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Full-Text Articles in Engineering

Understanding Effective Elastic Properties And Stress-Strain Evolution In Composite Granular Rocks Using Discrete Element Modeling, Prasad Pothana, Fernando E. Garcia, Kegang Ling Mar 2024

Understanding Effective Elastic Properties And Stress-Strain Evolution In Composite Granular Rocks Using Discrete Element Modeling, Prasad Pothana, Fernando E. Garcia, Kegang Ling

Petroleum Engineering Posters and Presentations

The mechanical behavior of composite granular rocks is a multifaceted phenomenon relevant to various geoengineering applications. Traditional homogenization models and continuum mechanics-based numerical methods often fall short of accurately capturing the intricacies of granular materials. Granular materials exhibit heterogeneity and arching mechanisms governing the force networks that ensure system stability. Unlike continuum-based approaches, particulate discrete element methods have an advantage in assessing effective material properties by considering material heterogeneity and grain-level physical interactions. This study evaluates effective elastic properties using particle flow code using flat-joint contact law for composite binary mixtures with a stiff inclusion embedded within a matrix material. …


Integrated Petrophysical Evaluation And Rock Physics Modeling Of Broom Creek Deep Saline Aquifer For Geological Co2 Storage, Prasad Pothana, Ghoulem Ifrene, Kegang Ling Feb 2024

Integrated Petrophysical Evaluation And Rock Physics Modeling Of Broom Creek Deep Saline Aquifer For Geological Co2 Storage, Prasad Pothana, Ghoulem Ifrene, Kegang Ling

Petroleum Engineering Student Publications

Fossil fuels, such as coal and hydrocarbons, are major drivers of global warming and are primarily responsible for worldwide greenhouse gas emissions, including carbon dioxide CO2. The storage of CO2 in deep saline reservoirs is acknowledged as one of the top practical and promising methods to reduce CO2 emissions and meet climate goals. The North Dakota Industrial Commission (NDIC) recently approved the fourth Class VI permit for a carbon capture and storage project in the Williston basin of North Dakota for the geological CO2 storage in the Broom Creek formation. The current research aimed to …


Characterizing Nonlinear Fluid Flow In 3d Printed Rock Fractures: Effects Of Roughness, Aperture, And Intersection Angles, Ghoulem Ifrene, Prasad Pothana, Sven Egenhoff, Nicholas Bittner, Kuldeep Singh Jan 2024

Characterizing Nonlinear Fluid Flow In 3d Printed Rock Fractures: Effects Of Roughness, Aperture, And Intersection Angles, Ghoulem Ifrene, Prasad Pothana, Sven Egenhoff, Nicholas Bittner, Kuldeep Singh

Petroleum Engineering Posters and Presentations

Understanding fluid flow behavior at fracture intersections is vital to geothermal energy extraction, underground water flow, and CO2 storage. Here, laboratory experiments were performed to study the effect of surface roughness, intersection angles, and aperture on nonlinear flow behavior in simple fracture networks. A FormLabs (3B+) 3D printer was used to fabricate 8 samples of 38.1mm in diameter and 59.43mm or 54.9mm in length with 2 intersecting fractures of 10o and 40o respectively. The surface roughness of the fractures was based on laser profilometry measurements from two induced mode 1 rock fractures, with a joint roughness coefficient …


Stress-Dependent Petrophysical Properties Of The Bakken Unconventional Petroleum System: Insights From Elastic Wave Velocities And Permeability Measurements, Prasad Pothana, Ghoulem Ifrene, Kegang Ling Sep 2023

Stress-Dependent Petrophysical Properties Of The Bakken Unconventional Petroleum System: Insights From Elastic Wave Velocities And Permeability Measurements, Prasad Pothana, Ghoulem Ifrene, Kegang Ling

Petroleum Engineering Student Publications

The net-effective stress is a fundamental physical property that undergoes dynamic changes in response to variations in pore pressure during production and injection activities. Petrophysical properties, including porosity, permeability, and wave velocities, play a critical role and exhibit strong dependence on the mechanical stress state of the formation. The Williston basin’s Bakken Formation represents a significant reservoir of hydrocarbons within the United States. To investigate this formation, we extracted core plugs from three distinct Bakken members, namely Upper Bakken, Middle Bakken, and Lower Bakken. Subsequently, we conducted a series of measurements of ultrasonic compressional and shear wave velocities, as well …


Experimental Data Supporting Co2 Enhanced Oil Recovery And Storage Potential In The Bakken Petroleum System (Bps), University Of North Dakota. Energy And Environmental Research Center Sep 2023

Experimental Data Supporting Co2 Enhanced Oil Recovery And Storage Potential In The Bakken Petroleum System (Bps), University Of North Dakota. Energy And Environmental Research Center

EERC Brochures and Fact Sheets

Fact sheet on CO2 enhanced oil recovery (EOR) in the Bakken petroleum system. Highlights experimental data concerning CO2’s role in oil recovery in the region.


