Process Design and Optimization of a Once-Through Dimethyl Ether Process Using AVEVA Process Simulation

The primary purpose of the project on which I wrote this thesis was to design an optimize a once-through dimethyl ether process utilizing a software called AVEVA Process Simulation. The process was initially modeled and optimized to minimize the EAOC of the distillation column. The result of that effort was an optimized column with six stages with the feed entering the column at stage six. It had a height of 3 m, diameter of 0.44 m, and an EAOC of $65,100. This optimized solution was submitted to a Toller. The Toller provided available equipment to model the plant. From here, another optimization was conducted to find the appropriate equipment combination that would have both the lowest rent and utility cost. This solution was then further optimized by manipulating process variables such as temperature, pressure, and feed stage. The most optimal configuration was reactor B and column A. The metric used to gauge the most optimal configuration is the total annual cost which includes rent and utilities. After optimization, the estimated utility and rent cost for the entire process was approximately$642,000 per year. Of course, there are other costs to consider such as raw materials and labor, but they are not included in this price. The final recommendation is to proceed with this project considering the fixed equipment cost and economic potential of $6.8 million per year. The next steps would be complete a more thorough economic analysis and purchase the equipment from the Toller to get the process running as soon as possible to increase potential profit

Process and design of a once-through dimethyl ether process using aveva process simulation

In this project, an optimization and preliminary economic analysis based on the lowest rent and utility cost was performed on a dimethyl ether process plant. This process model was performed with AVEVA Process Simulation software. Basic chemical engineering design principles as well as 3D response surface modeling and the native AVEVA optimization tool were used to select the most cost-effective equipment by varying process specifications to minimize utility cost, finding the least expensive equipment combinations possible, and selecting the feed tray location. The rental prices were fixed, so only utility and limited process specifications such as feed tray location could be varied to find the minimum equivalent annual operating cost. It was found that dimethyl ether process has the ability to be profitable with an economic potential of $6.8 million annually and the rent and utility cost being about$642,000 annually. It is recommended based on the economic potential to continue the analysis of the project as outlined in this thesis

Signal processing applications for fiber optic links

This work focuses on the use of signal processing, both digital and optical, for robust signal identification and adaptive impairment correction in coherent optical links. The objective of this research is multi-pronged. First, to develop and validate a blind architecture for the classification of practical coherent waveforms for 100G to 400G links, which requires the consideration of 64QAM formats, time-domain hybrid modulation formats, probabilistic shaping, and constellation shaping. Second, to develop and validate a blind architecture for OFDM waveforms transmitted over fiber-wireless links. Third, to demonstrate and investigate the utilization of hybrid fiber-wireless systems for high-bandwidth wireless transmission and low loss fiber remoting, using single- and multi-carrier modulation formats. Fourth, to develop and validate an optical cyclostationary processor using nonlinear optical signal processing to evaluate the spectral correlation function of wide bandwidth waveforms.Ph.D

Nonelective coronary artery bypass graft outcomes are adversely impacted by Coronavirus disease 2019 infection, but not altered processes of care: A National COVID Cohort Collaborative and National Surgery Quality Improvement Program analysisCentral MessagePerspective

Objective: The effects of Coronavirus disease 2019 (COVID-19) infection and altered processes of care on nonelective coronary artery bypass grafting (CABG) outcomes remain unknown. We hypothesized that patients with COVID-19 infection would have longer hospital lengths of stay and greater mortality compared with COVID-negative patients, but that these outcomes would not differ between COVID-negative and pre-COVID controls. Methods: The National COVID Cohort Collaborative 2020-2022 was queried for adult patients undergoing CABG. Patients were divided into COVID-negative, COVID-active, and COVID-convalescent groups. Pre-COVID control patients were drawn from the National Surgical Quality Improvement Program database. Adjusted analysis of the 3 COVID groups was performed via generalized linear models. Results: A total of 17,293 patients underwent nonelective CABG, including 16,252 COVID-negative, 127 COVID-active, 367 COVID-convalescent, and 2254 pre-COVID patients. Compared to pre-COVID patients, COVID-negative patients had no difference in mortality, whereas COVID-active patients experienced increased mortality. Mortality and pneumonia were higher in COVID-active patients compared to COVID-negative and COVID-convalescent patients. Adjusted analysis demonstrated that COVID-active patients had higher in-hospital mortality, 30- and 90-day mortality, and pneumonia compared to COVID-negative patients. COVID-convalescent patients had a shorter length of stay but a higher rate of renal impairment. Conclusions: Traditional care processes were altered during the COVID-19 pandemic. Our data show that nonelective CABG in patients with active COVID-19 is associated with significantly increased rates of mortality and pneumonia. The equivalent mortality in COVID-negative and pre-COVID patients suggests that pandemic-associated changes in processes of care did not impact CABG outcomes. Additional research into optimal timing of CABG after COVID infection is warranted