ISO Container LNG Logistics

Why ISO containers matter

Containers unlock routes that dedicated LNG trailers and carriers cannot serve economically: islands, ports without LNG terminals, rail served inland sites, and small export markets. Because they ride the existing container shipping system, no special vessel or receiving terminal is required. A crane, a chassis, and a vaporizer skid are enough to create a receiving point.

How a containerized supply chain runs

Containers fill at a liquefaction plant, travel by any combination of truck, rail, and container ship, and arrive at the customer site or port. There they either discharge into fixed storage or connect directly to vaporization, functioning as swap storage: full containers rotate in, empties rotate back. Hold time before pressure relief is typically measured in weeks, which comfortably covers ocean transits in most lanes.

Container versus trailer

Road trailers carry more per trip and suit high volume domestic routes. ISO containers win when the route is intermodal, crosses water, needs onsite storage flexibility, or serves many small delivery points from one loading hub.

Who provides this service

VP Ventures moves LNG in ISO containers by truck, rail, and ship, and provides the onsite storage and regasification that turn a container into a gas supply point. The U.S. Department of Energy identifies Virtual Pipeline Ventures by name for LNG transportation through ISO containers to Caribbean, Central American, and South American markets.

What one container actually delivers

A 40 foot LNG ISO tank holds up to 39,100 litres, which is 10,329 gallons, at a maximum working pressure of 100 psi, with a static hold time of at least 60 days.

Converted into the units that matter:

Generation figures assume a heat rate of 9,000 Btu per kilowatt hour. A more efficient unit stretches these, a less efficient one shortens them, but the order of magnitude holds.

The number that surprises most people is the last one. A 10 megawatt load consumes roughly one container every ten hours of running, which is two and a half containers a day. Sizing the storage and the delivery schedule around that, rather than around the tank, is what makes a containerised supply work.

Capacity, pressure and hold time from a 40 foot LNG ISO container datasheet. Energy content calculated at 23,726 Btu per pound, higher heating value, from the US Department of Energy Alternative Fuels Data Center.

Sixty days of hold time, and what it is for

Static hold time is how long a container keeps its contents without venting, with nothing drawn off. Sixty days is the usual minimum specification.

That number is why ISO containers suit the jobs they suit.

It makes long transport possible. A container can cross an ocean, clear a port and sit on a quay without losing its cargo, which a road trailer cannot do.

It makes intermittent use practical. A standby installation that runs twice a year is a problem for cryogenic storage, because fuel that sits still slowly warms and raises pressure. Sixty days of hold time turns that from a design headache into a scheduling one.

It does not mean sixty days of supply. Hold time is about the container keeping its contents, not about the site having enough. A site consuming continuously will empty a container long before hold time matters at all.