Economics and sustainability of making hydrogen

[Keith Henson]

There is much hype about hydrogen, but some of it is justified. It is
on topic here because however, we solve the energy problem, there will
still be a need for hydrocarbons and you need hydrogen to make them.
Plus it seems unlikely we will give up synthetic nitrogen fertilizer.

Hydrogen is used in huge tonnages (87 million t/yr) by the
petrochemical refining industry to remove sulfur from fuel, upgrade
fuel, and to make ammonia fertilizer (about half). The source of this
hydrogen is usually natural gas. The value of the hydrogen was US$155
billion putting the cost at around $1800/ton.

Electrolytic hydrogen takes about 50 MWh/ton plus the capital for the
electrolyzer cells. If you are right next to a hydro plant, the power
cost might be as low as $20/MWh or $1000/ton for the energy. The
capital cost for the electrolyzers is currently $1000/kW or $50
million. Hydrogen production over five years is 5 x 365 x 24 tons.
Capital cost is around $1100/ton for a total $2100/ton. It's not hard
to see why electrolytic hydrogen does not have a large market share.

Some hydrogen is made from coal or petroleum coke via reactions that
date back to the dawn of the Industrial Revolution. The coal or coke
is burned in oxygen and steam. The resulting gas stream contains
hydrogen and carbon monoxide. The gas is fed through "water gas
shift" reactors which convert steam and CO to hydrogen and CO2, The
CO2 is sorted out by absorbers and vented or sequestered. Examples
where this is used include the Sasol synthetic hydrocarbon plant in
South Africa, the Great Plains Synfuels Plant, and Coffeyville
Resources.

Converting carbon and water to syngas is endothermic, it takes 3 MWh
of heat energy to vaporize a ton of coal in steam. A considerable
amount of coal is turned into syngas using oxygen to burn part of the
coal and provide heat. I don't know how exact this is, but
considering coal combustion at 6.7 kWh/kg 3 MWh will require burning
450 kg of coal. This is done with oxygen so there is a cost for the
oxygen at 7 to 10 cents per kg, 1194 kg of O2 costing $84 to $119.
What this means is that close to half a ton of coal must be burned to
vaporize a ton of coal. There is also more CO2 in the gas stream that
increases the size of the absorber section and the amount of CO2
vented or sequestered.

So the cost per ton vaporized would be 1.448 x the cost per ton of
coal plus the oxygen. For coal at $20/ton, the cost to make syngas
would be about $130/ton of coal, most of it from oxygen. A ton of
coal makes 1/6th of a ton of hydrogen at a cost of around $800/ton
(ignoring capital costs).

Compare: to a submerged arc to heat coal in steam. For dedicated PV
at 1.35 cents per kWh, ($13.50/MWh) the electrical cost to evaporate a
ton of coal would be $40.50. For coal at $20/ton the cost of hydrogen
would be around $360/ton. (Again ignoring capital cost.) Grid
electricity gets down to zero at times. But to use this power would
require a syngas or hydrogen storage of considerable size. An empty
gas field would be ideal.

This is a very rough analysis. Point being that combining coal and
PVlooks like a promising way to reduce the cost of an important
industrial commodity--hydrogen.

Keith

[John K. Strickland, Jr.]

One way nitrogen production can be reduced is to steadily work on plants that produce their own nitrates like legumes.
We are already aware of the giant south-central Mexican corn variety that grows 16 feet tall with no nitrogen fertilizer.
Nitrifying bacteria live in the mucus covering the multiple red and green-colored ariel root rings (above ground level), and get nutrients from the roots and give nitrates to the corn plants.
This was discovered over 6 years ago, but if the efforts to try to grow this corn in our corn belt are being hamstrung by nationalism and local jealousies
So far all the media reports are covering which Oaxaca villages can get credit ($$$$) for originating the corn,
and Mexico is resisting allowing any other country to try to raise it, even if it would save billions in fertilizer costs and reduce nitrification.
You do not even need GMO to use this corn, but regular breeding could enhance it.

Note that researchers in Madison, WI have already grown some of it there with no problems

See the clear image of the mucus blobs covering the roots that the bacteria grow in in the images here:
https://www.ttbook.org/interview/seeds-tomorrow-defending-indigenous-mexican-corn-could-be-our-future

The anti GMO crowd would also resist efforts to create legume like plants, no matter how many people would starve.
Genetics of monocots like the golden corn and rice are different from those of Dicot plants, but the effort could be made if the lawyers and bureaucrats would get out of the way.

John S

--
You received this message because you are subscribed to the Google Groups "Power Satellite Economics" group.
To unsubscribe from this group and stop receiving emails from it, send an email to power-satellite-ec...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/power-satellite-economics/CAPiwVB6Zjt3YNBkHGe0J4CV5Sx_3gq_%2BN0WwGdn9gzgShZZeVw%40mail.gmail.com.

[Bryan Zetlen]

As I read through these detailed comments and analyses, it often strikes me that little attention or focus is given to large-scale hydrogen gas and fluid transport, storage and bulk handling. My only direct experience with this is in fueling and launching heavy rockets. In those activities early on there were terrible incidents of release and explosion until provisions and revisions were made to reduce gas pooling and dumping. In particular, hydrogen management at STS site required extensive pad redesign. To complicate these and other safety issues, hydrogen is not only colorless and odorless, it is invisible when it burns. Your thoughts and experience on bulk hydrogen management?

To view this discussion on the web visit https://groups.google.com/d/msgid/power-satellite-economics/04a901da78ae%24cf4f3c10%246dedb430%24%40sbcglobal.net.