Chemical Engineering Commons^™

Leveraging Oxygen Mobility With Zirconia In Low-Temperature Plasma For Enhanced Methane Reforming To Syngas, Fnu Gorky, Levy Pile, Grace Jones, Apolo Nambo, Mourad Benamara, Maria L. Carreon

Chemical Engineering Faculty Publications and Presentations

Despite extensive efforts to optimize the single-step production of syngas, hydrocarbons, and oxygenates via plasma catalysis, several challenges remain unresolved. In particular, understanding the various reaction pathways is hindered by the complexity of the reactions and the diverse range of chemical products formed. In this study, our main objective is to evaluate and compare the influence of zirconia on reaction pathways, methane (CH4) and carbon dioxide (CO2) conversions (%), and syngas selectivity (%) relative to the plasma-only route. Experiments were conducted at a low radio-frequency plasma power of 50 Watts without external heating. The results demonstrated significantly enhanced conversions of …

A Comparative Techno-Economic Analysis Of Aqueous And Anhydrous Hcl Electrolysis Processes, O. Felix, K. Likit-Anurak, K. Ngamsanroaj, Sirivatch Shimpalee, Ben Meekins

Faculty Publications

The state-of-the-art aqueous HCl electrolysis process is a well-established process for chlorine production but faces challenges such as limited conversion efficiencies, corrosion, and additional pre- and post-electrolyzer processing steps that add to its cost. This study evaluates whether a recently demonstrated anhydrous HCl electrolysis process is more economically viable than the state-of-the-art aqueous process. A 1D electrolyzer model was developed using Aspen Custom Modeler® and integrated into Aspen Plus® for process modeling. Multiple conversion efficiencies (30.5 %, 50 %, 80 %, and 93.4 %) were analyzed for the anhydrous process, with various heat recovery and heat exchanger configurations assessed using …

Electrochemical Investigation Of Moisture Byproducts In Molten Calcium Chloride, Rankin Shum, Marah Gragun, Tyler Williams, Devin Rappleye

Faculty Publications

Residual water in molten CaCl₂ reacts to form different byproducts, such as HCl, which can impact the corrosivity of the salt and efficiency of electrochemical operations, such as electrolytic oxide reduction and electrorefining. The ability to detect and quantify these byproducts electrochemically can provide feedback on the efficacy of vacuum drying and other purification methods, as well as the impact of these byproducts on process operations. An electrochemical signal’s association with the production of H₂ is verified and characterized using cyclic voltammetry (CV) and residual gas analysis. CV estimated a 2-electron exchange process associated with H2 production. CV …

The Reversal Of Carbonate Wettability Via Alumina Nanofluids: Implications For Hydrogen Geological Storage, Amer Alanazi, Mujahid Ali, Muhammad Ali, Alireza Keshavarz, Stefan Iglauer, Hussein Hoteit

Research outputs 2022 to 2026

Underground hydrogen storage (UHS) has been recognized as a key enabler of the industrial-scale implementation of a hydrogen-based economy. However, the efficiency and storage capacity of hydrogen (H2) in carbonate aquifers can be influenced by the presence of organic acids. Nevertheless, the existing literature contains few investigations of H2/calcite/brine wettability and the influence of organic acids on H2 storability in carbonate reservoirs. Therefore, the present study examines the influence of stearic acid on the dynamic H2/brine wettability of calcite substrates (as a proxy of carbonate formation) under various geological conditions (0.1–20 MPa at 323 K), equilibrated in 10 wt% NaCl …

Applications Of Catalytic Ammonia Chemistry: From Low-Pressure Ammonia Synthesis To The Decomposition Of Tritiated Ammonia As A By-Product Of Magnetically Confined Nuclear Fusion, Jennifer Kules Naglic

Theses and Dissertations

Ammonia is the 2nd most produced chemical in the world with vital importance for its use in fertilizer as the global population has grown in accordance with the industrialization of NH3. While 80% of NH3 produced goes to fertilizer, it has gained attention recently as a hydrogen storage and transportation vessel. Industrially, NH3 is produced at high temperatures and pressures which in turn require high electrical input. Turning to a green NH3 cycle with low temperature and pressure membrane reactors for both NH3 synthesis and decomposition would allow for much lower energy input as well as a renewable energy to …