Optimization Of A Bioreactor, Ali Alshami Aug 2023

Optimization Of A Bioreactor, Ali Alshami

AI Assignment Library

The primary objective of this assignimentis to learn to work effectively as a team, and to design an experiment where optimization is essential.


Investigation Of Cyclic Gaseous Solvent Injection For Enhanced Oil Recovery In Unconventional Formations, Samuel Asante Afari Aug 2023

Investigation Of Cyclic Gaseous Solvent Injection For Enhanced Oil Recovery In Unconventional Formations, Samuel Asante Afari

Theses and Dissertations

Unconventional resources have been known to hold vast quantities of hydrocarbons. However, exploiting the oil and gas they hold was previously challenging due to their low permeabilities. Recent advances in horizontal well drilling and hydraulic fracturing have enabled oil and gas production from these reservoirs, leading to significant increases in energy supply to meet the growing energy demand. However, despite the relative technological success, considerable obstacles persist; oil production from unconventional wells often declines by more than 20% of their initial production rate within the first two years, leaving significant volumes of residual oil trapped in the formations. This overarching …


Comparing Fishbone Drilling And Hydraulic Fracturing In Ultra-Low Permeability Geothermal Reservoirs, Aimene Aihar, Nassim Bouabdallah, Ghoulem Ifrene, Doina Irofti Jul 2023

Comparing Fishbone Drilling And Hydraulic Fracturing In Ultra-Low Permeability Geothermal Reservoirs, Aimene Aihar, Nassim Bouabdallah, Ghoulem Ifrene, Doina Irofti

Petroleum Engineering Posters and Presentations

Harnessing geothermal energy through Enhanced Geothermal Systems (EGS) offers a sustainable and renewable means of tapping the Earth's subsurface heat. However, in ultra-low permeability formations like those found in the Williston Basin, the effectiveness of conventional hydraulic fracturing techniques is limited. This study evaluates the potential of fishbone drilling technology as an alternative approach, focusing on the efficiency and engineering aspects of both methods in the context of geothermal reservoirs with extremely low permeability.

We carried out an extensive literature review, numerical simulations, and case studies to compare fishbone drilling and hydraulic fracturing in EGS applications. Fishbone drilling, which involves …


Evaluation Of Hybrid Prediction Models For Accurate Rate Of Penetration (Rop) Prediction In Drilling Operations, Abdelhakim Khouissat, Mohamed Riad Youcefi, Ghoulem Ifrene, Doina Irofti Jul 2023

Evaluation Of Hybrid Prediction Models For Accurate Rate Of Penetration (Rop) Prediction In Drilling Operations, Abdelhakim Khouissat, Mohamed Riad Youcefi, Ghoulem Ifrene, Doina Irofti

Petroleum Engineering Posters and Presentations

The precise prediction of the rate of penetration (ROP) is of utmost importance for optimizing drilling operations and minimizing costs while increasing efficiency. However, the complex and nonlinear nature of the drilling process can pose significant challenges in achieving accurate ROP predictions. To address this challenge, multiple hybrid prediction models have been developed, and their accuracy in ROP prediction has been compared.

