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#51 2018-08-08 03:52:40

louis
Member
From: UK
Registered: 2008-03-24
Posts: 3,590

Re: Sulfuric Acid on Mars

I'm not a totalitarian, quite the reverse, but it's a fact that the Soviet command economy got people into space before the American mix of government agency and free enterprise did. It's also a fact that there isn't really any sort of free market operating on Antarctica - people place themselves under a command system, and while there, living under a strict system of rules,  are issued with supplies and tools etc free of charge.

You tend to overstate my claims. I didn't say all facilities can be shared for all chemicals. I simply observed it is possible in many cases to use the same facilities for different purposes. People in labs do it all the time. Of course on Earth, it is much more efficient to have large dedicated industrial plants dealing with one process - whether sulphuric acid manufacuture or chlorine manufacture. But on Mars, in a small colony, it is much more efficient to develop a multi-purpose approach rather than build a dedicated plant to produce a few kgs per sol of product A and then another dedicated plant B  to produce a few kgs  per sol of something else.



Oldfart1939 wrote:
louis wrote:

I think we would design in small scale multi-purpose facilities so that the same hab space could be used to produce a range of chemicals and also manufacture a range of final goods.

Louis-your total lack of knowledge is showing here. Not all processes can be carried out in some basic simple reactions system, especially one involving containment of the by-products of reaction, as well as the product itself. The chemical industry is very specific in cross usage of equipment, especially if pharmaceuticals are at all involved--even feed stock for pharmaceutical products.

Louis wrote:

I really don't see any need to seek Earth investment to build a Mars sulphuric acid plant. As long as we have the equipment to manipulate steel, glass, ceramics and plastics, we can build sulphuric acid manufacturing facilities. We might import computer control equipment, thermocouples and the like, as they can probably be produced on Earth much more easily. The sulphuric acid doesn't need to be "sold" to anyone - it can just be used. I think moving away from a command economy to a proper functioning market economy with currency pricing of goods would take several decades at least and would require the establishment of a range of market participants including individuals, private and public companies, public corporations and co-operatives. A fully functioning market economy won't spring up of its own accord...or rather it would have a very limited focus if you allowed it to.

I really think you should re evaluate what you have written here. Your views on economics are totalitarian and would be more at home in the former Soviet Union than on Mars!

Everything you are "wishing into existence" needs paid for--by someone or by some means. The comment that "sulphuric acid doesn't need to be 'sold' to anyone--it can just be used." comment really blew my mind.


Let's Go to Mars...Google on: Fast Track to Mars blogspot.com

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#52 2018-08-08 16:15:43

knightdepaix
Member
Registered: 2014-07-07
Posts: 121

Re: Sulfuric Acid on Mars

JoshNH4H wrote:

To expound on sulfates a bit:
You might heat the sulfates as part of a batch process to bake out the SO3 and probably also some SO2 (if there are any Iron (II) Sulfates mixed in.  From there you can proceed as in the contact process, catalyzing the remaining SO2 to SO3, and then reacting it with water in a concentrated sulfuric acid to get purer sulfuric acid.
I know it's untraditional, and I'm probably oversimplifying the process, but it seems workable.  Thoughts?

Per this paper, electrolysis can split sodium sulfate into sodium hydroxide and sulfuric acid. If alkali metal sulfates solid or suspension is found in bulk on Mars, things are great because their solutions are splitting into hydroxides and sulfuric acid. The hydroxides are reused to dissolve other metal sulfate, for example Iron(III) sulfate to yield the alkali metal sulfate again and the ferric hydroxide, which is heated at lower temperature than the 1000K mentioned to release water and ferric oxide. The ferric oxide is roasted into pig iron using conventional metallurgy so well known on Earth for a hundred years and more.

A slippery slope is the gradual loss of water into carbon oxides; however, per this discussion on this forum, large volume of water has been found on Mars.

Else, alkali metal hydroxide can be imported from Earth and recycled in use in factories.

