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Claims that gas is cleaner then coal.

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Majin
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« on: March 02, 2016, 22:56:51 PM »

It is a common occurrence that things are promoted as better for your health or better for the environment, when it's usually far from the truth.
Especially in the promotion of fracking and natural gas.

Quote from this article:
"Don't forget gas is much cleaner than coal and government is trying to promote cleaner energy. So, from an environmental point of view, gas is also a big plus for the country," he said."

http://www.fin24.com/Companies/Industrial/sacoil-on-step-closer-to-gas-pipeline-from-mozambique-to-gauteng-20160302

When in fact this study finds natural gas no cleaner than coal etc.

http://www.aljazeera.com/news/europe/2014/10/study-finds-natural-gas-no-cleaner-than-coal-20141016641418947.html

I also read a very disturbing article the other day of a gas leak. "The state would estimate that in less than a month, Aliso released more than 68 million pounds of methane. Since then, it’s leaked 132 million pounds more. That makes Aliso potentially the largest-ever single release of methane into the atmosphere—at least, the largest ever recorded."


Here is the article if anyone wishes to read it...
http://www.bloomberg.com/news/articles/2016-02-10/how-do-you-stop-the-biggest-gas-leak-ever

Oh, but gas is cleaner! What ever. I just don't understand the gullibility. And when I try to educate people I hear crickets.




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brianvds
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« Reply #1 on: March 03, 2016, 05:08:25 AM »

I think a lot hinges on what exactly we mean by "cleaner." It's a word that is frequently left undefined.
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Rigil Kent
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« Reply #2 on: March 03, 2016, 06:24:25 AM »

Brian you are right. "Clean fuel" to me as the man in the street simply means how effectively it is burnt up. In that case gas probably pips coal a bit since it leaves so little residue. But as Majin points out,to evaluate "environmental cleanliness" you have to take lots more things into account. I'm sure the two concepts get confused, even deliberately.

Rigil
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Tweefo
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« Reply #3 on: March 03, 2016, 08:14:31 AM »

I don't know.. Middelburg is surrounded by coal mines and coal-fired power stations. Even our rainwater is dirty, rivers are acid and farmland gets destroyed, so I think it's going to be difficult to beat. Sure, the early days of fracking had it's problems but they've learned a lot since. Bottom line is that while wind and solar are uneconomical it's dirty energy that we will rely on. 
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BoogieMonster
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« Reply #4 on: March 03, 2016, 09:51:33 AM »

Another thing Coal has going against it, which is also largely ignored by so called environmentalists in their foaming hate of all things "Nuclear", is that it usually contains radioactive isotopes... that also end up in the furnace and also goes out the chimney and into the air we breathe. That this is never mentioned while the Cancer rates are so high I frequently find surprising. Man I wish mefi were here to confirm and/or bitchslap me about it's effect...

But I wonder whether gas suffers the same problem? (EDIT: I checked, IT DOES, but it's still not clear what's present in the final product. But in fact the radioactivity is used to find the deposits in the first place).

The outrage over fracking was justified and it has spurred a lot of corrective action from fracking operations. They are cleaning up their act by quite a bit and investing in technologies that mitigate the problems that were experienced in the past. For that they should get props.

However at the end of the day the entire point of "alternative energy" is to dump fossil fuels because of their inherent problems: Unsustainable and may just kill all of us (yes I say this despite our recent conversations). Focussing so intensely on gas as a form of alternative energy is often missing the point entirely, prolonging the problem, instilling a false sense of security, and kicking the real solution down the road.
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Majin
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« Reply #5 on: March 03, 2016, 10:02:34 AM »

I don't know.. Middelburg is surrounded by coal mines and coal-fired power stations. Even our rainwater is dirty, rivers are acid and farmland gets destroyed, so I think it's going to be difficult to beat. Sure, the early days of fracking had it's problems but they've learned a lot since. Bottom line is that while wind and solar are uneconomical it's dirty energy that we will rely on.  

