Proposed US Pipeline Network For Capturing 30 Million Metric Tons of Carbon Dioxide Every Year

• A proposed pipeline network could elevate improved oil recovery in the United States by 50%.
• With proper infrastructure, the nation could double the amount of CO₂ emissions stored within 6 years.

Carbon Capture, Utilization, and Storage (CCUS) is one of the most important technologies that could help reduce emissions of carbon dioxide (CO₂) to the atmosphere and limit warming to the 2 degree Celsius (as per the Paris Agreement). The combination of CCUS with direct air capture or bioenergy is also a crucial alternative among negative emissions technologies that might be required to eliminate CO₂ from the atmosphere.

A few months ago, researchers at Princeton University proposed a United States pipeline network that would capture, transfer and store underground as much as 30 million metric tons of CO₂ emissions annually. This would be equivalent to reducing 6.5 million vehicles from the road.

In early 2018, the US approved significant financial incentives for CCUS that will make the CO₂ capturing process economically viable. According to the researchers, with proper infrastructure investments, the nation could almost double the amount of CO₂ emissions stored within 6 years.

The Pipeline Network

The proposed pipeline network (central blue line) would transport CO₂ waste from ethanol fermentation at biorefineries in the Midwest (green discs) to oilfields in West Texas. Then it would be pumped into dried oil fields, where CO₂ would eventually get trapped underground, helping the residual oil to recover.

Image credit: Ryan Edwards | Princeton University 

Currently, Midwest biorefineries emit approximately 43 million metric tons of CO₂ each year. It is located far from already built CO₂ pipeline (thin orange lines).

Reference: PNAS | doi:10.1073/pnas.1806504115 | Princeton University 

Similar massive-scale infrastructures like electric-power grids and the Interstate Highway System have already been developed with government investment and coordination.

According to the analysis, if the government provides low-cost loans for only 50 percent of the total pipeline network, it would still capture 19 million metric tons of CO₂ annually.  As of now, nearly 31 million metric tons of CO₂ is trapped and stored per year worldwide.

To enable such large-scale deployment in the near future, it’s necessary to have additional public support along with tax credits. Though state governments play a crucial role in this matter. One of the most impressive recent examples is Texas state government that led the clean-energy infrastructure and bought a big wind-energy boom in the state.

Why Ethanol Refineries?

Ethanol refineries produce gas that contains 99% CO₂, making it the most cost-effective place to trap carbon dioxide. As far as burning coal is concerned, it has only 10% to 15% CO₂, and its capturing technique is bit expensive too.

The cost of capturing CO₂ from gas and coal sources ranges from $50 to $75 per metric ton, whereas for ethanol sources, the cost lies between $20 and $30.

The midwest ethanol refineries that generate 43 million tons of CO₂ every year are situated far from the existing pipeline networks. Thus they can’t be efficiently utilized to store the gas.

Moreover, traditional recovery from an oil well produces nearly 40% of the total oil inside the rock. One can recover more oil — up to 15% more — by inserting CO₂ into the reservoir. The gas is isolated from the oil at the surface, which is then returned into the ground and eventually trapped there.

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According to the analysis, the proposed pipeline could elevate improved oil recovery in the US by as much as 50%. It will be a win-win for domestic energy security and climate conditions.