To accomplish this objective, we created three different hybrid models, including Artificial Neural Network – Genetic Algorithm (ANN-GA), Artificial Neural Network-Particle Swarm Optimization (ANN-PSO), and Support Vector Regression (SVR) to estimate ROP. These models were trained and tested …


Exploring Underground Hydrogen Storage Options In North Dakota: A Review, Aimen Laalam, Olusegun Stanley Tomomewo Jun 2023

Exploring Underground Hydrogen Storage Options In North Dakota: A Review, Aimen Laalam, Olusegun Stanley Tomomewo

Petroleum Engineering Posters and Presentations

As the world shifts towards a low-carbon future, the demand for efficient, safe, and cost-effective energy storage solutions has become increasingly critical. Hydrogen has emerged as a promising energy carrier with numerous advantages, such as high energy density, zero emission combustion, and versatile applications. Nevertheless, the challenge of effective hydrogen storage remains. This study examines the potential of underground hydrogen storage (UHS) in North Dakota, assessing its opportunities and challenges in supporting the region's renewable energy objectives. North Dakota's unique geological features, abundant renewable energy resources, and growing energy demands make it an ideal location for UHS implementation. This review …


Advancing Our Understanding Of Non-Linear Flow Behavior In X-Crossing Fractures Through 3d Printing Technology, Ghoulem Ifrene, Sven Egenhoff, Doina Irofti, Nicholas Bittner, Tyler Newman Jun 2023

Advancing Our Understanding Of Non-Linear Flow Behavior In X-Crossing Fractures Through 3d Printing Technology, Ghoulem Ifrene, Sven Egenhoff, Doina Irofti, Nicholas Bittner, Tyler Newman

Petroleum Engineering Posters and Presentations

Fractured reservoir systems play a critical role in the efficient management of hydrocarbon resources, CO2 storage, and geothermal energy extraction. Understanding the behavior and characteristics of these systems is essential for optimizing recovery, reducing carbon footprint, and increasing efficiency. However, fractures within reservoir systems create complex geometries and can make fluid flow behavior complex and difficult to predict. Replicating these complex geometries in the laboratory has been challenging, but advancements in 3D printing technology have made it possible to create accurate models of rough-walled fracture geometries. In this study, the impact of geometric characteristics on fluid flow behavior in connected …


Design And Performance Analysis Of Dry Gas Fishbone Wells For Lower Carbon Footprint, Habib Ouadi, Aimen Laalam, Amjed Hassan, Abderraouf Chemmakh, Vamegh Rasouli, Mohamed Mahmoud Feb 2023

Design And Performance Analysis Of Dry Gas Fishbone Wells For Lower Carbon Footprint, Habib Ouadi, Aimen Laalam, Amjed Hassan, Abderraouf Chemmakh, Vamegh Rasouli, Mohamed Mahmoud

Petroleum Engineering Student Publications

Multilateral well drilling technology has recently assisted the drilling industry in improving borehole contact area and reducing operation time, while maintaining a competitive cost. The most advanced multilateral well drilling method is Fishbone drilling (FbD). This method has been utilized in several hydrocarbon fields worldwide, resulting in high recovery enhancement and reduced carbon emissions from drilling. FbD involves drilling several branches from laterals and can be considered as an alternative method to hydraulic fracturing to increase the stimulated reservoir volume. However, the expected productivity of applying a Fishbone well from one field to another can vary due to various challenges …


Evaluation Of Liquid Loading In Gas Wells Using Machine Learning, Abderraouf Chemmakh, Olusegun Stanley Tomomewo, Kegang Ling, Ahmed Shammari Feb 2023

Evaluation Of Liquid Loading In Gas Wells Using Machine Learning, Abderraouf Chemmakh, Olusegun Stanley Tomomewo, Kegang Ling, Ahmed Shammari

Petroleum Engineering Student Publications

The inevitable result that gas wells witness during their life production is the liquid loading problem. The liquids that come with gas block the production tubing if the gas velocity supplied by the reservoir pressure is not enough to carry them to surface. Researchers used different theories to solve the problem naming, droplet fallback theory, liquid film reversal theory, characteristic velocity, transient simulations, and others. While there is no definitive answer on what theory is the most valid or the one that performs the best in all cases. This paper comes to involve a different approach, a combination between physics-based …


Applications Of Underbalanced Fishbone Drilling For Improved Recovery And Reduced Carbon Footprint In Unconventional Plays, Habib Ouadi, Siamak Mishani, Vamegh Rasouli Feb 2023

Applications Of Underbalanced Fishbone Drilling For Improved Recovery And Reduced Carbon Footprint In Unconventional Plays, Habib Ouadi, Siamak Mishani, Vamegh Rasouli

