Several climate-tech startups are planning to siphon massive amounts of carbon dioxide from the air and trap it underground in Wyoming. The Verge reports: The goal of the new project, called Project Bison, is to build a new facility capable of sequestering 5 million metric tons of carbon dioxide annually by 2030. The CO2 can then be stored deep within the Earth, preventing it from escaping into the atmosphere where it would continue to heat the planet. Los Angeles-based CarbonCapture is building a facility called the Direct Air Capture (DAC) plant, which is expected to be operational as early as next year. It will start small and work up to 5 million metric tons per year. If all goes smoothly by 2030, the operation will be orders of magnitude larger than existing direct air capture projects.
CarbonCapture’s hardware is modular, which the company says makes the technology easy to scale. The plant itself will consist of modules that look like stacks of shipping containers with vents through which air passes. Initially, the modules used for the Bison project will be manufactured at CarbonCapture’s headquarters in Los Angeles. The first phase of the project, which is scheduled to be completed next year, will deploy about 25 modules in Wyoming. Together, these modules will be able to remove about 12,000 tons of CO2 from the air per year. The plan is to deploy more modules in Wyoming over time and potentially manufacture modules there one day.
Inside each of the 40-foot modules are about 16 “reactors” with “sorbent cartridges” that essentially act as filters that capture CO2. The filters capture about 75 percent of the CO2 from the air that passes over them. Within about 30-40 minutes, the filters absorb all the CO2 they can. Once the filters are fully saturated, the reactor is shut down so the filters can be heated to release CO2. There are many reactors in one module, each operating at its own rate, so they are constantly collecting CO2. Together, they create concentrated streams of CO2 that can then be compressed and sent straight to underground wells for storage. A DAC is still very expensive – capturing a ton of carbon dioxide can cost upwards of $600. This number is expected to decrease over time as technology advances. But at the moment, it takes a lot of energy to run DAC factories, which contributes to the high price. Filters need to reach about 85 degrees Celsius (185 degrees Fahrenheit) within minutes, and reaching that high a temperature for DAC plants can be quite energy intensive. in the end […] The bison plan to get enough energy from new wind and solar installations. When the project is at full capacity in 2030, it is expected to use about 2 GW of solar energy per year. By comparison, according to the Department of Energy, about 3 million photovoltaic panels together generate a gigawatt of solar energy. But initially, the energy used by the Bison project could have come from natural gas, Corless said. So Bison must first capture enough CO2 to offset the amount of emissions it creates by burning that gas before it can reduce the amount of CO2 in the atmosphere. “The geology in Wyoming allows Project Bison to store captured CO2 on-site next to the modules,” adds The Verge. “Project Bison plans to permanently store the CO2 it captures underground. Specifically, project managers are considering placing it 12,000 feet underground in ‘saline aquifers’ – areas of rock saturated with salt water.”