MAKING TREATING FACILITIES A DIFFERENTIATOR FOR AN LNG PLANT

摘要

For a typical LNG plant, front-end treating to remove contaminants is essential to meet the gas specifications. In actual operation, a range of contaminant content, typically different from design values, is experienced, indicating that treating facility operation can be optimized. Consequently, increased product recovery, higher plant availability and/or lower operating expenditure can be achieved. In this article, three examples which can result in significant savings by optimization of the actual operation of the treating facility are presented. The examples pertain to acid gas removal units (AGRUs), dehydration units (DHUs) and mercury removal units (MRUs), which are typically the three main units of the treating facility in an LNG plant. In AGRUs, foaming can be reduced by implementation of an alternative liquid routing. Proper routing the DHU water stream to the AGRU could prevent DHU inventory change-outs resulting in unplanned LNG plant shutdowns, with a monetary value equivalent to ~50 million US$ per change-out. The examples for the DHU and MRU are focusing on enhancing the adsorbent lifetime. This is achieved by tuning operational parameters and sampling, which are all tailored to the actual operating conditions. Over the project lifetime of an LNG plant, the resulting monetary savings could be above 100 million US$ as absorbent inventory change-outs are postponed. All of these examples showcase that regular monitoring of the treating facilities is required to optimize their performance. The optimization of treating facilities can result in major savings with minimal capital investment. The slight modifications presented can bridge the gap between the original design conditions and actual plant circumstances present during actual operations. Paying sufficient attention to the treating facilities in both operation and design ultimately turns the treating facilities into a key differentiator for existing and future LNG sites.