Petroleum Engineering Student Publications

Fishbone Drilling (FbD) consists of drilling several micro-holes in different directions from the main vertical or deviated wellbore. Similar to multilateral micro-hole drilling, FbD may be used to enhance hydrocarbon production in naturally fractured formations or in refracturing operations by interconnecting the existing natural fractures. When combined with underbalanced drilling using a coiled tubing rig, FbD enhances the production further by easing the natural flow of the hydrocarbon from the reservoir to the wellbore. The design aspects of the Fishbones include determining the number, length, distance between the branches, and the angle of sidetracking of the branches from the main …


Synthesis And Evaluation Of A Novel Polyacrylamide Functionalized Nano-Silica As A Calcium Carbonate Inhibitor In Upstream Applications, Nadhem Ismail, Ali Alshami, Ibnelwaleed A. Hussein Feb 2022

Synthesis And Evaluation Of A Novel Polyacrylamide Functionalized Nano-Silica As A Calcium Carbonate Inhibitor In Upstream Applications, Nadhem Ismail, Ali Alshami, Ibnelwaleed A. Hussein

Chemical Engineering Faculty Publications

Calcium carbonate scale forms in production and injection wells, precipitating upon pressure and temperature changes, incompatible water mixing, and dehydration. Production shutdown is one of the most dramatic consequences caused by calcium carbonate scale formation. We synthesized, characterized, and tested a polyacrylamide functionalized nano-silica (PAM-SiO2NPs) inhibitor that prevents calcium carbonate formation at high temperatures and high brine. Positive compatibility results were confirmed before the inhibition efficiency test, whereby the efficiency was calculated by quantifying the calcium ions left in solution using ICP-OES. The inhibitor was effective at temperatures of 40, 60, and 80 °C, with pH values of …


Comparative Scoping Study Report For The Extraction Of Microalgae Oils From Two Subspecies Of Chlorella Vulgaris, Jasmine Kreft, Eric Moe, Nicholas Garcia, Andrew Ross, Wayne Seames Jan 2020

Comparative Scoping Study Report For The Extraction Of Microalgae Oils From Two Subspecies Of Chlorella Vulgaris, Jasmine Kreft, Eric Moe, Nicholas Garcia, Andrew Ross, Wayne Seames

Chemistry Faculty Publications

The production of microalgae as a fatty acid oil resource for use in biofuels production is a widespread research topic at the lab scale. Microalgae contain a higher lipid content on a dry-weight basis compared to oilseeds such as soybeans. Additionally, the growth and cultivation cycle of microalgae is 15 days, in comparison to soybeans, for which the cycle occurs once or twice annually. However, to date, it has been uneconomical to produce microalgae oils in a world-scale facility due to limitations in cultivating microalgae at commercial scales. Recent developments suggest that the use of heterotrophic microalgae may be economically …


Exploring Large Pore Size Alumina And Silica-Alumina Based Catalysts For Decomposition Of Lignin, Sara Pourjafar, Jasmine Kreft, Honza Bilek, Evguenii Kozliak, Wayne Seames Dec 2018

Exploring Large Pore Size Alumina And Silica-Alumina Based Catalysts For Decomposition Of Lignin, Sara Pourjafar, Jasmine Kreft, Honza Bilek, Evguenii Kozliak, Wayne Seames

Chemical Engineering Faculty Publications

Evaluation of copper doped silica-alumina and γ-alumina catalysts for lignin decomposition was conducted using a suite of chemical analysis protocols that enabled a comprehensive characterization of the reaction product. X-ray diffraction analysis was used to verify the concentration of doped copper on catalyst supports. Then, batch experiments were performed to study the significance of catalyst support type, catalyst dopant concentration, lignin concentration, catalyst-to-lignin ratio, reactor stirring rate and reaction time. Aqueous products were extracted with dichloromethane and analyzed using a detailed gas chromatography-mass spectrophotometry analytical protocol, allowing for quantification of over 20 compounds. Solid residues were analyzed by thermogravimetric analysis …


Foam Materials With Controllable Pore Structure Prepared From Nanofibrillated Cellulose With Addition Of Alcohols, Jinbao Li, Te Song, Huijuan Xiu, Meiyun Zhang, Rui Cheng, Qiang Liu, Xuefei Zhang, Evguenii Kozliak, Yun Ji Dec 2018

Foam Materials With Controllable Pore Structure Prepared From Nanofibrillated Cellulose With Addition Of Alcohols, Jinbao Li, Te Song, Huijuan Xiu, Meiyun Zhang, Rui Cheng, Qiang Liu, Xuefei Zhang, Evguenii Kozliak, Yun Ji