Maximizing Charge Dynamics In Znin2s4/Cn Van Der Waals Heterojunction For Optimal Hydrogen Production From Photoreforming Of Glucose, Jinqiang Zhang, Xinyuan Xu, Lei Shi, Huayang Zhang, Shaobin Wang, Hongqi Sun

Research outputs 2022 to 2026

Biomass photoreforming stands out as a promising avenue for green hydrogen, leveraging solar energy for the generation and transformation of clean and renewable energy resources. The pursuit of efficient photocatalysts is motivated by the unsatisfied hydrogen evolution performance arising from the complex and stubborn structure of biomass. Herein, we loaded 2-dimensional (2D) ZnIn2S4 onto 2D carbon nitride nanosheets, resulting in the formation of Van der Waals (VDW) heterojunctions (ZIS/CN). Band structure and morphology of CN were rationally tailored through precursor engineering to effectively magnify interfacial internal electric field and minimize diffusion pathway within the VDW heterostructure, realizing optimal charge dynamics …

First Principles Doping Analysis Of Perovskite- And Ruddlesden-Popper-Based Solid Oxide Fuel Cells, Nicholas Alexander Szaro

Theses and Dissertations

Solid oxide fuel cells (SOFCs) have shown significant promise as a high efficiency energy conversion technology. SOFCs are solid-state, high temperature (600 – 1000 °C), and electrochemical conversion devices that can operate with a wide variety of fuels such as hydrogen, syngas, and hydrocarbon feedstocks. The state-of-the-art SOFC is manufactured with a lanthanum strontium manganite (LSM) cathode, an yttria-stabilizedzirconia electrolyte (YSZ), and a nickel on yttria-stabilized-zirconia (Ni/YSZ) cermet anode. LSM || YSZ || Ni/YSZ SOFCs operate at or above 800 °C to achieve sufficient oxide mobility. The high temperatures introduce problems such as long device start-up, particle sintering, and material …

Hydrogen Storage In Depleted Gas Reservoirs: A Comprehensive Review, Nasiru S. Muhammed, Md Bashirul Haq, Dhafer A. Al Shehri, Amir Al-Ahmed, Mohammad M. Rahman, Ehsan Zaman, Stefan Iglauer

Research outputs 2022 to 2026

Hydrogen future depends on large-scale storage, which can be provided by geological formations (such as caverns, aquifers, and depleted oil and gas reservoirs) to handle demand and supply changes, a typical hysteresis of most renewable energy sources. Amongst them, depleted natural gas reservoirs are the most cost-effective and secure solutions due to their wide geographic distribution, proven surface facilities, and less ambiguous site evaluation. They also require less cushion gas as the native residual gases serve as a buffer for pressure maintenance during storage. However, there is a lack of thorough understanding of this technology. This work aims to provide …

Interfacial Tensions Of (Brine + H2 + Co2) Systems At Gas Geo-Storage Conditions, Zoha Dalal Isfehani, Ali Sheidaie, Mirhasan Hosseini, Jalal Fahimpour, Stefan Iglauer, Alireza Keshavarz

Research outputs 2022 to 2026

In hydrogen geological storage, cushion gas has vital role to retain adequate reservoir pressure to keep the hydrogen withdrawal stable. Presence of the cushion gas in the storage reservoir can affect the flow characteristics of hydrogen during injection and production cycles. One of the most crucial parameters that control the fluids flow in porous media is interfacial tension (IFT) between fluids. However, the literature data lacks in terms of IFT between cushion gas mixed with hydrogen and brine at geo-storage conditions. In this study, the pendant drop method was used to measure the IFT of (brine + H₂ + …

Ambient Ammonia Synthesis Via Microwave-Catalytic Materials And Plasma Chemistry, Siobhan Brown

Graduate Theses, Dissertations, and Problem Reports (ETD)

Ammonia is critical to supporting human life on earth because of its use as fertilizer. The Haber-Bosch process to produce ammonia has been practiced for over 100 years. This process operates at high pressure and temperature to overcome the thermodynamic and kinetic limitations of the ammonia synthesis reaction thus researchers have tried to overcome it for decades. At present this process represents 1% of global energy usage and 2.5% of global CO₂ emissions. The proposed chemical looping ammonia synthesis approach seeks to reduce the environmental impact of this critical process and to elucidate microwave-catalytic principles.