Well the water get's polluted near fracking wells too. One of the issues I think, is that the industry isn't as regulated as it should be. One example is the depth of the drilling being done. There has been instances where because the well wasn't drilled deep enough there was spillage. There are negligence risk involved too. As well as other risks.
Think it's pretty much the same.

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Mefiante
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« Reply #6 on: March 07, 2016, 20:38:04 PM »

Actually, gas is a cleaner energy option than coal in SA, both in the combustion and the production thereof, for reasons I’ll attempt to make clear.

Radioactive emissions from coal-fired power plants are a concern, albeit a lesser one.  The three biggest concerns re burning coal are CO₂ emissions, sulphide and oxides of sulphur, and particulates.  The CO₂ emissions are obviously the result of burning the coal for energy.  SA coal tends to have a high sulphur content and power station feed coal is typically not especially clean in this regard.  SA has lots of steam coal but far less clean coal like coking coal and anthracite needed for smelting and steel production.  The sulphides and oxides of sulphur go into the upper atmosphere and cause acid rain.  The particulates, which include radioactive constituents, are very fine ash and mineral dust that don’t make for healthy air.  Scrubbing power station emissions is possible but expensive and fraught with technical challenges.

The gas horizons identified for fracking in SA (Karoo) are two to three times as deep as those in the US and Canada.  Moreover, they are in areas with perched water tables.  What this means is that there’s far less risk of adverse consequences such as gas leakage or dropping of water tables in SA than what has been the case elsewhere.  (This topic is among my father-in-law’s expertise and livelihood.)  It’s true that the initial setup requires fairly large volumes of water that gets contaminated with chemicals but this can be managed by suitable containment and is a relatively small price to pay for the usable energy that can be extracted.  The relative amount of water over the viable life of a gas well is in fact very small.

The radioactive aspect is also quite low risk.  The article BM linked to speaks a lot about radon but doesn’t explain the risk adequately.  Virtually all underground endeavours are at risk from radon, which is itself a product of radioactive decay.  Radon is a noble gas (which means it’s chemically inert and doesn’t react with anything much) that is also radioactive.  Its decay paths have relatively short half-lives and—this is its main hazard—its decay products are solids that are also radioactive and that settle or stick to surfaces.  So, you breathe in small amounts of radon which decays rapidly, leaving radioactive solids in your lungs that decay further, eventually becoming lead (Pb), a protoplasmic heavy metal that kills cells.  Insidious cycle, this:  Cancer and cell poisoning.

But this hazard is also manageable through a sufficient residence period of the gas recovered from underground to allow any radon, if present in sufficient quantities, to decay to below acceptable levels.  The solid radon decay products will settle in the residence tanks in a safe way because they aren’t high-energy gamma emitters.

The short of it is that fracking is actually a quite safe and reasonable intermediate solution to SA’s energy problems.

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Mefiante
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« Reply #7 on: March 09, 2016, 17:58:25 PM »

Here’s a typical example of a state employee who fails in her duty to weigh up carefully impartial expert testimony, and succeeds only in agitating counterproductive public sentiment.

Yes, water’s a crucial issue.  Nobody is challenging that.  But rather than jangling alarm bells and inciting unreasoned public controversy, she should take the time to consider locality differences and what those in the know recommend in terms of obviating these known potential problems.  Based thereon, she could then formulate a sound policy with which all tenders need to comply.

(Yes, yes, I know.  This is SA.  Tender compliance can easily be bought.  Still, a solid and well-grounded policy is worth 55 million ad populi sirens.)

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BoogieMonster
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« Reply #8 on: March 09, 2016, 18:10:21 PM »

I must apologise I somehow missed your earlier reply. Thanks that's quite an informative bit on Radon, If a alarming!

Quote from: Mefiante
Yes, yes, I know.  This is SA.  Tender compliance can easily be bought

This is a worry... even in the 1st world profit often trumps taking the required precautions (ala Deepwater Horizon).

Quote
Still, a solid and well-grounded policy is worth 55 million ad populi sirens

True, true. So can we thus say that gas is cleaner than coal, if it is managed properly?

