Achieving “carbon neutrality” is the crucial step along the road to “net zero” which includes the removal from Earth’s atmosphere of all “greenhouse gases”, including methane, nitrous oxide and other hydrofluorocarbons. Indispensable to creating sustainable environments, the health of the planet and the survival of the human race depend on it.
No wonder both goals are now global priorities. Since 1995, the United Nations has been bringing together almost every country for global climate summits or COPs (Conference of the Parties). Most recently in Sharm Al Sheikh, Egypt, COP27 saw the parties reaffirm their emissions-reduction goals and the race is very much on.
Which us where the rubber hits the road bringing into play a range of technology and energy sources. However, not all solutions are created equal.
One technology, carbon capture and storage (CCS), or carbon capture and sequestration, stands tall for its ability to help energy-intensive sectors like power generation and heavy industry reduce their emissions. Indeed, the International Energy Agency has said that without CCS, achieving the world’s lower-emission targets will be virtually impossible. Though not new, it is increasingly coming to the forefront of the climate conversation.
In essence, CCS is the process of capturing carbon dioxide from industrial activity or power plants before it enters the atmosphere and then injecting it deep underground for safe, secure and permanent storage. One of the few technologies proven to help decarbonize energy-intensive industries, up to 90% of emissions from industrial activities can be captured this way, making it an unparalleled tool in mitigating climate change.
How does carbon capture and storage work?
Carbon capture and storage is a safe and proven technology that captures carbon and permanently stores it before it can reach the atmosphere. It isn’t easy, though. Separating molecules as small as carbon dioxide requires tremendous precision. For example, carbon dioxide makes up only 4% of the exhaust from natural gas turbines.
First, CO2 is separated from other gases at the industrial facilities or directly from the air. Then comes transportation where captured CO2 is compressed and transported for geological storge. Next, the CO2 is injected into rock formations thousands of feet below earth’s surface.
Zooming in, once captured, the carbon dioxide is typically pushed into a pipeline and sent to injection wells at the storage site. Finding the right location to store carbon underground and keep it secure is the work of geologists and scientists. Any formation chosen for CO2 storage will be at least 2700 feet and can be as deep as 18,000 feet. That way it poses little risk to people and is far enough beneath the surface to prevent interaction with the water table, which is in the top 500 feet. The injection sites will also be far enough away from faultlines and earthquake prone areas to eliminate the risk of CO2 migrating to other formations.
Once injected, the CO2 will be held in place by thick, impermeable seal blocks similar to the rocks that have kept oil and gas underground for millions of years. The CO2
will also be pressurized to increase its density by 300 to 500 times, so large amounts of CO2 can be stored in relatively small areas.
A three-tier system of technologies then monitors sites for leaks at atmospheric, near surface and subsurface levels. Over hundreds of years the CO2 will start to mineralize and over tens of thousands of years, it will begin to transform from a gas to a solid.
Where are we now?
Heavy-emitting sectors, such as power generation, refining, petrochemical production and industrial manufacturing, currently make up more than 70% of all global energy-related emissions. In Asia Pacific alone as recently at 2019, these industrial emissions reached around 4 billion tonnes.
Meanwhile, as of 2020, the world’s total CO2 capture capacity from power and industrial facilities stood at 40 million metric tons. To put that into perspective, according to the National Academies of Sciences, Engineering and Medicine, the world must remove around 10 gigatons of carbon dioxide from the atmosphere each year by mid-century. One gigaton equals one billion metric tons.
Enter CCS to help industries offset their emissions while still being able to increase production to meet growing demand. According to the International Energy Agency (IEA), CCS technology will account for up to 15% of the emissions reductions needed to meet global targets set at COP in 2050.
Besides environmental benefits CCS has a range of economic benefits. IEA estimates between 70 and 100 CCS facilities are need to be built each year by 2050, requiring between US$655 billion and US$1.28 trillion in investment.
ExxonMobil leads the way
Having captured more carbon dioxide over the past 30 years than any other company, ExxonMobil leads the world in CCS. Currently, ExxonMobil captures more than 9 million tonnes of carbon dioxide per year in the United States, Australia and Qatar and has removed more than 120 million tonnes in total. Across Asia Pacific, the company envisions creating CCS hubs, regional networks that connect high-emitting industries to world-scale storage. Accordingly, it is placing carbon capture hubs in Southeast Asia’s heavy industrial areas, with their captured carbon dioxide transported to carbon storage sites elsewhere in the region.
Eyeing more need for CCS on the horizon, ExxonMobil is deploying its expertise to expand the use of the technology, taking on a key role in helping to keep the world on the path toward lower emissions.
