Anindita Sharda

Liquefied Natural Gas (LNG) production requires stringent feed gas specifications to ensure safe, efficient, and cost-effective operation. Natural gas entering LNG facilities contains a range of contaminants—including water, carbon dioxide (CO₂), sulfur compounds (e.g., mercaptans, COS, hydrogen sulfide), and mercury—that must be removed prior to liquefaction. These contaminants, if not adequately treated, can lead to equipment corrosion, freezing issues, catalyst poisoning, and environmental hazards. Typical pretreatment targets include H₂O < 0.1 ppmv, CO₂ < 50 ppmv, total sulfur < 50 ppmv, and Hg < 0.01 μg/Nm³.

Conventional LNG pretreatment typically involves four key steps: (1) acid gas removal utilizing generic solvent technologies, (2) dehydration via molecular sieves, (3) mercury removal with non-regenerable adsorbents, and (4) heavy hydrocarbon removal and/or cryogenic recovery of C3+ species (and optionally, even real-time flexible C2+), when advantageous. While these technologies are well-established, they are often deployed as standalone units, which may not be optimized for varying feed compositions or operational constraints. Additionally, the complexity of integrating multiple technologies can lead to increased capital and operating costs, longer commissioning times, and reduced flexibility.

Honeywell UOP has developed end-end hybrid pretreatment solutions that integrate, a). Special Activated solvent technologies for Acid Gas Treatment, b) Adsorbents with higher capacities for Mercury removal and Dehydration, and c) Advanced cryogenic fractionation with industry-leading energy efficiency. These solutions are tailored to specific feed conditions and customer requirements, offering improved efficiency, additional revenue-generating product streams, reduced footprint, and simplified operations. By leveraging advanced process modeling, solvent / adsorbent expertise, and commercial experience, Honeywell UOP delivers scalable solutions that address both technical and economic challenges in LNG pretreatment.

This paper presents a commercial case study that illustrates the application of Honeywell UOP’s hybrid designs:

Customer 1: A greenfield LNG facility designed for high-capacity acid gas, water and total sulfur removal, followed by adsorption-based mercury removal and NGL recovery unit. The integrated design offers a complete hybrid pretreatment package, reducing the need for multiple vendors and simplifying project execution.

Honeywell UOP’s hybrid pretreatment solutions represent a forward-looking approach to LNG processing—combining technical innovation with commercial practicality. They also highlight Honeywell UOP’s ability to provide innovative, integrated solutions while mitigating operational risks such as bed fouling, pressure drop, and regeneration inefficiencies through optimized process design. As global demand for LNG continues to grow, these solutions offer producers a reliable, cost-effective pathway to meet evolving market and regulatory requirements.