Natalie Beasley, Samuel Bunch and Kailee Lavigne
Dr. Yang Xiao
Louisiana power plants produce substantial quantities of waste gases, including carbon dioxide. In this project, we were tasked with capturing carbon dioxide from the flue gas of a power plant and converting it into a valuable chemical feedstock for further industrial use, while simultaneously reducing emissions. To ground the analysis in a realistic case study, operating data from the Hargis–Hebert Electric Generating Plant in Lafayette Parish were used as the basis for the feed stream. Carbon dioxide is captured from the flue gas using the weak-base solvent methyldiethanolamine (MDEA) and recovered as a purified CO₂ stream. The recovered carbon dioxide is subsequently converted to methanol via catalytic hydrogenation in a plug flow reactor. The overall process therefore consists of three major sections: CO₂ capture and recovery, catalytic conversion of CO₂ to methanol, and downstream methanol purification. The process is designed to achieve approximately 99% carbon dioxide recovery and a high overall conversion of CO₂ to methanol, demonstrating a potential pathway for transforming power-plant emissions into valuable chemical products.
Caleb Aillet, Randie Arinder and Ethan Englert
Dr. Yang Xiao
Carbon emissions from natural-gas-fired power plants remain a major contributor to greenhouse gases, requiring scalable mitigation strategies that preserve existing infrastructure. Integrating carbon capture with methanol synthesis offers both environmental and economic benefits. Post-combustion CO₂ capture is energy-intensive and costly, especially for dilute flue gas such as that from the Hargis-Hebert Electric Generating Plant. This project evaluates whether CO₂ can be efficiently captured using MDEA and converted into methanol to offset operational costs. Aspen Plus was used to simulate an MDEA absorber–stripper system (ELECNRTL model) operating at 1–2 bar. Captured CO₂ (>98% purity) was fed to a fixed-bed reactor modeled at 250°C and 50 bar with 75% conversion using a Cu/ZnO/ZrO₂ catalyst. Mass and energy balances were verified across all units. From 2,928 kg/hr CO₂ emissions, 75% conversion yielded 1,233.85 kg/hr methanol with a 2,348.9 kW reactor heat duty. The integrated system demonstrates technical feasibility and economic potential, supporting scalable carbon utilization and future optimization of reactor design and energy integration.
Austin DeLee, Janae Dotson and Cameron Leonard
Dr. Yang Xiao
Reducing carbon dioxide (CO2) emissions while producing value-added chemicals is an
important objective in modern chemical engineering. This project investigates an integrated
carbon capture and utilization process designed to capture CO2 from post-combustion
flue gas and convert it into methanol, a widely used chemical feedstock. The work
evaluates the feasibility of coupling CO2 capture and catalytic conversion within
a single conceptual process design. The process addresses the integration of CO2 absorption,
solvent regeneration, and catalytic conversion under realistic industrial operating
conditions. A process flowsheet was developed using methyldiethanolamine (MDEA) for
CO2 capture, followed by catalytic hydrogenolysis of the recovered CO2 to methanol
in a fixed-bed reactor. Process simulation was carried out using Aspen modeling tools
with literature-supported thermodynamic methods and kinetic expressions to represent
system behavior. Design assumptions, operating conditions, and property methods were
selected based on established industrial practices to ensure technical realism. Preliminary
simulations indicate that integrated capture and conversion are technically feasible
and highlight several key design considerations, including thermodynamic limitations,
reactor operating conditions, and the importance of recycle and heat integration.
This work provides a conceptual
foundation for future optimization, detailed equipment design, and further evaluation
of integrated carbon utilization systems.
Katherine Cortez, Sabrina Stone and Laura Todd
Dr. Yang Xiao
With increasing concern over carbon dioxide emissions and their contribution to climate change, innovative process solutions are required to repurpose CO₂ into value-added products rather than treating it solely as a waste stream. One promising approach is carbon utilization through chemical conversion, where captured CO₂ serves as a feedstock for fuel production. This project investigates an integrated process that converts dilute flue gas CO₂ from local emission sources into methanol via absorption in MDEA followed by catalytic hydrogenolysis. In this system, CO₂ is selectively absorbed into an MDEA solution within an absorber column, regenerated in a stripper, purified, and subsequently fed to a reactor where it reacts with hydrogen to form methanol. This approach shifts the focus from traditional carbon capture and storage toward carbon capture and utilization, promoting circular carbon management and improving overall resource efficiency. The integrated absorber-stripper-reactor configuration enhances solvent recovery, maximizes CO₂ utilization, and supports the development of a more sustainable and economically viable carbon cycle.
