Addressing Nitrogen Challenges in Natural Gas Processing

As natural gas production, particularly from shale plays like the Permian Basin, continues to grow, operators face increasing challenges with elevated nitrogen (N2) levels in associated gas. High nitrogen content can jeopardize pipeline and LNG specifications, impacting both market compliance and profitability. This blog explores why Nitrogen Rejection Units (NRUs) are becoming critical in the natural gas value chain and how operators can strategically address these challenges.

The Nitrogen Problem

In regions like the Permian Basin, nitrogen levels in residue sales gas often average 4-5 mol%, exceeding typical pipeline specifications of less than 3 mol% and stricter LNG requirements of less than 1 mol%. This trend, driven by shale gas production, is compounded by growing export markets, such as the EU’s commitment to purchase $750 billion in US energy. Compliance with inert gas specifications is non-negotiable, making NRUs essential for maximizing the Gross Caloric Value (GCV) of LNG. :

Strategic Integration of NRUs

Operators must evaluate how to integrate NRUs into existing infrastructure for capital efficiency and operational flexibility. When a facility includes multiple cryogenic plants, key considerations include:

Individual Plant Treatment: Treating gas at each cryogenic plant is inefficient due to space constraints and non-standard designs.
Full Stream Treatment: Treating the entire sales gas stream is cost-prohibitive due to oversized equipment and unnecessary “over-treating.”
Slip Stream Treatment: This approach, where only a portion of the gas stream is treated, offers consistent flow, standardized NRU designs, and better integration with cryogenic facilities.

By adopting a slip stream approach, operators can balance cost, scalability, and performance, ensuring compliance with sales specifications while minimizing capital expenditure.

Key Takeaways

Elevated nitrogen levels in shale gas production necessitate NRU deployment.
Slip stream treatment provides a cost-effective and flexible solution for integrating NRUs into existing cryogenic plants.
Strategic NRU placement enhances compliance with pipeline and LNG specifications, supporting growing export markets.

In our next blog, we’ll dive into the technology options for nitrogen rejection and how to choose the right one for your operation.