|Keywords:||Interface; Magnetic suspension balance; Adsorption isotherms; LabVIEW|
|Full text PDF:||http://www.rcaap.pt/detail.jsp?id=oai:run.unl.pt:10362/11390|
Dissertação para obtenção do Grau de Mestre em Engenharia Química e Bioquímica This work aims to develop a LabVIEW interface for monitoring, controlling and automate the simultaneous experimental determination of one adsorption isotherm of gas in two distinct solid adsorbents. The magnetic suspension balance has two samples and this way it’s possible to determinate, simultaneously, the equilibrium adsorption for two different adsorbents. The developed software allows the registration of weight values and the control of the state of the balance, which has three main positions (ZP, MP1 and MP2). To determine a isotherm point is necessary for the system to reach the equilibrium. The software records the different values of ZP, MP1 and MP2, calculating the adsorbed mass values for each of the adsorbents. When the average of the adsorbed masses remain constant, the pressure value is changed and is possible to proceed with the determination of a new point isotherm. The software was developed in LabVIEW utilizing a software previously developed for a balance with only one sample. The old software was built using just one interface, which made the process of changing routines and new programming interfaces complicated. It was developed a sketch of a new software, now built in five separate blocks . To validate the interface for monitoring the magnetic balance, multiple tests were conducted at the installation, in order to confirm that the interface gets accurate results. The tests measured adsorption isotherms for CO2 in two simultaneous adsorbents, MIL-53(Al) and Zeolite 5A at different temperatures: 30 °C, 50 °C and 80 °C. From the results, it can be confirmed that the developed interface is acquiring the values of the weight correctly and applying well the correction of the zero point, allowing the user to simplify the process of determining adsorption isotherms.