At 2:33 AM 2/16/5, Nick Palmer wrote: >This looks like a good way of "transporting" renewable energy (in this >case from hot sunny countries). > >Nick > > >http://www.dbresearch.com/PROD/DBR_INTERNET_EN-PROD/PROD0000000000079095.pdf
Sorry for the delay in responding to this. This is an excellent and stimulating paper. I did not get around to reading this sooner due to my typical bumbling around. This is a very well developed concept with many robust positive ramifications. It clearly shows a means of transporting energy long range and storing energy that is highly compatible with an otherwise principly hydrogen economy and which is also achievable by engineering using existing principles and processes. This closes the gap on the critical missing functions for a global renewable energy economy - long range transportation and storage. It also utilizes solar energy and equatorial regions, which is a good compliment to the extensive energy available from wind and the good thermodynamic conditions in polar regions. This seems to absolutely nail down the fact that a global carbon free renewable energy economy is feasible now if the political will exists to make it so. Some first impressions follow. There are clearly risks associated with transporting silicon by ship. As the author points out, silcon combusts spontaneously in air and produces ammonia in the presence of water. The author points out that this risk can be minimized for handling purposes by crystalization and occupation of the surface sites. Still, a ship grounding accident could be very hazardous, but nothing like the Exxon Valdez in the way of a long term environmental hazard, so that is a huge improvement. Unloading or handling solid silicon (in an inert invironment?) might be a significant engineering and safety challenge, though maybe those problems would be minimal if the silicon is hermetically containerized or encapsulated. Loading and unloading would be greatly facilitated by using a liquid technology. There is still missing a good technology for vehicle fueling, which might be handled by LN2, etc., but which might also be handled by a silicon compound. Given that silicon is so similar to carbon energetically, I have to wonder if it is not economically possible to hydrogenate it to make a liquid which is biodegradeable or at least which decomposes to SiO2 and water fairly quickly, i.e. in a matter of months. Silane (SiH4) can clearly be produced, and is environmentally friendly, but it has all the shipping and storage problems associated with natural gas. I don't know what problems are associated with tetrasilane (Si4H10) production, or how environmentally degradeable it is, but it boils at 84.3 deg. C. so can be shipped and stored as a liquid. It appears the principle idea proposed for obtaining the energy of Si was the production of ammonia. The following information was given: Compound Energy to produce 1 g hydrogen -------- ------------------------------ Water 143 kJ Methane 18.75 kJ Ammonia 15.4 kJ The ability to produce ammonia is significant in that is serves as a feedstock for furtilizer production and many other things. Since ammonia is valuable in its own right as a feedstock, and energetically valuable as well, the idea of producing ammonia in windfarms and shipping and storing as a liuid may not be totally impracticable (though the very thought makes me uncomfortable!) There have been attempts at producing ammonia powered fuel cells, but this has not worked out AFIK. Hyrdazine (N2H4), which can be produced from ammonia does work in fuel cells by: N2H4 + O2 -> N2 + 2H2O but does not strike me as a good approach for vehicles due to the toxicity and other problems with N2H4. It seems reasonable that Si and/or NH3 can be used for long range trades, and bulk electrical energy production. It may be reasonable that LN2 or liquified air be produced in a local fashion for vehicle propulsion. Direct electricity generation by wind or solar could be backed by energy storage involving Si or NH3 related storage and generation facilites. Nuclear can continue to be used for electical generation and possibly for hydrogen or NH3 production for energy storage or transportation, and furtilizer production. For intermediate energy transportation by ground, hydrogen can be piped directly. A carbon free global energy supply is seeming to be a very real possibility through only the application of existing technology. This is an incredibly wonderful possibility. The development of new technologies, like an effective hydrogen storage medium, room temperature superconductors, or cold fusion, only enhance these possibilites. Regards, Horace Heffner