This research aims to …

Modular Supply Network Optimization Of Renewable Ammonia And Methanol Co-Production, Benjamin Akoh

Graduate Theses, Dissertations, and Problem Reports (ETD)

To reduce the use of fossil fuels and other carbonaceous fuels, renewable energy sources such as solar, wind, geothermal energy have been suggested to be promising alternative energy that guarantee sustainable and clean environment. However, the availability of renewable energy has been limited due to its dependence on weather and geographical location. This challenge is intended to be solved by the utilization of the renewable energy in the production of chemical energy carriers. Hydrogen has been proposed as a potential renewable energy carrier, however, its chemical instability and high liquefaction energy makes researchers seek for other alternative energy carriers. Ammonia …

Modeling And Performance Analysis Of Deb Based Hydrogen Getters, John A. Matteson

Chemical and Biological Engineering ETDs

Hydrogen getter materials are used to irreversibly absorb hydrogen gas in sealed environments. The DEB based getter system, despite finding widespread use in this application, still posses challenges with respect to experimental performance analysis and fundamental understanding of reaction mechanism. The second chapter of this report addresses the experimental challenges of this getter system by demonstrating the utility and experimental strengths of a custom magnetic suspension balance (MSB) based gravimetric sorption system. This apparatus enables performance evaluation in process relevant conditions including dilute mixed gas environments which our results indicate is necessary for accurate performance evaluation of getter systems. Chapter …

Recovery Of The Recovery Zinc Concentrate In A Weakly Reducing Gas Atmospheric Environment, B T. Berdiyarov, S T. Matkarimov, J B. Ismailov

Technical science and innovation

This article provides information on the formation of substances resulting from the roasting of sulfide-zinc concentrates, which negatively affects the course of subsequent stages. The resulting calcine was sent for reduction roasting in a weakly reducing inert gas atmosphere. Based on this, it can be assumed that the impact on the calcine of "weak" energetic inert gases the reduce minimises or formation of ferrites and zinc silicates. Since the principal primary using agent is gaseous H₂, (hydrogen) in a mixture of gases with a weak reducing environment, all redox reactions occurring in total reduction were studied. The course …

Materials And Interfaces For Electrocatalytic Hydrogen Production And Utilization., Alexander Jiya Gupta

Electronic Theses and Dissertations

Mass industrialization over the last few centuries has created a global economy which is dependent upon fossil fuels to satisfy an exponentially increasing demand for energy. Aside from the possible depletion of this finite resource, the combustion of fossil fuels releases greenhouse gases into the atmosphere which cause the global temperature to rise – a phenomenon which has already begun to create geologic and geopolitical instability and shows no signs of abatement. One proposed method to rid humanity of its dependence on fossil fuels is to use green hydrogen as an energy carrier. In this scheme, excess electricity from a …

Koh Vs Deionized Water Operation In Anion Exchange Membrane Electrolyzers, Noor Ul Hassan, Yiwei Zheng, Paul A. Kohl, Mustain E. William

Faculty Publications

Anion exchange membrane water electrolyzers (AEMELs) have recently received significant attention due to their potential advantages over proton exchange membrane electrolyzers (PEMELs). However, some AEMELs feed an aqueous salt solution to the cell where PEMELs typically feed deionized (DI) water. DI water is preferred to keep the system and maintenance costs low. Because of this, many AEMEL researchers report performance both in the salt solution (typically KOH) and DI water. However, the methodology for switching between KOH and DI water is often poorly defined, and it is unclear what impact the residual salt has on cell performance after switching from …

