"Synthetic Natural Gas" - How's That For A Name Change?
by John Laumer, Philadelphia on 02.27.08
People are filling up our "You Can't Make Up Stuff Like This" file far too quickly; but this one just has to be posted.
Coal industry-hired PR agencies must have come to the realization that the "Clean Coal" mantra isn't working out as they'd planned. How else to explain advocates referring to a billion dollar coal gasification project as making "synthetic natural gas?" Reminds us of an old George Carlin routine from Saturday Night Live.
"The term Jumbo Shrimp has always amazed me. What is a Jumbo Shrimp? I mean, it's like Military Intelligence - the words don't go together, man."
Here's where we first came across the "synthetic natural gas" phrase:
Power Holdings first announced it had chosen the Waltonville area of Jefferson County [Illinois] as its choice for construction of a $1 billion synthetic natural gas plant. The gas would be created using an "environmentally friendly" specialized technology designed to use Illinois coal. At the time of the announcement, the company stated the area was chosen due to its proximity to water, coal reserves and transportation systems and one of the main natural gas pipelines for the state.
On a more serious note: downstate Illinois is underlain by vast beds of highly sulfurous coal, which are of little economic value unless some way is found to extract the energy while leaving the sulfur behind, minimizing, also, the C02 emissions.
Coal Gasification is really the only technology option. If this is going to happen - and it probably is to varying degrees -we hope the discussion will revolve more around jobs, resource efficiencies, acid rain, and climate impact, and less around semantics.
Via::Mt. Vernon Register-News, "Synthetic natural gas plant to become a regional enterprise" Image credit::Citizens Utility Board
You should have googled a little more widely before assuming that "synthetic natural gas" was the creation of a half-literate PR flack with a tin ear for irony. Usually shortened to "syngas", it is a common term for the product of the coal gasfication process.
Very simply: coal goes into a large apparatus ("gasifier") in which it is transformed at high temperatures into a hydrocarbon-laden gas ("syngas") and miscellaneous leftover solids. Essentially all of the bad stuff-- mercury, heavy metals, sulfur-- falls out with these solids. (Note that there are very effective ways to control these things with conventional coal plants too; gasification is not the only solution for controlling these particular pollutants.) The syngas is then piped to a next-door power generator, a turbine-powered setup that is identical to any other new, natural-gas fired plant (aka combined-cycle gas turbine, or CCGT).
Coal gasification is much more expensive than conventional coal plants, because you are building not just the power plant but also in essence a large chemical factory to gasify the coal. So why is it of interest? Because it is much easier to pull the CO2 out of syngas before it is combusted than it is to capture CO2 after it is combusted.
But I digress. Short version: "synthetic natural gas" is not an attempt to fool you. "Natural gas" is not a value judgement, it is just the only term in English for the particular combination of molecules being discussed.
=== authors' response follows ===
Thanks for the comment.
FYI I happen to have a chem Egr background. Just wanted to have a little fun with the way ideas have been slung to people who have paid no attention to process technology up to now, even though it has great prospective relevance to their lives.
It's my feeling that the "clean coal" term, which is rather meaningless except for political purpose, has been and is being overused. Perhaps we'd agree that Syngas just makes more sense because it is more precise and, with a long tradition, is the preferred term for the described operation.
That said, "synthetic gas" sounds a lot less like Jumbo Shrimp than does "synthetic natural gas."
Well, if you're a chemical engineer you're streets ahead of me in understanding gasification; if someone asked me precisely *how* coal was turned into syngas, I'd have to say "magic."
I fully agree with your reply to my comment, which I offered in the spirit of deepening the discussion a bit. Please don't be shy about putting that technical background to use, because that's the value-add of TH.
Process technology indeed has a a great relevance to people's lives-- I could not have put that better (and will probably steal that line for cocktail-party-discussion purposes). And TH could be the means by which people learn about those technologies, and the costs and trade-offs that go with them.
Thanks for your reply!
Yes, even though there are other ways of removing pollutants from coal fired power plants, gasification can do it cheaper and more throughly, and is the only form of coal power plant where CO2 sequestering is economical.
