Capturing Carbon's Potential: These Companies Are Turning CO2 into Profits
On May 11, carbon dioxide levels in our atmosphere reached 415.26 parts per million for the first time in human history. The last time CO2 levels were this high was probably 2.5 to 5 million years ago, when temperatures were 2 to 3˚C higher than today. The Intergovernmental Panel on Climate Change (IPCC) has warned that we need to limit global warming to 1.5˚C to avert the most catastrophic effects of climate change. This cannot be achieved, however, without removing CO2 from the atmosphere. Besides capturing carbon from fossil fuel plants directly, there are a variety of ways to remove CO2 from the atmosphere. The problem is that many of these strategies are still relatively expensive. Finding new commercial uses for the captured CO2 is key to lowering the costs of these technologies and scaling them up.
Captured CO2 has long been injected into depleted oil fields to enhance oil recovery. It has also been pumped into greenhouses to boost plant growth. But today, many companies and researchers are developing new uses and products for captured CO2, such as varieties of concrete, chemicals and fuels. McKinsey & Company estimates that by 2030, CO2-based products could be worth between $800 billion and $1 trillion, and the use of CO2 for producing fuel, enriching concrete and generating power alone could reduce greenhouse gas emissions by a billion metric tons yearly. The Global Carbon Initiative projects that, with the proper incentives, by 2030 the overall CO2 based product industry could utilize seven billion metric tons of CO2 each year—about 15 percent of our current global emissions.
“I think it [the CO2-based product sector] has very high potential and could be an important part of the climate mitigation tool kit,” said David Sandalow, a fellow at Columbia University’s Center on Global Energy Policy, an affiliate of the Earth Institute and co-author of a report on CO2 utilization. “If we had genuinely marketable products using CO2, that could be transformational with respect to carbon capture technology. There are challenges, but I think with enough investment and enough commitment, many of those can be overcome.”
Captured CO2’s potential
Captured CO2 can theoretically be made into any kind of fuel or chemical that is currently based on petroleum. The trick is figuring out how to do it so the product is cost-competitive with fossil fuel-derived products and ends up benefitting the environment. Because CO2 is a stable and non-reactive molecule—meaning that it won’t react to form other chemicals unless a substantial amount of energy is added—processes to convert it to other products can be expensive. Overcoming this means finding products that don’t need this energy boost, or finding less energy-intensive ways to convert CO2.
To solve these problems and spur development of new technologies, the X Prize Foundation launched a $20 million competition to award “breakthrough technologies” that use the most CO2 to create products with the most economic value. Forty-seven teams from seven countries entered the competition; ten finalists are now building commercial-scale demo projects. The winners will be announced in 2020.
In 2017, an Innovation for the Cool Earth Forum report by Columbia University experts (including Sandalow) and their colleagues examined the technical and commercial development of CO2-based products. They noted that there are many potential uses for CO2 and a wide range of technologies in development, but the report focused on building materials, fuels, chemicals, polymers for plastics, and carbon fibers and carbon materials.
The most promising uses for CO2
Incorporating CO2 into concrete is the best prospect for widespread use of CO2 in the near term. We use enormous amounts of concrete to construct buildings and infrastructure around the world. Moreover, regular production of cement (one of the main ingredients of concrete) is responsible for about eight percent of global greenhouse gas emissions because of the energy needed to mine, transport and prepare the raw materials, so finding ways to lessen its carbon intensity is important.
To create cement, limestone, shells, or chalk are crushed and combined with other ingredients such as shale, fly ash or iron ore, then heated to form rock-like “clinker,” which is then ground into a fine powder and mixed with gypsum and limestone. Combining this cement with water and aggregates (such as sand, gravel, and crushed stone) creates concrete.
CO2 gas can be turned into a solid aggregate for concrete; this can be done with only minimal external energy—which is one reason why CO2 use in concrete has the largest potential in the short term. CO2 can also be used to cure concrete. For this strategy, wet concrete is infused with CO2, which reacts with water and calcium to form solid calcium carbonates. This spontaneous chemical reaction, which also does not require much added energy, results in concrete that is four percent CO2. Incorporating CO2 into cement could sequester it for hundreds of years in buildings, sidewalks and walls.
Alissa Park, the director of Lenfest Center for Sustainable Energy at Columbia University’s Earth Institute, is using industrial solid waste and CO2 to make greener construction materials and other value-added products. She is working with the Baotou Steel plant in Inner Mongolia, which generates huge amounts of solid waste that it needs to deal with. Park’s process leaches calcium and magnesium from the steel slag, and combines them with CO2 from flue gas or a chemical waste stream.
The CO2 bubbles into the solution containing calcium and magnesium ions and forms solids, which are then filtered and dried. The result is a white powdery substance that can be used for paper fillers (which influence paper’s texture and weight, among other properties), plastic fillers or construction materials. Park and her colleagues are currently doing a pilot scale demonstration, and have just started making papers, which they will test before the material can officially be used in paper fillers or construction materials.
