While the process of piping natural gas to market is relatively simple, the LNG value chain is far more complex and involves carbon emissions along the chain prior to final combustion. As a result of the relatively high energy – and consequently carbon – intensity associated with liquefaction of natural gas and the requirement for any contaminating CO2 to be removed from the feedstock gas before the liquefaction process, the levels of emissions from LNG projects can be significant. In fact a typical LNG project ranks comparably with Canadian oil sands, which are often considered to be the most carbon-intensive upstream projects. However, directly comparing LNG and pipeline gas may not be entirely fair, as contaminating CO2 is typically left in the gas stream in pipeline projects and the CO2 is then emitted when natural gas is burnt in the consuming market, where it is no longer counted as an upstream emission.
Table of contents
Liquefaction of natural gas is a relatively carbon-intensive process
and CO2 venting can significantly impact LNG project emissions
Opportunity for mitigation?
But natural gas in any form is still the lowest carbon fossil fuel for power generation
Tables and charts
This report includes 3 images and tables including:
Emissions intensities of ‘typical’ natural gas projects in comparison with selected Canadian oil sands projects
Example gas project monetised via pipeline or LNG
Generic comparison of life cycle carbon emissions from natural gas and coal