Application of Hydrogel in Fixed Bed for Water Removal from Fuels: Effect of Operating Conditions

Abstract

The concentration of water above the specification defined by regulatory agencies can impact performance and reliability of the use of fuels (e.g., corrosion and filter clogging), thus separation processes are necessary to reduce or control the water content of fuels. This necessity may lead to high investments or operational costs, so alternative technologies to remove water from fuels have been considered. They include the use of polymeric hydrogels. As demonstrated in recent studies, hydrogels can remove free, emulsified and soluble water, and based on that, in his work poly(sodium acrylate-co-acrylamide) hydrogel packing, similar to Raschig Rings, here named Ring Packed Hydrogel Bed, was designed and applied as a hydrophilic bed for water removal from diesel and biodiesel. The effects of temperature, flow rate and the hydrogel initial water content on the efficiency of water removal were analyzed. The results for diesel demonstrated that under the operating conditions explored, the use of hydrogels can reduce the water content to meet the commercial standards. Also, it was shown that the efficiency of the process to dry a high hygroscopic biodiesel, where water content reductions of up to 36.9 wt% (from 2146 ± 8 ppm) were achieved. The results can be used for the design of industrial equipments that use the hydrogel technology.