Carbon Dioxide Solution

Have you heard of the Stenger Wasas Process (SWAP)?

Apparently, it’s an exothermic reaction (produces heat) that takes place between carbon dioxide and hydrogen sulfide and “eliminates” both. It operates over a secret heterogeneous catalyst that is apparently readily available and inexpensive. Sounds too good to be true: Solve global warming and acid rain in one go!

According to the Wiki entry on the subject:

The SWAP is not a CO2 capture process. It is a CO2 conversion and elimination process. In a near-instantaneous reaction, it breaks down CO2 and H2S, rearranges their components and produces water, carbon and sulfur.

It then goes on to tell us that SWAP “permanently removes carbon from the carbon cycle.”

I was followed last week on Twitter by Swapsol and my curiosity was piqued. Behind the Swapsol twitter account is Evan Howell (Swapsol’s EVP, Marketing & Communications) and his twitter bio says: “Our company has verified a process that reacts CO2 and H2S, converting the compounds into water, carbon and sulfur.”

The Wiki entry references just one “paper” entitled: “The Kinetic and Thermodynamic Behavior of Gaseous H2S and CO2 over a Heterogeneous Catalyst” from 2008, by a Dr Roy Drayton, who is president of Thermal Hazard Solutions ( who apparently did independent tests.

Howell just sent me a report apparently from Drayton that doesn’t give an awful lot away, although it mentions efficiencies being significantly higher above 150 Celsius and at raised pressure; it leaves me totally unconvinced of their earth-changing claims though, I’m afraid:

The Stenger-Wasas Process (SWAP) as described, in which the gaseous reaction between hydrogen sulfide and carbon dioxide over treated solid heterogeneous catalyst (i.e C09-0108t) was observed to be thermodynamically and kinetically favorable at or below 25oC to 150oC and above. The reaction process is spontaneous and liberates heat. This conclusion is based upon physical experiment data (adiabatic and isothermal calorimetry), as well as theoretical predictive methods.

I asked Howell a direct question about the nature of the catalyst, known enigmatically as C09-0108, this is what he had to say:

Actually, the catalyst is key and what is confidential. Studies are on-going to improve its efficacy.

Fair enough, no company is going to give away trade secrets on such a potentially important development, they’re not going to profit if they do. But I’m worried that so much is being claimed and so little is being said about this. The patent application is for the “process” rather than the key catalyst and only describes the process. The extended abstract doesn’t even mention a catalyst.

This technology could change the world if it’s viable. Morally, shouldn’t it be in the public domain so that it can be validated and applied in industry to clean up the planet?

“Independent verification is important,” Howell told me, “Chemical kinetics and gas chromatography are coming. We’re going slow right now.”

There is one more issue, the process apparently produces carbon and the Wiki entry claims this permanently removes it from the global carbon cycle. Well, that’s not strictly true, unless the carbon byproduct is buried deep underground in an oxygen-free environment it will ultimately revert to its low-energy chemical form – carbon dioxide and re-enter the cycle at some point. Of course, it could be used as fuel or feedstock, which is what I think the company intends, so ultimately it will revert to carbon dioxide sooner rather than later.

Apparently, it was in a New Jersey garage, that “entrepreneur chemist” Jim Wasas and “environmental engineer” Ray Stenger discovered how to convert and eliminate CO2, opening the door to a new energy economy. After pressing Howell a little he eventually told me that the process is more important in terms of oil and gas refining, regarding H2S disposal rather than for its potential in CO2 elimination and solving global warming.

The Swapsol website says: “It’s time to rewrite the chemistry textbooks.” But, I’m afraid that kind of phrase always sets alarm bells ringing and reminds me of the dozens of emails I’ve received over the years making similar claims about the physics textbooks. The energetics don’t quite add up, but at the time of writing Swapsol is offering very little additional information and is holding off engaging with the media until the autumn. That’s an odd stance too, given that I am in the media and it’s only Spring. Moreover, if they’re holding off engaging with the media what are they doing following science journalists on twitter?

