Boomer Posted June 14, 2006 Posted June 14, 2006 This is my complaint from the vent room (truncated): "Anyone here tried cyanamide via lime nitrogen (kalkstickstoff)? I just bought a 25 pound sack for ten bucks ... I spent half the weekend converting about a pound of the shit, getting a pathectic 2.4 grams only. Ruined my kitchen as well ..." I found out what I did wrong. FIRSTLY, reading - not overlooking - the part in COPAE does help. It says ..."dilute sulfuric hydrolises (dicyandiamide) to urea...".Now what did silly Boomer do? Boil 200g in 500ml water and *excess sulfuric*, then filter while hot and cool in the frideg. Zero yield for this one! Next time a stoich amount acid was used, 37ml (96%) for 100g fertiliser. The fert has 18% nitrogen, which equals 51% calcium cyanamide. I went as close to pH7 as I could, then stopped adding acid, boiled down and filtered hot. Got above mentioned 2.4g dicyandiamide. SECONDLY: reading - not overlooking - in COPAE does help again. It says "on evaporation it (cyanamide sln) yields crystals of dicyandiamide". On *evaporation* - the solution has the monomer in it! So no crystals on cooling, even though the dimer should be hardly soluble (1.3g/100ml@0C), the monomer stays in solution! Silly Boomer did what he should have done in the first place, and got around 8g more. Thats 70% yield considering half the solution was dumped in the wet filter. I tried the hot-pot/cold-fear synth for guanidine nitrate, melting it with 2.2 parts on AN in an oil bath on the stove for a good two hours at 165C . This time it went like the book, it "solidified completely to the nitrate" (like Davis sez). Yield was in the 70-80% range, not bad. Since from here on (nitro guanidine etc) it becomes HE, I better stop. The nitrate is still considered a propellant, at least Swany got his without questions via mail.
AreteVeteran Posted June 15, 2006 Posted June 15, 2006 Wait, you only got 2.4 grams from 100 grams? BOB SAGET thats awful...Just keep the pH in better control and you will get loads more than 8 grams. Isnt it strange, Guano is bat shit, and you're making Nitrogaunidine. Connection maybe? /AV/
Mumbles Posted June 15, 2006 Posted June 15, 2006 Yes, guanidine was first isolated from bat shit. 2.4g might seem aweful, but one must remember only 1/2 the original weight is actually reacting. The rest is Ca(OH)2, CaCO3 and graphite mostly. If I did everything right, the theoretical yield from 100g is 21.4g 2 CaCN2 + 2H2O ---> 2 CaO + N(CN)2
Boomer Posted June 19, 2006 Author Posted June 19, 2006 I calculated 26.77g. 51g Ca(CNC)2 is 0.638 mol, cyanamide weighs 42g/mol (you forgot the hydrogen), which makes 0.638x42g = 26.77g. Whether it crystallises as the dimer does not matter for the weight. And I said ANOTHER 8g came out later, so 10.4g from HALF the 26.77g since I dumped half the solution. Hence 70+% yield out of what I did not dump. If it were not so cheap one could extract most of the part I dumped (just filtering work), getting 70% overall yield easily. Considering it gets *heavier* after reaction with AN, we might expect 4-5 pounds of guanidine nitrate per 10-dollar sack of fertilizer. Or 20-25 pounds per 20-dollar sack (farm supply).Not bad at all!
Mumbles Posted June 19, 2006 Posted June 19, 2006 No idea what I just did, but I just got around 13g. I am sure there is something in my calculation somewhere that I totally messed up. I think partially it has to do with my equation being messed up. I combined the condensation of the monomers to dicyamamide. 2 CaCN2 + 2 H2O ---> HN(CN)2 + 2 CaO + NH3 [edit] Found my problem. I was using your value for molar mass of cyanamide. I was calculating for dicyanamide, while you were for cyanamide. The crystals you have are dicyanamide, you said it yourself. The condensation involves loss of NH3, so you cannot just assume they would be the same mass. The molar mass of dicyanamide is 67.06. Using this value and my balanced equation from above, you get the 21.35g I stated before.