In 2017, the Innovation for the Cool Earth Forum identified over 20 organizations developing processes to convert CO2 into carbonate products such as aggregates, concrete and pre-cast concrete for the building sector. But the costs of transporting and crushing the limestone, adding energy or chemicals to speed reactions, and capital and operating expenses still limit their economic viability.
Montreal-based Carbicrete, an X Prize finalist, is replacing cement with ground steel slag, then curing it with CO2, which becomes a solid and binds the slag granules together into concrete. This technology eliminates the production of 2kg of CO2 per concrete block and injects 1kg of CO into each block, so it is considered carbon negative.
Blue Planet in California uses CO2 from power plant flue gas to create carbonate rocks that substitute for limestone. This alternative aggregate was used in the concrete for a new terminal at the San Francisco Airport.
Chemicals for commodities
The use of fossil fuels for the production of organic chemicals that make up solvents, synthetic rubber, plastics and more, is responsible for about 2 gigatonnes of CO2 emissions per year. These products can also be made from CO2, but because it is a non-reactive molecule, outside energy—from heat, hydrogen, electricity, enzymes, a combination of these, or ideally renewable energy—must be added. Ultimately the benefit of CO2-based chemicals depends on the carbon intensity of the energy inputs, as well as the durability of the product. (CO2-based chemicals and fuels may be burned or processed within days or weeks, releasing their CO2 back into the atmosphere.)
Calgary-based Clean O2 has created a carbon capture device the size of a residential air conditioner that can be attached to a natural gas boiler to capture CO2 from the flue gas. Called CARBiNX, it converts the CO2 into potash, which is then used to make detergent, soaps, and fertilizer. Clean O2 maintains that it recycles 1.2kg of CO2 in every four-liter container of its biodegradable liquid hand soap.
The English company Econic has developed catalyst technologies that reduce the amount of energy needed to convert CO2 into polyols (short chain polymers), the building blocks of polyurethane. The technology replaces half the fossil fuel-based material with CO2, saving 50 percent of the cost of fossil fuel raw materials that would be needed for plastic production while utilizing waste CO2. Moreover, the amount of CO2 content can be “tuned” to modify the products. Econic polyurethanes can be made into home furnishings, insulation and structural foams, clothing, shoes, adhesives and protective coatings.
Newlight Technologies, a California company and X Prize finalist, is using a microorganism-based biocatalyst (similar to an enzyme) to turn CO2 captured from air into a bioplastic. The biocatalyst pulls carbon out of methane or carbon dioxide from farms, water treatment plants, landfills, and energy facilities. The carbon is then combined with hydrogen and oxygen to synthesize a naturally occurring biopolymer material the company calls AirCarbon. The AirCarbon is purified and made into pellets, which can be melted down and used for a variety of products. In 2016, IKEA signed a deal with AirCarbon to make furniture. Dell, Hewlett Packard, and the Body Shop use AirCarbon for packaging. If made using renewable energy, the product can be carbon negative.
Fuel and energy
CO2 is also being used to create synthetic fuels and increase energy efficiency.
A CO2 to methane plant run by Carbon Recycling International in Iceland captures CO2 from the nearby geothermal power plant’s steam emissions. Then, with electricity from hydro and geothermal sources, the plant makes hydrogen, which is converted into methanol through a catalytic reaction with CO2. The company sells the methanol as a gasoline additive and for biodiesel production. Because of the low-carbon grid electricity, the overall process produces few emissions.
Canadian Carbon Engineering’s Air to Fuels technology makes carbon-neutral liquid fuel using CO2 from the atmosphere. The technology captures CO2 directly from the air, and employs renewable energy to split water into hydrogen and oxygen. The hydrogen and CO2 are then recombined to form hydrocarbon fuels like diesel or gasoline, which can replace fossil fuels and are compatible with existing engines and infrastructure.
Researchers at UNIST in South Korea and Georgia Institute of Technology took inspiration from the fact that when the ocean absorbs CO2, it becomes acidic. They introduced CO2 into a solution containing seawater and sodium hydroxide, and as acidity increased, the number of protons in solution increased, drawing electrons and creating electrical energy and hydrogen. The researchers think this technology could eventually be used to create a battery that converts CO2 into energy.
Sandia National Laboratories is using CO2 in place of steam to make turbine-generated electricity more efficient. CO2 that is heated and pressurized into a supercritical fluid (meaning it has properties between a liquid and a gas) can replace steam to drive turbines. Because supercritical CO2 transfers heat more efficiently and requires less energy to compress, it results in more electricity production for the same amount of energy input, and reduces the use of water.
Carbon materials—graphene, carbon nanotubes, carbon fibers—made from CO2 are in the early stages of development.