Maybe I am missing something. Is the Stenger Wasas Process (SWAP) a genuine solution to our problems waiting to be unleashed? It’s a very happy coincidence that the names of the two inventors mesh nicely together to form a neat acronym, isn’t it? It’s not that I’m doubting their integrity, I’d just like to see some more chemistry. Let’s hope this is not simply another slow burn to dying embers like Steorn was slow, or cold fusion was, or Perepetia was…

It seems that humans are pre-programmed either to predict the end of the world and to monger doom or to tout global panaceas for energy, climate, and all the world’s ills. It’s almost like a collective bipolar syndrome fed by the fragility of the human condition. Personally, I do not believe the end of the world is nigh, but neither do I believe that are any wonder solutions to the serious problems we currently face.

UPDATE: June 2, 2009

I asked a chemist colleague to take a look at the claims, this is what he had to say:

“Concerning this SWAP process, the essence of their claim is:

(1) “Our company, Swapsol, has verified a process that reacts CO2 and H2S, converting the compounds into water, carbon and sulfur.”

(2) The process is exothermic.

The first statement is obviously inaccurate, since the stoichiometry doesn’t work. You have to add a half-molecule of oxygen to the output to make it balance:
H2S + CO2 -> H2O + C + S + 1/2O2

Although, they seem to have used a different approach to balancing their stoichiometry. I’ve dropped irrelevant CH4 terms from both sides, this is how it comes out:

2H2S + CO2 -> 2H2O + 2S + C

Concerning the second statement, this must be true or false regardless of whether the catalyst is known. A catalyst only affects the activation energy needed to drive a reaction. It can’t affect the chemical potential energies of the inputs or outputs. The trouble is that we don’t know exactly what forms the output C and S take, so we can’t do an exact energy budget to verify “exothermicity”. There is talk of the C coming out as nanotubes, for example. However, if the process really is exothermic and has a low activation energy, that would be crucially important to its economics. An endothermic process is expensive.

That said, we can do an energy budget of sorts. If you assume the C and S are not bonded at all, then in that state their energy is higher than if bonded. Once they bond, more energy is released. Therefore, if the process is exothermic even if the C and S on the output are unbonded, then it is exothermic no matter what form the C and S take.

It may be possible to find the bond energies in a reference like the CRC Handbook of Chemistry and Physics and work out a crude energy budget. I’ll try to get around to doing that sometime. The results probably won’t be conclusive.

My trusty old CRC gives the following bond energies in these molecules (in units of kcal/mol):

H-S in H2S = 90
C-O in CO2 = 127
H-O in H2O = 119
C-C in C crystals (probably meaning graphite) = 171
S-S in S crystals = 66

If we take the above chemical equation at face value, then on the left we have:
4 (H-S) bonds + 2 (C-O) bonds = 614 kcal/mol

while on the right we have

4 (H-O) bonds = 476 kcal/mol

Thus if the C and S end up as free atoms, the reaction is endothermic.

If we manage to bond the C and S into typical crystal structures, then on the right we need to add:

1/2 of a (C-C) bond + 1 (S-S) bond = 151.5 kcal/mol

for a grand total of 476 + 151.5 = 627.5 kcal/mol

In this case, the reaction is indeed marginally exothermic.

However, we don’t know a lot of things, such as, what is the actual output state of the C and S. We also don’t know the pressures and temperatures required to drive the reaction in the presence of the mystery catalyst. That is important. For example, taking free C atoms and turning them into diamond is hugely exothermic, but requires absurdly difficult-to-achieve conditions.”

My chemist friend’s hunch is that the claims probably aren’t true, but since we have been given so little information it is difficult to make a definitive assessment one way or the other.


  1. The process ends up with pure carbon
    and pure sulpher and both have
    potential industrial value.
    You will not need to bury it just sell it..

  2. David Bradley

    @Tom You would have to bury it to take the carbon out of the carbon cycle, which is what the developers are claiming.

  3. Isn’t that better then dealing with
    the potential risks of carbon sequestration?

  4. David Bradley

    Well…this is carbon sequestration isn’t it, they’d be sequestering CO2 from the atmosphere and reacting it with hydrogen sulfide over the mystery catalyst to produce carbon and sulfur, although I’m still not convinced they can do that. But, the point I was making is that they say they’d be removing the carbon from the carbon cycle. They won’t be doing anything of the sort if they then feed the carbon back into industry where it will be processed into carbon-based starting materials for other products, chemical reactants, or fuel. I it works, however, it is a great idea. Like I said in the post. My main truck with them is the fact that they’re reluctant to provide details and it all just sounds too good to be true.

