With natural gas prices at a historic low in the United States, Liquefied Natural Gas (LNG) export facilities are growing in popularity in the United States. LNG is natural gas that has been converted to a liquid form, bringing it to 1/600th the size of its gaseous state to make storage and transportation easier. Currently, there are multi-billion dollar proposals from developers across the country interested in developing LNG facilities - particularly, LNG export facilities. Not only is natural gas inexpensive at this point in time, but it also burns cleaner - making it less expensive to add environmental controls to natural gas power generation facilities. However, with the added number of LNG facilities and natural gas plants, what are the added fire protection systems needed to protect people, property, and plants across the country?
The Surge in Natural Gas Plants
The Clean Air Act was enacted in 1963, but has been a major focus in the political climate for the past decade. In 2011, the EPA began regulating
greenhouse gases. With this addition to the act, power plants began getting strictly regulated. Coal-fired power plants are slowly being replaced by more green solutions. One of the cleanest fossil fuels is natural gas. When it is fully burned, it converts to carbon dioxide and water vapor. Natural gas has fewer impurities, is less chemically complex, and its use results in less pollution. Natural gas produces significantly less carbon dioxide, which is a primary greenhouse gas; sulfur dioxide, which is a primary precursor to acid rain; nitrogen oxides, which is a primary cause of smog; and particulate matter. Technology allows all fuels to burn as a cleaner energy; however, because natural gas burns cleaner, naturally, it is the least expensive energy source because adding environmental controls to this type of fuel is inexpensive, if required at all.
Natural gas is a highly efficient fuel. While most fuels lose approximately 70% of available energy to production, generation, and transmission (delivering about 30% of power to customers), 90% of natural gas is delivered to customers as energy.
The versatility and price of natural gas makes it the current favorite in the energy sector. It can be used as either a compressed natural gas or liquefied petroleum gas. It is easy to store and transport through pipelines, small storage units, cylinders, or tankers by land or sea. Natural gas is abundant, making it an easy choice. That is why in the 2015-2016 winter (November 2015 - February 2016), power generated by burning natural gas was higher than any other year. It averaged 25 billion cubic feet per day, up 17% from last year. In fact, in 2015, 40% (totaling 6,200 MW) of new utility scale plants were natural gas plants.
The Growth of Liquefied Natural Gas
In 1917, the first LNG plant was built in West Virginia. When natural gas is liquefied, it condenses to 1/600th the space that the gaseous version takes. When natural gas is liquefied, it is more efficient to transport and store.
Natural gas is cooled to -260 degrees Fahrenheit, and the cooling process removes water, carbon dioxide, nitrogen, oxygen, sulfur compounds, and other hydrocarbons - leaving mostly methane. The gas is very light - so light, it would float on water, so it makes for an easy transport.
An added benefit of LNG is it is much safer than gaseous natural gas. It is estimated that LNG has been shipped approximately 100 million miles and has never had a major accident. In its liquid state, natural gas isn't flammable. However, as it vaporizes and mixes to a concentration of 5-15% in air, it can become flammable and explosive. Because of this, LNG facilities need to be protected with proper fire protection systems and alarms for the various fire hazard event types.
Protecting LNG Facilities from Fire
While there is a small window of flammability with LNG, it is still a very real risk. Static pool fires, two dimensional flowing fires, three dimensional spill fires, pressurized spray fires, and explosions can occur as a result of LNG. Fires become a threat in LNG facilities when LNG is accidentally released and creates a vapor cloud. The vapor cloud mixes with oxygen and becomes flammable. When the LNG vapors are ignited at a distance from the spill or release source, a flash fire can occur. If the LNG vapors are confined or in a congested area of the plant, they are at risk of exploding. Often, the ignition source is electrostatic discharge.
Because of the fuel source, water solubility needs to be taken into consideration. For burning pool fires, high-expansion foam, dry chemical, and exposure protection are recommended. Various types of alarms are needed for these types of facilities too: flame detectors, gas detectors, low temperature spill detectors, heat detectors, and elevated oscillating monitors.
As natural gas becomes the go-to fuel source for the energy sector, LNG facilities will grow in demand. We already see a sharp increase in the building of LNG export facilities and it is bound to increase as environmental regulations will likely not lessen. These facilities must be kept safe with proper fire protection and detection.
F.E. Moran Special Hazard Systems' Experience
One of the first LNG export facilities in the US was built on over 1,000 acres of land, and several more are being built on all coasts. F.E. Moran Special Hazard Systems is providing the fire and gas detection for this particular facility. With various fire hazards – natural gas, refrigeration gases (propane, methane, and ethylene) – several different types of detection are needed. Flame detectors, gas detectors, low temperature spill detectors, heat detectors, elevated oscillating monitors, fire pumps, and clean agent systems are used on this project to keep the facility and workers safe from fire.
One of the biggest challenges in a project of this size are routing cabling over 1,000 acres. The key is to pre-plan cabling routes to meet the facilities’ needs while minimizing the impacts on daily operations.