Kinetics Of Photolysis And Photocatalytic Oxidation Of Ammonium Sulfite For Hydrogen Production, Moustafa A. Soliman, Maryam Zakaria

Chemical Engineering

The production of hydrogen via photocatalytic water splitting is one of the most promising technologies for obtaining chemical energy from direct solar energy while maintaining the least possible waste and pollutants. In this paper, we obtain the kinetic parameters necessary for the design of a photoreactor for photolysis and photocatalysis of ammonium sulfite solution. For the case of photolysis, we obtain the kinetics for the effect of changing the pH on the produced amount of hydrogen. For the case of photocatalysis, the intrinsic kinetic parameters of photocatalysis of water splitting reaction of ammonium sulfite and water in the presence of …

Development Of Novel Catalysts For Hydrogen Gas Production From Biomass Compounds, Boanerges Bamaca

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

Hydrothermal biomass gasification technologies (sub- and supercritical water gasification and aqueous-phase reforming) have considerable economic, environmental, and technical advantages over other energy-extensive technologies (e.g. natural gas reforming) for hydrogen gas production. However, lack of economically feasible and highly active catalysts is a main challenge that impedes upscaling of these technologies for hydrogen gas production.

The goal of this study was to develop innovative, economically feasible and active heterogeneous supported metal catalysts for hydrothermal processes for producing hydrogen gas from biomass-derived compounds. Because of its stable structure and chemical inertness, graphene was used as catalyst support. Graphene supported metal catalysts were …

Enhancement Of Graphene Biocompatibility As A Potential Nano-Carrier For Drug Delivery Applications Using Natural Deep Eutectic Solvent, Zainal Abidin Mohamad Hamdi

Student Works (2020-2029)

Graphene has attracted massive interest in numerous biomedical applications such as anti-cancer therapy, drug delivery, bio-imaging and gene delivery. Therefore, it is important to ensure that graphene is nontoxic, and that its cellular biological behavior is safe and biocompatible. Herein, a new route was used to enhance the biocompatibility of graphene as a nano-carrier for potential drug delivery applications, using different compositions of natural deep eutectic solvents (DESs) as functionalizing agents, owing to their capability to introduce various functional groups and surface modifications. To meet this end, eight different combinations of binary and ternary DESs were synthesized using choline chloride …

The Artificial Leaf: An Investigation Into The Sociotechnical Integration Of New Solar Energy Innovations, Alexandra K. Treml, Jamie M. Mears

Senior Honors Projects, 2020-current

Increasing global demand, combined with the volatility of fossil fuels, has called for a large-scale increase in renewable energy production. Photovoltaics hold significant potential, but by nature, solar energy is intermittent and lacks dispatchability. Researchers around the world are working to create innovative solutions that utilize semiconductors found in solar cell technologies in new ways. This project harnesses photoelectrochemical water-splitting, which uses light energy to dissociate water molecules into hydrogen and oxygen. When the water-splitting device is submerged in saltwater and illuminated by sunlight, oxygen and hydrogen gas are produced on opposite surfaces, and can be either released or stored …

Process Intensification Of Fuel Synthesis And Electrolysis, Jeremy Lee Hartvigsen

Doctoral Dissertations

”As more renewable energy is added to the electric grid, energy storage becomes a high priority. Suggestions have been made for energy storage in the form of fuel and chemicals. Currently, Solid Oxide Electrolysis systems can operate in endothermic mode and reduce the electrical requirement by supplying heat. Fuel synthesis from syngas is exothermic and can supply heat. However, the temperature mismatch in the normal operation of the electrolysis step and fuel synthesis step makes the direct utilization of this heat impossible. This work explores possibilities of alternate arrangements of coupling electrochemical systems and chemical synthesis. This work also explores …

Synthesis, Characterization, And Evaluation Of Metal Complexes With Cancer Selective Anti-Proliferative Effects And Hydrogen Evolution Catalytic Properties., Nicholas Vishnosky

