Topic: Comparison Test: Best Fuel Efficient Cars

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[quote
The Germans have roughly 25GW of photovoltaic solar generation on top of wind. They have enough solar to depress the spot price of electricity. That makes is difficult for gas plants to make money. Coal plants are so cheap to run they can still make money even at their pathetic 30% efficiency. Gas plants are 60%.
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IIRC Germany has plenty of coal but their gas ends up coming from Russia.

Wish they could clean the up the emissions from coal to make it clean

It can be done for most combustion byproducts. It's harder to deal with the CO2, because you have to find a place to store it.
A 1000MW plant consumes roughly 3M tonnes of coal a year and produces 9M tonnes of CO2 (depending on coal quality).
Hard to strip and pump that much CO2 underground economically.

Indeed and I bet that a fair number of people are working on that one as NA has ENORMOUS amounts of coal as well.

[Sir Osis of Liver]

Indeed and I bet that a fair number of people are working on that one as NA has ENORMOUS amounts of coal as well.

There's a reason I moved to Saskatchewan. 

[dirtyjeffer]

Actually it's because the higher compression version (14:1 I believe?) requires premium unleaded and Mazda things putting "premium required" on a $30,000 compact SUV will hurt sales (look at how many people are bashing the Volt or the smart fortwo because they recommend premium fuel) so Mazda detuned the engine just a bit so that it can run happily on regular unleaded.

makes sense...i have filled up a couple of times with Shell Premium gas...the car does run better with it, and i wanted "Pure Gas" after readying numerous articles about the harmful effects of ethanol on engines...i was running good with regular gas, but it would sometimes ping a bit under light throttle, then the car would adjust its timing and the pining would go away, but with the premium, it doesn't do it at all...not sure if i will use premium with every tank, but i might do the occasional fill up with it to "clean things" up a bit...not really sure...need to do more research about it.

[Ex-airbalancer]

Wish they could clean the up the emissions from coal to make it clean

It can be done for most combustion byproducts. It's harder to deal with the CO2, because you have to find a place to store it.
A 1000MW plant consumes roughly 3M tonnes of coal a year and produces 9M tonnes of CO2 (depending on coal quality).
Hard to strip and pump that much CO2 underground economically.

Can you explain , if you start with 3m tonnes of coal how do you get 9m tonnes of co2 ?
What am I missing 

[Sir Osis of Liver]

Can you explain , if you start with 3m tonnes of coal how do you get 9m tonnes of co2 ?
What am I missing 

It's a bit of a simplification, but if we assume we're burning high quality anthracite coal (Pennsylvania coal), it's mostly carbon (~90%) with little contaminants like sulphur.

That would give us:

C+O₂=CO₂

Which by weight is:
12g/mol + 16g/mol = (12g/mol+16g/mol+16g/mol)= 44g/mol

Most coal plants are burning lower quality coal. In Sask and a few other jurisdictions, they burn lignite or brown coal which contains ~30% carbon, so the CO₂ yield is lower per tonne burnt.

So the rule of thumb is 1:3 for tonnes of coal burnt to CO₂ produced.

[PJungnitsch]

The way I understand it the system for scrubbing CO2 out of the stack is very expensive at the moment. Cheaper than the $600.00/tonne or so it costs to scrub it out of the air, as the gas is concentrated, but still way up there, in the neighborhood of $100.00/tonne. Alberta has the only working regulated Carbon market in the country, and the price of $15.00/tonne is far too low for removal to directly pay.

One of the big four Alberta Carbon Capture and Storage (CCS) projects was to clean it out of a coal plant at Wabamun, for deep ground injection, but that was put on hold recently at the engineering study stage because of the cost problem.

The way to make it pay at the moment is to use the CO2 for enhanced oil recovery. CO2 can pull a lot of extra crude out of the ground, and $100.00/barrel oil can make that pencil out pretty fast. Saskatchewan is halfway through a billion dollar CCS project at Estevan and is making it work that way.

[PJungnitsch]

Indeed and I bet that a fair number of people are working on that one as NA has ENORMOUS amounts of coal as well.

There's a reason I moved to Saskatchewan. 

Interesting. Are you working with the U of R on this?

[Sir Osis of Liver]

Saskatchewan is halfway through a billion dollar CCS project at Estevan and is making it work that way.

  I'm an E,I&C guy, I don't figure out the process, just (virtually) connect the wires.

[safristi]

  an E I & C guy   ..Vanna I want to buy a BOWEL............

[Sir Osis of Liver]

 Electrical Instrument And Control 

[dirtyjeffer]

So the rule of thumb is 1:3 for tonnes of coal burnt to CO₂ produced.

i'm no scientist, but that still doesn't make sense...when you burn coal, you are releasing the contents of coal as it is burnt for fuel...you aren't using nuclear fusion here, combining molecules to end up with "more weight" than what you started with...if you are burning 90% carbon coal, then let's pretend the left over 10% is the O2...if you burned 10 tons of coal, you would have 1 ton of O2 released.

isn't that how it works?

[PJungnitsch]

It is fusion, kinda. The oxygen necessary for combustion comes from the air.

[PJungnitsch]

One project that is being looked at in Alberta is deep coal gasification. Coal seams a km down or so are burned underground together with water injection and the resulting gas is burned like natural gas:



The CO2 still has to be removed and injected but it is apparently much easier due to the high pressures and concentrations.

http://swanhills-synfuels.com/

[dirtyjeffer]

It is fusion, kinda. The oxygen necessary for combustion comes from the air.

ummm, oxygen being used to burn coal is not the same as fusion.

[PJungnitsch]

It is fusion, kinda. The oxygen necessary for combustion comes from the air.

ummm, oxygen being used to burn coal is not the same as fusion.

Not the same as the fusion you are thinking of, of course. But the oxygen from the air does combine with the carbon from the coal. Which is why 1 ton of coal when burned makes 3 tons of carbon dioxide.

[Sir Osis of Liver]

So the rule of thumb is 1:3 for tonnes of coal burnt to CO₂ produced.

i'm no scientist, but that still doesn't make sense...when you burn coal, you are releasing the contents of coal as it is burnt for fuel...you aren't using nuclear fusion here, combining molecules to end up with "more weight" than what you started with...if you are burning 90% carbon coal, then let's pretend the left over 10% is the O2...if you burned 10 tons of coal, you would have 1 ton of O2 released.

isn't that how it works?

Every unit of carbon is oxidized by two units of oxygen to give one unit of carbon dioxide.
C + 2xO = C(2xO)

This is due to carbon having 4 bonding sites, while oxygen has two.

In chemistry, this is written as:

C+ O₂ = CO₂

Now the weights are expressed as g/mol or grams per Avogadro's constant. This allows us to compare the different relative weights of substances. So one mole of lead weighs much more than one mole of helium for instance.

In this case carbon is 12g/mol while oxygen is 16g/mol.

So the math is 12 +2x16 = 44g/mol. The product of combustion is the sum of the elements being burned.

[dirtyjeffer]

ah, i see now...i took physics and chemistry in high school, but nothing higher level than that, and that was almost 25 years ago.

[chamadarla]

A head turner for sure, beautiful car.

[safristi]

 CO2 is good.....................

[hemusbull]

This article is a boxing week gimmick...All cars here are overpriced in their respective categories. Even the most normal "ordinary" gas engined SkyActive Mazda is more expensive that its own non SkyActiv Mazda sister...I don't buy it!