Virtual Pipeline: CNG and LNG Trucking

A virtual pipeline uses trucks and specialized containers to deliver compressed natural gas (CNG) or liquefied natural gas (LNG) to industrial sites, power plants, and remote communities beyond the reach of traditional steel pipeline networks. It is “virtual” because it provides pipeline-like continuity of supply without the permanence or capital intensity of buried infrastructure.

CNG trucking: high pressure, modest range

Compressed natural gas (CNG) is natural gas squeezed into steel tubes at 200–250 bar pressure (roughly 250 atmospheres). A truck bed can carry 4–5 ISO containers, each holding 5–15 tonnes of CNG, depending on tank design. A single truck round trip might cover 100–200 km with standard trailers.

The advantage is simplicity. CNG compressors are standard industrial equipment found in many industrial parks and town gas works. A supplier near a pipeline feeds gas into a compressor, fills truck-mounted cylinders, and dispatches them. At the destination—a remote refinery, cement plant, or petrochemical facility—the truck connects to an unloading system that pipes the gas into a receiving tank or directly into the customer’s process.

CNG is economical for:

• Short-to-medium distances (50–200 km) where a permanent pipeline network is not yet built
• Intermittent or seasonal demand where a plant runs part-time (e.g., seasonal mining, seasonal power generation)
• Emergency bridge supply while a main pipeline is under maintenance or during supply disruptions
• Decentralized small users too dispersed to justify one trunk line (e.g., clusters of small industrial consumers across a region)

The cost to ship CNG is roughly 1–3 dollars per million BTU (energy unit) for moderate distances, including compression, truck transport, and handling. By contrast, a long-distance pipeline incurs high capital cost upfront (50–100 million dollars per 100 km for a large-diameter trunk line) but very low per-unit operating cost thereafter. CNG is best for niche scenarios, not bulk or long-distance supply.

LNG trucking: higher density, more infrastructure

Liquefied natural gas offers higher energy density: one tonne of LNG contains as much energy as ~1,380 cubic meters of gas at standard pressure. A truck can carry 20–60 tonnes in an insulated cryogenic container, delivering the equivalent of a very large volume of gaseous gas in a single trip.

An LNG truck typically sources from a regional liquefaction facility (often integrated with a major LNG regasification terminal or industrial plant that has excess LNG). The truck, fitted with a vacuum-insulated tank and boil-off safety vents, is filled and dispatched. At the destination, gas is unloaded via heating coils or vaporizers that boil the LNG and meter it as gas into pipelines or directly into on-site equipment.

LNG trucking is favored for:

• Longer ranges (200–500 km), where the higher energy density justifies transport time and insulation cost
• Seasonal or peak demand (e.g., peaking power plants, winter heating)
• Industrial parks or clusters where one small-scale liquefaction source can service multiple nearby customers
• Islands or remote regions where LNG ships cannot reach but trucks can (e.g., inland remote communities, mountain valleys)

Operating cost is 2–4 dollars per million BTU for moderate distances, higher than CNG per unit because of liquefaction energy and insulation maintenance, but justified by the smaller number of trips needed.

Economics: pipeline versus virtual pipeline

A rule of thumb: if demand is steady, distance exceeds 300 km, and volume justifies a 6-inch diameter or larger pipeline, a fixed pipeline is cheaper over 20+ years. Below that threshold or for temporary demand, trucking is economical.

Example calculation for 100 km distance, 5 million cubic meters per year demand:

Fixed pipeline route:

• Capital: 50 million dollars (100 km × 500K per km for 6-inch line)
• Annual opex: 1 million dollars
• Annual cost (20-year amortization + opex): 4 million dollars per year
• Cost per unit: 0.80 $/million BTU

Virtual pipeline (LNG trucking):

• Trucks + containers: 1 million dollars (5 trucks at 200K each)
• Liquefaction (assuming it exists nearby): outsourced, built into commodity price
• Labor, fuel, insurance: 1.5 million dollars per year
• Cost per unit: 2.0–2.50 $/million BTU

The pipeline wins on cost if demand is steady. But if demand is seasonal (halves in summer), the pipeline sits idle and its unit cost explodes; the virtual pipeline can be scaled down (fewer truck trips). Or if demand is temporary (3 years), the truck amortization is faster.

Small-scale liquefaction and mobile units

Increasingly, small-scale liquefaction plants (5,000–50,000 tonnes per year) are built near industrial clusters, gas fields, or landfills. These plants, costing 50–150 million dollars, liquefy gas into small-batch storage, which is then loaded onto trucks. This hybrid approach (fixed plant + mobile delivery) combines capital investment with delivery flexibility.

Similarly, mobile regasification units (barge-mounted vaporizers) can be stationed offshore or in ports, regasifying LNG and metering gas to land-based customers or industrial facilities at the dock.

Regulatory and safety considerations

CNG and LNG transport is tightly regulated. Trucks must pass rigorous inspections, drivers require hazmat licensing, and routes are often restricted (e.g., no urban centers, specific hours). LNG trucks are particularly scrutinized because cryogenic spills can cause burn injury and frost damage.

In most jurisdictions, a single truck can carry only a limited amount of CNG or LNG without special permits. A truck with 10 tonnes of LNG might require police escort, route notifications, and real-time tracking. These requirements increase cost but are essential for public safety.

Global adoption and constraints

Virtual pipelines are most developed in countries with dispersed industrial demand and incomplete pipeline networks: Indonesia, India, Argentina, and parts of sub-Saharan Africa. Japan and South Korea also use CNG trucking extensively for seasonal and small-user supply.

The US and Europe, with mature pipeline networks, use virtual pipelines mainly for emergency supply or peak-demand bridging. During the 2021–2022 European energy crisis, virtual pipelines (both CNG and LNG trucks) were mobilized to supply remote regions when Russian pipelines were cut off, though at much higher cost than normal supply.

Limitations remain. Weather affects trucks (icy roads, extreme heat); boil-off in LNG trucks can exceed 0.5% per day on long journeys; and labor availability for drivers and technicians is often tight in developing regions. Nonetheless, as renewable energy intermittency grows and industrial decarbonization accelerates, virtual pipelines for hydrogen and biogas may expand their role beyond natural gas.

See also