[ExI] cure for global warming

[Keith Henson]

On Sun, Dec 26, 2010 at 4:30 AM,  Samantha Atkins <sjatkins at mac.com> wrote:

> On Dec 25, 2010, at 7:50 PM, Keith Henson wrote:
>
>> On Sat, Dec 25, 2010 at 7:13 PM,  John Clark <jonkc at bellsouth.net> wrote:
>>
>>> On Dec 21, 2010, at 10:32 PM, Keith Henson wrote:
>>>>
>>>> The best way I see is to come up with an energy source considerably
>>>> less expensive than fossil fuels.
>>>
>>> That would be a great way to cure global warming but unfortunately nobody has figured out how to make a cheap clean substitute for fossil fuels yet, nobody has figured out a cure for CO2 emissions (if that is indeed the cause of the problem) that is not worse than the disease.
>>
>> You must not have read the rest of my post where I discussed how to do it.
>>
>> The *easy* part is making a clean cheap substitutes for fossil fuels.
>> We know how to suck CO2 out of air at a cost of around 100 kWh/t (360
>> kWh per ton of carbon).  We know how to make hydrogen either directly
>> from heat (S I process) or by electrolysis.  We, or rather Sasol,
>> knows how to bulid a plant that will turn these two into synthetic
>> fuel at a cost of around $10 per bbl.\
>
> Hydrogen is a not a very efficient fuel.

Unless you are fusing it in the sun, it isn't a fuel at all.  It is a
really bad way to move energy around unless you make it into
hydrocarbons, then it become familiar hydrocarbons.

> Why not hype thorium reactors?  The better designs can produce electricity far cheaper than from the best grade of coal - which is currently the cheapest energy source we have.   There are many paths to syngas and such, it is true.  But not one of them produces energy that cheap.   Much of the case for such today is made on the basis of how "green" they are.  One case in particular that I know well gave up on more green sources for the gas, gave up on using concentrated solar to fire the original biomass and ended up burning natural gas in a process that doesn't produce a lot more than when into it and produces some nasty waste gases to boot.   This is not at all a panacea in any form I have seen to date.

It depends on how inexpensive the capital and energy costs are.  Bio
is a really poor source for energy, but if you have plenty of energy,
it's not a bad place to source carbon for synthetic hydrocarbons.  But
if your carbon cost go over the cost of electric power to suck carbon
out of the air and reduce the CO2 to hydrocarbons then you can just
get the carbon from the air.
>>
>> $1 B written off over ten years is $100 M/year.  The plant makes
>> 34,000 bbls of oil a day or  about 12.5 M B of oil a year at a capital
>> cost of $100 M per year.
>
> So by your above figures it barely breaks even.

It and similar plants run by Shell in Indonesia make a ton of money
based on low cost "stranded" gas.  But I wasn't analyzing profit, just
capital cost.

> You do know that 34K bbls is a barely registering drop in the proverbial bucket, right?

Of course.  Current US consumption is about 20 M bbls a day.  It would
take around 590 plants this size to feed our refineries.

>>  So the capital cost is around $8 per bbl
>> plus maybe $2 per bbl maintenance and labor.  It's using gas as the
>> source of carbon and hydrogen, but it would be just as happy on carbon
>> dioxide from the air and hydrogen from water.
>
> Not really.  Please do the math and show your work.  I know several people working various variations of this and I don't believe this story.

I did the math above for the capital cost.  Are you asking about the
chemistry?  Starting with CO2 instead of CO takes one extra molecule
of hydrogen.  It's the reverse water gas shift
http://spot.colorado.edu/~meyertr/rwgs/rwgs.html.  The excess of
hydrogen in the mixed gas feed forces the reaction in the right
direction to make CO and water.  If that isn't what you are asking
about, please clarify
>>
>> The hard part is getting energy cost down to where you can make
>> inexpensive synthetic hydrocarbons.  StratoSolar *might* do it.  The
>> engineering to cope with maximum wind is very hard.
>>
> What for?  As a temporary until you can convert most transportation to electric?  Perhaps.  But electric is the way to go not far down the line.

How do you intend to replace jet fuel?

>> Power satellites could also do it if you can get the launch cost to
>> GEO down to $100/kg.-
>
> That is step #1 - and it is a real doozie from here as you know.

It's big, I agree, but it isn't conceptually hard now.  Before high
efficiency laser diodes, I don't think anyone had a good idea of how
to do this at all..

> Step #2 which we don't have much of a clue about is how to assemble and maintain that large a solar field in GEO in perpetuity.  We don't do space walks out there for some pretty good reasons.

You are probably thinking about the Van Allen belts.  No problem to
drain them.  http://en.wikipedia.org/wiki/Van_Allen_radiation_belt#Removal

> Without major space robotics advances I don't see it happening for at least a couple of decades.

Given only a modest improvement over WW II Liberty ship production
rates (tons per hour) 1000 people could assemble 200 GW of power sats
per year.  Sold at only $1.6 B per GW (a small fraction of nuclear
costs) that's a revenue stream of $320 B per year against a lift cost
(the major factor) of $100 B.  On the basis of a ten year return on
capital, $1.6 B/GW is 2 cents per kWh.

> Fortunately we have better ways of resolving the energy crisis or looming crisis in the meantime.

Oh?  Please explain.  I spent 3 years on reducing the cost of power
satellites and have worked the last year on StratoSolar.  The
fundamental problem with solar energy is that it is dilute and
intermittent.  Wind has the same problem.  Both require huge capital
costs that translate into high cost per kWh.
>>
>>> So until somebody dose figure that out and if the problem is really as catastrophic as the doomsayers say it is then we'd better have another idea; and Nathan Myhrvold, the former chief technical officer at Microsoft, may have one, build an artificial volcano.
>
> Now that is Big Thinking.  Incredibly stupid perhaps but BIG.

Having spent a lot of time working on the effects of wind on tethered
buoyant structures, I have my doubts they have really analyzed the
problem.  Big structures such as StratoSolar take advantage of cube to
area ratios.

Keith