| Author | Maung Nyunt Wai |
| Call Number | AIT Thesis no.ET-92-11 |
| Note | A thesis submitted in partial fulfillment of the requirement for the degree of Master of Engineering |
| Publisher | Asian Institute of Technology |
| Abstract | The transport phenomenon of transmembrane distillation using stripping air to remove the permeate at the downstream side was studied. The experiments were conducted using Cuprophan hollow fiber membrane which is hydrophilic in ultrafiltration regime and PMMA membra ne which is hydrophobic in nature. The transport mechanism was found ultrafiltration followed by evaporation for Cuprophan membrane and membrane distillation for PMMA membrane. Both processes are similar for the ultrafiltration regime. The only differenc e is the nature of the membrane and the resist ivity to the solvent used. The experimental investigations and results show that the mass transfer is a function of feed temperature , feed composition and liquid flow rate. An increase in temperature increased the flux exponentially for both types of membranes. The same trend is found for the increase in fe ed liquid flow rate. As the ethanol concentration in the feed solution was increased the flux decreased. Selectivity did not change appreciably over the ultrafiltration regime evaluated. The selectivities of both types of membranes for alcohol-water system in the ultrafiltration regime were low and the membranes are not highly selective. The PMMA membrane have a higher flux and selectivity than Cuprophan membranes. The selectivities are lower than that of vapor liquid equilibrium (VLE) for ethanol-water system showing that the membranes are not highly selective in ultrafiltration regime. Other parameters such as air flow rate, humidity, temperature polarization a nd concentration pola rization are not much affected. At the high water composition of the feed solution, the mass transfer was governed by ultrafiltration. The experimental results are followed the same trend as theory of sorption diffusion model. The mass transfer rate can be enhanced by temperature gradient between the both sides of the membrane. At high ethanol concentra tion, the membrane materials become dense and behave as pervaporation membrane. |
| Year | 1992 |
| Type | Thesis |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Department of Energy and Climate Change (Former title: Department of Energy, Environment, and Climate Change (DEECC)) |
| Academic Program/FoS | Energy Technology (ET) |
| Chairperson(s) | Mora, J. C.; |
| Examination Committee(s) | Bhattacharya, S. C. ;Visvanathan, C.; |
| Scholarship Donor(s) | Swiss Dev elopment Cooperation, Switzerland; |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology |