- 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).
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.
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.