When Trunkline LNG Lake Charles, La., terminal’s new re-gasifying enhancement goes online in 2008, it is expected to save the company millions in fuel costs and provide a more environmentally-friendly alternative to traditional methods. Under a $250-million contract, Mustang Engineering of Houston will be installing the first Smart Air Vaporization process in the United States. The LNG Smart Air Vaporization process captures the natural heat in ambient air and humidity to vaporize LNG, greatly reducing fuel costs. “At $6 per unit for gas, you’re saving $25 million a year in fuel per Bcf (billion cubic feet), and gas has gone up as high as $14,” says Joe Nelson, midstream engineering manager for Mustang. click here to view image >>
By the time Trunkline completes ongoing expansions in 2008, the terminal’s average daily sendout will be 1.8 Bcf per day, with a peak at 2.1 Bcf/d. A Trunkline spokesperson would not indicate what percentage of sendout will be heated using the new process, but it is likely to translate into substantial savings in the cost for fuel that would normally be required to regasify the LNG. Trunkline filed for Federal Energy Regulatory Commission certificates and authorizations March 31, and is awaiting approval to begin construction.
The smart air process involves using air exchangers to pull in surrounding air, Nelson says. “We use a potassium formate solution as an intermediate fluid that is circulated through the air heaters. That warms up the fluid, which then goes through the LNG vaporizer and counter flows. When they are pumped out together, it is natural gas.”
The only emissions from the process are water and whatever contaminants exist in the ambient air, including dust particles and bird feathers, Nelson says. “We generate 800 gallons per minute per Bcf of fresh water based on 80% humidity, which is about 900 gallons per minute,” he says. “It’s really no different than rainfall. If you were able to collect it and do it in the Middle East, you could probably sell it for more than oil products.”
Comparatively, all re-gas terminals in the United States are submerged combustion vaporizer (SCV), and the fuel burned for heating releases emissions of carbon dioxide and carbon monoxide, Nelson says. The new Trunkline LNG closed system features a KF/glycol exchanger and LNG Smart supplemental heat system with shutoff valves make it possible to alternate production between the two methods, depending upon ambient air temperature. “In the Gulf coast, 89 percent of the time, you would be using just the KF,” Nelson says.
The smart air system provides a welcome alternative to the open rack vaporizer (ORV) method that is widely used in Japan but has met with considerable opposition in the U.S. “If you use the ORV, you are taking large amounts of seawater, pumping it through, adding chemicals to keep corrosion down, and discharging this water at 8 or 10 degrees cooler than when it comes back in,” Nelson said. “That does have a lot of people concerned about the environmental effects.”
Although this is the first time Mustang has designed a re-gas terminal using the technology, an ambient air re-gas facility using different fluids and design criteria has been in service in India for a couple of years, Nelson says. However, that system uses different fluids and design criteria. Although it has been successful in reducing emissions, “it had to have a lot more equipment and horse power because it used a glycol, which gets gummy,” Nelson says. Louisiana is the ideal environment for Mustang’s process, which is most efficient at 70 degrees and 80% humidity, he says. “The more humid the climate, the better the pf solution works.” At the Lake Charles, La., facility, heat backup would still be required during colder months, but “between March and mid-October, a large amount of the heat will likely be provided by these air vaporizations,” Nelson says.
The National Gas Company of Trinidad and Petroleum Corporation of Jamaica, which is the Jamaican counterpart, partners in a new LNG facility that is being constructed near Port Esquivel, about 40 miles west of Kingston, are considering using the process. “It is a perfect place because it never gets below 50 degrees, and they don’t want to burn the fuel because it happens to be in a shallow bay,” Nelson says. “We are in the process of putting the final report out to them in about two weeks. The actual construction award is not until the second part of 2007.”
Mustang’s Trunkline contract also involves installation of a natural gas liquids (NGL) extraction plant, which will allow the terminal to import supply from more diverse locations without concern for varying composition of the LNG. “Both pipeline and terminal customers likely will see benefits of the project for year to come, whether it is in increased supply, improved gas quality or more competitive usage costs,” says Rob Bond, president and chief operating officer of Panhandle Energy, Trunkline’s parent company.