[lpetrich]

Green Car Congress: Rutgers chemists develop new high-performance, platinum-free electrocatalyst for electrolysis; licensing available noting Rutgers Chemists Develop Technology to Produce Clean-Burning Hydrogen Fuel | Media Relations

From the first one:
$this->bbcode_second_pass_quote('', '
')Rutgers researchers have synthesized cobalt-embedded nitrogen-rich carbon nanotubes (NRCNTs) that 1) can efficiently electrocatalyze the hydrogen evolution reaction (HER) with activities close to that of costly platinum and 2) function well under acidic, neutral or basic media alike, allowing them to be coupled with the best available oxygen-evolving catalysts—which also play crucial roles in the overall water-splitting reaction. ...

The materials are synthesized by a simple, easily scalable synthetic route involving thermal treatment of Co2+-embedded graphitic carbon nitride derived from inexpensive starting materials (dicyandiamide and CoCl2).

[efarmer]

http://www.tinaja.com/glib/muse153.pdf

Is where to read an opinion similar to mine on this.
To break the hydrogen-oxygen bond in water and free
them as gasses takes a huge amount of change of state
energy input. Regardless of expensive or cheap electrodes
to use, this energy input is the real show stopper, cause it
takes more energy in that you can get from burning the hydrogen
output once you yield it.

Even with a cheaper hammer (electrode) the blow still takes
more power that it frees when it breaks the water down.

[vtsnowedin]

$this->bbcode_second_pass_quote('efarmer', 'h')ttp://www.tinaja.com/glib/muse153.pdf

Is where to read an opinion similar to mine on this.
To break the hydrogen-oxygen bond in water and free
them as gasses takes a huge amount of change of state
energy input. Regardless of expensive or cheap electrodes
to use, this energy input is the real show stopper, cause it
takes more energy in that you can get from burning the hydrogen
output once you yield it.

Even with a cheaper hammer (electrode) the blow still takes
more power that it frees when it breaks the water down.

[lpetrich]

True, there will be an energy cost from imperfect efficiency. The EROEI (energy returned on energy invested) will necessarily be less than 1. But if the hydrogen produced is cheaper than hydrogen produced by natural-gas reforming, then it's still a gain.


To get an idea, I'll use current fossil-fuel prices and electricity-generation efficiencies.

I'll use these recent US numbers:
Coal Prices and Coal Price Charts - InvestmentMine
Petroleum -- 60.49 USD/bbl
Natural Gas -- 2.93 USD/mmBTU
Thermal Coal CAPP -- 51.25 USD/st
CAPP = Central Appalachian

How much coal, natural gas, or petroleum is used to generate a kilowatthour of electricity? - FAQ - U.S. Energy Information Administration (EIA)
1,842 kWh per ton of Coal
127 kWh per Mcf (1,000 cubic feet) of Natural gas
533 kWh per barrel of Petroleum

Assumptions:

Power plant heat rate -> energy efficiency
Coal = 10,498 Btu/kWh -- 33%
Natural gas = 8,039 Btu/kWh -- 42%
Petroleum = 10,991 Btu/kWh -- 31%

Fuel heat contents
Coal = 19,336,000 Btu per short ton (2,000 lbs) Note: heat contents of coal vary widely by types of coal.
Natural gas = 1,023,000 Btu per 1,000 Cubic Feet (Mcf)
Petroleum = 5,861,814 Btu per Barrel (42 gallons) Note: Heat contents vary by type of petroleum product.

So I find:
Oil: 0.113
NatGas: 0.024
Coal: 0.028
all USD/kWh

That makes crude oil about 4.3 times more expensive for generating electricity than natgas or coal. That also makes the raw energy content of oil cost 0.035 USD/kWh, about 1.35 the cost of electrical energy generated by natgas or coal.

Using a natgas-coal average, 0.026 USD/kWh, if production of some synfuel is only 50% efficient in applied electrical energy, then that synfuel's energy content will cost 0.052 USD/kWh. But if the price of oil goes up by a factor of 2, then its raw energy content will cost 0.070 USD/kWh, and the synfuel will undersell oil.

