Ethanol CO2 & Concrete Cement a Relationship

CarbonCure Technologies strengthens concrete while reducing its carbon footprint. This feature on a new use for the ethanol coproduct appears in the February print issue of Ethanol Producer Magazine.
By Ann Bailey | January 20, 2017

Carbon dioxide from a Wisconsin ethanol plant is strengthening the cement in pours at sites in Chicago. Ozinga, a fourth-generation, family-owned business in Illinois has installed CarbonCure technology at its downtown Chicago ready mixed plant.

CarbonCure Technologies Inc., based in Halifax, Nova Scotia, licenses its technology to about 40 U.S. and Canadian customers, most of them concrete producers like Ozinga, says Jennifer Wagner, vice president of sustainability. CEO Robert Niven, a clean-tech developer, founded CarbonCure Technologies nine years ago and after several years of research and development, launched it commercially in 2012. The company promotes its technology as lowering greenhouse gas emissions while improving the material performance of concrete.

“Once we were commercialized, our initial focus was on concrete blocks, or masonry. Since then we’ve expanded to the much larger ready mixed industry, or poured concrete, which is where we operate today,” Wagner says. “We are paid a license fee,” she continues. “The concrete producer pays us on a monthly basis to use the technology.” It is more cost-effective for their ready mix customers to purchase the gas from sources that are near their plants—a power plant, fertilizer plant, or, as in the case of Ozinga, an ethanol plant, she says. CarbonCure’s customers buy the CO2 from third-party gas suppliers, which typically are multinational corporations supplying companies such as Coca Cola and Pepsi Cola.

Ozinga purchases its CO2 from Helget Gas, Elk Grove Village, Illinois. Helget captures the gas from a Wisconsin ethanol plant, says Shaun Albeck, beverage gas specialist, sales. He declined to name the ethanol plant, but notes that it is one of several in the Midwest where Helget captures CO2, selling all grades of the gas to customers from bars to restaurants and now, concrete companies. “We are direct to the consumer for the concrete industry,” Albeck says. “Not only do we provide the CO2, but we also provide the equipment for the CO2—bulk tanks and any other equipment that would be necessary.” Helget Gas delivers the CO2 to CarbonCure in liquid form and it is stored in a 3,000 liter bulk tank. Helget Gas refills the tank as needed.

Multiple Benefits
CarbonCure’s concrete customers, such as Ozinga, install bolt-on technology, Wagner says.  “The CO2 is injected into concrete where it becomes sequestered. It actually is converted from gas to a solid; it is converted into calcium carbonate, commonly known as limestone,”  she says. “To make concrete, all of the ingredients, including the sand, stone, water and cement, are blended together in a large-scale mixer. At this point, we add the CO2. As soon as the CO2 is added, a chemical reaction takes place where the CO2 forms a bond with the cement particles to form nanosized solid calcium carbonate particles. It’s these nanoparticles that give concrete its additional strength. It’s called a seeding reaction, so a small amount of CO2 can provide a significant benefit to the manufacturer.”

Ozinga learned about CarbonCure at a National Ready Mixed Concrete Association convention, says Paul Ozinga, executive vice president. “People were talking about it and we were approached by CarbonCure. They came by and told us what it was, what the process was. We found it very interesting with a lot of opportunity, so we decided to go forward with it.  We first started talking about it two years and then implemented the system about six months ago,” Ozinga says. There are several reasons Ozinga decided to adopt the CarbonCure technology. “There are economics that play into it. There are environmental reasons that play into it. There are performance reasons that play into it,” he says. “Obviously, any time we can reduce the carbon we emit, that is a good thing.”

Cement is a key ingredient in concrete and also one of the largest industrial emitters of carbon dioxide. By putting the carbon dioxide back into concrete, not only does it repurpose the CO2, it also improves the compressive strength, which allows concrete producers to reduce the amount of cement in the mix design, Ozinga says. “With increased strength, we can reduce the cement content in a mix. By taking cement out of a mix, we further reduce the carbon footprint of concrete products.” Ozinga estimates that the CO2 replaces from 3 to 6 percent of the cement in the mix.

“It’s a win-win where the producers are able to reduce their costs and save money,” Wagner says. “They also are able to claim (carbon) credits where there is a system in place. In places like California, British Columbia or Ontario, CO2 reductions can provide carbon offset revenue, which creates even more value for the customer. It’s sort of the icing on the cake that makes this even more economically favorable.”

Most of CarbonCures’ customers are companies in the Northeast and Southeast, but the company is growing, Wagner says. “We’re expanding very quickly and many of our customers are large companies that have dozens or even hundreds of concrete plants. What we’re seeing is, they test the technology at one or two plants and if they like what they see, and so far all of them do, they quickly expand across their fleets of plants. It won’t necessarily take us long to be available pretty much everywhere in North America. We have pockets where we are seeing exponential growth, so we are building on those markets; we’re seeing most of the growth along the eastern seaboard, from Atlanta, up through to the Carolinas, D.C. and Boston.”

Typically, when companies, such as ethanol plants, look for places to put the CO2 that is emitted, they think of geological carbon capture and storage, which is putting the gas in abandoned mines or aquifers, Wagner notes.  “But this concept of CO2 utilization is emerging. Instead of thinking of CO2 as a waste material, we are thinking of it as an asset where you can use CO2 to actually make better products. We’re applying this concept of CO2 utilization to concrete, which is the most abundant man-made material on earth, so it’s a game changer for global CO2 emissions.”

Down the road, Ozinga likely will increase the amount of CO2 it uses in its concrete, Ozinga says. “When we get data under our belt, we intend to continue to expand and grow how much we’re utilizing.”

“Ozinga was founded on the principal of service to others; service to our colleagues, to our customers and to our community,” Martin Ozinga IV., Ozinga president said in a statement announcing the installation of CarbonCure technology at the company.  “The CarbonCure technology allows us to further serve our community by being better stewards of the environment.” Adaption of the technology made sense for the family business founded in 1928 by Martin Ozinga Sr., a Dutch immigrant. “We faced many challenges over the past decade because of the economic recession,” said Ozinga’s president. “The recession forced us to reflect on our true purpose as a company, which is to serve others and to provide high-quality products. We look forward to continuing to grow as a company with CarbonCure as a partner.”

Reducing carbon’s concrete footprint is appealing to architects, engineers and building developers. Rand Ekman, chief sustainability officer for Chicago architectural firm HKS Inc., is an advocate for carbon reduction emissions within the design community. “As architects, we have a responsibility to understand and mitigate the environmental impacts of the building materials we use,” he said in a statement offering his congratulations to the Ozinga family for leading the industry with the CarbonCure innovation.

Author: Ann Bailey
Associate Editor, Ethanol Producer Magazine