Scientist Engineers Bacterium That Inhales CO2, Produces Energy • Hacker News Board

Re: Scientist Engineers Bacterium That Inhales CO2, Produces Energy

#81

Post by eru » Tue, May 31, 2016, 1:23 AM UTC

deciplex wrote: post #78

ams6110 wrote: post #59

Earlier quoted context omitted.

It's the smallest molecule there is. It's really difficult to contain. It will leak out of steel containers while embrittling the metal. However it's not necessary to use pure hydrogen as vehicle fuel. Alcohol or other hydrocarbons can be used directly in a fuel cell to produce electric power, or be burned in an more traditional combustion engine.

Hydrogen leaks out of steel containers because it's "small"? Doesn't the size of even the largest atom (or, for that matter, molecule) pale in comparison to even the smallest leaks you will typically find in a steel container?

It's not normal leaks. It's about hydrogen and helium diffusing through the container.

Re: Scientist Engineers Bacterium That Inhales CO2, Produces Energy

#82

Post by gherkin0 » Tue, May 31, 2016, 1:33 AM UTC

stplsd wrote: post #71

steffenfrost wrote: post #67

Earlier quoted context omitted.

If this is so, then why can invasive species wreak havoc in an ecosystem? http://ocean.si.edu/ocean-news/5-invasive-species-you-should...

How is even related to the points discussed by parent comment?

It's related to the parent's points by a misunderstanding.

Re: Scientist Engineers Bacterium That Inhales CO2, Produces Energy

#83

Post by gherkin0 » Tue, May 31, 2016, 1:41 AM UTC

fabian2k wrote: post #4

The headline is seriously misleading, the energy comes from sunlight which is used to split water into hydrogen. And the bacteria use the hydrogen as an energy source to create biomass from CO2. That biomass is mostly in burnable fuel. The article is very interesting, but the headline makes it sound like a fundamental misunderstanding of thermodynamics.

> The headline is seriously misleading

I think it's more a difference between technical vocabulary and colloquial vocabulary. I think a lot of people use the word "energy" to to refer to something more like "fuel." That's how you get terms like "energy production" which include activities like drilling for oil.

Re: Scientist Engineers Bacterium That Inhales CO2, Produces Energy

#84

Post by sdenton4 » Tue, May 31, 2016, 2:06 AM UTC

ams6110 wrote: post #58

evunveot wrote: post #47

Earlier quoted context omitted.

I think he's selling it short. Imagine if all 1 billion+ cars used this fuel instead of diesel/gasoline. Even if all the carbon ultimately ends up as CO2 again eventually, at any given moment there would be a whole lot of it temporarily sequestered in fuel tanks. The "base load" of atmospheric CO2 would be lower. I don't know enough chemistry or climate science to estimate whether the amount of carbon in ~5 billion g…

Given that the current level of CO2 in the atmosphere includes the output of over 100 years of industrial world-wide burning of petroleum and coal, then no I don't think the amonut of carbon that could be sequestered in current fuel inventories would make a significant difference. Unless you stockpile decades worth of fuel.

Yeah, but it's a hundred years of industrial burn which was growing at an (approximately) exponential rate; the most recent burn has a much, much larger impact than the burn in 1916.

Re: Scientist Engineers Bacterium That Inhales CO2, Produces Energy

#85

Post by mark-r » Tue, May 31, 2016, 2:57 AM UTC

eru wrote: post #80

shaqbert wrote: post #8

Earlier quoted context omitted.

Hydrogen fuel is indeed really difficult to manage. The Hindenburg accident come to mind, or the weight problems of fuel cell cars...

The Hindenburg had some other problems, too. The paint on the outside was extremely flammable. (And still, casualties came mostly from people jumping off the ship. The people that stayed on mostly survived.)

The thing that made the Hindenburg transformative is that it was caught on film. After everyone had seen the disaster for themselves, they were never going to trust the technology again.

Re: Scientist Engineers Bacterium That Inhales CO2, Produces Energy

#86

Post by pfarnsworth » Tue, May 31, 2016, 3:10 AM UTC

jerf wrote: post #37

amelius wrote: post #17

Earlier quoted context omitted.

> The novel aspect of these bacteria is that they apparently do the job 10x more efficiently than natural organisms. This makes me wonder why this solution was not found by evolution directly.

It's 10x more efficient for human purposes . It's not a 10x more efficient mechanism in general. Evolution has no need to produce 10x more rather energy-expensive molecules than it needs, so it doesn't produce bacteria that do that. Which is also the answer to everybody else wondering about what happens if this gets into the biosphere. Well, have you ever been walking in a relatively natural forest area and come acro…

> Evolution has no need to produce 10x more rather energy-expensive molecules than it needs, so it doesn't produce bacteria that do that.

You don't seem to understand natural selection. The idea of evolution producing something that an organism "needs" is akin to saying that God decided that the organism "needed" it and changed its genes.