  5. Ansem Mayfield

    Actually, the carbon that is removed is in the form of Carbon nanotubes. Currently, there is no inexpensive way to manufacture these buckyballs. But the swap process offers a way to tackle three problems at once.

    1) They remove CO2 emmissions and sulfides.
    2) They conviently provide an efficient means to build carbon nanotubes.
    3) They create a sulfur compound that can be reused in the process for further removal of greenhouse gases.

    When they say remove carb from the carbon cycle, this solely refers to the greenhouse gas cycle of CO2. As a pure carbon, it is effectively removed from the cycle in that it will not enter the atmosphere as a gas.

    Enough said!

  6. David Bradley

    Ansem, enough said? I don’t think so…

    Can you show me the reference that demonstrates CNT production? Incidentally, CNTs are not buckyballs.

    Yes, I realise they are removing it from the atmosphere, but there will be a point somewhere down the line where the carbon they’ve extracted will be vented again, unless it’s being used solely to make solid non-degrading products.

    But, aside from all that, they are yet to provide evidence of anything.

  7. David: I am one of the first investors in Ray & Jim’s process. I am not a chemist nor physicist. I have known Ray since 1964 and invested in his process solely on Ray’s reputation for being thorough and honest. If you are a qualified investor and sign the confidentiality agreement I am sure that Ray & Jim would be glad to demonstrate the process and answer any questions.

  8. David Bradley

    I’m not a potential investor, I’m a journalist investigating. I certainly have no intention of signing a confidentiality agreement and then paying to receive information, what would be the point in that for a journalist? I’d know what they’re up to, but I wouldn’t be able to tell my readers about it.

    As to investing in a company because you trust the people involved but don’t know anything about the science yourself…that’s an interesting approach. Isn’t the first rule of investing in a company to at least have a basic understanding of its products or services before you commit money.

    I do not doubt the integrity of anyone involved, but I want to see wholly independent, detailed, and open results before I can proclaim this as a breakthrough to my readers. Valid scientific results will stand on their own regardless of the reputation of the scientist.

  9. David Bradley

    I asked a chemist friend to look in detail at the thermodynamics of the process suggested by the company and have added his analysis to the post.

  10. William Connolley

    I hacked the wiki page a bit. Others may follow.

  11. If you are removing carbon dioxide, but producing heat, doesn’t that defeat the purpose of removing the carbon dioxide, which is to prevent global warming?

  12. David Bradley

    That’s another good point…but I guess the heat would be usable and so avoid the need for an external heat source for some process in the same industrial plant…depends on how much and the “quality” of the heat released.

  13. William Connolley

    Nooo… its not, its a very bad point, and you should have realised it. (a) Waste heat is far smaller than CO2-radiative effects and more importantly (b) exothermic just means you don’t need to pump lots of energy in to make it work, so industrially it is more likely to be plausible.

  14. David Bradley

    I’d still like to know what catalyst they’re using. I hope it does work, was just opening up debate!

  15. Yeah, I suppose I was just being a smart-ass and after I posted the comment I realized that the effect of carbon on the atmosphere probably has an exponentially higher production of heat than the waste heat produced.

  16. this is very hard to understand just want to find out what does it really mean by climate change or global warming,and if there is any method that they use to suck the carbon dioxide from atmosphere other than the forest?

  17. Raymond Stenger and James Wasas invite members of the academic and professional communities on Wednesday, Oct. 21, 2009, to learn about the Stenger-Wasas Process (SWAP), proposing that a reaction between carbon dioxide (CO2) and hydrogen sulfide (H2S) eliminates both (2H2S + CO2 => 2H2O + 2S + C) in a mildly exothermic reaction and could alter the course of global warming and impact escalating energy costs. Hear and discuss the science behind the SWAP and its potential impact on the hydrocarbon industry.

  18. Carlos, what would we do with all of the 2S produced

  19. Sulfur has lots of industrial uses.