Carbon sequestration in pavement is not a new idea. Over the past decade, road building has increasingly been treated as a potential sink for waste streams and avoided emissions, from crumb rubber to recycled plastics to carbon-mineralized concrete. What has remained unresolved is not whether carbon can be placed into roads, but whether it stays there in any meaningful, durable way.
That question is central to the work Verde Resources is now doing with biochar in asphalt. Founded in 2011 as a mining company, Verde Resources began a strategic shift around 2021 toward sustainability-driven materials, a pivot that ultimately led the company away from extractive industries and into carbon-based building products.
“Around 2021 Jack was tasked to be the CEO of the organization, to turn the company from mining to green,” said Eric Bava, COO of Verde Resources. “And hence the name Verde.”
That transition led the company first into agricultural applications of biochar, and then, after limited adoption in farming, into construction materials.
“We started with biochar on the agricultural side of the industry,” Bava said. “Unfortunately, farmers just weren’t catching on as quickly as we wanted them to. So we attended a conference and started doing some digging on where biochar can be used. And that’s when we realized that biochar can be used in building materials… specifically asphalt.”
Biochar itself is often misunderstood, even within sustainability circles. Carl Strahl, director of biochar at Verde Resources and COO of Oregon Biochar Solutions, described it as a category rather than a single material. “Biochar is a class of materials. It’s a carbon material, and the bio before the char just indicates that it’s coming from a plant material, an organic base material,” Strahl said. In Verde’s case, the biochar is produced primarily from residual wood waste with no marketable value as lumber.
Unlike traditional charcoal, Strahl emphasized, biochar is not designed as a fuel. “Biochars are typically optimized for adsorption or other kinds of similar markets,” he said. “It could be water holding capacity. It could be contaminant holding capacity. So they’re generally not designed to have a high fuel content.”
That distinction becomes important in asphalt, where permanence matters. Verde’s flagship product, a cold-recycled bio-asphalt surface mix, is designed around 100 percent RAP, biochar, and a proprietary emulsifier. The goal is not to bury carbon in a base layer, but to integrate it into a working surface material. “A lot of the cold mix designs that are currently in the market are used at the base layer,” Bava said. “But we are specifically designing this to go as a surface material.”
At first glance, placing a carbon-bearing material in a surface that will eventually be milled might seem counterintuitive. But according to Verde CEO Jack Wong, lifecycle analysis was addressed early in the process. “When you’re dealing with biochar and sequestration, you’re dealing with life cycle analysis,” Wong said. “They also asked us extensively about the end of life. We told them that if you design the product well, there is no end of life. It’s all about the design life.”
Because biochar is not combusted during recycling, the carbon remains stable even as the pavement is milled and reused. “So long as we do not incinerate or burn the char, the carbon is still stable,” Wong said. “The carbon still stays intact.”
Performance was another gating factor. According to Verde, biochar functions as a performance additive as much as a carbon carrier. “Biochar helps with extending the lifespan of the pavement,” Bava said. “Biochar acts as a sponge. So if water gets through the voids, biochar will kind of suck it up.” He added that the mix has demonstrated freeze-thaw durability and year-round constructability, including placement at temperatures between 35 and 40 degrees Fahrenheit.
The product was mixed and placed at NCAT with plant burners turned off, stockpiled overnight, and placed the following day. “We don’t need any heats or solvents, and there’s no odor,” Bava said. “It’s definitely better for frontline workers as well.”
Carbon accounting is where Verde’s approach diverges most sharply from prior pavement-based sustainability claims. The company worked with carbon registries to validate removal credits tied to biochar permanence rather than avoidance. “These are carbon removal credits,” Wong said. “Biochar permanence in asphalt is 200 years under the Pure Earth methodology.”
In a proof-of-concept project, five tons of biochar yielded eight tons of verified carbon removal credits after lifecycle adjustments. Those credits were sold on the voluntary market, with revenue shared between Verde and its biochar production partner.
Verde is now in the process of developing environmental product declarations, beginning with biochar itself and moving toward full mix EPDs. “We actually just triggered our EPD efforts,” Bava said. “The next step will be getting the EPD for the entire mix design.”
For producers, the appeal may be less about sustainability messaging and more about operational flexibility. Year-round production, reduced burner use, and extended paving windows represent tangible economic levers. Whether biochar-based asphalt becomes a mainstream tool will depend less on climate rhetoric and more on how it performs in plants, on roads, and in specifications.
As with many sustainability technologies in asphalt, the industry will ultimately decide whether the numbers and the pavement align.
