Choosing a Refinery Gas Analyzer: Top 5 Considerations for Making the Right Decision

Choosing refinery gas analyzers and sampling systems are critical for enabling refineries to monitor gases produced during crude oil refining—such as stack emissions, flare emissions, reformative streams, and hydrotreatment streams. For stack and flare emissions, it is imperative to obtain representative samples of the emissions in order to comply with regulatory authorities, such as the Bay Area Air Quality Management District (BAAQMD). For reformative streams and hydrotreatment streams, the purity of the hydrogen must be measured to calculate accurate rates of conversion from the reactor. This is also important for process quality control and process accuracy relative to managing operational expenses within refineries.

Most refinery gas analyzers work on the principle of gas chromatography. This entails separating components in a mixture through the variation in partitioning behavior between mobile and stationary phases. The differences in structure and properties of each component result in the components moving out of the column in different orders, allowing for the gas composition to be characterized. 

As an exact measurement of refinery gases is essential for optimizing refinery processes and controlling product quality, there are quite a few considerations for making the right decision.

Considerations for a Refinery Gas Analyzer

When choosing a refinery gas analyzer, there are a number of criteria to consider to ensure regulatory and process quality requirements are met. The first step is to narrow down analyzer options based on what part of the refining process the analyzer is going to be integrated with. There are three fundamental criteria to consider: speed of analysis, accuracy and reliability, and finding the right sampling system to integrate with the analyzer. Ease of calibration and ergonomics should also be considered but are less of a priority.

Measurement Type

While refinery gas streams vary considerably in composition, there are common components to look for in each use case. If the analyzer is to be integrated for purposes of measuring stack and flare emissions, the analyzer must be able to characterize the following: C1 through nC6 paraffins, C6+ hydrocarbons, hydrogen sulfide, and inert gases (hydrogen, nitrogen, helium, oxygen, carbon monoxide, and carbon dioxide).

Speed of Analysis

While gas chromatography is an inherently quick method to characterize gas, some refinery gas analyzers are quicker than others. Knowing a process chemistry in minutes versus hours or even days later makes all the difference in refinery operations. For stack and flare emissions, it is important to obtain results from the analyzer in a matter of minutes, as the heating value of the stack or flare can change rapidly. A quick response is necessary to prevent potentially hazardous conditions for personnel and to meet emissions regulations.

Accuracy and Reliability

Refinery gas analyzer accuracy and reliability play heavily into a refinery’s ability to make quick decisions regarding the process and avoid disruptions due to environmental impact. Accurate actionable data is necessary to allow engineers to make informed decisions to adjust process conditions accordingly. If an analyzer is unreliable and stops working, this can halt the entire process until emission measurements can be taken.

Calibration and Ergonomics

Once a refinery gas analyzer has been selected, it is time to consider the logistics of implementation. This entails deciding where and how the analyzer will fit into the process, whether that be in a shed or a more robust design by a local vendor.

Refinery gas analyzers typically have two types of necessary calibration: daily or weekly checks and periodic calibration. Daily or weekly checks may include a single-point calibration with a known gas that is being measured, such as hydrogen sulfide. Initial and periodic calibration may involve a three-point (high, middle, and low) calibration with three to four gases. These checks and/or calibrations can either be done manually or can be automated to save time, improve record-keeping, and reduce field labor.

The Final and Most Important Consideration: Finding the Best Sampling System for Your Analyzer

Finding the best refinery gas analyzer is critical for everyday refinery operations. However, it is just as important, if not more, to find a sampling system to work with the analyzer. The ability to comply with local regulations with regards to gas emissions is highly dependent on the combination of a refinery gas analyzer with a high-quality sampling system. The sampling system can make or break analyzer speed and reliability. When running an analyzer, an adequate amount of time is needed to purge the sample lines to allow for a representative sample to be taken. Without a speedy and reliable sampling system, the analyzer will not be able to provide accurate and representative data.

If you are uncertain about how to match the right sampling system with a refinery gas analyzer, Field Engineers at Swagelok Northern California are available to provide expert advice on gas analyzer sampling systems in refineries. Swagelok Field Engineers will perform an on-site review of your process and analyzer to help you choose a reliable sampling system tailored to your specific sampling needs.

To find out more about how Swagelok Northern California can help you find the right sampling system for your refinery gas analyzer, contact our team today by calling 510-933-6200.

Morgan Zealear | Product Engineer – Assembly Services

Morgan holds a B.S. in Mechanical Engineering from the University of California at Santa Barbara. He is certified in Section IX, Grab Sample Panel Configuration, and Mechanical Efficiency Program Specification (API 682). He is also well-versed in B31.3 Process Piping Code. Before joining Swagelok Northern California, he was a Manufacturing Engineer at Sierra Instruments, primarily focused on capillary thermal meters for the semiconductor industry (ASML).