Effects of Feed Pressure and Retentate Flow Rate on the Performance of Locally Developed Polysulfone Membrane Oxygen Enrichment System

Abstract

Pengkayaan oksigen daripada udara persekitaran dengan menggunakan teknologi membran diterima secara meluas di seluruh dunia sebagai teknologi alternatif kepada kaedah konvensional seperti penjerapan ayunan tekanan dan sistem kriogenik. Pemisahan udara menggunakan membran adalah proses yang lebih anjal di mana ia memerlukan pelaburan modal yang rendah, kaedah operasi yang mudah dan murah jika dibandingkan dengan kaedah konvensional. Kajian dan pengujian telah dijalankan ke atas sistem membran gentian geronggang polisulfona, di mana kesan tekanan suapan dan kadar alir baki dikaji. Pada kadar alir malar, pengkayaan telapan meningkat dan kemudian menurun dengan peningkatan tekanan disebabkan oleh kesan perbezaan tekanan merentasi membran mempengaruhi kebolehtelapan lapisan kulit. Manakala pada tekanan suapan malar, nilai pengkayaan telapan maksimum dicapai pada kadar alir maksimum disebabkan oleh peningkatan rintangan penelapan. Nilai maksimum ketulenan telapan oksigen yang diperolehi dalam uji kaji ini ialah 27.2%.

Kata kunci: Pemisahan udara; membran gentian geronggang; pengkayaan oksigen; kebolehtelapan; polisulfona

Oxygen enrichment from surrounding air by using membrane is gaining wide acceptance through out the world today as an alternative to the conventional methods such as pressure swing adsorption and cryogenic system. Air separation using membrane is a more flexible process that requires lower capital investment and simple operation. Studies and testing had been performed on a locally new developed polysulfone hollow fiber membrane system, where effects of feed pressure and retentate flow rate on the oxygen enrichment were observed. At constant retentate flow rate, permeate enrichment increased and then decreased with pressure due to the effect of pressure difference across the membrane, which affects the permeability of the skin layer. While at constant pressure, the highest permeate enrichment value was obtained at highest retentate flow rate due to the increase of permeation resistance. The highest oxygen purity obtained in this experiment was 27.2% and the O2 permeate enrichment was 1.295.

Key words: Air separation; hollow fiber membrane; oxygen enrichment; permeability; polysulfone