The theory of natural selection is a completely passive process. For every generation of an organism, the genes are naturally randomized, producing various expressions of genes, and once there is selecting event, those that are not selected for will go extinct. That's what natural selection means. The idea that a giraffe "needed" a long neck is preposterous because it implies that the animal willed itself to have a longer neck. Instead, the giraffe's ancestors had a variable length neck, but given its particular circumstances, those with longer necks survived, and passed those genes on.

So there very well might be naturally occurring bacteria that produce 10x efficiently, but they haven't been selected for, yet.

Re: Scientist Engineers Bacterium That Inhales CO2, Produces Energy

#87

Post by kbenson » Tue, May 31, 2016, 3:30 AM UTC

pfarnsworth wrote: post #86

jerf wrote: post #37

Earlier quoted context omitted.

It's 10x more efficient for human purposes . It's not a 10x more efficient mechanism in general. Evolution has no need to produce 10x more rather energy-expensive molecules than it needs, so it doesn't produce bacteria that do that. Which is also the answer to everybody else wondering about what happens if this gets into the biosphere. Well, have you ever been walking in a relatively natural forest area and come acro…

> Evolution has no need to produce 10x more rather energy-expensive molecules than it needs, so it doesn't produce bacteria that do that. You don't seem to understand natural selection. The idea of evolution producing something that an organism "needs" is akin to saying that God decided that the organism "needed" it and changed its genes. The theory of natural selection is a completely passive process. For every gene…

> You don't seem to understand natural selection. The idea of evolution producing something that an organism "needs" is akin to saying that God decided that the organism "needed" it and changed its genes.

I'm pretty sure he understands it fine, and is just using shorthand that makes it easier to describe.

There exists no approximation of a fitness function in nature that selects for this output because it's not efficient for survival, until we come along and create custom environments and select for survival based on energy output.

Re: Scientist Engineers Bacterium That Inhales CO2, Produces Energy

#88

Post by GauntletWizard » Tue, May 31, 2016, 3:38 AM UTC

pfarnsworth wrote: post #86

jerf wrote: post #37

Earlier quoted context omitted.

It's 10x more efficient for human purposes . It's not a 10x more efficient mechanism in general. Evolution has no need to produce 10x more rather energy-expensive molecules than it needs, so it doesn't produce bacteria that do that. Which is also the answer to everybody else wondering about what happens if this gets into the biosphere. Well, have you ever been walking in a relatively natural forest area and come acro…

> Evolution has no need to produce 10x more rather energy-expensive molecules than it needs, so it doesn't produce bacteria that do that. You don't seem to understand natural selection. The idea of evolution producing something that an organism "needs" is akin to saying that God decided that the organism "needed" it and changed its genes. The theory of natural selection is a completely passive process. For every gene…

I can't decide which I find more annoying; The grandparent's misuse of terms, or the people pointing out that 'that's not how evolution works, it doesn't go towards anything, just away from what doesn't work.' I'm sure plenty of people don't get it, but it's really, really, really convenient shorthand for "Selective pressure has thus far favored" to say that "Evolution wants" or "Evolution needs". It's simple, it's unambiguous, and it's often backed up by our own human perceptions - Most of our wants and needs are based on selective pressure, so generalizing that to other selective pressures as 'wants' and 'needs' is a very natural abstraction.

(I've decided which is the most annoying: Meta-pedants like me.)

Re: Scientist Engineers Bacterium That Inhales CO2, Produces Energy

#89

Post by perilunar » Tue, May 31, 2016, 4:53 AM UTC

ams6110 wrote: post #58

evunveot wrote: post #47

Earlier quoted context omitted.

I think he's selling it short. Imagine if all 1 billion+ cars used this fuel instead of diesel/gasoline. Even if all the carbon ultimately ends up as CO2 again eventually, at any given moment there would be a whole lot of it temporarily sequestered in fuel tanks. The "base load" of atmospheric CO2 would be lower. I don't know enough chemistry or climate science to estimate whether the amount of carbon in ~5 billion g…

Given that the current level of CO2 in the atmosphere includes the output of over 100 years of industrial world-wide burning of petroleum and coal, then no I don't think the amonut of carbon that could be sequestered in current fuel inventories would make a significant difference. Unless you stockpile decades worth of fuel.

But the current level is not ALL the output of over 100 years of burning petroleum and coal — a lot of it has been re-absorbed by plants and the sea.

Re: Scientist Engineers Bacterium That Inhales CO2, Produces Energy

#90

Post by thereisnospork » Tue, May 31, 2016, 5:45 AM UTC

I wonder how much of the efficiency increase comes from simply bypassing photosynthesis (e.g. what is the thermodynamic efficiency of yeast for glucose -> ethanol)?

In any case there are a few important questions re feasibility. Do these bacteria work at atmospheric partial pressures of CO2? Do they perform at the advertised rate at the ~0.0015g/L of hydrogen you'd be lucky to get in solution from his leaf?

Nocera is a blow hard, so pending the full paper I expect the answers aren't encouraging.