Electronic Theses and Dissertations

Bis-thiosemicarbazones (BTSC) and their metal chelates have properties that are useful in several different scientific fields. These systems have already received attention in major fields of biology and engineering. Hydrogen evolution reaction (HER) catalysts need to be cheap and operate under minimal overpotentials with a long lifetime. The treatment of cancer requires, novel agents that have potent cytotoxic activity against cancer cells while displaying minimal side effects. In this dissertation the modular synthesis of these bis-thiosemicarbazone systems is utilized to regulate the redox chemistry for employment in the desired sector of chemistry. The ligand and metal chelates synthesized were characterized …

Improving The Distribution And Use Of Biogas By Conversion To Methanol, Zachary Christman

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

In this technology review, the process of turning an average biogas into methanol will be presented. The purpose is to find a better method of transporting the energy contained within biogas so that it may be used in industry as a value added product. The first step is removal of hydrogen sulfide, a corrosive chemical that can breakdown mechanical parts. The second step is carbon capture and conversion of the biogas into hydrogen. The final step is the hydrogenation of carbon dioxide into methanol using a copper catalyst and an alcohol co-catalyst.

Targeted Illumination Strategies For Hydrogen Production From Purple Non-Sulfur Bacteria, John D. Craven

Theses and Dissertations--Chemical and Materials Engineering

The movement towards a more sustainable energy economy may require not only the generation of cleaner fuel sources, but the conversion of waste streams into value-added products. Phototrophic purple non-sulfur bacteria are capable of metabolizing VFAs (volatile fatty acids)and generate hydrogen as a byproduct of nitrogen fixation using energy absorbed from light. VFAs are easily produced from dark anaerobic fermentation of food, agricultural, and municipal wastes, which could then be fed into photobioreactors of purple bacteria for hydrogen production.

The process of photofermentation by purple bacteria for hydrogen production remains attractive due to the capability of reaching high substrate conversions …

Uncoupling Fermentative Synthesis Of Molecular Hydrogen From Biomass Formation In Thermotoga Maritima, Raghuveer Singh, Derrick White, Yaşar Demirel, Robert Kelley, Kenneth Noll, Paul H. Blum

Department of Chemical and Biomolecular Engineering: Faculty Publications

When carbohydrates are fermented by the hyperthermophilic anaerobe Thermotoga maritima, molecular hydrogen (H₂) is formed in strict proportion to substrate availability. Excretion of the organic acids acetate and lactate provide an additional sink for removal of excess reductant. However, mechanisms controlling energy management of these metabolic pathways are largely unexplored. To investigate this topic, transient gene inactivation was used to block lactate production as a strategy to produce spontaneous mutant cell lines that overproduced H₂ through mutation of unpredicted genetic targets. Single-crossover homologous chromosomal recombination was used to disrupt lactate dehydrogenase (encoded by ldh) with …

Oxygen/Steam Charcoal Gasification In A Fluidized Alumina Bed, Rui Moreira, Rui Vaz, António Portugal, Noemí Gil-Lalaguna, Fernando Bimbela, José Luis Sánchez

5th International Congress on Green Process Engineering (GPE 2016)

Mixtures of oxygen and steam were used as gasifying agents to produce a gas stream with high hydrogen content. The effects of the equivalence ratio (ER) and steam to carbon ratio (S/C) on gasification performance were studied at 900 ºC. The highest hydrogen yield (0.412 Nm³/kg charcoal) and apparent energy efficiency (33.43%) were achieved using a mixture that had a S/C ratio of 0.625 and an ER equal to 0.3 (pure oxygen). The results showed that the carbon conversion improved when the ER and the S/C ratio were augmented, and that the production of tars increased when the …

Hybrid Sulfur Process For Solar Production Of Hydrogen, John Jacob Isenhower, Katherine Cross Henderson, Nicholas Joseph Eigenbrot

Senior Theses

Lowering dependence on fossil-based fuels has become a major area of focus in research, especially in transportation fuels. One particularly interesting field is that of hydrogen production. Hydrogen is promising because it has the potential to emit no greenhouse gases when used as fuel and is an excellent vessel for energy storage. Because traditional methods for its generation are inefficient and require nonrenewable fuel use, researchers have begun to focus on thermochemical cycles.