Chemical Engineering Faculty Publications

Low-density foams based on nanofibrillated cellulose (NFC) made from Pinus massonianesoftwood pulp were prepared from NFC aqueous suspensions containing one of four C2–C4alcohols followed by freeze-drying, with the goal of controlling their pore structure and reducing the shrink rate. The foams prepared from NFC suspensions containing ethanol, isopropanol and n-butanol exhibited highly porous structures with a honeycomb-like cellular texture featuring well-defined “cell walls” between the layers. By contrast, the tert-butanol/NFC foam featured a higher number of smaller size pores with irregular shape. The foams prepared by freezing at −196 °C with ethanol also revealed small size pores, with no layered …


The Aromatization Of Propene Via Nano-Size Hzsm-5, Wayne Seames, Swapnil Fegade, Inna Sakodynskaya, Darrin Muggli, Brian Tande, Alena Kubatova, Evguenii Kozliak Oct 2018

The Aromatization Of Propene Via Nano-Size Hzsm-5, Wayne Seames, Swapnil Fegade, Inna Sakodynskaya, Darrin Muggli, Brian Tande, Alena Kubatova, Evguenii Kozliak

Chemistry Faculty Publications

Zeolite (ZSM) catalysts are known to convert small-size alkenes, e.g., propene, into aromatic hydrocarbons, specifically benzene, toluene and xylenes (BTX), with both high efficiency and specificity. The efficiency of conventional and hierarchical nano-size ZSM-5 for propene aromatization was compared in this study using a Design of Experiments (DOE) approach combined with detailed product analysis. Contrary to our expectations, the former showed a significantly greater BTX yield than the latter. Analysis of the obtained data by DOE and additional experiments with soybean oil cracking using both catalyst types indicated that a reason for the observed reduced activity of nano-scale zeolites may …


An Initial Study Of The Catalytic Reforming Of Crop Oil‐Derived 1‐Alkenes With Hzsm‐5 To Aromatic Hydrocarbons, Shelby Amsley‐Benzie, Swapnil Fegade, Brian Tande, Alena Kubotava, Evguenii Kozliak, Wayne Seames Aug 2018

An Initial Study Of The Catalytic Reforming Of Crop Oil‐Derived 1‐Alkenes With Hzsm‐5 To Aromatic Hydrocarbons, Shelby Amsley‐Benzie, Swapnil Fegade, Brian Tande, Alena Kubotava, Evguenii Kozliak, Wayne Seames

Chemical Engineering Faculty Publications

This study explored the production of aromatic hydrocarbons from the longer‐chain alkenes produced by the pyrolysis/cracking of crop oils. 1‐Tetradecene, serving as a model compound for these alkenes, was reformed in a batch reactor with a HZSM‐5 catalyst to produce a liquid hydrocarbon mixture with a high‐aromatic content. These reactions resulted in a >99% conversion of the 1‐tetradecene feedstock with a yield of up to 22 wt% of aromatic hydrocarbons. Surprisingly, isomers of C3‐substituted benzenes along with xylenes and diaromatics (lower homologs of alkyl‐substituted indanes and naphthalenes) were the main aromatic products rather than their lower‐molecular‐weight (MW) homologs, benzene, toluene, …


Kinetic Modelling And Experimental Studies For The Effects Of Fe2+ Ions On Xylan Hydrolysis With Dilute-Acid Pretreatment And Subsequent Enzymatic Hydrolysis, Hui Wei, Xiaowen Chen, Joseph Shekiro, Erik Kuhn, Wei Wang, Yun Ji, Evguenii Kozliak, Michael E. Himmel, Melvin P. Tucker Jan 2018

Kinetic Modelling And Experimental Studies For The Effects Of Fe2+ Ions On Xylan Hydrolysis With Dilute-Acid Pretreatment And Subsequent Enzymatic Hydrolysis, Hui Wei, Xiaowen Chen, Joseph Shekiro, Erik Kuhn, Wei Wang, Yun Ji, Evguenii Kozliak, Michael E. Himmel, Melvin P. Tucker

