LNG versus pipeline gas: how do lifecycle emissions compare?

LNG accounts for only 10% of total natural gas traded across the globe, yet its rate of growth is almost twice as fast as pipeline gas, making it an important part of the portfolios of major oil and gas companies.

But while the process of piping natural gas to market is relatively straightforward, the LNG value chain is more complex. This is due to the relatively high energy — and consequently carbon — intensity associated with the liquefaction of natural gas and the requirement for any contaminating CO₂ to be removed from feedstock gas.

When likening the emissions associated with typical pipeline and LNG projects (wellhead to FOB point) to carbon-intensive Canadian oil sands developments, we found the emissions of the former were relatively low while the latter ranked comparably.

However, making a direct comparison between LNG and pipeline gas isn’t entirely fair. One of the most important variables affecting emissions from an LNG project is the contaminant CO₂ content of the feedgas — a high concentration of which can result in substantial additional emissions from venting.