Matching Items (2)
Filtering by
- All Subjects: Simulations
- Creators: Blasko, Vincent
- Creators: Cook, Alexander Charles
Description
Separation of carbon dioxide and methane for the upgrade of natural gas through use of pressure swing adsorption could potentially save large amounts of energy from the current, costly process of cryogenic distillation and provides greater cost effectiveness for carbon dioxide capture, and provide larger product flowrates than membrane permeation separation. The purpose of this study is to analyze the effects of varying initial conditions of a MatLab simulation, courtesy of Mai Xu, a graduate student at ASU, designed to use Langmuir isotherms, mass transfer equations, and adsorbent and gas properties to simulate a pressure swing adsorption process with a mixture of methane and carbon dioxide gas feed. The effects that will be varied are the adsorption/desorption time, pressurization/depressurization time, adsorption feed composition, desorption purge composition, adsorption pressure, desorption pressure, adsorption flow rate, and desorption flow rate. The study found that the trends in methane purity and production generally follow the trends predicted by literature and relevant equations, with pressure boundaries being the largest impacting factor. In addition there was a markedly inverse correlation between purity of methane product and the productivity of the system. This trend was only violated in one instance, at very low vacuum pressure during desorption, which could indicate an area that requires further study. Overall, the main areas of improvement in pressure swing adsorption for this system would be improving the selectivity of adsorption of carbon dioxide over methane, which requires improvement and change of the adsorbent, and more extreme vacuum pressures during desorption, both of which will increase methane yield and reduce operating costs.
ContributorsCook, Alexander Charles (Author) / Deng, Shuguang (Thesis director) / Mu, Bin (Committee member) / Chemical Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
ABSTRACT The purpose of this study was to investigate the effects of E Bucks, a simulated classroom economy (a token economy system), in business classes on students' grades, absences, and tardiness. The study compared these variables in classes using E Bucks to those in similar classes before E Bucks was initiated. The following research questions were addressed: (a) How did the mean term grades in business classes that included E Bucks compare to those in similar classes prior to the E Bucks implementation? (b) How did the mean number of student absences in business classes that included E Bucks compare to those in similar classes prior to the E Bucks implementation? (c) How did the mean number of student tardies in business classes that included E Bucks compare to those in similar classes prior to the E Bucks implementation? Four teachers in 3 high schools in Phoenix, Arizona, participated in the study that included 22 sections of business classes with a total of 568 students. All participating teachers implemented the token economy voluntarily, although some implemented the program more consistently than others. All of the teachers administered district-aligned assessments with the same terms/occasions throughout the district. Archival data (term grades, attendance, and tardies) from 3 years of business, technology, and marketing courses were collected and analyzed. The results of 4 analyses of variance examining the dependent variables of grades, absences, and tardies were mixed. The results demonstrated significance for some but not all of the teachers' classes on all 3 dependent variables. In 1 of the 4 analyses 2 teachers had approached significant increases in grades when students were "paid" for grades. The same two teachers had nonsignificant decreases in the mean number of student absences during the grading period students were "paid" for grades. Recommendations included studying a larger number of students and measuring the impact of gender and socioeconomic status on the effects of the E Bucks simulation.
ContributorsWaggoner, Schavon T (Author) / Rader, Martha H (Thesis advisor) / Gryder, Robert (Committee member) / Blasko, Vincent (Committee member) / Arizona State University (Publisher)
Created2010