444d Composite Bed Configuration for Organic Sulfur Removal from Model Logistical Fuel by Using Microfibrous Entrapped Adsorbent

Hongyun Yang1, Sachin Nair1, and Bruce J. Tatarchuk2. (1) Center for Microfibrous Materials Manufacturing, Department of Chemical Engineering, Auburn University, Auburn, AL 36849, (2) Center for Microfibrous Materials Manufacturing, 230 Ross Hall, Dept. of Ch. E., Auburn, AL 36849-5127

Several different bed configurations of Cu-Y type zeolite based adsorbents have been tested at room temperature for organic sulfur compounds removal from a model fuel of 2000 ppmw benzothiophene in n-octane. A composite bed, a packed bed followed by a thin polishing layer made of glass fibrous entrapped adsorbent significantly improved the breakthrough sulfur capacity of Cu-Y adsorbents. At 1 ppmw breakthrough, the capacity of composite bed is 22.3 mg Sulfur/ g adsorbent, which is twice that of a packed bed made of 100-150 ƒÝm Cu-Y zeolite particles. Pressure drop test showed that small particle sizes introduce unbearably high pressure drop (i.e. 3.6 psi per cm of bed thickness) even at a low face velocity of 0.12 cm/min for 100-150 ƒÝm zeoite particles, while the pressure drops of larger particles (0.8-1.4 mm) and 1/16" extraduates are negligible (less than 0.1 psi per cm of bed thickness) even at a higher face velocity of 1 cm/ min. The breakthrough test shown that the saturation capacity of a packed bed made of 0.8-1.4 mm particles is about 80 % of the capacity of a packed bed made of 100-150 ƒÝm particles. The optimized composite bed made of large particles and microfibrous entrapped adsorbents synergistically combines the high volume loading of packed beds and the overall heterogeneous contacting efficiency of small particulates.