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Trunkline LNG approved to start vaporization, NGL recovery

Warren R. True
Chief Technology Editor-LNG/Gas Processing

HOUSTON, Mar. 15 -- Southern Union Co. subsidiary Trunkline LNG has received approval to start up new vaporizers and NGL extraction at its LNG terminal at Lake Charles, La.

Four ambient-air vaporizers and an NGL plant comprise Trunkline’s Infrastructure Enhancement Project, approval for which Southern Union received in December 2006 from the US Federal Energy Regulatory Commission. It is only the second US use of that vaporization technology, after Freeport LNG’s seven trains on Quintana Island, Tex.

Trunkline’s NGL recovery operation, on the other hand, is the first installed in North America and aims to widen the heating-value range of cargoes the terminal can accommodate. The sole customer at the South Louisiana terminal is BG LNG Services, which will own all liquids from the recovery operation and to which the terminal is fully contracted through 2030.

Southern Union said in its announcement that the project cost about $430 million, excluding capitalized interest, and is expected to generate operating income of $55-60 million/year.

In its initial March 2006 FERC application and its July 2006 amended application, Southern Union estimated total capital cost of about $244 million, excluding allowance for funds used during construction (AFUDC), but total capital cost would reach nearly $274 million.

What’s new
Southern Union told OGJ that Trunkline’s four new vaporizers are now the primary vaporizers, with the 14 existing submerged combustion vaporizers retained for when the weather prevents use of the ambient-air technology. Freeport LNG has similar back up vaporization available.

Using the surrounding air temperature to regasify LNG permits the terminal to “reduce the amount of fuel that would typically be used” by existing SCVs. The technology is often cited as more environmentally benign than SCV because it doesn’t burn a hydrocarbon fuel to heat water to render LNG back into natural gas.

Trunkline has installed the “LNG Smart” vaporization process licensed by Mustang Engineering, Houston. Installing NGL processing permits extraction of a C2+ stream for BG LNG.

According to the 2006 FERC documents, Trunkline’s NGL processing can extract liquids from about half the terminal’s daily sendout volumes before the residue gas is sent to pipeline for delivery to downstream markets. Current sustained sendout capacity for the terminal is 1.8 bcfd; peak capacity is 2.1 bcfd.

The application stated design of the processing would allow for a second NGL recovery train at an unspecified later date. The document also listed the make-up of the single train, designed with an inlet capacity of 1.184 bcfd and out of 1.05 bcfd:

• Two propylene glycol heaters (150 MMbtu/hr each).

• Glycol storage and circulation.

• One NGL recovery unit.

• Two parallel 12-in., 1,160-ft pipelines to move an ethane and C3+ stream to metering.

Also part of IEP is construction of an NGL product meter station downstream of the recovery operation, expansion of existing electric substation, and two 16.4-mile takeaway pipelines consisting of a 12-in. C2 line and an 8-in. C3+ line.

The metering and everything downstream of it, according to the 2006 FERC document, will be operated by BG LNG under contract with PetroLogistics Olefins LLC, Houston, which operates storage at Sulfur, La.

Contact Warren R. True at warrent@ogjonline.com.


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