Gas and Flame Detection Technology for the LNG / CNG Industry

While there may exist several solutions, which will allow energy demands to be met in the future, natural gas has one crucial advantage; it’s available immediately. Recently many technological advancements have revolutionized the gas industry. Improvements in producing gas from shale deposits have facilitated a high increase in the supply of natural gas. This production has escalated competitiveness, promoted job growth, and has bolstered economies with lower, more stable natural gas prices.¹

Natural gas can be converted into a liquid form to aid storage and transport. In this form it is known as liquefied natural gas (LNG), and its use in this form allows for the production and marketing of natural gas deposits that were previously economically unrecoverable. LNG is used for natural gas supply operations and domestic storage, as well as being used for vehicle fuel.

Alternatively, natural gas can placed under pressure, the result of which is a clear, odourless and non-corrosive fuel known as compressed natural gas (CNG). CNG’s primary use is as a substitute fuel in the place of gasoline (petrol), diesel or propane/LPG. What’s more is that CNG is substantially better for the environment than these fuels, as well as being safer in the event of a spill.

Interest in both LNG and CNG has recently been renewed, and it is therefore believed that both will play an important role in the natural gas industry and energy markets in the coming years.

¹http://www.powerincooperation.com

Application Profile:  Portable LNG Vaporizers – Drill Sites

Gas wells are typically drilled at remote sites. This often comes about simply due to the location of the gas, the proximity to the public or a combination of the two. There is one large obstacle that presents itself as a result of this remoteness, and that is the availability and cost of providing sufficient power in a remote area. One solution to this, which many drillers are moving towards, is the employment of portable vaporizers and temporary liquefied natural gas (LNG) sources.

An LNG truck is sent to a potential drill site along with the portable vaporizer. After the connection is made, Compressed Natural Gas (CNG) is available to run a large generator that is capable of providing power to the entire drill site. The LNG and vaporizer remain on site until it is producing gas and has therefore become self-sustaining, at which point they can be moved on to the next site.

As a result of the inherent explosive nature of LNG, safety devices must be employed whenever LNG is stored or is in use in an area. LNG is stored at 162 C (260 F), however when it is heated and begins to vaporize it rapidly expands by up to 600 times its volume. The force of this expansion can place a large amount of strain on piping and valves, and this stress can result in leaks.

Application

For the above reasons, portable vaporizers are fitted with detection systems for gas and flames, so there is the ability to rapidly shut off the flow of LNG in the case of a leak thus minimizing the fuel source of a potential explosion or fire. Ultima^® X5000 Series Gas Monitors and FlameGard^® 5 UV/IR Flame Detectors are ideally suited for this application.

Application Profile: Portable CNG/Permanent Filling Stations for Vehicles

Similar to the trailers made for drill sites, companies are also buying portable units for the purpose of supplying fuel to fleet vehicles. Due to the rising cost of diesel, coupled with the abundance of natural gas, many companies are converting delivery trucks to run on LNG instead of diesel. As the infrastructure needed to support the refuelling of these vehicles does not yet exist, many companies are installing fuelling stations across strategic locations in their local areas.

Application

In order to protect the equipment housed within from vandalization by the public, these stations are often enclosed. Gas and flame detectors are installed inside the trailer. MSA’s Ultima X5000 Gas Monitors, UV/IR Flame Detectors, Observer-i Ultrasonic Gas Leak Detectors and Ultima OPIR-5 Open Path Infrared Detectors all provide optimal solutions for a safe work environment in enclosed spaces.

Application Profile: LNG Vehicle Maintenance Facilities

Due to the long distances regularly travelled by LNG vehicles - thousands of miles per week - they require maintenance more frequently than passenger cars. In order to minimize the down-time of trucks and as a result of the regular maintenance needed, many companies have large garages with fleets of mechanics. Being indoors, a leak from one of the pressurized CNG tanks would rapidly collect at the ceiling and could exceed the Lower Explosive Limit (LEL) in a short amount of time.

Application

As a result, the maintenance and storage facilities are typically outfitted with gas detection at the ceiling. Due to the size of the buildings, a combination of point and open path gas detectors are often employed. Together, MSA’s Ultima X5000 Gas Monitors and Open Path Gas Detectors would provide full detection coverage.

Fixed Gas and Flame Detection Instruments

Ultima X5000 Gas Monitors

The Ultima X5000 combines innovative design, including a touch-button interface, Bluetooth technology and dual sensing technology to reliably and rapidly provide live data relating to the detection of any two combinations of combustible gases such as H₂S or CO and 0-25% O₂.

FlameGard 5 UV/IR Flame Detector

MSA’s FlameGard 5 UV/IR Flame Detector is specifically designed for the detection of fires. It is able to do so within a robust casing, whilst providing alarm outputs directly from the detector. Furthermore the FlameGard 5 UV/IR Flame Detector is designed to do this while maintaining false alarm immunity.

Observer-I Ultrasonic Gas Leak Detector

Ultrasonic gas leak detectors respond to the ultrasonic noise created by a pressurized gas leak, as opposed to measuring % LEL as other more conventional gas detectors do. This ultrasonic noise provides a measurement of the leak rate and establishes warning and alarm thresholds. The Observer-i Gas Leak Detector is ideally suited for outdoor installations and indoor spaces with high ventilation rates.

Ultima OPIR-5 Open Path Infrared Detector

MSA’s Ultima OPIR-5 Open Path Infrared Detector is designed to provide constant monitoring of methane, propane and various other combustible gases. It is capable of monitoring in both LEL-m and ppm-m ranges, rendering it sensitive to both small and large leaks. The Ultima OPIR-5 Open Path Infrared Detector can cover large open areas, along a line of several potential leak sources such as a row of valves or pumps, and for monitoring the perimeter.

References and Further Reading

Total U.S. natural gas production, consumption, and net imports, 1990-2035 - https://www.eia.gov/

This information has been sourced, reviewed and adapted from materials provided by MSA - The Safety Company.

For more information on this source, please visit MSA - The Safety Company.