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Void

Member

Registered: 2011-12-29

Posts: 7,818

Formation of H2 and CH4 by weathering of Olivine.

OK, I run the risk of making a speculative, ignorant fool of myself, but I stumbled on this article and liked it, wanted to bookmark it.

https://www.researchgate.net/publicatio … 30_and_70C

The subject phrase is a good one to search for more information.

Parts of the chemistry are a very far reach for me, but I found the article, so far to be capable of giving me hints about what potentials there are.

It looks like there was a lot of volcanic ash pumped to the surface of Mars at some point, and much of it may not have been processed entirely.  I believe that the sand dunes may have a good potential to generate chemicals in reactions with water and perhaps dissolved CO2, and other additions.

The temperatures in these experiments are below the typical notion of production of CH4 and H2. 

Am interested in what these processes may have done over the history of Mars.
Also, interested in taking a look at the possibility of generating Hydrocarbons in similar reactions, facilitated by human technology, and also to consider, the use of microbes.

One thing I recall is that you can have hydrothermal vents that are not directly tied to current volcanism.  The process of serpentinization, can generate it's own heat, something like a wet hay pile, but in the case of hot serpentinization, it would I suppose be an abiotic process.

So, since Mars may have so much of it, and it does have water and CO2, and Nitrogen, I both think of using microbes at lower temperatures, and also trying to kick start a hot abiotic process using something like fracking.

It seems though that the chemistry, the actual composition of the rock, will determine if there can be a potential for it.

I am by no means expert on this.

One thing I picked out of the article, is that they went to great efforts to make their experiments abiotic at lower temperatures.

Also, there was some mention of the potential to produce not only H2, and CH4, but waxes.

Short on time.

Done.

Last edited by Void (2019-05-27 08:54:58)

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Void

Member

Registered: 2011-12-29

Posts: 7,818

Re: Formation of H2 and CH4 by weathering of Olivine.

I guess I will include this next:
https://www.sciencedirect.com/science/a … 3708006467
Quote:

Abstract
In recent years, serpentinized ultramafic rocks have received considerable attention as a source of H2 for hydrogen-based microbial communities and as a potential environment for the abiotic synthesis of methane and other hydrocarbons within the Earth’s crust. Both of these processes rely on the development of strongly reducing conditions and the generation of H2 during serpentinization, which principally results from reaction of water with ferrous iron-rich minerals contained in ultramafic rocks. In this report, numerical models are used to investigate the potential influence of chemical thermodynamics on H2 production during serpentinization. The results suggest that thermodynamic constraints on mineral stability and on the distribution of Fe among mineral alteration products as a function of temperature are likely to be major factors controlling the extent of H2 production. At high temperatures (>∼315 °C), rates of serpentinization reactions are fast, but H2 concentrations may be limited by the attainment of stable thermodynamic equilibrium between olivine and the aqueous fluid. Conversely, at temperatures below ∼150 °C, H2 generation is severely limited both by slow reaction kinetics and partitioning of Fe(II) into brucite. At 35 MPa, peak temperatures for H2 production occur at 200–315 °C, indicating that the most strongly reducing conditions will be attained during alteration within this temperature range. Fluids interacting with peridotite in this temperature range are likely to be the most productive sources of H2 for biology, and should also produce the most favorable environments for abiotic organic synthesis. The results also suggest that thermodynamic constraints on Fe distribution among mineral alteration products have significant implications for the timing of magnetization of the ocean crust, and for the occurrence of native metal alloys and other trace minerals during serpentinization.

So for abiotic production of H2 from water and certain ultramafic rocks, a higher temperature is much preferred.

…..

The upper temperature endurance for life is according to this article:
https://bioinfo.bact.wisc.edu/themicrob … T/b10.html
Quote:

Archaea
Methane-producing bacteria
110 C
230 F
Sulfur-dependent bacteria
115 C
239 F

I will bring this back in from post #1: https://www.researchgate.net/publicatio … 30_and_70C
Quote:

Abstract
Hydrocarbons such as CH4 are known to be formed through the Fischer-Tropsch or Sabatier type reactions in hydrothermal systems usually at temperatures above 100°C. Weathering of olivine is sometimes suggested to account for abiotic formation of CH4 through its redox lowering and water splitting properties. Knowledge about the CH4 and H2 formation processes at low temperatures is important for the research about the origin and cause of early Earth and Martian CH4 and for CO2 sequestration. We have conducted a series of low temperature, long-term weathering experiments in which we have tested the CH4 and H2 formation potential of forsteritic olivine. The results show low temperature CH4 production that is probably influenced by chromite and magnetite as catalysts. Extensive analyses of a potential CH4 source trapped in the crystal structure of the olivine showed no signs of incorporated CH4. Also, the available sources of organic carbon were not enough to support the total amount of CH4 detected in our experiments. There was also a linear relationship between silica release into solution and the net CH4 accumulation into the incubation bottle headspaces suggesting that CH4 formation under these conditions could be a qualitative indicator of olivine dissolution. It is likely that minerals such as magnetite, chromite and other metal-rich minerals found on the olivine surface catalyze the formation of CH4, because of the low temperature of the system. This may expand the range of environments plausible for abiotic CH4 formation both on Earth and on other terrestrial bodies.

So to me that is interesting, as the upper limits of life can tolerate the lower temperature bounds of Serpentinization it seems.

They also seem to suggest that H2 and CH4 can be developed over a much longer time period by weathering rocks at colder temperatures.

……

My interests in this are:
#1 Are their hydrocarbons on Mars in quantity of use? (That is most important, of secondary importance is how the hydrocarbons occurred).
2# Can we produce (Abiotic) serpentinization of a most ideal sort with higher temperatures?
3# Are their situations where we can tolerate a low rate of weathering of the ultramafic rock at lower temperatures?
# 4 Can biology be involved in producing hydrocarbons from ultramafic rock, and H20, CO2, N2, ??? at lower temperatures, that life can tolerate.

So, these could be cut into two processes to facilitate.  The two processes abiotic, and biotic, can overlap a bit when you get to somewhere at or below 115 DegC.

Abiotic first then.  Typically you want geothermal heat, and a large fracture surface area.  We are not guaranteed geothermal heat of value, but it is not yet ruled out.  By two processes it may be possible to dig very deep on Mars.  First of all a tunneling process, where you would dig a deep caver, where you could put up drill rigs to try to "Frack" down much deeper.  By fracking you would create a large surface area of ultramafic rock below.  It is possible that you could get to a minimum desired temperature, say 100 DegC, but maybe hotter.  You then push a fracking solution including water, Carbon???  What ever is needed to get an abiotic process going.

I do not actually have reference to an article I read long ago, about how the abiotic process itself can heat up the rock even more.  It may or may not have been flawed or wrong.  But until proven wrong, there is a chance that once you got the process going the temperature of the well might go above 100 DegC.  And then you might facilitate Serpentinization to produce H2 and perhaps CH4.

If you can do this it should also be noted that the fluids that exit the well may well have valuable minerals that would precipitate out.

If you can't get a self sustaining Serpentization going, then there is also the possibility of sending hot water down.  Sourced from Solar or Nuclear, in order to get the Hydrogen and minerals.  This would also be a thermal storage device.

For instance you might shoot for this:  35 MPa,  200–315 °C.  (See the first linked article).  So, this method of thermal storage, could work well for Mars, with it's global dust storms about every 3 years, and with it's ~22 month years and much longer winters and summers.

……

But many of you know that I like solar ponds, or rather gradated salinity ponds/lakes/seas, for their thermal storage potentials.  On Mars and in Antarctica, I would expect to create, and on Earth have found such lakes.  In Antarctica, lakes have been found that have a bottom temperature say 20 DegC? But human created solar ponds on Earth have a range of:
https://en.wikipedia.org/wiki/Solar_pond
Quote:

The energy obtained is in the form of low-grade heat of 70 to 80 °C compared to an assumed 20 °C ambient temperature.

The above is in the range of abiotic weathering at a slower rate, and the production of H2 at a lower rate.  However such bodies of water could well support life, and the life in it may be able to digest the rock, accelerating the weathering process.

But if you wanted to get into the range of serpentinization, you might be able to get bottom temperatures greater than 100 °C.  I don't know if salt ponds of they type I have mentioned, (Not directly solar), can get to those temperatures or not.  However up to 115 °C, you might be able to include some extreme organisms in the process.

It appears that there are large reserves of volcanic ash derived rock on Mars. For instance: https://en.wikipedia.org/wiki/Medusae_Fossae_Formation
It may be possible to mine stuff like that, but....
Martian dust dunes are already granulated, so as to produce a large surface area to act on relative to mass.
martian dust dunes: https://www.bing.com/images/search?q=ma … &FORM=IGRE

Well that was plenty.