Manufacturing them from CO2 is expensive because it relies on electrochemical processes to convert the CO2. However, the market potential for these materials is great and demand for them is growing rapidly. These carbon nanomaterials—engineered on a tiny scale measured in billionths of a meter or nanometers, sometimes just a single atom thick—are very valuable: Graphene is an efficient electrical conductor and one of the strongest materials known; carbon nanotubes are used in batteries, electronics, sporting goods and more; carbon fiber can be used in aerospace, energy, concrete, automobiles and sporting goods. Because of the materials’ attributes, they can also help reduce greenhouse gas emissions in other ways.
For example, they can increase the fuel efficiency of aircraft and vehicles by making them lighter weight, improve wind turbine performance, and boost the capacity of lithium-ion batteries. And while the amount of CO2 used in these products is small, they are durable, meaning CO2 could remain embedded in them for a long time.
X Prize finalist C2CNT, based in Calgary, Canada, has found a way to produce carbon nanotubes 100 times more cheaply than usual. Its technology uses low-cost nickel and steel electrodes and low voltage current to create carbon nanotubes from flue gas that conduct electricity better than copper. Valued at over $100,000 per ton, the nanotubes can be used by steel, aluminum, textiles, ceramics and cement producers, and in electronics, packaging, manufacturing and construction.
Other promising products
Here are two more innovations that use CO2 that could potentially revolutionize entire industries.
Conventional textile dying requires large amounts of water and produces wastewater filled with dye and chemicals. DyeCoo, a Dutch company, has transformed the dyeing process with CO2. The technology pressurizes CO2 so that it becomes supercritical and allows dye to readily dissolve, so dyes need no chemical processing and can enter easily into fabrics. The process uses no chemicals or water, produces no wastewater, requires no drying time because the dyed fabric comes out dry, and 95 percent of the CO2 is recaptured and reused, so the process is a closed loop system. Because the dye is used so efficiently and there is no wastewater treatment needed, costs are reduced by 40 to 60 percent. Moreover, the process can be employed anywhere, since it doesn’t require water. DyeCoo technology is currently being used in Nike, Ikea, Adidas and Peak Performance products and in commercial mills in Thailand and Taiwan.
As the demand for seafood grows globally, so does the need for fishmeal, the protein pellets used to feed farmed fish as well as livestock.
Aquaculture requires 400 billion small fish to be caught, ground up and combined with grain to feed its fish each year, and the price of fishmeal has quintupled since 1995. California-based NovoNutrients uses CO2 from industrial emissions to feed lab-created bacteria. The bacteria consume CO2 to produce protein similar to the amino acids fish get by eating smaller fish; the bacteria replace fishmeal, providing the fish with protein and other nutrients. The company estimates that four million tons of CO2 a year, the amount a large cement plant produces, could be used produce 2 million tons of protein meal. Late this year or early next year, NovoNutrients plans to begin selling its fishmeal product.
What is needed to further the CO2 products sector
Columbia’s Alissa Park said that having cheap, abundant electricity from renewable sources and carbon-free hydrogen are the keys to making CO2-based chemicals and fuels. The processes to convert CO2 to a product require many reaction and separation steps and large energy inputs along the way. “The minimum number of transformation steps with the highest efficiency steps is the only way,” said Park. “People often forget this. As a result, there is a lot of technology out there which doesn’t make sense.” She explained that life cycle assessments are essential to understanding the true merits of a product. This means looking at the entire lifetime of a product from sourcing of raw materials through processing through use to disposal or recycling; and since keeping CO2 out of the atmosphere is the primary goal, how long the CO2 can be sequestered and kept out of the air is another critical factor.
But so far, there is no consistent way to analyze the benefits of products that utilize CO2 because many of the technologies are still relatively new, there are a variety of different approaches, and life cycle assessments are challenging because of the countless variables. Questions remain about the products’ cost, market potential, ability to reduce greenhouse gas emissions, and how much they could potentially disrupt existing markets. Nevertheless there is growing global interest in CO2 utilization.
“In this whole area there are literally dozens of different product streams that are possible, so scientists, technologists are working to make breakthroughs and reduce costs across a wide range of areas,” said Sandalow. “But those researchers need support, they need markets, and that’s what’s critical to making the breakthroughs… There is very inadequate funding for research and development and clean energy technologies broadly. And this area is particularly underfunded, but its potential is enormous.”
Beyond R&D funding, Sandalow asserts that government support and the right policies could make a big difference—such as setting carbon standards for concrete, buying products for the government that incorporate CO2, and passing carbon pricing policies.
Although Park is doubtful that many projects will become game-changers in the next five to ten years, she’s optimistic about the long-term outlook. “Hopefully in our children’s generation, their renewable energy will be so abundant and so cheap, that they can use really low energy carbon to transform CO2 into different material forms,” she said. “There’s no silver bullet on any of this. You have to do it all. We should really be committed for centuries, not five or ten years.”