Channing Amedee, Elizabeth Dieguez and Kamden Perkins
Dr. Yang Xiao
This project presents the conceptual design of a 10,000 t/y methyl tert-butyl ether (MTBE) production process utilizing catalytic distillation. MTBE is widely used as a gasoline blending component to increase octane rating and improve combustion performance. The proposed process uses a mixed C₄ hydrocarbon stream from fluid catalytic cracking (FCC) units, which contains approximately 14% isobutylene along with other C₄ hydrocarbons. Because isobutylene is the primary reactant for MTBE synthesis, upstream purification and separation steps are implemented to remove catalyst-fouling impurities and condition the feed prior to reaction. The core unit operation is a catalytic distillation column, where isobutylene reacts with methanol over an acidic ion-exchange resin catalyst to form MTBE. Integrating reaction and separation within a single column enables continuous removal of the higher-boiling MTBE product, shifting the equilibrium toward higher conversion while reducing energy consumption and equipment requirements. Process simulation and design calculations were conducted in Aspen Plus to determine material balances, operating conditions, and equipment sizing. The final design achieves 99.5 wt% MTBE purity, demonstrating an efficient and industrially relevant process configuration.
Regina Fletcher, Evan Keaton and Nathan Walters
Dr. Yang Xiao
This report develops an Aspen Plus flowsheet for industrial methyl tert-butyl ether (MTBE) production using catalytic reactive distillation. A mixed C3–C5 stream is conditioned to protect the acid resin catalyst and sharpen separations: propane is removed in a depropanizer, C5+ in a debutanizer, and trace diolefins (butadiene) are hydrogenated in a stoichometric reactor unit at 11 bar (0.999 conversion), followed by a flash to remove H2. The purified C4 cut is contacted with a slight excess of methanol in a 10-stage RadFrac reactive distillation column (top pressure ~8 bar; top temperature ~62°C). Liquid-phase nonideality is captured with the NRTL model to represent methanol–hydrocarbon interactions. Conditions are selected to balance equilibrium, kinetics, and catalyst stability (purity declines above ~85°C). Downstream methanol recovery and MTBE polishing enable recycling and final specification. The integrated simulation achieves an MTBE bottoms mole fraction of 99.92% in excess of 10,000 t/y and discusses key safety and operability concerns.
Ethan Ivey, Drake Cardwell and Noah Ferguson
Dr. Yang Xiao
Methyl tert-butyl ether (MTBE) is used as a gasoline octane booster produced through the etherification of isobutylene with methanol. Although its use in domestic gasoline blending has declined, MTBE continues to be produced in the United States for export because of its high octane value and compatibility with refinery C₄ streams. This project presents the conceptual design of a 10,000 t/y MTBE production facility utilizing catalytic distillation to enhance reaction efficiency and reduce equipment requirements. Process simulations were conducted in Aspen Plus using literature-reported parameters and industrial operating ranges. The NRTL RK property method was selected to account for liquid-phase non-idealities and azeotropic behavior in the system. Feed purification includes debutanization and palladium-catalyzed hydrogenation modeled using LHHW kinetics. A catalytic distillation column enables simultaneous reaction and separation. Key design variables evaluated include reflux ratio, number of stages, and methanol-to-isobutylene ratio to improve conversion. Simulation results demonstrate high isobutylene conversion while maintaining stable catalytic operation.
Drew Cate, Jacob Hedges and John Littleton
Dr. Yang Xiao
Methyl tert-butyl ether (MTBE) is a gasoline additive to improve combustion efficiency and reduce engine knocking. MTBE is primarily produced in the U.S for export to international fuel markets. It is produced by reacting methanol with isobutylene, typically using an acidic ion-exchange resin catalyst. The objective of this catalytic distillation project is to produce 10,000 tons per year of MTBE with a product purity of 99.5% or greater. The process design was developed through systematic data collection, validation, process development, and simulation optimization using Aspen Plus. During the research and development phase, it was determined that placing a plug flow reactor upstream of the catalytic distillation column significantly increases the conversion of isobutylene. Two additional distillation columns are then used to purify the MTBE product and recover excess methanol for recycle. The resulting design represents an industry-relevant process configuration that can be scaled to meet global fuel additive demand.