Chemical Engineering Faculty Publications

High-temperature (150–170 °C) pretreatment of lignocellulosic biomass with mineral acids is well established for xylan breakdown. Fe2+ is known to be a cocatalyst of this process although kinetics of its action remains unknown. The present work addresses the effect of ferrous ion concentration on sugar yield and degradation product formation from corn stover for the entire two-step treatment, including the subsequent enzymatic cellulose hydrolysis. The feedstock was impregnated with 0.5% acid and 0.75 mM iron cocatalyst, which was found to be optimal in preliminary experiments. The detailed kinetic data of acid pretreatment, with and without iron, was satisfactorily modelled …


Fiber Evolution During Alkaline Treatment And Its Impact On Handsheet Properties, Yun Ji, Yangyang Peng, Anders Strand, Shiyu Fu, Anna Sundberg, Elias Antero Retulainen Jan 2018

Fiber Evolution During Alkaline Treatment And Its Impact On Handsheet Properties, Yun Ji, Yangyang Peng, Anders Strand, Shiyu Fu, Anna Sundberg, Elias Antero Retulainen

Chemical Engineering Faculty Publications

To understand the swelling effects of alkaline treatment on the morphological properties of fibers and physical properties of handsheets, bleached softwood kraft pulp was treated with NaOH at different concentrations. The results showed that the fiber swelling increased, but the shrinkage and elongation of the paper at a NaOH concentration of 6% or higher did not improve. Dissolution of amorphous material occurred during the treatment together with peeling reactions. The fiber length and shape factor decreased and the fines content increased with an increasing alkali concentration. The cellulose crystallinity decreased with an increasing NaOH concentration. This was confirmed by X-ray …


High Octane Gasoline Using Renewable Aromatic Hydrocarbons, Wayne Seames, Malhar Khambete, Nahid Khatibi, Shelby Amsley-Benzie, Evguenii Kozliak, Darrin Muggli, Brian Tande Oct 2017

High Octane Gasoline Using Renewable Aromatic Hydrocarbons, Wayne Seames, Malhar Khambete, Nahid Khatibi, Shelby Amsley-Benzie, Evguenii Kozliak, Darrin Muggli, Brian Tande

Chemical Engineering Faculty Publications

Background:

The replacement of leaded high octane aviation gasoline with an unleaded renewable alternative would decrease the emissions of lead and fossil-derived carbon into the atmosphere. Replacement has been limited by the requirement of a very high octane number in many existing general aviation aircraft engines.

Method:

Two separate process pathways were developed that generate an unleaded octane fuel with a motor octane number >96 from triglyceride oils (TGs), such as crop oils and algae oil. A series of experiments coupled with process simulations was used to verify the feasibility of both pathways and to provide preliminary laboratory scale data …


Production Of Mesophase Pitch From Gasified Lignin-Derived Tars, Adedayo O. Idowu May 2017

Production Of Mesophase Pitch From Gasified Lignin-Derived Tars, Adedayo O. Idowu

Theses and Dissertations

Lignin tars are created as a by-product of lignin gasification. Significant effort has gone into minimizing tar production. However, no process has been shown to completely eliminate its formation. As a result, the tar is being used to manufacture low value products such as asphalt, or is being used as a fuel in fixed combustion systems.

The research presented here is part of an effort to increase the viability of using lignocellulosic biomass as a feedstock to produce high value products. We tested the postulate that tars derived from lignin could be processed into a mesophase pitch allowable for conversion …


Development And Validation Of A Kinetic Model For Enzymatic Hydrolysis Using Candida Rugosa Lipase, Ammar Jamie, Ali Alshami, Zuhair O. Maliabari, Muataz A. Ateih Jan 2017

Development And Validation Of A Kinetic Model For Enzymatic Hydrolysis Using Candida Rugosa Lipase, Ammar Jamie, Ali Alshami, Zuhair O. Maliabari, Muataz A. Ateih

Chemical Engineering Faculty Publications

Biochemical processing involving enzymatic catalysis of hydrolysis reactions of oils and fats must overcome significant technological barriers before the full benefits of the technology can be realized. Owing to their selectivity and mild reaction conditions, lipases are becoming increasingly important as biocatalysts provided that their kinetics and optimum reaction conditions are well-understood. In this study we report on the development and validation of a kinetic model for the degradation of oils using Candida rugosa lipase, from which a better understanding of the influence of different reaction conditions on hydrolysis kinetics is elucidated. Variations of reaction temperature, mixing speed, enzyme loading …


