Pages

October 17, 2011

A lot of Nuclear energy could enable Ammonia as a sustainable fuel

Nuclear Ammonia - A Sustainable Nuclear Renaissance's 'Killer App' (114 pages, Darryl Siemer, Idaho
National Lab (retired), with Kirk Sorensen, FLiBe Energy, Bob Hargraves, Institute for Lifelong, Education at Dartmouth College, 8TH Annual NH3 Fuel Conference 19-21Sep11)

Ammonia could replace all fossil fuels

Ammonia can fuel vehicles requiring range and power that cannot be provided by batteries.
Ammonia fuel produced from sustainable nuclear energy would be cheap and “green”
forever.
Nuclear power generated ammonia fuel can replace the usage of all oil, natural gas and coal.




Ammonia produced from Nuclear energy

• Ammonia is energy dense. It is liquid at ambient temperature and moderate pressure
• Ammonia possesses about one-half of the energy density of gasoline (same as methanol) and has 50% more energy volume-wise than liquid hydrogen
• Ammonia can be used directly in fuel cells, internal combustion engines (ICEs), and combustion turbines. It is straightforward and inexpensive to convert existing engines and turbines. Engine conversion kits are commercially available now.
• Ammonia is easy to store, deliver, and dispense. An extensive ammonia distribution infrastructure already exists.
• No “great leaps of faith” required because ammonia is already used at a significant scale. The proposal is to scale up ammonia usage by about one hundred times.

The rest is Nuclear Hydrocarbon
• Special and small engine applications and aviation will still require CHx-based fuels
• It’s possible to synthesize CHx (methanol, DME, diesel, etc.) from
“nuclear” hydrogen and any carbon source
• There wouldn’t be enough cheap biomass to implement it with “renewable” carbohydrate/fat (food vs fuel conundrum)
• Collecting sufficient CO2 from the air going through nuclear reactor cooling towers (e.g., LANL’s “Green Freedom”) is apt to be difficult. Close-coupling nuclear reactors with cement-lime kilns would be far more practical and equally GHG-neutral

however

• The US wouldn’t need enough cement-lime to provide the carbon required to make all of the synfuel it’s apt to need

The what we use list if for the economy of the USA and does not include water or fuel. Water is used the most and food comes in below cement.

Why Green house Gas (GHG) neutral?
• Lime-OPC based concretes inevitably absorb CO2 from the atmosphere
• That process increases their strength but lowers their pH
• pH lowering is “bad” only if/when embedded rebar corrodes (a fundamental weakness of today’s concrete structures)

Solution?

Use a more durable (and cheaper) rebar material which is basalt fiber rebar

Basalt Fiber Concrete Rebar

1. Higher specific strength - one ton of basalt rebar replaces 9.6 tons of steel
2. Far more resistant to corrosion/deterioration
3. Same coefficient of thermal expansion as concrete
4. No permanent deformation when bent
5. Chemically inert, compatible with concretes having different pH

Basalt fiber would be very cheap to make with Nuclear power

http://pulwell.en.alibaba.com/product/211051519-200709139/Basalt_fiber_rebar_BFRP_rebar_composite_rebar.html


How Much Synthetic Fuel and how much Nuclear Power for the USA

At 22.5 kJ/g, 15.27 quads/a worth of ammonia corresponds to 715 million tonnes - about 35 times the USA’s current consumption and 60 times its current production

• At 145k BTU/gal, 2.965 quads/a of CHx synfuel* corresponds to about 20.4 billion barrels per year (vs today’s roughly 260 billion barrels per year)

It would take about 613 full-size (~1 GWe) reactors for the ammonia and 100 reactors for the CHx synfuel. About 7 times more than the USA has today.

However, with some economic growth and reindustrialization it would be a higher number.

Today’s reactors use only 3% of their fuel’s potential energy

Liquid Flouride Thorium Reactors (LFTR) produces less than 1% of the long-lived radiotoxic waste of today’s reactors.


More Killer Apps
• Desalination: the Mid East’s and North Africa’s chronic drought-famine-economic problems could be solved with about 100 reactors

• No more resource limitations: cheap electricity means that we could wouldn’t need “ores”


(H/T to Brave new climate) and Brave new climate also discusses the presentation

Ammonia as Vehicle Fuel Risk Analysis

Comparative Quantitative Risk Analysis of Motor Gasoline, LPG and Anhydrous Ammonia as an Automotive Fuel (59 pages, Iowa State University, 2009)

In summary, the hazards and risks associated with the truck transport, storage, and dispensing of refrigerated anhydrous ammonia are similar to those of gasoline and LPG. The design and siting of the automotive fueling stations should result in public risk levels that are acceptable by international risk standards. Previous experience with hazardous material transportation systems of this nature and projects of this scale would indicate that the public risk levels associated with the use of gasoline, anhydrous ammonia, and LPG as an automotive fuel will be acceptable.

It is also important to note that the risk associated with traveling in a vehicle powered by any one of these fuels is dominated by accidents that do not result in a release of the fuel.

Engines need to be run temperatures from 760 °C-1093 °C to prevent nitrous oxide from forming. Nitrous oxide is a greenhouse gas. Reddit Energy has a discussion about nitrous oxide formation

If you liked this article, please give it a quick review on ycombinator or StumbleUpon. Thanks
blog comments powered by Disqus