Separation Of Propylene From Propane By Adsorption

Abstract

Propylene is the second most important starting product in the petrochemical industry after ethylene. It is the raw material for a wide variety of products. The separation of propane and propylene is an energy intensive process due to close boiling point. The separation of propane and propylene is an energy intensive process due to close boiling point. Researchers are interested to develop less energy consuming processes for separation of propane propylene mixture. Nonconventional methods like physisorption by 4A, 5A, 13X zeolites, MOFs, and chemisorption by Ag+ and Cu+ solution shows suitability for propane propylene separation. Experiments carried out by addition of stabilizing agent (pyridine) to the copper salt solution. Additionally this solution is lees corrosive than other anhydrous system. From the experiments it is found that 2.0M CuNO3•2.1 pyridine shows best results during separation of propane and propylene. Propylene loading is 23 cm3/cm3 of adsorbent propane loading is 1 cm3/cm3 of adsorbent. From the experiment carried out by taking unsaturated LPG as feed, it was found that the copper pyridine complex can be used for the separation of olefin and paraffin of C4 hydrocarbon with less severity. From the experiments with silver nitrate solution and propane propylene mixture it was found that, silver nitrate is more suitable for the separation of propane propylene mixture. Propylene loading is 5.6 mmol/g of silver nitrate salt. The separation factor of propane propylene achieved 92 by silver nitrate solution. The separation factor is more than cuprous pyridine complex. 61% pure propylene achieved from adsorbed stream of the experiment carried out with C3 splitter bottom and silver nitrate. So, after single recycle polymer grade propylene can be achieved. The separation factor of propylene increases with increase in mol fraction of propylene in the feed. Adsorption of propylene carried out by silver nitrate impregnated on highly porous silica (MCM-41). The propylene loading found 1.7 mmol/g of adsorbent and 3.54 mmol/g of silver nitrate. The propane loading is 0.3 mmol/g of adsorbent. From C3 Splitter bottom product (95% propane and 5% propylene) propylene recovery achieved is 22% with purity 65%.