A company proposing four liquefied natural gas export terminals in south Louisiana plans to capture climate-changing greenhouse gases from at least two of its projects for storage deep underground to prevent carbon from entering the atmosphere.  

Arlington, Virginia-based Venture Global LNG expects to use advanced technology to capture carbon from the liquefaction process, compress the CO2, then inject it into saline aquifers for permanent storage. The company did not say what percentage of total carbon produced would be captured for storage, and not enough is known from permit documents about its plant emissions to determine how significant the reduction is.

The company said it could extend the carbon capture effort beyond the two projects to all four of its proposed terminals in Louisiana. One already is under construction in coastal Cameron Parish, where another project is proposed. Two others are proposed south of New Orleans.

"Our location in Louisiana uniquely positions us to pioneer the deployment of this technology due to geology that can support industrial-scale injection and storage of CO2," Mike Sabel, chief executive officer of Venture Global, said in a news release. "Through this historic carbon capture and sequestration project, we will build upon our existing state-of-the-art technology to develop even cleaner LNG at our facilities to displace coal around the world."

Demand for a cleaner version of LNG is high among countries that have plans to reach net-zero carbon emissions by 2050. Carbon is a greenhouse gas that contributes to climate change by entering the atmosphere and causing the Earth's protective ozone layer to deteriorate.

The company said the 1 million tons of carbon captured each year would equal the emissions of 200,000 cars no longer driving on the road for 20 years.

Venture Global LNG said it already has completed "comprehensive engineering and geotechnical analysis" for the carbon sequestration plan for two projects — its Calcasieu Pass site south of Lake Charles and Plaquemines LNG south of New Orleans — and is awaiting regulatory approvals.

Between the two export terminals, the company expects to sequester 500,000 tons of carbon each year.

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If granted regulatory permits, a third Venture Global LNG project, known as CP2 LNG, would also use carbon sequestration for another 500,000 tons of carbon each year. That project is near Calcasieu Pass LNG in Cameron Parish.

The company also has proposed a Delta LNG project south of New Orleans, for which it did not share any carbon sequestration plans. 

It's unclear exactly how much carbon Venture Global LNG's export terminals would collectively emit once in operation, and making a determination from permit documents is difficult because of the mix of emissions that occur in processing the LNG. 

For example, the Calcasieu Pass LNG terminal now under construction is permitted to emit 3.9 million tons of greenhouse gas equivalents a year — which includes carbon. The equivalents also can include methane and N20 — not just carbon alone. While that makes it difficult to calculate a ratio of carbon captured to the total amount released, it does appear a project that size would not likely be a net-zero carbon facility. 

Still, "about 1 million tons a year is a sizable number," said David Dismukes, executive director of the LSU Center for Energy Studies. "It's not huge compared to the likes of the Exxon proposal in Houston of 50 million up to 100 million, but it's a solid project. Not net-zero, but it's a solid start," he said. "It's a big deal in terms of (being) a first mover. Everyone's (LNG projects) are going to have to do it (carbon capture) to get a project to its COD (commercial operations date)."

Meanwhile, Venture Global and companies seeking similar carbon capture projects, would need to make sure total costs — not just the upfront drilling — would stay below $50 per ton of carbon, or $50 million for 1 million tons, over the lifecycle of the wells.

That's because there's a $50 per ton tax credit available through the federal government and the potential cost for carbon capture could decline as the technology is more widely adopted. The U.S. Department of Energy projected by 2030 carbon capture could drop to $30 per ton, or in this case $30 million for 1 million tons.

Email Kristen Mosbrucker at kmosbrucker@theadvocate.com.