GISERA research assesses CSG-LNG greenhouse gas emissions

An assessment of whole-of-life greenhouse gas emissions associated with the Queensland coal seam gas (CSG) to liquefied natural gas industry (LNG) is detailed in a new report released today by CSIRO’s Gas Industry Social and Environmental Research Alliance (GISERA).

The report — ‘Whole of Life Greenhouse Gas Emissions Assessment of a Coal Seam Gas to Liquefied Natural Gas Project in the Surat Basin, Queensland, Australia’ — assesses greenhouse gas emissions of a CSG-LNG project in Queensland, and the relative climate benefits of using Queensland natural gas in place of thermal coal as fuel for the generation of electricity in Australia.

A unique feature of the research is the use of commercial-in-confidence data from a CSG to LNG project in the Surat Basin, Queensland, to provide accurate estimates of whole-of-life greenhouse gas emissions associated with CSG-LNG operations in Australia.

The report found that greenhouse gas emissions associated with CSG production, compression, dehydration, water treatment and liquefaction represented 1.4% of likely future production for this CSG-LNG project (576 PJ/year).

The primary activities in the CSG-LNG supply chain contributing to emissions in Australia were electricity use on-site for CSG extraction, and combustion of natural gas for electricity for LNG production. Outside Australia the primary activities contributing to emissions were combustion of natural gas, which represented 83% of total emissions when all processes from wellhead through liquefaction, shipping, regasification and combustion were considered.

Fuel switching from black thermal coal to Queensland coal seam gas for electricity generation using high-efficiency closed-cycle gas turbines in Australia — avoiding liquefaction, shipping and regasification — represents a potential reduction in GHG emissions of around 50%.

GISERA Director Dr Damian Barrett said the results of this latest research aligned with other studies completed by the CSIRO and GISERA in Queensland and other parts of Australia to understand methane and other GHG emissions associated with unconventional onshore gas activities.

“These results are consistent with other CSIRO studies in this region which suggest that the fugitive emissions component of the total greenhouse gas emissions identified in this latest study are at the lower end of the scale,” he said. “The climate benefits of using natural gas in place of thermal coal for electricity generation are generally accepted when fugitive emissions are less than 3% of total production.

“Replacement of coal-fired power by gas-fired generation, renewables and other low-carbon technologies is part of CSIRO’s vision for Australia’s energy transition. Results of this latest research underline the potential climate benefits of using gas in place of coal to generate electricity, particularly when using high-efficiency closed-cycle gas turbines.”

GISERA is a collaboration between CSIRO, Commonwealth and state governments and industry, established to undertake publicly reported independent research.

The purpose of GISERA is for CSIRO to provide quality-assured scientific research and information to communities living in gas development regions, focusing on social and environmental topics.

The governance structure for GISERA is designed to provide for and protect research independence and transparency of research outputs.

In this case the report focuses solely on GHG emissions, and not on other potential environmental impacts of coal seam gas production.