Also, since wind and solar electricity generation are still-growing technologies, their price per unit electricity may drop further. If they drop by a factor of 2, then that will cancel out my assumed 50% synfuel efficiency factor.

[lpetrich]

That was for petroleum. Let's see about the economics for refined products.

I checked on various petroleum-derived fuel products, and I found these numbers for the US as of today (Today in Energy - Daily Prices - Prices - U.S. Energy Information Administration (EIA), Feb 27, 2015):
Propane: $0.60 / gallon
Gasoline: $1.60 - $2.00 / gallon -- using $1.80 / gallon
Diesel Fuel: $2.00 - $2.30 / gallon -- using $2.15 / gallon
Heating Oil: $1.80 - $2.10 / gallon -- using $1.95 / gallon

Densities from Liquids - Densities
Propane: 0.4935, Gasoline: 0.737, Diesel fuel: 0.885, Heating oil: 0.920 all g/cm^3

Marine-grade bunker fuel is a bottom-of-the-barrel petroleum product in a very literal sense: it's what's left over after the lighter hydrocarbons are distilled off. Source: Bunkerworld Prices, as of Feb 23, 2015, avg. of IFO380 prices available to unregistered users.

Cost per unit weight: Propane: 0.32, Gasoline: 0.65, Diesel fuel: 0.64, Heating oil: 0.56, Bunker fuel: 0.34 -- all $/kg

Energy content: Energy density - Wikipedia, Energy Content in Common Energy Sources

Working out the numbers, I find these energy-cost values:
Propane: 0.023, Gasoline: 0.050, Diesel Fuel: 0.050, Heating Oil: 0.043, Bunker Fuel: 0.026 -- all $/kWh

I'd earlier calculated that the comparable cost for petroleum is 0.035 $/kWh. Using the Engineering Toolbox's numbers and the current price of petroleum, it's 0.036 $/kWh.

To get an idea of how much gasoline and crude-oil prices are correlated, I checked Trends in Crude Oil and Gasoline Prices | farmdocdaily.illinois.edu. Their correlation is remarkably good. So one gets a gasoline-to-petroleum energy-price ratio of about 1.4.


My previous estimate of a natgas-coal avereage, 0.026 $/kWh, suggests that electricity-generated synfuels will almost be competitive with gasoline and diesel fuel for a production efficiency of 50%. However, it will need 100% efficiency to compete with bunker fuel, something unfeasible.

[Ulenspiegel]

OK, the much shorter version is:

1 kWh methane from P2G costs according the guys at Fraunhofer Institutes 12 cent, 5 cent for electricity, 7 cent for capital and operating costs of the production facility. This was small scale.

Even with 100% conversion efficiency in a G2L process (additional step with additional costs) a kWh liquid fuel would cost let's say 15 cent, or a litre fuel around 1.5 EUR, a barrel around 250 EUR at least.

Therefore, I do not see how synfuel can be a substitute for oil even in large scale.

This only makes sense for special applications, like storage in a 100% RE scenario or substitution of oil that can not be replaced by electricity.

[vtsnowedin]

All your prices are last years prices and next years will probably be a lot different. But perhaps you miss my point. Say your in command of the US air force and your running out of petroleum derived jet fuel for you F 48.2 super fighter. Do you care what a workable substitute costs? No you go to Niagara falls and commander the hydo electric station there and start splitting water by electrolysis and then convert the hydrogen into liquid jet fuel using what ever process works best. You then fuel up your plans , fly off and blow up whoever's butt is bothering the USA that day. It doesn't matter if it took a million KWH of Niagara electricity to make one barrel of jet fuel as long as we can whoopass with it.

[Ulenspiegel]

Sorry, that is from a economical POV nonsense, power to liquid makes sense where transporting fuel is the cost driver and electricity is "cheap", i.e. on nuclear carriers.

Otherwise the USA have enough alternatives, not necessarily green ones, to provide cheaper fuel than from power to liquid.