Onsite Adsorbent Testing Approach for Challenging Condensate Mercury Removal Unit Design

Abstract

Abstract A test skid was designed and installed onsite to simultaneously pilot test multiple commercial adsorbents for mercury removal from a condensate feed. A slipstream of the condensate directly sampled from the existing plant (side stream test concept) was used for the test campaign. The respective performance of each adsorbent was determined during the test. To gauge the presence of particulate mercury in the condensate feed, and to prevent sand, sludge and water carry-over to the different adsorbents tested, four stages of filtration and water coalescence were implemented into the test skid. Daily mercury analyses were conducted. Following a one-month pilot test campaign, the spent adsorbents were then retrieved, analyzed, and tested to assess the performance and stability of each product. Several adsorbents were severely impacted by the test conditions, losing their mechanical strength or their active phase, or being highly contaminated with heavy hydrocarbons. Overall, the test results showed a limited efficiency of all the adsorbents tested. The mercury adsorption capacity was found relatively low due to a high level of contamination for all the adsorbents tested. The adsorbents lifetime was estimated based on the unit pre-sizing, the test results and average feed conditions, anticipating high operating costs for this unit.