Adsorption and stripping of ethanol from aqueous solution using sepabeads207 adsorbent

Abstract

There is a problem of increasing of CO2 and CO in environment from the use of fossil fuel. Ethanol is a good alternative fuel or additive to gasoline to improve octane number, using ethanol will decrease CO and CO2 emissions. For these reasons, production of ethanol by fermentation is a promising solution. This work aimed to evaluate suitable technique of separation using adsorption method. Best conditions of adsorption and stripping processes were studied in this work. The ethanol solution with 10wt% concentration, i.e., similar to the product of fermentation process was used as feed. The separation was occurred in adsorber tube containing polymer Sepabeads207 at different temperatures (20 - 40°C), also (pH) (4 - 7), time of adsorption (5 - 25 minutes). Also time of stripping (desorption) was studied between 15 and 35 minutes at different temperatures of air (80 - 95°C). The evaporated ethanol was condensed by cold water and the concentration of liquid ethanol was measured using refractometer and gas chromatography. The results show the best conditions for adsorption process are: time = 5 minutes; temperature = 20 °C and pH= 4, while the best conditions for striping process are: time = 15 minutes and temperature = 80 °C. By applying the best conditions for both adsorption and stripping processes, ethanol concentration of 46wt% was able to be obtained. The adsorbent capacity of Sepabeads207 is 0.22g ethanol/g adsorbent, while the adsorbent selectivity is 7.75 — g e th an o l/ g water ( adsorbed)— the g e th a n o l/g water (original so lu tio n ) efficiency of adsorbent is 100%. From this study can be concluded that using of Sepabeads207 to adsorb ethanol in static solution better than continues with applying best conditions.