The_Duke Posted June 19, 2006 Posted June 19, 2006 I wish you would have posted this in the HE section as we really could have some fun with this one. Calcium Cyanamide->Dicyandiamide->Guanidine Nitrate->Nitroguanidine->Nitrosoguanidine Dicyandiamide->Guanidine Nitrate->Nitroguanidine->Aminoguanidine->Tetracene->Tetracene salts (mmm…like the Perchlorate)… Guanidine Nitrate->Nitroguanidine->Aminoguanidine->Tetracene->Guanyl Azide->Guanyl Azide salts… Guanadine Nitrate->Nitroguandine->aminogaunidine->tetracene->triazonitrosoaminoguanidine (isolated as the Cu salt)->Tetrazolyl Azide (5-aminotetrazol)->ALMOST ANY TETRAZOL YOU CAN THINK OF! I could go on and on, but the point I’m making is that all those compounds can easily be synthesized from lime nitrogen as a starting material! And those are only the important ones I could think of off the top of my head!
Swany Posted June 20, 2006 Posted June 20, 2006 I wish you would have posted this in the HE section as we really could have some fun with this one.... I recently prepared a large amount of nitroguanidine for those exact purposes, and if I have it my way, there will be a thread. Would you care to start it please? I am currently researching the subject and would butcher it badly, my foresight says.
Boomer Posted June 27, 2006 Author Posted June 27, 2006 Got another batch cooking. Found out some tricks doing it: - Putting 750g of the prills into 3.75l hot water, adding only 175ml (66%) of the required sulfuric, and stirring mechanically for hours does *not* get the pH up at all. It stays strongly acidic even with 50% excess base! The cyanamide is *sintered together* with the carbon, no chance of extracting as-is. 3 minutes in the blender at max power (without most supernatant liquid, mixed back in later) got it caustic as hell. I could start titrating with the remaining sulfuric after that (~100ml). - Keeping the filters this time, I ended up with 2.8l of filtrate from the first extraction. The first liter was boiled down to 150ml in two steps, removing a few grams of Ca sulfate (?) in between, and on cooling yielded 20.6g of dicyandiamide. BUT: The remaining 100ml, when boiled to dryness, yielded a partly decomposed goo and zero crystals. Moral: Don't boil to dryness, rather discard a little mother liquor. - Using only low heat (kitchen stove on smallest setting, power halved with a diode in the breaker board), but blowing lots of air over the pan, the last 2.8 litres were evaporated down to 150ml without going above 45C. It took 8 hours and an alarm clock to get up three times during the night for checking progress. (We need a yawning smiley) Moral: A little patience goes a long way. The pan is thick with crystals, I will filter/weigh them tonight. Was in a hurry this morning, due to sleeping as long as possible after the chem-night-shift. EDIT:The pan yielded another 26.2g, making it 47.8g dicyandiamide or 36%, assuming one third is still in the ~2 kilos of wet filters, which are currently soaking for a second extraction with more water. I know 48g from 2/3 x 750g sounds less than 36%, but remember the fertiliser is 50% carbon, chalk, CaO, Ca(OH)2 etc, and the resulting calcium cyanamide is 50% calcium, so 17.5% of starting weight would be 100% yield (plus half that from the filters). But I was too inpatient again. The last 120ml I boiled down with too much heat, and they burned again, yielding sticky goo. Acetone is being tried to get the rest to crystallise. Maybe it cannot be extracted quantitatively, or maybe it has to be evaporated without any heating? I seem to remember that the first leftover motherliquor completely crystallised after putting aside and forgetting… But even if there is no big improvement possible, 48g means 100g guanidine nitrate for a dollar (140g theoretical). Or two dollars a pound from lime nitrogen in 100 pound bags!
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