Some thoughts from Thomas James:
...the amusing part is that it is theoretically a carbon-negative fuel source -- the microbes take more carbon out of the atmosphere than what they excrete as a useable oil (if that doesn't seem to make sense, recall that the microbes themselves require carbon for their own structure).
On the other hand, since this approach requires genetic engineering, the watermelons and luddites will no doubt put the kibosh on it regardless of its benefits -- the only thing more intolerable than the idea of environmental-guilt-free petroleum sustaining the Western lifestyle of individuality, independence, and material happiness is the knowledge that that guilt-free petroleum comes from "frankenbacteria."
They'll hate it even without the bioengineering. As noted, it doesn't require us to tighten our hair shirts, or depopulate the planet.
The weak part of all biomass-derived energy sources is gettng enough biomass. This is why there's been interest in algae, due to its much higher potential yield/area, but that has its own set of problems (getting enough CO2 into the medium to support growth, for example; obtaining that CO2 from fossil fuel combustion is not a scalable or sustainable solution).
The biggest concern would not be the escape of "frankenbacteria", but that this technology (or any successful lignocellulose-derived fuel technology, really), once matured, would turn the world's forests into profitably exploitable oil reserves that would be quickly cut down.
How is it not scalable or sustainable? Power plant emissions could be treated and put in a pipeline. EOR requires CO2 obtained from natural gas treating. CO2 is injected into storage for that now. At what $/bbl equivalent does this makes economic sense?
I'd have to agree that getting CO2 from points sources is scalable. Sure, it'd be extraordinarily costly and difficult to harvest the CO2 from all fossil fuel-based automobiles, but power plants as Bill notes, are a different matter. That's a big portion of the US's CO2 emissions right there.
Why do "the watermelons and luddites" get anything more than a marginal voice? Why do they get to set policy for the rest of us? How is it we are captives of morons?
Ken Anthony wrote:
"How is it we are captives of morons?"
Can you handle the truth? We're all morons ^_^
It's not scalable or sustainable because the fossil fuels are limited, and the carbon from them escapes into the atmosphere after one pass through the algae/fuel processor. Moreover, many of the point sources are in locations poorly suited to algae production, and much of the CO2 is produced at night or in deep winter when the algae aren't able to use it.
It's not scalable or sustainable because the fossil fuels are limited, and the carbon from them escapes into the atmosphere after one pass through the algae/fuel processor. Moreover, many of the point sources are in locations poorly suited to algae production, and much of the CO2 is produced at night or in deep winter when the algae aren't able to use it.
Huh, I think I see where you're going with this. Namely, that CO2 would come from point sources (which we'd eventually stop using due to scarcity of fossil fuels) and directed to distributed sources. So it'd only pass through algae recycling once. I don't consider that a scalability or sustainability issue since algae can continue to extract CO2 directly from the atmosphere. The rest isn't that significant. Algae needs sunlight, warmth, and CO2. You can get sunlight and warmth that in most places even in deep winter. The places you can't aren't significant.
Can these little bugs eat sanitary sewage?
There are substantial municipal waste treatment plants everywhere in America and in my town the village also collects yard waste.
For example, Chicago's Metropolitan Water Reclamation District
Add these little bugs into the sewage treatment cycle since large tracts of land have already been dedicated to waste processing, buildings built, and other substantial infrastructure is already in place.
Factory farms could "double dip" as well. Maybe some additional genetic modification needs to be done to help them eat poop but why not?
I'd have to agree that getting CO2 from points sources is scalable. Sure, it'd be extraordinarily costly and difficult to harvest the CO2 from all fossil fuel-based automobiles, but power plants as Bill notes, are a different matter. That's a big portion of the US's CO2 emissions right there.
If the crude oil that gets refined into gasoline comes from agricultural (or sanitary) waste and from atmospheric CO2 then the need to capture emissions (especially from automobiles) is reduced since the agricultural waste itself extracted CO2 from the atmosphere. Sequester CO2 from power plants (where it is relatively easy) and forget about the cars since the creation of the gasoline itself required taking CO2 from the atmosphere.
Finding carbon sinks may remain a good idea however ending the practice of digging up and burning million year old carbon sinks seems like a good place to start.
algae can continue to extract CO2 directly from the atmosphere.That's the problem -- the potentially highly productive algae systems being developed do not, AFAIK, extract CO2 from the atmosphere. Dissolution of CO2 from the air into a pond is not very fast; algae in closed bioreactors are of course not in contact with air at all.
To really make this work, you'd need special algae that grow in highly alkaline solution, and then make that solution serve double purpose by (say) spraying it into the air to maximize contact and absorb CO2 (and hope not too much water evaporates; this could rule out doing it in deserts). There are algae like this (growing in soda lakes, particularly in Africa; these are some of the most photosynthetically productive ecosystems in the world precisely because they are loaded with dissolved inorganic carbon), but I don't believe these are the species being proposed to be used by today's algae startups.
Paul, sorry, I missed your post earlier. It looks to me to be a simple matter to bubble air through a closed bioreactor. Recycling water vapor is a technical detail. And using different algae species that are capable of using lower levels of CO2 isn't a big deal. I do like your idea of using highly alkaline solutions. That's an interesting idea.
And if you put it someplace (like near Los Angeles) where elevated CO2 levels are likely, that might help. For example, here's a study that indicates that Phoenix, Arizona carbon dioxide concentrations were elevated in the center of the urban area by up to 24 ppm (the outskirts ranged between 377 ppm and 385 ppm). It's not greatly exciting but an average 5% increase in CO2 concentration does mean that it takes less work to extract that carbon dioxide.