When Sylvia Little fried her eggs at her Adelaide home one November morning in 1969, she became Santos’s first customer for natural gas from Moomba, 800 kilometres north in the Strzelecki Desert.
It is doubtful Mrs Little would have known or cared that the natural gas originally contained CO2 when it emerged from the ground – or that Santos stripped it out before piping methane to customers.
CCS is one of the big hopes for achieving net zero emissions, with the International Energy Agency pushing for a massive increase between now and 2050 – going from 40 million tonnes of CO2 stored annually to 5.6 billion tonnes by 2050.
It’s supposed to bury the carbon dioxide it separates from natural gas – up to 14% of the volume – into a siltstone and sandstone formation 2.3km under the island.
Before injection underground, it’s transformed into supercritical CO2, which is dense like a liquid but moves like a gas and totals just 0.0036% of the original volume.
CO2 is also in natural gas extracted by Santos from its Cooper Basin wells.
While he says it won’t be easy, he believes the geological conditions for the Moomba project are “far superior” to those Chevron faces on Barrow Island.
Unlike Chevron, which had to use CCS to win permission to extract the gas, Santos is driven by shareholder pressure for a greener profile, new access to federal government subsidies in the form of tradeable carbon credit units for every tonne of CO2 it buries, and a plan to pivot its fossil gas into touted future fuel hydrogen.
So, to suddenly say, well, carbon sequestration, we’re going to wave a wand, it’s going to work reliably.
But he says it has worked reliably for enhanced oil recovery in North America, where CO2 is pumped underground to help release oil that is hard to access.
“It’s bullshit; it is going to be buried essentially for ever,” he says.
Santos has plans for three CCS projects, with another at the depleted Bayu-Undun gas field in the Timor Sea, using CO2 from its Barossa gas project off Darwin, and a third in Western Australia.
“I don’t know of any true CCS project in a gas project that I’d describe as a failure,” he told an Australian Financial Review business conference last week.
Finkel says it may have failed when applied to coal-fired power stations, because catching and separating CO2 from flue gasses is difficult and expensive.
Santos says with all three hubs it could store 30 million tonnes a year, equal to 6% of Australia’s emissions of just under 500 million tonnes.
The CO2CRC has been investigating and testing capture, separation, and storage technology at its Otway test centre since 2006 and its test field holds 100,000 tonnes of CO2.
To make room for the gas between the grains in the sandstone, the salty water had to be extracted.
But he says Santos has “definitely an easier proposition” at Moomba, with ready access to the CO2 and storage in depleted oil and gas reservoirs.
He is hopeful Santos can now “really show the world” how CCS can be done, with best practice as an economic proposition and a benefit for society.
And unlike planting trees, which can take decades to grow and absorb carbon, CCS can remove huge amounts quickly and permanently.
The Australian Government’s decision to grant CCS projects access to carbon credit units should also spur development, he says.
But success by Santos would still only reduce a part of the emissions it creates.
Federal Energy and Emissions Reduction minister Angus Taylor recently gave $250 million in grants to design CCS hubs and support research and commercialisation of CCS technology, including identifying geological storage sites.
Dr John Kaldi, University of Adelaide emeritus professor and state chair of CCS, says the technology can work for many industries, but costs will generally be higher than for gas producers.
But extracting flue gasses from coal-fired power stations is comparatively very expensive and not economic in Australia – although he thinks costs will go down.
This article first appeared in Cosmos Weekly on 22 October 2021.
He has worked for The Age, The Australian, The Advertiser and The Bulletin, and written for Time magazine and The Times of London.
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