(175g) Effect of Contact Angle Hysteresis on Solid Plugging of Condenserslel55

There is a continuing issue with solid plugging of maleic anhydride (MA) condensers within days to weeks in chemical factories. Previous studies suggested that the solid plugging results from the reaction between MA and ambient water, which produces the maleic acid that is the solid at the condensing temperature. To reduce the solid plugging and the loss of thermal conductivity, it is desirable that MA forms droplet and easily rolls off the surface of condenser. Unfortunately, MA wets the surface of the condenser completely, and thus results in fast solidification. In the current presentation, our recent progress in mitigating the issue will be discussed. First, a vacuum treatment method has been developed to reduce the static contact angle and the contact angle testing showed that the method is effective. However, the MA droplet is still pinned due to large contact angle hysteresis. Second, the topography of the condenser surface has been investigated and it was found that texturing the condenser surface via grinding or machining is effective in reducing the contact angle hysteresis. As a result, MA droplets are not pinned to the condenser surface any more. Lastly, it was also found that fluorinated coatings with low surface energy further reduce the pinning of the MA droplets and thus reduce the solid plugging. Our research highlights the importance of contact angle hysteresis and provides the viable approach to optimize the liquid-solid adhesion.