Pervaporation of ethanol-water mixtures through cuprophan hollow fibers : I. equipment and energy prefeasibility estimation. II. behavioral analysis of air perstripping | |
| Author | Acda, Reynaldo I. |
| Call Number | AIT Diss. no. ET-90-2 |
| Subject(s) | Alcohol Distillation |
| Note | A Dissertation submitted to the Di vision of Energy Technology, Asian Institute of Technology in partial fulfillment of the requirements for the degree of Doctor in Engineering, School of Environment, Resources and Development |
| Publisher | Asian Institute of Technology |
| Abstract | The first part of t h is study introduced the concept of potentiality as a criterion for assessing the performance of the cuprophan hollow fiber membrane module for ethanol - water pervaporation. Potentiality was developed thru the congruous adaptation of a n analogy with availability (or exergy ) from thermodynamics. This parameter is the combination of quantity a nd quality, specifically global flux density a nd selectivity factor. Since generally the global flux density is inversely related to the selectivity, the potentiality is a useful tool in finding the compromise condition where the flux and the selectivity are both acceptable. An equation was developed to describe the relation ship of potentiality with liquid phase composition. The equation in conjunction with the material balance for a flow recycle pervaporation process was utilized to define the operating condition s of the process. At fixed values of liquid feed rate a nd composition, t h e most suitable liquid product composition and membrane area requirement can be obtained from the established model. The u se of potentiality thru its maximum value permits us to determine a theoretical minimum membrane surface area for a given separation. This estimation technique appears to be appropriate and convenient in a prefeasibility study for coupling pervaporation with distillation . The determination of the capital and energy requirements of the distillation-pervaporation process can begin with the base figure of the membrane area provided by the maximum potentiality criterion. Air perstripping sing the cuprophan ho low fiber module was a l so studied to determine the behavior an d mass transport characteristics of the process. The effects of the liquid phase composition, temperature and the relative humidity of the sweep air stream on the selectivity and the fluxes of ethanol a nd water were evaluated . The behavior of the process was also analyzed in relation to the conventional vacuum operated pervaporation process. Pervaporation of ethanol - water solutions through cuprophan hollow fibers using air perstripping is feasible but limited to some compositions of the liquid feed. The limitation is dictated by the water content of the inlet air. Air perstripping is referred to an equilibrium stage operation different from that of vacuum operated pervaporation which is highly kinetic. The mass transport model developed to describe the process was based on the partial pressure departure from equilibrium of t h e liquid and gas phases. Th e formulated model can be used as t h e simulation equation for the design of this kind of pervaporator. |
| Year | 1990 |
| Type | Dissertation |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Other Field of Studies (No Department) |
| Academic Program/FoS | Energy Technology (ET) |
| Chairperson(s) | Mora, Jean-Claude |
| Examination Committee(s) | Prida Wibulswas ;Bhattacharya, Sribas C. ;Tabucanon, Mario T. ;Vigneswaran, Saravanamuthu |
| Scholarship Donor(s) | Government of Australia |
| Degree | Thesis (Ph.D.) - Asian Institute of Technology, 1990 |