Economic Analysis of Upfront Nitrogen Removal from LNG Plant

Abstract

The global demand for liquefied natural gas (LNG) is expected to continue increasing over the next decays. Qatar, as one of the largest LNG exporters with a 22% global share, announced in 2020 a plan to increase the production capacity by more than 60% over the next five years. This work aims to evaluate the economics of upfront nitrogen removal (UNrem) that should save energy, improve efficiency, increase production, and boost economic feasibility. This novel idea of UNrem was investigated through a detailed economic analysis of several UNrem cases. Results showed that the total power requirement and the production rate could be decreased upon the implementation of the UNrem concept. Compared with baseline operation, removing up to 87.5% of nitrogen from the feed was found optimal as it decreases the total power requirement by 0.24 MW and increases the LNG product flow rate by 4.4 %, while exergy loss decreased by 7.08 MW. The UNrem of 87.5% scenarios showed a profit of 24.2 billion USD in 20 years. Results confirmed the importance of the UNrem process for energy savings, process improvement, and profit without the need for structural changes.