Both studies found that thicker, more thermally insulating catalyst layers increase the effectiveness of the exothermic reaction by allowing for accumulation of reaction heat while thinner catalyst layers for the …

Simulation Of A Tubular Solid Oxide Fuel Cell Stack Operating On Biomass Syngas Using Aspen Plus, Wayne Doherty, Anthony Reynolds, David Kennedy

Articles

A tubular solid oxide fuel cell (SOFC) stack was modelled and its operation on biomass syn-gas was investigated. The objective of this work was to develop a computer simulation model of a biomass gasification-SOFC (BG-SOFC) system capable of predicting performance under various operating conditions and using diverse fuels. The stack was modelled using Aspen Plus and considers ohmic, activation and concentration losses. It was validated against published data for operation on natural gas. Operating parameters such as fuel and air utilisation factor U_f and U_a, current density j and steam to carbon ratio STCR were varied and …

Transesterification And Recovery Of Intracellular Lipids Using A Single Step Reactive Extraction, Daniel R. Nelson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A single-step, extractive reaction for extraction of lipids such as biodiesel components, omega-3 fatty acids, or other triglycerides from microbial cells was examined. Conventional methods for lipid extraction use toxic solvents, and require multiple steps and long processing times. When the goal is to produce fatty acid methyl esters or FAMEs, the extracted lipids are subjected to a separate transesterification reaction with simple alcohols in the presence of an acid or base catalyst. A simplified, single-step reactive extraction method can be applied that combines the sequential extraction followed by transesterification using acidified alcohols - a process known as in situ …

Nutrient Utilization From Anaerobic Digester Effluent Through Algae Cultivation, Shantanu Wahal

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Nutrients present in digested animal waste can be utilized for algae cultivation under suitable conditions. Algal growth, however, depends on the chemical forms and speciation of these nutrients. In this study a chemical equilibrium model was first used to describe nutrient speciation and predict conditions that enhance the solubility of nutrients in anaerobic digester effluent. Dilution with water and separation of large particulates greatly improved nutrient availability and light penetration - conditions favorable for algal cultivation. Algae growth was tested using three strains - Scenedesmus dimorphous (UTEX # 417), Chlorella vulgaris (UTEX# 265), and an algal isolate (designated as LLAI …

Comparative Studies On Oxygen Mass Transfer For The Design And Development Of A Single-Use Fermentor, Kristan L. Sorenson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Accurate experimental oxygen mass transfer coefficient, a measure of how quickly oxygen travels from a gas bubble to the bulk liquid, is important for comparing performance and for evaluating the oxygen transfer capability of a fermentor. Delays in probe response and changing gas volumes upon start-up of gassing affect the accuracy of oxygen transfer measurements. To mitigate these inaccuracies, a standard correction procedure for oxygen mass transfer data was established for highly oxygenated, well-mixed fermentation systems. Probe response time correction was generated by applying a second-order response model to dissolved oxygen probes and shown to be effective within 4%. By …

Rapid Diagnosis Of Tuberculosis In A Peripheral Setting, Elsje Pienaar

Department of Chemical and Biomolecular Engineering: Dissertations, Theses, and Student Research

Tuberculosis is an ancient and worldwide epidemic affecting millions of people in mainly the developing world, killing almost 2 million people in 2008. Current diagnostic techniques are outdated and have proven insufficient to control the disease. Smear microscopy has poor sensitivity and culture is slow to yield results. Modern diagnostic techniques are making great strides in shortening time to result but are restricted by two qualities: 1) prohibitively high costs prevent implementation in resource poor areas, and 2) equipment and technician requirements limit application to centralized laboratories. There exists a divide between new technologies and the people that need them …

Liquid-Liquid Equilibrium For Iodine-Hydroiodic Acid-Water Mixtures At Elevated Temperatures And Pressures For The Sulfur-Iodine Cycle, Sarah Mena

All Theses

An alternative scenario to the overdependence on fossil fuels is the use of thermochemical cycles to split water into hydrogen and oxygen. The Sulfur-Iodine (SI) cycle, developed at General Atomics in the mid 1970s, is a leading candidate of international interest for the centralized production of hydrogen from nuclear and/or solar power. For a comprehensive assessment of the SI cycle, thermodynamic data for I2-HI-H2O mixtures at elevated temperatures and pressures have been identified as a basic research need.

