5096

4792

كارشناسي ارشد

شيمي تجزيه

اصفهان: دانشگاه صنعتي اصفهان،دانشكده شيمي

1388

چهارده،90ص.: مصور،جدول،نمودار

ص.ع.به فارسي و انگليسي

حسن قاضي عسگر

89/1/21

عزت كشاورزي،محمد قريشي

شيمي

ID4792

به فارسي و انگليسي: قابل رويت در نسخه ديجيتالي

Ternary Solubility and Selective Extraction of Mono and Di tert Butyl Ethers of Glycerol in Supercritical Carbon Dioxide Gholamhossein Paniri Varnosfaderani Paniri62@gmail com March 6 2010 Department of Chemistry Isfahan University of Technology Isfahan 84156 83111 IranDegree M Sc Language FarsiDr Hassan S Ghaziaskar ghazi@cc iut ac irAbstract Mono and Di tert butyl ethers of glycerol are potential oxygenate additives of diesel fuel Their synthesisand the solubility measurement of the isomers in scCO2 has been our main interest Addition of these ethersto diesel fuel increases its quality and decreases the particulate matter emissions carbon oxide and carbonylcompounds in exhaust gases Di tert butyl ether of glycerol DTBG is usable as potential oxygenate additiveto diesel fuel because it blends good enough with diesel fuel Mono tert butyl ether of glycerol MTBG hasa low solubility in diesel fuel and therefore the separation of MTBG from DTBG is important and useful Using a continuous flow apparatus ternary solubility of MTBG and DTBG in supercritical carbon dioxide scCO2 were measured at temperatures of 313 15 333 15 and 348 15 K in the pressure range of 80 200 bar and the expanded gas flow rate of 180 10 mL min 1 At 333 15 and 348 15 K the ternary solubility increased with pressure up to 152 bar where it reaches aplateau While the ternary solubility of MTBG and DTBG in scCO2 at 313 15 K increased with pressurealmost linearly until 200 bar and no plateau is observed The experimental data for ternary solubility of MTBG and DTBG were correlated by Bratle equation At348 15 K and pressure of 80 bar MTBG was found insoluble in scCO2 Moreover the extraction selectivityof MTBG and DTBG of ym yd 2 43 at 348 15 K and pressure of 200 bar The flow rate of 0 3mL min 1 of liquid CO2 was found as optimum flow rate for extraction of more than 93 MTBG and DTBGby scCO2 For extraction of DTBG the recovery of 38 04 and 61 85 was obtained at 2h and 4h extractiontime respectively at pressure of 80 bar temperature of 348 15 K and flow rate of 180 10 mL min 1 After 2h of extraction time at pressure of 80 bar temperature of 348 15 K and flow rate of 180 10 mL min 1DTBG were obtained with 96 purity By increasing the pressure up to 200 bar and after 1h of extractiontime MTBG were extracted with 93 purity For extraction of MTBG the recovery of 28 9 and 41 75were obtained at 1h and 3h after extraction at pressure of 200 bar and temperature of 348 15 K with flow rateof 180 10 mL min 1 respectively Higher recovery of MTBG and DTBG was achieved using a counter current column with packing height of50 cm The highest recovery was reached at 348 15 K and 80 bar with flow rate of 0 3 mL min 1 of liquidCO2 and 0 1 mL min 1 of sample with 88 and 95 for MTBG and DTBG at 5h of extraction time respectively Key words Supercritical carbon dioxide Solubility Tert butyl ethers of glycerol

حسن قاضي عسگر

عزت كشاورزي،محمد قريشي