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Environmental Carbon Capture Technology for Urban Residential Properties

At an apartment tower in New York, CO2 is captured, cooled into a liquid and trucked nearby to a factory where it's mixed with cement and sealed into cement blocks.

On cold mornings in New York City, the boilers in the basements of thousands of buildings burn natural gas or oil to provide heat to the residents. Carbon dioxide (CO2) emissions from the boilers waft up chimneys and into the outdoor environment, one of the city’s biggest sources of global warming emissions. But there is one exception, which involves an environmental engineering concept used in the chemical industry.

At the Grand Tier, a 30‑story apartment tower on Manhattan’s Upper West Side, the CO2 from its two giant gas boilers is captured, cooled into a liquid and then trucked nearby to a cement factory in Brooklyn, New York. At this facility, the liquid CO2 is mixed with cement and sealed into cement blocks. The building’s owner, Glenwood Management, didn’t install the technology purely out of concern for the planet but as a matter of necessity for environmental justice.

Why is this innovation so important? A sweeping new climate law in NYC aims to cut greenhouse gas emissions from large residential buildings by 40 percent by 2030 and 80 percent by 2050. Starting in 2024, buildings that exceed emissions limits will face escalating fines. The NYC law is designed for residential building owners to swap gas and oil for cleaner electric heating. But the costs and logistics for that environmental shift can be extremely challenging for some building owners. This is forcing change and innovation as NYC building owners scramble to avoid huge penalties.

In a steamy room next to the parking garage, two industrial boilers roar as they burn natural gas for heat. But the hot exhaust from the boilers is funneled through a duct to a small, spotless room filled with overhead pipes, rumbling compressors and metal tanks. Inside several of the tanks dry absorbents that look like lentils bind to CO2, allowing the machines to filter out other gases like nitrogen and oxygen. The remaining CO2 is chilled to -10 degrees Fahrenheit and turned into liquid CO2.

The equipment is similar to carbon capture machinery used at ethanol or natural gas processing plants. The specific system design currently captures about 60 percent of the CO2 emitted by boilers. It reduces the building’s overall emissions by about 25 percent, enough to meet the limits set by the new climate law.

Every week or so, the liquefied CO2 is pumped outside the building and transported by truck to a cement plant in nearby East Flatbush, Brooklyn. The liquid CO2 is converted into a powder that resembles dry ice and then dumped into giant mixers with concrete, sand and aggregate. 

The cement reacts with the CO2 to turn it into calcium carbonate, which is formed into the cement blocks. If the cement blocks are later smashed up during demolition, the CO2 can’t escape. 

Some proponents of injecting CO2 into cement claim that it can make the cement blocks stronger and reduce the amount of building material needed for construction. Around NYC, a younger generation of architects are interested in using “greener” materials in their building design.

While the property owner, Glenwood Management, wouldn’t disclose the cost of the CO2 recovery system, they said it was cheaper than electrification. The return on investment (ROI) was also a deciding factor. The CO2 recovery system will pay for itself within six years through avoided penalties and the sale of hundreds of tons of CO2. (CO2 can sell for more than $300 per ton.) 

For now, carbon capture faces an enormous challenge: It has not been approved by NYC as a solution that complies with Local Law 97, since the technology didn’t exist when the law was drafted. The NYC Department of Buildings, which enforces the law, said it is reviewing the specific CO2 recovery system but has a number of questions to verify the CO2 emission reductions claimed by the Grand Tier apartment complex.

Experts and environmentalists both point out that electrification still has considerable advantages, like curbing indoor air pollution and being insulated from market swings in fuel prices. The technology is also improving quickly; New York State is currently funding a round of novel electric heat pump and efficiency projects that could serve as models for other commercial and residential buildings.

New Jersey recently passed a law providing incentives for lower‑carbon cement. So, what about using the technology to make bricks and mortar? Could the environmentally friendly technology be used to make other essential building materials while promoting environmental and social governance?

The original article by Brad Plumer was featured in the New York Times on March 10, 2023. Read more about this carbon capture technology here.

About the Author

Bernard L. Fontaine, Jr. CIH, CSP, FAIHA is the Managing Partner of The Windsor Consulting Group, Inc.

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