Worldwide, combustion of fossil fuels for power generation emits vast amounts of carbon dioxide (CO2) to the atmosphere and contributes to climate change. Technology that can reduce the amount of CO2 entering the atmosphere will be key to tackling the climate crisis.
Pacific Northwest National Laboratory (PNNL) has developed a carbon capture technology to absorb CO2 cheaply and efficiently, at the source during pre- or post-combustion, in power plants and other flue gas emitting facilities. The technology requires 17 percent less energy to accomplish the same task as its commercial counterparts, surpassing barriers that have kept other forms of carbon capture from widespread industrial use. This translates to a 19 percent reduction in capture cost—as low as $38 per metric ton—plus the technology can be easily applied to existing capture systems.
The chemical process for extracting CO2 from post-combustion gas involves mixing water-rich amines with CO2-containing gas, which absorb CO2 and are later stripped of the gas, which is then compressed and stored. But aqueous amines have limitations. Because they’re water-rich, they must be boiled at high temperatures to remove CO2 and then cooled before they can be reused, driving costs upward.
To sidestep the challenges of water-rich solvents, PNNL has designed “water-lean” solvents that contain less than 5 percent water, reducing the energy required to release the captured carbon dioxide by boiling. This results in a more efficient, less energy intensive process. PNNL’s custom-tailored solvents are designed for maximum efficiency and reduced costs while still being simple. They are low viscosity and use molecules that align in a way that promotes internal hydrogen bonding, leaving fewer hydrogen atoms to interact with neighboring molecules. Ultimately, this lower viscosity results in a lower solvent circulation rate and reduced pumping cost.
A CO2BOL solvent is a single component, not complex mixtures of different compounds. Unlike most commercially available, amine-based carbon capture solvents, PNNL’s technology doesn’t require co-solvents to lower viscosity. PNNL’s solvents make it simple to handle each solvent’s properties, such as boiling point, using a single dataset.
Benefits to Gas and Coal Plants and Other Manufacturing Facilities
The PNNL technology can be a drop-in replacement at existing facilities because the solvents are designed to be flexible and can be optimized for most common CO2 capture and regeneration configurations. PNNL technology can be adapted to pre-combustion gas streams along with natural gas or any other CO2-containing gas stream. Applications include things like CO2-producing facilities, such as gas or coal plants interested in decarbonization, along with industrial applications like cement production plants. Once captured, the CO2 can be injected into the subsurface to enhance oil recovery or for long-term storage.
PNNL is further developing ways to convert captured CO2 directly from the solvent in its CO2-loaded state into valuable products like fuels and chemicals. Find out more about PNNL’s capture and conversion technology, which offers environmentally green solutions to efficiently convert captured carbon to fuels, such as methanol.
PNNL’s custom solvents for pre- or post-combustion carbon capture are cheap, durable, efficient, nontoxic, and easy to manufacture. These water-lean, drop-in solvents are 19 percent cheaper and use 17 percent less energy than commercial counterparts.
CO2BOL Solvent Technology
CO2BOL solvent technology offers the following advantages:
- Has up to 97% capture rates
- Reduces capture cost by 19 percent (and as low as $38 per metric ton) relative to commercial technologies
- Requires 17 percent less energy than commercial counterparts
- Is a drop-in replacement for lower-performing solvents in existing systems
- Is adaptable to any CO2-concentrated gas stream