Refinery Gas Analysis by Gas Chromatography

UOP Method 539-97: Refinery Gas Analysis by Gas Chromatography

Accurately characterizing the composition of refinery gas streams is essential for process optimization, product quality control, and regulatory compliance. UOP Method 539-97 provides an industry-leading, proven approach for this critical task, offering engineers and chemists a comprehensive and authoritative standard for gas chromatographic analysis.

What is UOP Method 539-97?

UOP Method 539-97 is a standardized procedure developed by UOP for the quantitative analysis of refinery gas and expanded liquefied petroleum gas (LPG) samples. This proven method utilizes automated gas chromatography (GC) to precisely determine the mol-percent composition of various components, from light gases to C5 hydrocarbons, and provides composite reporting for heavier fractions. Its primary purpose is to deliver reliable analytical data crucial for operational decision-making in downstream processing.

Scope & Purpose

This comprehensive method governs the determination of specific components within refinery gas streams and expanded LPG samples. It covers the reporting of non-condensable gases, hydrogen sulfide, C1-C4 hydrocarbons, and C5 paraffins individually, with C5 olefins and C6+ hydrocarbons reported as a composite. The method is designed for quantitative results ranging from 0.1 to 99.9 mol-% for most components, with specific limitations for hydrogen sulfide. It explicitly excludes the separation of oxygen from argon.

Who Must Comply?

• • Primary audience: Process Chemists, Analytical Chemists, Laboratory Technicians, Refinery Operators, and Quality Control Analysts.
• • Industries affected: Petroleum Refining, Petrochemical Manufacturing, Natural Gas Processing, and Chemical Analysis Laboratories.
• • Compliance nature: While often adopted as a best practice, compliance is typically voluntary but strongly recommended for achieving consistent and verifiable analytical results that meet industry expectations.
• • Enforcement: Compliance is generally self-enforced by organizations to ensure the reliability of their analytical data. However, it may be specified in contractual agreements or as part of internal quality management systems.

Key Requirements Overview

• • The standard requires the use of a dedicated, automated gas chromatographic system configured for multi-column, multi-detector operation.
• • Professionals must ensure the system employs specific chromatographic columns and detectors (e.g., thermal conductivity detectors) to achieve the necessary component separations.
• • Key provisions include the use of validated calibration blends with known component concentrations for accurate quantification.
• • The method mandates the application of relative response factors and normalization to 100% for reporting final component percentages.
• • It also outlines procedures for handling and analyzing LPG samples, including expansion from a liquid to a gaseous state for analysis.

Related Standards & References

UOP Method 539-97 often works in conjunction with other ASTM International standards and internal company procedures. Complementary standards might include those for general gas chromatography principles, sample handling, or specific purity requirements for carrier gases and calibration standards, ensuring a holistic approach to analytical accuracy within the refining and petrochemical sectors.