No, I don't know what happens if you do that. Calcium carbonate or calcium oxide as a byproduct? I would guess it might just as well go the other way-- Ca-Mg carbonate + H2SO4 --> CaSO4 + MgS04. (H2SO4 + any metal does release hydrogen.) Limestone/fish bones/crab & oyster shells (carbonate) and gypsum are used for fertilizer. It might be difficult separating metal plates (if you use them) from setting blocks of gypsum, or limestone! Please keep us posted.
...Uh, back again. I think with all your help and clues I might have figured it out. Sulfuric acid at 98% has a specific gravity of 1.83, and i believe the reactant is probably calcium carbonate (fish bones) that companies might give away to AlaskaStar by the truckload. (Agricultural lime, rock dust, limestone should also work, about $2.50 per 50 lb. bag, retail.) Reacting the two would give calcium and calcium-magnesium sulfate, respectively, sold as fertilizer. Is gypsum a waste material for construction companies? I suppose it could be if you need to demolish buildings made of wallboard.
I actually did this experiment a few years back for an entirely different reason (found a recipe for making artificial pearls although I have to say the H2SO4 was no help, since found a better way.) Anyway the oyster shell/acid brew fizzed like the dickens, but it's a hot reaction tho, not a cool one. There has to be a trick to controlling the reaction, maybe hydrating the carbonate and then adding acid very slowly, to keep the H2 production linear, like a metering pump, that might actually fit in a suitcase. Doh! I never actually tried igniting the gas, so need to do the experiment again. Could the reaction be driven even further with added electricity? More hydrogen off-gassed as Ca-H2SO4 bonds are made and (later) broken?
Now if it were possible to get our CaCO2 back just by adding carbonated water (recovering H2SO4?) ...and in process making more hydrogen, like an endothermic reaction both ways, wouldn't that be sweet?Statistics: Posted by thrival — Wed Jul 20, 2005 12:46 am
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