By Bonnie Crossland, Product Manager, Gas Chromatographs, Emerson Automation Solutions

As you may know, by January 30, 2019, 40 CFR Part 63 requires that petroleum refinery owners or operators of flares used as control devices for emissions points must meet the requirements of §63.670, regardless of the construction date of the flare. The regulation is part of the 1990 Clean Air Act that regulated emission standards for hazardous air pollutants (HAP) and is in addition to 40 CFR 60 Subpart Ja requirements. 40 CFR Part 63 regulations require determining the concentration of individual components in the flare vent gas within 15 minutes or direct monitoring of the net heating value of the flare vent gas at standard conditions.

I’m happy to tell you that Emerson Automation Solutions has developed two standard solutions that are compliant with 40 CFR Part 63 using its Rosemount 1500XA gas chromatograph (GC).

Why use a GC? Generally, you can consider three possible approaches when trying to meet petroleum refinery flare requirements – a calorimeter, a mass spectrometer, or a GC. A calorimeter is a relatively low-cost instrument, the measurement principle of which is burning the gas and measuring the heat generated. It has analysis time in the seconds range and simple maintenance, which all sounds very desirable. However, it requires a shelter for outdoor use, which adds significantly to its cost, and most important, it provides no information on what’s happening in the process or what’s going up the stack. Without composition information, there’s no way to determine which unit is generating the flare gases, which limits your response to a flare event.

A mass spectrometer provides individual component concentrations within the flare but at a very hefty price. Likewise, it requires a shelter, and is very difficult to maintain, often requiring a calibration gas for every component as well as a multicomponent blend. It usually requires monthly adjustments with notoriously high operating costs.

Which brings us to the GC solution. Like the mass spectrometer, the GC provides individual components (including isomers) within the flare but without the high price. The Emerson GC specifically requires no enclosure (saving even more money), it’s easy to maintain with simple thermal conductivity detectors (TCDs) for this application, provides information on what’s happening in the process through its easy-to-use software, and it provides updates well within 40 CFR Part 63 requirements.

Emerson Rosemount’s 1500XA gas chromatograph offers the greatest flexibility in measuring, calculating, and recording the individual component concentrations present in the flare vent gas. Emerson is offering two standard 8-minute solutions using the Rosemount 1500XA with multiple TCDs to meet the requirements of 40 CFR Part 63, Subpart CC (Refinery MACT 1) and 40 CFR Part 63, Subpart UUU (Refinery MACT 2). Solution 1 looks at hydrocarbons, H2S, H2, CO and CO2, and Solution 2 adds benzene detection. Custom solutions that measure, calculate, and record operators’ specific flare compositions are also available.

A GC provides an efficient and cost-effective approach to meeting the 40 CFR Part 63 requirements which every petroleum refinery plant is facing. If you’d like to discuss the possible implementation in your plant, give me a call at 713.396.8832, or contact gc.csc@emerson.com.

How far along are you in meeting 40 CFR Part 63?

By Chris Duncan, Business Manager, Emerson Automation Solutions

Detecting flammable gas that has the potential to threaten people and property in areas where gas clouds easily disperse is a problem in many applications. This recent case history is a classic example.

A UKCS (United Kingdom Continental Shelf) operator was issued an improvement notice from the Health and Safety Executive after a large volume gas leak went undetected on one of their North Sea platforms. The release had not been picked up by the platform’s existing flammable gas detection system because the gas had been dispersing as soon as it escaped.

The company contacted Emerson for help. The solution was to provide the Incus, an ultrasonic gas leak detector that, while working in conjunction with the existing gas detection system, added another line of defense and provided an early warning when gas releases occurred. Most importantly, it increased the safety of platform personnel.

Ultrasonic gas leak detection uses acoustic sensors to identify fluctuations in noise that are imperceptible to human hearing within a process environment. The sensor and electronics are able to detect these ultrasound frequencies (25 to 100KHz), while excluding audible frequencies (0 to 25KHz).

Unlike traditional gas detectors that measure the accumulated gas, ultrasonic gas detectors “hear” the leak, triggering an early warning system. The sensors respond to sound generated by escaping gas at ultrasonic frequencies. Leak rate is mainly dependent on the size of the leak and the gas pressure. In most facilities, the majority of process noise is in the audible range, while limited ultrasonic noise is generated in normal operation. Highly pressurized gas releases produce ultrasound (25-100 kHz) which the sensors are able to pick up despite the presence of audible noise. Ultrasonic (acoustic) gas leak detection technology has several advantages over conventional gas sensor technologies: it does not have to wait until a gas concentration has accumulated to potentially dangerous concentrations; it does not require a gas cloud to eventually make physical contact with a sensor; and the response is instantaneous for all gas types.

The Incus is ideally suited for monitoring outdoor applications such as on an oil platform. The Incus has been engineered to withstand even the most extreme conditions. Performance is not affected by inclement weather, wind direction, leak direction or any potential gas dilution, with an instantaneous response to all gas types. It is an excellent addition to many safety systems adding another layer of detection to existing technologies.

The Health and Safety Executive subsequently inspected the platform and approved the solution provided, resulting in a very happy customer!

Do you have an application that might require the addition of ultrasonic detection? It might be worth a discussion. Contact us HERE today.