Royal Dutch Shell PLC said its Alberta government-backed carbon capture and sequestration system has trapped 4 million tonnes of carbon dioxide, the most of any onshore facility in the world with dedicated geological storage.

The Quest Carbon Capture and Sequestration, or CCS, project near Edmonton in central Alberta went into operation in late 2015 and has exceeded operating and cost expectations, Shell's Canadian unit said in a May 23 statement. Shell led the construction of the project, which captures emissions from its refinery and partially owned oil sands upgrader in Scotford, Alberta. The company continues to operate Quest, although its interest in the oil sands business that underpins it has dropped to about 10% since it sold most of those assets in 2017.

Construction of Quest started before oil prices collapsed in late 2014, and Shell said a similar facility would cost less to build today. Since it was funded primarily by Canadian governments, data and intellectual properties — including detailed engineering plans Shell claims are valued at C$100 million — are available to the public. Alberta put up C$745 million in funding for the project, while Canada's federal government kicked in C$120 million of Quest's estimated C$1.35 billion cost.

"Quest continues to show the world that carbon capture and storage is working, its costs are coming down and that Canadians are leaders in CCS," Michael Crothers, Shell Canada president and country chair, said in the statement. "If Quest were to be built today, we estimate it would cost about 20-30% less to construct and operate. With our know-how, strong regulatory frameworks and ideal geology, Canada is uniquely positioned to capitalize on CCS technology."

Quest has fared better than Canada's only other large CCS project, the Boundary Dam project, which is linked to a coal-fired electricity generator owned by SaskPower that has been plagued by operating and cost struggles. Boundary Dam beat revised storage targets in 2018 with 625,996 tonnes of carbon dioxide captured. Its original planned capture was 1 million tonnes annually, which is also Quest's target.

The underground formations the Quest project uses have provided better-than-expected quality for carbon dioxide storage. "The geological formation used for storage, which is prevalent across much of Western Canada, is demonstrating incredible capacity for carbon dioxide injection," the statement said.