Amine Leakage From CCS Plants Deserves More Scrutiny
Amine-based solvents are widely used in current practical-level CCS (Carbon Capture and Storage) plants, and personally I had accepted this without any particular doubt or concern.
I was also aware that efforts to replace them are progressing, but honestly the toxicity angle had never really registered with me (I simply didn’t know about it). So this is more of a memo than anything, but I’m putting it together here.
I’m summarizing what’s written in this article:
“What Is the Impact of Amine Emissions?“https://www.envirotech-online.com/news/gas-detection/8/breaking-news/what-is-the-impact-of-amine-emissions/58352
Amines are extremely useful for carbon dioxide removal
Removing carbon dioxide from exhaust gas (primarily from power plants) is an extremely important technical challenge from an energy policy standpoint as well. Amine-based solvent processes operate at ordinary temperature and pressure, so they’re easy to retrofit onto existing plants, and they hold up well in terms of cost and efficiency too.
When used at thermal power plants, they can draw on waste heat to release the CO2, and it’s also relatively easy to secure the energy needed to pressurize and liquefy it for pipeline transport.
For these reasons, amine-based systems are currently the mainstream approach.
Amine leakage
Amine leakage can occur at various points throughout the process. It can be contained in exhaust gas, contained in wastewater, or leak out from the components themselves.
And the important point here is that proper regulations covering this leakage simply don’t exist.
As a result, discussion of the purity of captured carbon dioxide is extremely active, but discussion of amine leakage and its concentration is hardly active at all.
Nitrosamines
Nitrosamines are compounds that form when amines are released into the atmosphere.
- Extremely low biodegradability (they don’t naturally disappear if left alone)
- High toxicity
- High mobility (contamination spreads easily)
Given these characteristics, they can be described as substances that are about as bad as it gets for both health and the environment.
However, the amounts of nitrosamines currently found in drinking water and similar sources are in practice extremely small, and it’s generally believed that there’s no need to worry about their effects. Because of this, nobody has adequately researched what level of impact would occur, and at what concentration, if amine-based substance levels were to rise even slightly.
Also, because no substantive regulations exist, there isn’t even measurement data on how much amine is actually being emitted, or at what rate, in real-world industrial settings.
In the IEA’s assessment, from a carbon offset standpoint, CCS plants will need to scale up not by a few times their current level but by several tens of times. The IPCC shares this view.
But when that time comes, we actually have no idea how much amine these plants will release, or how much environmental damage and health harm will result (or fail to result).
Originally published in Japanese at https://clazytech.com/2022/10/1498/. Translated with LLM assistance and reviewed before publication.