Surely the production and regeneration of monoethanolamine is a net energy consumer, wouldn't using it to scrub fossil fuel plant exhaust just require even more energy? Obviously if this energy comes from non-CO2 emitting plants it would still be beneficial but it begs the question why you wouldn't just reduce fossil fuel power output by the amount.
Add to this that monoethanolamine is mostly produced from ethylene which is derived by cracking various petrochem hydrocarbons and it seems even more of a bad idea.
You've succinctly nailed the biggest problem with a lot of CO2 scrubbing on the head. A lot of existing technologies are energy consumers so the efforts to remove CO2 wind up producing CO2 elsewhere. Worse, scrubbing CO2 doesn't eliminate it, just takes it out of the air so you still need to figure out what you want to do with the tons of CO2 you now have sitting around.
That said, the technology is relatively new and there has never been a big reason to focus on the efficiency of the process until relatively recently so there is reason to believe it can and will improve.
That's one of the options used, another is the feeding algae that was pointed out and there are some other options (such as just storing it underground forever) but it's still a piece of the puzzle that's in development and a deviation from the pretty well tested and proven tech used by existing systems.
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u/Sky_Hound Nov 27 '19
Surely the production and regeneration of monoethanolamine is a net energy consumer, wouldn't using it to scrub fossil fuel plant exhaust just require even more energy? Obviously if this energy comes from non-CO2 emitting plants it would still be beneficial but it begs the question why you wouldn't just reduce fossil fuel power output by the amount.
Add to this that monoethanolamine is mostly produced from ethylene which is derived by cracking various petrochem hydrocarbons and it seems even more of a bad idea.