The focus of this study was liquid-liquid equilibrium (LLE) measurements for the above system. To carry out the measurements, a continuous-flow apparatus …

Isolating Petroleum Pitch Oligomers Via Multistage Supercritical Extraction, Eduardo Cervo

All Dissertations

Petroleum pitches are carbonaceous materials that serve as precursors for advanced carbon products. Because of their highly graphitic nature, such pitches are of particular interest for producing high thermal conductivity carbon fibers for thermal management applications, such as microelectronics packaging for hybrid and plug-in vehicles.
Even though the properties of the final carbon products are impacted by the molecular composition of the starting pitch precursor, a fundamental understanding of this relationship has yet to be established. To this end, dense-gas extraction (DGE), a fractionation technique that allows for the production of pitches of controlled composition for both analytical and rheological …

Hydrogen Fuel Cell Analysis: Lessons Learned From Stationary Power Generation Final Report, Scott E. Grasman, John W. Sheffield, Fatih Dogan, Sunggyu Lee, Umit O. Koylu, Angie Rolufs

Materials Science and Engineering Faculty Research & Creative Works

This study considered opportunities for hydrogen in stationary applications in order to make recommendations related to RD&D strategies that incorporate lessons learned and best practices from relevant national and international stationary power efforts, as well as cost and environmental modeling of pathways. The study analyzed the different strategies utilized in power generation systems and identified the different challenges and opportunities for producing and using hydrogen as an energy carrier. Specific objectives included both a synopsis/critical analysis of lessons learned from previous stationary power programs and recommendations for a strategy for hydrogen infrastructure deployment. This strategy incorporates all hydrogen pathways and …

Synthesis Of An Endothelial Cell Mimicking Surface Containing Thrombomodulin And Endothelial Protein C Receptor, Karl E. Kador

Department of Chemical and Biomolecular Engineering: Dissertations, Theses, and Student Research

Synthetic materials for use in blood contacting applications have been studied for many years with limited success. One of the main areas of need for these materials is the design of synthetic vascular grafts for use in the hundreds of thousands of patients who have coronary artery bypass grafting, many without suitable veins for autologous grafts. The design of these grafts is constrained by two common modes of failure, the formation of intimal hyperplasia (IH) and thrombosis. IH formation has been previously linked to a mismatching of the mechanical properties of the graft and has been overcome by creating grafts …

Effect Of Surface Freezing On Meniscus Relaxation In Side Chain Comb Polymers, Shishir Prasad, Zhang Jiang, Michael Sprung, Sunil K. Sinha, Ali Dhinojwala

College of Polymer Science and Polymer Engineering

We have observed a sharp slowing down of the relaxation of the liquid meniscus for polydn-alkyl acrylate) at temperatures where there are no abrupt changes in bulk viscosity or surface tension. This slowing down is due to the formation of a surface-ordered monolayer above the bulk melting temperatures. X-ray photon correlation spectroscopy measurements reveal that the surface capillary fluctuations are also significantly slower due to the formation of the ordered monolayer for film thicknesses comparable to that of the precursor films. The slowing down of the precursor film dynamics is responsible for slower meniscus relaxation below the surface ordering transition …

History Of Petroleum Engineering At Montana Tech, Leo Heath, Debbie Todd

Petroleum Engineering

In January, 2010, the Petroleum Engineering department at Montana Tech moved into a new building, the Natural Resources Building, to start a new chapter in the history of the program on campus. Occupying a new building is a positive event, and it coincides with a surge of student enrollment which is prompted by industry needs and world energy demand. This time of new facilities and growing student numbers leads to the question of what the future has in store for the department. It also leads to reflection about where the department has been in the past. This history is a …

Analysis Of Conjugated Polymer Nanotubules Formed By Template Wetting Nanofabrication, Steven D. Bearden Jr.

Doctoral Dissertations

Semiconducting and optoelectric conjugated polymers have potential in micro and nano-electronic applications. Their widely tunable physical conformations and orientations make these polymers ideal material for engineering small scale devices. The polymers have been incorporated into several electronic devices including light-emitting diodes, solar cells, and field-effect transistors. Widespread adoption of these materials will not be a reality until the issues of poor device performance, short lifespans, and device degradation are resolved.

Nanostructures have been demonstrated to have improvements in molecular ordering and electronic transport. In the work presented here, tubular nanostructures of conjugated polymers fabricated by the template wetting nanofabrication process …

Ontology-Based Automatic Classification For News Articles In Indonesian Language, Prajna Wira Basnur, Dana Indra Sensuse

Makara Journal of Technology

Ontology-Based Automatic Classification for News Articles in Indonesian Language. Searching specific information will be difficult if relying only on query. Choosing less specific queries will result in a lot of irrelevant information fetched by the system. One of the most successful ways to overcome this problem is to perform document classification based on the topic. There are many methods that can be used to conduct such a classification, such as using statistical and machine learning approaches. However, those document classification methods require training the data or learning the documents. In this study, the authors attempted to classify documents using a …