Pervapertion Overview

Membrane selectivity : what goes through and what gets rejected 2. Flux: Denote the amount of output (measured in relation to membrane area , thickness and time). What will influence the performance? Feed temperature: Refers to temperature of the feed stock or any other representative between feed and retentate streams. Membrane thickness: Refers to dry thickness. 3. Kinetic diameter: diameter of pore needed to let a specific molecule passPerformance Parameters – Selectivity 0 Membrane selectivity allows us to choose certain molecules to pass through the membrane 0 Improved membrane selectivity will increase absorption rates 0 more efficient and possible cost reduction 0 This can be achieved by better understanding of the material selected for the membrane Impact of Feed Temperature on Flux 0 Feed Temperature 0 Molecules movement increases exponentially with temperature 0 improve flux rate Impact of Membrane Thickness on Flux The thinner the membrane, the faster Influencing Pa rameters – Kinetic Diameter (1)Kinetic diameter can be understood as the diameter of a pore needed to let that specific molecule pass Source: Fundamentals and applications of pervaporation through Zeolite membranes, 2004 Influencing Parameters – Kinetic Diameter (2) Key Cost Components For Pervaporation The operating cost of pervaporation is heavily reliant on the cost of generating heat and the cost of the membrane used Current trend: decreasing heating cost and decreasing membrane cost Source: http://www. scielo. org. ar/scielo. php? Decreasing Trend in Membrane Cost from 1989 to 2000 Reasons of decreasing membrane cost: .Membrane surface area per module increase 0 lesser membrane modules to produce the same amount of output 2. Membrane mass production 0 production cost decrease 3. More compact module 0 cost savings in civil works overview of UF technology today, Desalination 131 (2000) 17-25 Similar Decreasing Trend in Membrane Cost from 1970 to 2010 Source: America n Membrane Technology Association (AMTA), wrww. amtaorg. com Improvement in cost of heat generation -Cost of Conserved Energy (CCE) summarizes annual costs associated with saving a GJ (approximately 0. 95 MBtu) of energy with a particular measure.Table shows that energy efficient measures lead to energy savings that have short payback periods from immediate to 2. 7 years. -Industry is looking towards reducing cost of heat generation Improvements in membrane 1) Membrane preparation methods 0 more methods are developed to prepare membranes with different structures for different application 0 Phase separation method developed in 1960 0 Scanning Electron Microscope became available in 1960 0 helped in the detailed study of the membrane structure 2) Membrane selective layer is getting thinner over 30 years 0. 2 – 0. 4 pm