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Coldbox freezing by heavy hydrocarbons (HHCs) causing reduced LNG throughput is a known problem in the industry. This challenge is particularly acute in the US, where LNG facilities are fed by lean pipeline gas, but also a concern in other parts of the world where plants are faced with changing feedgas compositions. To address this problem, and restore maximum throughput to LNG facilities, BASF has proposed an adsorbent solution for the removal of HHCs from lean gas.
BASF, working with Kinder Morgan at the Elba Island LNG facility, has implemented Durasorb technology, which eliminated deriming events, decreased operational complexity, and increased LNG production. In Summer of 2022, molecular sieves were removed from the dehydration unit and replaced with Durasorb products. After change out of adsorbent materials and minor modifications to cycle times, the two trains running Durasorb are removing water to LNG specifications and heavy hydrocarbons (C8+, BTX) to levels that do not cause freezing. The removal of HHCs in the adsorption section has resulted in steady pressure drop (dp) readings in the cold section, eliminating the need for deriming events, and increasing LNG production throughput. This simple drop-in solution did not require CapEx.