vistiek daug raideliu.
tai uzsikrovus 400kg misinio, vaziuotum 3 valandas? Kokiu greiciu? t.y., kiek km?

Ar kaip?






"MRT" <martynas@fastlink.lt> wrote in message news:omh77o$n8j$1@trimpas.omnitel.net...
>>> https://web.archive.org/web/20120914043825/http://www1.eere.energy.gov/hydrogenandfuelcells/pdfs/aluminium_water_hydrogen.pdf
>
>> daug skaityt.
>> Tu gal esme gali sutraukt i cia
>
> jei skaityt fragmentais, praleidziant kur daug raidziu ar vietas, kur nelabai susiskaito ar 
> sunkiau suprantama, tai to skaitymo nedaug :D
>
> Tikslumo gali ir nebut, nes cia is mokykliniu prisiminimu:
>
> 2Al + 6H2O = 2Al(OH)3 + 3H2 (1)
> 2Al + 4H2O = 2AlO(OH) + 3H2 (2)
> 2Al + 3H2O = Al2O3 + 3H2 (3)
>
> 2 moliai aliumo - 2*27 g/mol = 54 g.
> 3 moliai H2 - 3*2 g/mol = 6 g.
> 3-6 moliai vandens - 3-6 * 18g/mol = 54-108 g.
>
> Kuras (vanduo+aliuminis) - ~108-162g. duoda 6g. vandenilio
> 8 kg aliumo + 8-16 litro vandens = 1,6 g/s vandenilio (max 889 g., t.y. 555 sekundziu, t.y. ~10 
> min)
>
> 3 val kuro = 18*8=144 kg aliumo ir ~144-288 litrai vandens.
> Vanduo perdirbamas sakykim, bet aliuma redukuot reik, vadinasi 144 kg aliumo pavirto i ~288-296 
> aliumo-(hidr)oksido.
> Plius dar be situ komplikaciju ten yra ka veikt.. nu ner sarminis metalas tas aliumas, kad pyst su 
> vandeniu ir fygarina vandenili taip paprastai kaip mokykloj rode..
>
> Standartiskai Aliumas + rugstis => aliumo_druska + vandenilis
>
> ***************************
>
> Fragmentai:
>
> Even assuming high volume production, the DOE target range for
> hydrogen cost of $2-3 per kg H2 would not be met.
> Additionally, the supply of aluminum required for mass market vehicle applications may be 
> problematic.
> The following are possible reactions of aluminum with water:
>
> 2Al + 6H2O = 2Al(OH)3 + 3H2 (1)
> 2Al + 4H2O = 2AlO(OH) + 3H2 (2)
> 2Al + 3H2O = Al2O3 + 3H2 (3)
>
> All these reactions are thermodynamically favorable from room temperature past the melting point 
> of aluminum (660*C). All are also highly exothermic.
> Promoters: <...> katalizai
>
> Molten Aluminum Alloys: << aliuminio lydiniai
>
> A delivery rate of 1.6 g H2/sec is required for an 80 kW vehicular fuel cell. At a kinetic 
> reaction
> rate of 2 x 10-4 g H2/sec/g of Al for the aluminum-water reaction (the maximum value in the
> literature), one must react 8000 g of aluminum with the necessary amount of water in order to
> achieve the hydrogen delivery rate of 1.6 g H2/sec needed to supply the 80 kW fuel cell.
> Summary:
>
> The key aspects associated with the production of hydrogen using the aluminum-water reaction are:
>
> Aluminum Required: 9 kg Al per kg H2 assuming 100% yield
> Gravimetric Hydrogen Capacity: 3.7 wt.% (materials only)
> Volumetric Hydrogen Capacity: 36-46 kg H2/L (materials only)
> Reaction Kinetics: 2 x 10-4 g H2/sec/g of Al ? from published data to date
> Cost: $7 per kg H2 (based on the cost of electricity for aluminum production considering only the 
> reduction of alumina to aluminum step)