National Grid Demos Carbon-Sequestered Mix

Carbon capture seals demo project for National Grid

This case study of National Grid’s use of Modern Hydrogen’s carbon-sequestered asphalt in New York offers a look at sustainability in the pavement maintenance sphere. In a live demonstration at National Grid’s facility in Long Island on Sept. 30, 2024, Modern Hydrogen showcased its carbon-sequestering asphalt, Modern Asphalt, for the first time in the Northeast.

The technology integrates captured carbon into the asphalt mix and replaces a portion of the bitumen, offering a sustainable solution for decarbonizing road construction. Policymakers, labor unions, asphalt contractors and others came out to view the demonstration and ask questions, as this demonstration aimed to highlight a scalable approach that could be used by Department of Public Works (DPW) and Department of Transportation (DOT) teams in the region.

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Decarbonize Asphalt Production

In New York, over 18.5 million tons of asphalt are produced annually and the traditional asphalt binders used in that production are derived from crude oil. Reducing the carbon footprint of road construction requires innovative approaches like the one demonstrated by Modern Hydrogen. This event marks a milestone, as it is the first demonstration of carbon-sequestering asphalt in the Northeast.

At the event, which brought together regional DPW and DOT officials, engineers, and asphalt producers, the team from Modern Hydrogen introduced its carbon-sequestration technology. This process captures carbon from natural gas and renewable natural gas (RNG) and integrates it into the asphalt binder. By replacing a portion of the bitumen in asphalt, Modern Asphalt locks carbon away from the atmosphere, aligning with New York State’s ambitious climate goals.

With the successful demonstration of Modern Carbon, Tony Tata stated, “Municipalities and asphalt producers now have a scalable solution to reduce emissions during production while using lower-carbon input materials.”

Demonstrate Innovation

The demo showcased the practical application of Modern Asphalt by paving a 4×4-foot patch with hot-mix asphalt (HMA) containing 10 pounds of carbon derived from RNG. Key stakeholders and officials, including representatives from National Grid, Rason Materials, Nassau County DPW, Suffolk County DPW, highway engineers, and union leaders, witnessed firsthand how Modern Carbon was seamlessly incorporated into the asphalt mix.

Rason Materials and New York Paving handled the project’s execution. Michael Baba, senior product development manager for Modern Hydrogen, explained, “Rason Materials produced the asphalt. It was delivered in a truck as virgin material, with the final step of blending in Modern Carbon done on-site.”

To prepare the existing patch of damaged asphalt, Baba explained the contractor sawcut the 4-foot by 4-foot area and cleaned the edges. Next, the subgrade was leveled and compacted.

The crew elected not to use tack as it was deemed unnecessary. Baba explained: “No tack was required to be put down. Rason’s virgin HMA blended with Modern Carbon does not need it.”

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Once the HMA with Modern Asphalt was blended and placed in the patch area, “it was smoothed and graded with rakes,” Baba said. “Final compaction was done with a vibratory roll compactor.”

Baba shared the ambient temperature on the day of the demonstration was around 70F and the mix performed as expected. “Workability was as expected for a standard HMA.”

The event sparked excitement about the potential of the technology, with Matthew Aracich, president of the Building and Construction Trades Council of Nassau and Suffolk Counties, commenting, “the sky is the limit for hydrogen applications and technology.”

The Road Ahead: A Scalable Solution

Modern Hydrogen’s demonstration showed the technical feasibility of carbon-sequestering asphalt. For every ton of Modern Carbon integrated into asphalt, approximately 3.66 tons of CO2 emissions are prevented from entering the atmosphere. Read more about that in the white paper titled “Modern Carbon Slashes HMA Emissions and Costs” at TheAsphaltPro.com.

“Modern Carbon Slashes HMA Emissions and Costs” White Paper

Tony Tata, senior advisor for Infrastructure and Energy Security at Modern Hydrogen and former secretary of transportation of North Carolina, remarked, “Today’s demonstration represents a major milestone for the industry. Municipalities and asphalt producers now have a scalable solution to reduce emissions during production while using lower-carbon input materials.” The event underscored the importance of innovation in achieving global and regional climate goals.

With the success of the demo in Long Island, Modern Hydrogen plans to expand the application of its technology across the Northeast and beyond. The company is already looking ahead to scaling the technology for broader implementation.

“As the demand for low-CO2 paving materials continues to grow, municipalities and asphalt producers have two key levers to reduce emissions: first, by targeting the emissions generated during asphalt production, and second, by using input materials that inherently have a lower carbon footprint,” said Tata.

Technical Insights for Asphalt Producers

Throughout the Long Island demonstration, technical questions from asphalt professionals provided valuable insights into the performance and feasibility of Modern Asphalt. Several key areas were addressed:

• Recyclability of Carbon-Modified Asphalt: Modern Asphalt retains the recyclability of standard HMA blends, as the carbon does not chemically modify the binder. This means that the carbon-sequestering asphalt can be recycled similarly to traditional asphalt.
• Impact on Reclaimed Asphalt Pavement (RAP): Modern Hydrogen has successfully tested asphalt mixes that include 40% RAP without any negative impact. Following balanced mix design (BMD) principles ensures high performance, even with the addition of carbon.
• Compaction and Flowability: Testing conducted by the University of Wisconsin’s Modified Asphalt Research Center showed carbon-modified asphalt maintains similar compaction and flow characteristics as standard asphalt mixes. The compaction curve remained consistent, even at varying temperatures.
• Health and Environmental Considerations: Another concern raised was whether the inclusion of carbon in the asphalt would create environmental or health risks during recycling or use. Modern Hydrogen’s team assured attendees that once integrated into the asphalt, the carbon is permanently sequestered.