Caroline Cresap, Justin Dufresne and Kaleigh Louque
Dr. Yang Xiao
Ethylene glycol (EG) is a high-volume commodity chemical widely used in antifreeze
formulations, polyester fibers, paints, and plastics. Driven by expanding polymer
and automotive markets, global demand for EG continues to grow, with the market projected
to reach $47 billion by 2033. This project presents the conceptual design of a 100,000
ton per year EG production facility using ethylene and air as feedstocks. The process
consists of three sections: selective oxidation of ethylene to ethylene oxide (EO),
hydration of EO to produce EG with di- and tri-ethylene glycols (DEG, TEG) as side
products, and downstream separation and purification to obtain polymer-grade EG, DEG,
and TEG. Particular emphasis was placed on modeling the highly exothermic ethylene
oxidation reactor. Due to the competing complete combustion reaction and significant
heat release, thermal management and safety constraints dominate
reactor design. To address these challenges, a multi-bed fixed reactor system with
interstage cooling was implemented to control temperature rise, improve EO selectivity,
and mitigate runaway risks. Results demonstrate that reactor temperature control is
critical to overall process performance, as conversion, separation efficiency, and
purity depend directly on upstream selectivity. This work highlights the importance
of integrated reactor and separation design in large-scale EG production.
Tracy Chen, Alexander Henderson and Francisco Rubio
Dr. Yang Xiao
Ethylene glycol (EG) is a key chemical used in detergents, pharmaceuticals, and industrial solvents, driving the need for efficient and reliable EG production processes. This project presents the design of an integrated EG production facility capable of producing 100,000 tons per year by selectively oxidizing ethylene to ethylene oxide (EO), followed by hydration of EO to monoethylene glycol (MEG) and subsequent separation of MEG from heavier glycols. The design begins with modeling the oxidation of ethylene to EO using representative kinetics and selectivity data reported in the literature. The EO hydration reactor is then simulated to produce MEG along with undesired heavier glycols. To accurately predict phase behavior in these mixtures, vapor–liquid equilibrium data from the literature were used to select appropriate thermodynamic models in Aspen Plus. A separation train consisting of water removal, distillation, and recycle streams was developed to recover high-purity MEG. The final design meets the target production rate and provides realistic estimates of reactor performance and separation feasibility, demonstrating the viability of the proposed process configuration.
Courtney Breaux, Madeline Toups and Grant Vial
Dr. Yang Xiao
The objective of this design project was to produce 100,000 tons per year of purified monoethylene glycol (MEG). MEG is an important industrial chemical widely used in polyester fibers and polyethylene terephthalate (PET) resins. The process consists of two main reactions: the oxidation of ethylene to ethylene oxide (EO) and the subsequent hydration of EO to MEG. EO is produced in a fixed-bed reactor through the catalytic oxidation of ethylene. Because this reaction is highly exothermic, reactor thermal control, reaction kinetics, and process safety were critical design considerations. EO is then hydrated with excess water to produce MEG along with higher glycols. The overall process was modeled in Aspen Plus to achieve the desired MEG production rate and evaluate process performance, providing a basis for future optimization
Shea Brassette, Addyson Gautreaux and Brandon Kaske
Dr. Yang Xiao
Ethylene glycol (EG) is an important commercial chemical widely used across numerous applications. The global EG market was valued at approximately $28.2 billion in 2024 and is projected to reach $46.8 billion by 2032. EG applications include polyethylene terephthalate (PET) resins, textiles, cosmetics, solvents, and its use as a primary component in automotive and industrial cooling systems. Industrial production of EG involves three major steps: epoxidation of ethylene to ethylene oxide (EO), hydration of EO to EG, and downstream product purification. In the epoxidation step, ethylene reacts with oxygen in a fixed-bed reactor over a silver catalyst to produce EO. After purification, EO is fed to a high-selectivity hydration reactor designed to maximize formation of monoethylene glycol (MEG) while minimizing by-products diethylene glycol (DEG) and triethylene glycol (TEG). The resulting product mixture is separated through a series of distillation columns to recover high-purity MEG, DEG, TEG, unreacted EO, and water. The glycol stream undergoes further purification in two distillation columns: the first separates MEG from heavier glycols, while the second separates DEG from TEG.