As the population at the beginning is not large, an industrial complex of iron and aluminum metallurgy, sulfuric acid, hydrocarbons, fuel and perflurorocarbon manufacturing, research labs, launching pad for spacecrafts could be possible with extending road or rail to the mining sites on one end and to greenhouse agriculture and residences for the population on the other.

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#53 2018-08-08 22:26:15

JoshNH4H
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From: New York, NY, USA, Earth, Sol
Registered: 2007-07-15
Posts: 2,314
Website

Re: Sulfuric Acid on Mars

Oldfart1939 wrote:

Nothing was ever said about getting Sulfur from other forms being "impossible," but systemically just "very difficult." And energetically very expensive. In  the chemical process field, anything above superheated steam temperatures present extreme difficulties, since this is in a range where the seals in systems are subjected to almost impossible stresses. Most seals today are made of PTFE, which would not withstand such temperatures under high pressures involved. Yes. Things are always "possible;" on paper.

You make a good point there, and I hadn't thought of that.  I assume there are ways around that can be used, if necessary, but also assume that these ways are more expensive and difficult.  In my experience one way you can do it is to seal a container by screwing it shut, torquing down, and using a thick, high-temperature grease to make the seal.  But it takes tighter tolerances on your parts, more careful design, and more care to prevent wear.

You might try making seals out of a softer metal like Tin for higher temperatures but this naturally comes with lots of problems of its own, not least of which is the fact that to my knowledge there has been no concrete discovery of tin reserves on Mars.

Oldfart1939 wrote:

I see nothing in the flow diagram to indicate the liberation of any SO3. All I have is your interpretation to mean there is some? I wouldn't bet the farm on one of these processes as my first interpretation.

That's a good point.

From the paper the chart came from:

Absence of SO2 (No mass 64 fragment). Most sulfates evolve SO2 in the range of 25-1000 ºC; however, sulfates of alkali metals (i.e., Na, K), and Ca do not evolve SO2 in this region [8]. The absence of SO2 indicates that either there is no sulfate in the soils at the Phoenix landing site or that the sulfate is in a thermally stable form to 1000°C (i.e., Na-, K-, and/or Ca sulfate, see Fig. 1). The TEGA results eliminate the possibility of Mg- and Fe-sulfates occurring in the soils at the Phoenix landing site because these sulfates breakdown well below 1000°C and evolve SO2 [e.g., 8; 9].

Upon re-reading the other paper, the authors make it clear that the process results in a mixture of SO2, O2, and SO3 in mole ratios consistent with the high-temperature decomposition of SO3, which aligns with the expectations of the curiosity team while also making sense from a redox standpoint.  It's a bit unfortunate for us, as far as limiting the number of process steps is concerned.  A potential alternative is to separate out the SO3 via fractional distillation and then proceed with the SO2/O2 as in the contact process or potentially to discard the SO2 or use it for something else (Nothing springs to mind offhand). 

Oldfart1939 wrote:

I really think you should re evaluate what you have written here. Your views on economics are totalitarian and would be more at home in the former Soviet Union than on Mars!

I'm not going to defend Louis' description of how he believes a Martian economy would function as I believe it to be fantastical, but I will defend the notion of command economies.  Regardless of my opinion of capitalism more generally, I think it definitely doesn't make sense to pursue any kind of market economy when the settlement is too small for competition between different suppliers.  If you've ever had to deal with internet providers in the US (technically private but with no competition in the market) you know that the idea of a "market" is nothing more than an idea when there's no competition in it.

There's a lot to be said for central planning in a small economy with limited resources, too.  There are ways in which financial apparatuses can obscure costs as much as they clarify them.  Just as an example, regardless of what the marginal costs of labor and capital are it won't really be possible to directly substitute one for the other when you in fact have specific workers with specific skillsets and specific, enumerated (or at least, enumerable) machines, facilities, and resources for them to use.  Given that economic planning is perhaps the most critical determinant of how people on Mars will live their lives, it would hopefully be done with input by and approval from the community as a whole.  An even better system, if it could be implemented, would be one in which decisions that affect everyone are made by everyone, with narrower decisions made by the people responsible for implementing them.  But I digress.