Any comparisons we can make on the CO₂ emissions front?
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Mefiante
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« Reply #9 on: March 09, 2016, 18:46:32 PM »

I must apologise I somehow missed your earlier reply. Thanks that's quite an informative bit on Radon, If a alarming!
No worries, it happens. Wink

So can we thus say that gas is cleaner than coal, if it is managed properly?
Undoubtedly so in the SAn context for the gas field currently being eyed.  Significantly greater depth, the geology and the hydrology of these gas horizons make for conditions where the hazards are readily manageable with the right discipline.

Any comparisons we can make on the CO₂ emissions front?
Yes.  For gas, CO₂ emissions will be lower per unit of usable energy because the gas can be fed directly into suitably designed turbines without much further refinement or incurring other thermodynamic impairments.

In contrast, coal must be mined, requiring energy.  It must be washed, requiring energy.  It must be screened and sized, requiring energy.  It must, in some cases, be blended with coal from a different source to adjust its calorific value (CV), requiring energy.  (Washing, screening & sizing, and blending are all done to suit the design of the power station because without these steps the power station won’t last long.) Additionally, coal must be transported, usually by road or rail when, as it often does in SA, the distance exceeds practical conveyor belt limits, requiring energy.  Finally, coal must be burned to produce heat, to produce the steam that drives the generators, (i.e., unlike gas, the energy production is more indirect), which adds a significant thermodynamic inefficiency.  All of these factors encumber coal’s CO₂ “dirtiness”.

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BoogieMonster
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« Reply #10 on: April 19, 2016, 09:26:27 AM »

Should be noted these guys do appear to have pre-existing ideas. But they're reporting real world data.
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Tweefo
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« Reply #11 on: April 19, 2016, 20:01:54 PM »

At the start of their talk, they said that the water gets pumped back and that it contains some poisons. They do not say how much of these poisons. Also. from what I understand (very little) about fracking is that it doesn't affect the ground water that people use due to the depth of the wells. I am still a fence sitter, maybe leaning over to the pro side, about fracking at this point. Whether it can work here with our lax oversight is something else of course.
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Mefiante
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« Reply #12 on: April 20, 2016, 10:22:36 AM »

As I noted earlier, there are significant differences between the US and the Karoo in terms of their respective geological settings for shale gas.  These differences are sufficient to render comparisons something of a stretch, particularly in respect of ostensible contamination at the water table.

Also, many of the claimed adverse consequences attributed to gas exploitation happened when gas exploitation was a new technology.  They are avoidable through technological improvements and learnings acquired from experience, coupled with adequate control and supervision of a gas well’s development and operation.  (Of course, a failure in the latter presents by far the single biggest risk factor.  Disaster recovery plans for an assortment of scenarios should be a mandatory integral part of the plan before approval can be given.)

More immediately, viewers would do well to note the pervasive use of weaselly and suggestive phrasing in the video’s narration.  Potential hazards and failings are scaremongered into a giant menacing bogeyman.

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BoogieMonster
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« Reply #13 on: April 20, 2016, 15:22:41 PM »

Methinks you take my linking of a newly released video on the subject a bit too personally Mefi. Wink

My worries are more about the efficiency with which our govt is running SAA, Eskom, the Post Office and Transnet.... and what that means for environmental enforcement. But it doesn't really keep me up at night.
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Tweefo
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« Reply #14 on: April 20, 2016, 16:28:53 PM »


My worries are more about the efficiency with which our govt is running SAA, Eskom, the Post Office and Transnet.... and what that means for environmental enforcement. But it doesn't really keep me up at night.
The farm next to the one I grew up on had a coal mine on it. Their dump, the tailings, coal of very low quality mixed with rock, was on a slope above my father's farm. This stuff got washed on onto our farm. It was very acidic with who know what poisons. Nothing would grow, not just in the black stuff but wherever the water would flow. This was the old government, my father complained to the mining board but nothing was done. That dump was covered a few years ago with soil and today it's a low, grass-covered hill. I suppose our government is not all bad.
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