Just a nit: beer never had loads of NO2. So-called "nitro" pours are pushed with nitrogen gas (N2), not NO2. This is a good thing, since NO2 is rather toxic: https://en.wikipedia.org/wiki/Nitrogen_dioxide
I agree with this. Think of the mid to low-tier restaurants and the coffee the serve.
Unless I'm in some big city, most of time I'm just getting whatever bulk coffee they happened to buy from some wholesaler. They arent serving me $18/lb coffee from some boutique farm in Nicaragua.
That's an apples-and-oranges comparison. The system you cite differs from the one under discussion in several ways; the most important of which are:
1. The cited system does not include a light-harvesting component. It merely postulates that the required energy could be generated from photovoltaics. This would introduce additional cost and complexity along with an efficiency hit.
2. The cited system comprises a bacterium in conjuction with an electrode-supported catalyst, whereas the system under discussion is solely an engineered bacterium.
Finally, it is not correct to refer to cadmium and cysteine as feedstocks. They are components of the catalyst, and they are not consumed during catalysis. The only feedstocks for both systems are CO2 and water.
You're right that Liu's paper does use external electrodes. And as for Sakimoto's paper it's true that the cadmium should be reusable indefinitely, but if you read the second page it's clear than cysteine is consumed in stoichiometric amounts. I'd be excited to hear about more recent work which improves upon this and would be happy to be corrected.
>That said, relying on a fuel source that requires CO2 as
>input seems just as potentially destabilizing to the global
>carbon cycle as relying on a fuel source that produces CO2
>as byproduct.
Not really. Using CO2 to generate a fuel which then liberates CO2 when it is consumed ends up being CO2-neutral, which is exactly the way to go.
You've got a lot of it right, but you're missing the key advance described here, which--if true--is pretty wild.
Taking a step back, in 2016, this group did cover a bacterium with tiny semiconductor nanoparticles (specifically CdS) just as you say. That work is described here: http://www.pnas.org/content/113/42/11750.full In short, the semiconductors act as mini-solar cells, converting light into electrical current. The bacteria then use that electricity to convert CO2 into acetic acid. That already is pretty cool.
However, what they claim now is that they don't even need to make the semiconductor nanoparticles. They can simply grow the bacteria in an environment containing cadmium and sulfur sources and the bacterium will synthesize it's own cadmium sulfide coat, and use it for photosensitization.
This is really pretty wild. Bacteria will often incorporate various elements from their host medium, but the generally use them to make biomolecules, not semiconductors. Right now, this is just being presented at a conference, but it will be very interesting to see the details when the full paper comes out.
That may be the origin of this particular phrasing, but the idea is much older:
In 1973, the artist Richard Serra made a film called Television Delivers People which declares "You are the product of TV" [0]
Key to Noam Chomsky's _Manufacturing Consent_ (1988) is the idea that advertising-supported media caters to the desires of the advertiser, not the media consumer [1]
See also http://www.ccp4.ac.uk/dist/html/npo.html, which I'm surprised to see is still there, and fittingly also has Phil Evan's name on it. Note the production of stereo plots which needed practice looking at in the right way to get the effect.
I won't pass judgement on whether 410 micrograms/kg is an "unbelievable" amount, but I will just mention that it is 410 parts per billion, or less than 1 ppm.