Because the cold hard fact is that we're going to be using coal for the forseeable future, I think it'd be a good idea to, say, close the 5% most polluting coal power plants every year and force all new coal power plants to use gasification tech. I've read that if all coal power plants today used gasification istead of the technology they use, that would singlehandedly do 25% of the US' Kyoto requirments.
Syngas is short for synthesis gas which is a mixture of carbon monoxide and hydrogen. Coal gas in the old days was mostly synthesis gas and very dangerous due to the carbon monoxide content.
Natural gas is mostly ethane and methane. Both of those gases can be made from synthesis gas so "synthetic natural gas" might sound weird but it's more accurate than "syngas".
Syngas is short for synthesis gas which is a mixture of carbon monoxide and hydrogen. Coal gas in the old days was mostly synthesis gas and very dangerous due to the carbon monoxide content.
Natural gas is mostly ethane and methane. Both of those gases can be made from synthesis gas so "synthetic natural gas" might sound weird but it's more accurate than "syngas".
The term is actually "substitute natural gas" . I agree with the author's observation. Humorous treatment. Beyond the humor, SNG plants offer a very clean way of turning coal and other carbon feedstocks into a clean fuel (with carbon capture and sequestration). The IL plant referred to is one of many being developed in the U.S. in response to rising natural gas prices. They offer the prospect of providing gas to homes, businesses and factories based on domestic resources. The alternative is imported natural gas (LNG). Google that.
In today's political climate words matter. Think "substitute natural gas". For more information go to http://www.gasification.org.
===author's response follows ====
Thanks for this.
And yes, words really matter.
Few people appreciate that natural gas, as it leaves the wellhead, is variously contaminated with mercury vapor. Much less Hg per BTU than coal, of course, but the amounts are substantial enough that gas fired power plants have mercury limits in their air permits! Only natural gas destined for domestic use is mercury-scrubbed to avoid home interiors from becoming Mad-Hatter-villes.
"Substitute gas" (the term I will try to remember to stick with henceforth) I presume will be scrubbed to meet domestic use standards. If so, this means it becomes a net positive for the environment as it will reduce the mercury emissions of natural gas fired power plants.
WRONG! WRONG! WRONG!
Wrong....
Yahoo deeper: this plant is an extension of Great Point Energy whose original pilot plant was located right up I-57 just outside Champaign.
Natural Gas: a mixture of methane, but-, eth-, pen-, and pro-pane. Its essentially a nice way of saying methane...
Synthetic Natural Gas: methane gas created by a synthetic human process. Its not syn-gas in this case.
The Great Point Energy gasification process uses a doped potassium catalyst that helps reduce the activation energy necessary to swap carbon for hydrogen. The process is over 65% efficient and recovers sulfur, mercury, lead, et al as industry ready byproducts.
This methane, if produced at the mouth of the mine and transported via pipeline, would be provide a substantial EROEI compared to our current coal infrastructure while being substantially cleaner.
Calculation:
0.65 (recovery efficiency) x 0.65 (CCGT)= 42% efficiency which is better that a CFP at ~33% efficiency, not to mention the energy saved in transport.
We should see a new generation of ceramic turbines in the next couple years. Use waste heat to run a zeolite filter to get a pure oxygen stream (and burn) and use a heat exchanger to heat incoming air with the exhaust. 70% thermal efficiencies are projected with a pure CO2/H20 exhaust stream. Nice.
Also note that the CO2 could be readily captured and piped to old oil fields in the Illinois basin for enhanced oil recovery. No need to worry about leakage. Those are salt domes: if oil didn't get out, CO2 isn't getting out.
Link to Illinois basin oil field overview: http://sequestration.org/publish/oil_prod_map_dec05.pdf
Yes, not to mention the water, mercury, SO2, NOx, solid wastes, etc, are drastically reduced, and could be a cheap way of producing domestic hydrogen before renewables can produce enough to replace fossil fuels, assuming fuel cells become popular.
Yes, not to mention the water, mercury, SO2, NOx, solid wastes, etc, are drastically reduced, and could be a cheap way of producing domestic hydrogen before renewables can produce enough to replace fossil fuels, assuming fuel cells become popular.