Synthesis And Tribological Behavior Of Ultra High Molecular Weight Polyethylene (Uhmwpe)-Lignin Composites, Surojit Gupta, Mohammad F. Riyad, Yun Ji Aug 2016

Synthesis And Tribological Behavior Of Ultra High Molecular Weight Polyethylene (Uhmwpe)-Lignin Composites, Surojit Gupta, Mohammad F. Riyad, Yun Ji

Chemical Engineering Faculty Publications

In this paper, we report the synthesis and characterization of ultra-high molecular weight polyethylene (UHMWPE)-lignin composites. During this study four different compositions, namely UHMWPE, UHMWPE-13 wt. % lignin, UHMWPE-25 wt. % lignin and UHMWPE-42.5 wt. % lignin were fabricated by hot pressing. Detailed microstructural studies by scanning electron microscopy (SEM) showed that UHMWPE and UHMWPE-13 wt. % lignin had a uniform microstructure, whereas UHMWPE-25 wt. % lignin and UHMWPE-42.5 wt. % lignin samples were riddled with pores. UHMWPE and UHMWPE-13% lignin showed comparable flexural strengths of ~32.2 MPa and ~32.4 MPa, respectively. However, the flexural strength dropped drastically in UHMWPE-25 …


Fugitive Emissions, University Of North Dakota. Energy And Environmental Research Center Jul 2016

Fugitive Emissions, University Of North Dakota. Energy And Environmental Research Center

EERC Brochures and Fact Sheets

Fact sheet about fugitive emissions, their causes, and U.S. Environmental Protection Agency (EPA) methods of detection and regulation.


Maximizing Orc Performance With Optimal Match Of Working Fluid With System Design, Kirtipal Barse, Michael Mann May 2016

Maximizing Orc Performance With Optimal Match Of Working Fluid With System Design, Kirtipal Barse, Michael Mann

Chemical Engineering Faculty Publications

This article compares constrained system design to non-constrained system design for the basic Organic Rankine Cycle (ORC). The 12 working fluids studied include eight dry-type, three isentropic, and one wet-type fluids. The ORC model was developed using Aspen HYSYS® and validated with data obtained from the literature. The constrained design compared the performance of working fluids for a fixed heat exchanger and turbine configuration. A non-constrained design was studied by altering the design specifications for the heat exchangers and turbine to match the working fluid. An energy and exergy analysis was performed using first and second law efficiency. The exergy …


High Fidelity Chemistry And Radiation Modeling For Oxy-Combustion Scenarios, Hassan A. Abdul Sater Jan 2014

High Fidelity Chemistry And Radiation Modeling For Oxy-Combustion Scenarios, Hassan A. Abdul Sater

Theses and Dissertations

To account for the thermal and chemical effects associated with the high CO2 concentrations in an oxy-combustion atmosphere, several refined gas-phase chemistry and radiative property models have been formulated for laminar to highly turbulent systems. This thesis examines the accuracies of several chemistry and radiative property models employed in computational fluid dynamic (CFD) simulations of laminar to transitional oxy-methane diffusion flames by comparing their predictions against experimental data. Literature review about chemistry and radiation modeling in oxy-combustion atmospheres considered turbulent systems where the predictions are impacted by the interplay and accuracies of the turbulence, radiation and chemistry models. Thus, …


A Structural Study Of Some (H6-Arene)Ml2, First Row, Group Viii, Transition Metal Complexes And Their Derivatives, Stuart Kevin Janikowski Aug 1985

A Structural Study Of Some (H6-Arene)Ml2, First Row, Group Viii, Transition Metal Complexes And Their Derivatives, Stuart Kevin Janikowski

Theses and Dissertations

The structures of five organonickel compounds were determined using x-ray diffraction techniques. This study was conducted to ascertain the relationships between the compound's structures, bonding, and chemical properties. The first structural evidence for discrete complexes containing Ni-SiX3 bonds is (h6-mesitylene)Ni(SiCl3)2 and presented. The compounds (h6-toluene)Ni(SiF3)2, crystallize in space group P21/c with Z = 2. The lattice constants at 23° C are: a = 9.056(2), b = 14.426(1), c = 13. 3 0 3 ( 2) ~, {J = 10 0. 6 9 ( 1 )0 , and a = 11. 3 5 5 ( 3) , b = 11.268(4), c …