Costs remain very real in a command economy, although they may be accounted for differently: If this person works on this project, they can't work on this other project; If we dedicate energy to the production of sulfuric acid that's less energy we have available for steel production, agriculture, heating, etc.  You might introduce various accounting methods to simplify the planning (labor, energy, resources, machines, for example) as the economy gets larger.

It's probably worth mentioning that for all the many faults of the Soviet system, including its fundamental brutality, it is nevertheless true that Russia industrialized in the 1930s at a pace that no capitalist country has ever matched.

Oldfart1939 wrote:

A general comment on expense of industrial chemical processes. Every step added increases the infrastructure requirement in a major way, and one can figure on it being a 2x multiplier. The textbooks may say otherwise, but the bean counters say it's a killer to any economic outlook.

This is a great rule-of-thumb which I intend to keep at the front of my mind in all such future discussions


-Josh

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#54 2018-08-08 22:38:05

JoshNH4H
Moderator
From: New York, NY, USA, Earth, Sol
Registered: 2007-07-15
Posts: 2,314
Website

Re: Sulfuric Acid on Mars

knightdepaix wrote:
JoshNH4H wrote:

To expound on sulfates a bit:
You might heat the sulfates as part of a batch process to bake out the SO3 and probably also some SO2 (if there are any Iron (II) Sulfates mixed in.  From there you can proceed as in the contact process, catalyzing the remaining SO2 to SO3, and then reacting it with water in a concentrated sulfuric acid to get purer sulfuric acid.
I know it's untraditional, and I'm probably oversimplifying the process, but it seems workable.  Thoughts?

Per this paper, electrolysis can split sodium sulfate into sodium hydroxide and sulfuric acid. If alkali metal sulfates solid or suspension is found in bulk on Mars, things are great because their solutions are splitting into hydroxides and sulfuric acid. The hydroxides are reused to dissolve other metal sulfate, for example Iron(III) sulfate to yield the alkali metal sulfate again and the ferric hydroxide, which is heated at lower temperature than the 1000K mentioned to release water and ferric oxide. The ferric oxide is roasted into pig iron using conventional metallurgy so well known on Earth for a hundred years and more.

A slippery slope is the gradual loss of water into carbon oxides; however, per this discussion on this forum, large volume of water has been found on Mars.

Else, alkali metal hydroxide can be imported from Earth and recycled in use in factories.

As the population at the beginning is not large, an industrial complex of iron and aluminum metallurgy, sulfuric acid, hydrocarbons, fuel and perflurorocarbon manufacturing, research labs, launching pad for spacecrafts could be possible with extending road or rail to the mining sites on one end and to greenhouse agriculture and residences for the population on the other.

Interesting find!  Definitely useful on Mars if the energy costs are not prohibitive


-Josh

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#55 2018-08-09 00:41:36

Oldfart1939
Member
Registered: 2016-11-26
Posts: 1,430

Re: Sulfuric Acid on Mars

I'll close out my commentary on this thread by stating my views on central planning: yes, they can ensure that tasks are accomplished at the cost of stifling creativity. In order to get things done, the old Soviet Union employed the gun to the head as a means of enforcement of the central planner's will. I really don't hope we resort to that approach.

On the other hand, Zubrin very enthusiastically points out the opportunity for creativity on the new world. I hope he's correct.

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#56 2018-08-09 07:42:42

JoshNH4H
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From: New York, NY, USA, Earth, Sol
Registered: 2007-07-15
Posts: 2,314
Website

Re: Sulfuric Acid on Mars

Depends how involved people are in the planning, eh? Soviet style planning had many failures, but there's no reason, especially in a small settlement, why planning wouldn't be more of a discussion between neighbors on what needs to be done than orders from above.


-Josh

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#57 2018-08-09 10:34:34

Oldfart1939
Member
Registered: 2016-11-26
Posts: 1,430

Re: Sulfuric Acid on Mars

The real modern management system might not work as well as one I've experienced: state there's  a request for proposals on how to get job XYZ done, with a NMK dollar payout. Then step back and see how innovation really works.

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