mass transfer in multiphase systems - Greenleaf University

More documents

Recommendations

Info

MASS TRANSFER IN MULTIPHASE SYSTEMS: VOLATILE ORGANIC COMPOUND REMOVAL IN THREE-PHASE SYSTEMS The analytical instruments used were Fourier Transfer Infrared (FTIR) for the tested system and FTIR and photo-ionization detector (PID) for the theoretical system. The FTIR produces a large amount of data. However, for the tested system, there were few VOCs (consisting of PCE mainly). Therefore, the FTIR worked very well providing the data discussed in the results section. Briefly, a discussion on the FTIR and the PID follow: Some of us chemical engineers that went on in organic chemistry laboratory used infrared analysis to determine unknowns, usually from published spectra of pure substances. Infrared is absorbed by a bonds rotational energy, e.g., a spectrum from C=O is different than one from C- H. This provides the qualitative aspect. All of the source energy is sent through an interferometer and onto the sample. The light passes through a beam splitter, which sends the light in two directions at right angles. One beam goes to a stationary mirror then back to the beam splitter. The other goes to a moving mirror. The motion of the mirror makes the total path length variable versus that taken by the stationary-mirror beam. When the two meet up again at the beam splitter, they recombine, but the difference in path lengths creates constructive and destructive interference, i.e. an interferogram d : The recombined beam passes through the sample. A schematic is shown in Figure 4. The sample absorbs all the different wavelengths characteristic of its spectrum, and this subtracts specific wavelengths from the interferogram. The detector now reports variation in energy d This is similar to music which Fourier also used or any periodic function. In modern music digitization, the analogous interferogram is a compressed wave form that appears to mean nothing. However, it still plays! The tracks for the CD-ROM are transformed to show the actual music. 11
MASS TRANSFER IN MULTIPHASE SYSTEMS: VOLATILE ORGANIC COMPOUND REMOVAL IN THREE-PHASE SYSTEMS versus time for all wavelengths simultaneously. A laser beam is superimposed to provide a reference for the instrument operation. To make quantitative measurement, there was a sample gas in the FTIR used consisting of those VOCs anticipated. The Fourier transform is performed by the computer to determine the desired spectrum. The PID is based on the ionization energy signatures of the individual VOCs. Ultraviolet (UV) light is transmitted through the samples which breakdown VOCs at different energies. The PIDs are normally small and can be hand-held units. They have small vacuum pumps for pulling gases from the sample port. The PIDs require a sample calibration gas, normally isobutylene that determines part of the internal cell constant. Moving Mirror Stationary Mirror Beam Splitter Sample Detector S litt Source S litt Figure 4. Interferometer schematic. Initially, determination of gas concentration versus time was planned for the system based on theory also. However, there was a fire in an activated carbon bed while adding air to the 12
Page 1 and 2: MASS TRANSFER IN MULTIPHASE SYSTEMS
Page 3 and 4: Samuel Clay Ashworth ALL RIGHTS RES
Page 5 and 6: CURRICULUM VITAE Samuel C. Ashworth
Page 7 and 8: model results using Polymath, Excel
Page 9 and 10: Lead process engineer and assistant
Page 11 and 12: Determination of Viable Processes f
Page 13 and 14: ACKNOWLEDGMENT The work within was
Page 15 and 16: 5.0 INTERPRETATIONS, CONCLUSIONS, A
Page 17 and 18: NOMENCLATURE a a,b, etc. Parameter
Page 19 and 20: Sh v Sherwood number Velocity, L/t
Page 21 and 22: TOTAL CREDITS IN GREENLEAF UNIVERSI
Page 31: MASS TRANSFER R IN MULTIPHASE SYSTE
Page 35 and 36: MASS TRANSFER R IN MULTIPHASE SYSTE

mass transfer in multiphase systems - Greenleaf University

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?