I have an idea for exploiting serpentization but I don't know if it would work.

[ROCKM4N]

I was reading some random stuff, and I came across serpentization as an exothermic reaction that can liberate hydrogen from water under some circumstances. I think its pretty interesting because Olivine is not rare, and unlike most reactions that produce hydrogen this one is not energy negative or CO2 emitting. There are some examples of it at some hydrothermal vents where the reaction heats up the water and emits a mixture of hydrogen and methane.

https://en.wikipedia.org/wiki/Lost_City_Hydrothermal_Field

Idea is as follows:

I was thinking high pressure water could get pumped into the rock (basically fracking). All the tiny cracks would give surface area for the reaction to occur. The rock would heat up and a bit of hydrogen would be produced, which could both be exploited. According to everything I have read, the reaction will occur at up to about 400C, theoretically hot enough for dry steam. The hydrogen production could be exploited by something like current natural gas wells drilled on the site.

 

The main problems I can think of are:

1: The reaction may not be fast enough to be practical even if done over a wide area

2: The water would likely remain under pressure since it needs to stick around to react with the rock, making the gas well a very tricky proposition

3: The cracks would be lined with the reaction product, shielding the unreacted mineral from it.

4: Olivine concentration in the rock might need to be unnaturally high to be possible/practical.

5: Hydraulic Fracturing might not be a practical way to get the surface area needed

Despite identifying these problems, I don't know how big they would be, so I will leave it to everyone else to tell me I should be disappointed

[mikegarrison]

 

[farmerben]

It will probably work some.  It's mostly a question of yield and economics.

There are a lot more locations capable of geothermal heating.  I've often wondered why we don't have powerplants next to volcanoes.

[farmerben]

 

Olivine.  Looks like the reaction rate is too slow to matter.

 

[JoeSchmuckatelli]

On 12/16/2022 at 5:24 AM, ROCKM4N said:

serpentization as an exothermic reaction that can liberate hydrogen from water

.

Your idea is intriguing.  I think you'd really need a geochemist to comment.

[Nuke]

On 12/17/2022 at 1:18 AM, farmerben said:

It will probably work some.  It's mostly a question of yield and economics.

There are a lot more locations capable of geothermal heating.  I've often wondered why we don't have powerplants next to volcanoes.

not geologically stable. nobody wants to put something expensive on unstable ground.

[ROCKM4N]

On 12/18/2022 at 3:34 PM, farmerben said:

 

Olivine.  Looks like the reaction rate is too slow to matter.

 

It might be, however in other locations the reaction occurs fast enough to warm water and produce significant amounts of gas at hydrothermal vents (look up the "lost city" hydrothermal vent system). They think that chromium minerals may by some kind of catalyst to speed it up, however this reaction in general seems pretty unresearched.