Done

Last edited by Void (2019-05-27 12:46:37)

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Void

Member

Registered: 2011-12-29

Posts: 7,818

Re: Formation of H2 and CH4 by weathering of Olivine.

I have added this link for the phrases Catalyzes, Calcium Carbonate, tolerance of U.V., and other reasons.

I am not impartial to the intentions of the article, to identify life.  However here I am thinking of the potential mining aspects for artificial hot springs on Mars.

https://phys.org/news/2019-05-fettuccin … -mars.html
Quote(s):

'Fettuccine' may be most obvious sign of life on Mars, researchers report
by Diana Yates, University of Illinois at Urbana-Champaign

A rover scanning the surface of Mars for evidence of life might want to check for rocks that look like pasta, researchers report in the journal Astrobiology.

The bacterium that controls the formation of such rocks on Earth is ancient and thrives in harsh environments that are similar to conditions on Mars, said University of Illinois geology professor Bruce Fouke, who led the new, NASA-funded study.
"It has an unusual name, Sulfurihydrogenibium yellowstonense," he said. "We just call it 'Sulfuri.'"
The bacterium belongs to a lineage that evolved prior to the oxygenation of Earth roughly 2.35 billion years ago, Fouke said. It can survive in extremely hot, fast-flowing water bubbling up from underground hot springs. It can withstand exposure to ultraviolet light and survives only in environments with extremely low oxygen levels, using sulfur and carbon dioxide as energy sources.
"Taken together, these traits make it a prime candidate for colonizing Mars and other planets," Fouke said.
And because it catalyzes the formation of crystalline rock formations that look like layers of pasta, it would be a relatively easy life form to detect on other planets, he said.
The unique shape and structure of rocks associated with Sulfuri result from its unusual lifestyle, Fouke said. In fast-flowing water, Sulfuri bacteria latch on to one another "and hang on for dear life," he said.

"They form tightly wound cables that wave like a flag that is fixed on one end," he said. The waving cables keep other microbes from attaching. Sulfuri also defends itself by oozing a slippery mucus.
"These Sulfuri cables look amazingly like fettuccine pasta, while further downstream they look more like capellini pasta," Fouke said. The researchers used sterilized pasta forks to collect their samples from Mammoth Hot Springs in Yellowstone National Park.
The team analyzed the microbial genomes, evaluated which genes were being actively translated into proteins and deciphered the organism's metabolic needs, Fouke said.
The team also looked at Sulfuri's rock-building capabilities, finding that proteins on the bacterial surface speed up the rate at which calcium carbonate—also called travertine—crystallizes in and around the cables "1 billion times faster than in any other natural environment on Earth," Fouke said. The result is the deposition of broad swaths of hardened rock with an undulating, filamentous texture.
"This should be an easy form of fossilized life for a rover to detect on other planets," Fouke said.
"If we see the deposition of this kind of extensive filamentous rock on other planets, we would know it's a fingerprint of life," Fouke said. "It's big and it's unique. No other rocks look like this. It would be definitive evidence of the presences of alien microbes."

The tolerance of U.V. would be consistent with a hot spring exposed to an Oxygen free atmospheric sky.

I can imagine that early photo-life may have had greater tolerance to U.V., but upon the formation of an Oxygen rich atmosphere and Ozone, perhaps tolerance for U.V. became not as important for photo-life.  So, by studying this organism, it may be possible to identify what it takes to have a high tolerance of U.V., and to bring it back to photo-life we might hope to put on Mars early on.

As for mining by artificial hot springs, even if there is insufficient heat in the geosphere of Mars, I can suggest that by digging underground caves where you could set up even deeper fracking wells, you might provide yourself thermal storage of significance large enough to provide year around power on Mars, even during global dust storms.  In the process it may be that minerals can be leached out of the fracked wells, with high pressure hot water, and upon discharging that fluid back to lower temperatures, minerals may precipitate out.  It appears that a life form like this can catalyze the precipitation of Calcium Carbonate.  Perhaps similar methods can assist the precipitation of other materials that may be wanted.

Another aspect of solar hot springs like this is you might stumble on a "Mother-Load" of a mineral you want buried deeper down.  Then if it is a "Mother-Load" then you might actually do shaft mining for it.

Done.

Last edited by Void (2019-05-29 11:56:40)

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