Thermochemical cycles are systems that require heat transfer intrinsically and do not consume fossil fuels nor emit greenhouse gases if renewable energy is used for heating. The …

Pathways To Ultra-Low Platinum Group Metal Catalyst Loading In Proton Exchange Membrane Electrolyzers, Julie N. Renner

Faculty Scholarship

Hydrogen is one of the world's most important chemicals, with global production of about 50 billion kg/year. Currently, hydrogen is mainly produced from fossil fuels such as natural gas and coal, producing CO2. Water electrolysis is a promising technology for fossil-free, CO2-free hydrogen production. Proton exchange membrane (PEM)-based water electrolysis also eliminates the need for caustic electrolyte, and has been proven at megawatt scale. However, a major cost driver is the electrode, specifically the cost of electrocatalysts used to improve the reaction efficiency, which are applied at high loadings (>3 mg/cm2 total platinum group metal (PGM) content). Core-shell catalysts …

Effect Of Ce And Co Addition To Fe/Al2o3 For Catalytic Methane Decomposition, Ahmed S. Al-Fatesh, Ashraf Amin, Ahmed A. Ibrahim, Wasim Ullah Khan, Moustafa A. Soliman, Raja L. Al-Otaibi, Anis H. Fakeeha

Chemical Engineering

Catalytic methane decomposition is studied in a fixed bed reactor. Two sets of bimetallic catalysts are employed, namely: 30%Fe-X%Ce/Al2O3 and 30%Fe-X%Co/Al2O3, and compared with monometallic 30%Fe/Al2O3 catalyst. The effect of promoting Fe with Ce and Co and reduction temperature are investigated. The results reveal that Ce addition has shown a negative impact on H2 yield while a positive effect on H2 yield and catalyst stability are observed with Co addition. In terms of number of moles of produced hydrogen per active sites, Fe/Al2O3 has shown a higher number of moles of hydrogen compared to bimetallic catalysts. The catalyst reduced at …

Synthesis, Characterisation, Electrochemical, And Spectroscopic Studies Of Cobaloximes: Unique Clues Of Cobalt(I) Species In Various Solvents, Michael John Celestine

Chemistry & Biochemistry Theses & Dissertations

With the dwindling amount of fossil fuels in the world’s reserve is said to run out in the future. The use of alternative fuels such as hydrogen can be produced from renewable sources. One source is the use of first row transition metal complexes that can harness the power of the sun to reduce protons to hydrogen. In this thesis we investigated a well-known hydrogen evolution catalyst in a quest to understand the behavior of different oxidation states that occur during the catalytic cycle.

In an attempt to synthesize a binuclear ruthenium(II) complex, [{Ru(phen)2}2{µmes(1,4-phO-Izphen)3}](PF6)4, as a possible photosensitizer for the …

Alumina Supported Iron Catalyst For Hydrogen Production: Calcination Study, Anis H. Fakeeha, Wasim Ullah Khan, Ahmed A. Ibrahim, Raja L. Al-Otaibi, Ahmed S. Al-Fatesh, Moustafa A. Soliman, Ahmed E. Abasaeed

Chemical Engineering

Production of clean hydrogen from thermal decomposition of methane was studied over impregnated 30%Fe/Al2O3 catalysts in a micro-activity fixed-bed reactor. The reactant gases comprising CH4 and N2 in the ratio of 1.5 to 1 were passed through reactor at a flow rate of 25 mL/min. Moreover, effect of calcination was investigated as well. The catalytic activity results indicated that calcination temperature had a significant impact on the performance of 30%Fe/Al2O3 catalyst. The catalyst calcined at 450°C, having CH4 conversion as well as H2 yield over 70%, showed better activity as compared to all other calcination temperatures.