Many methods exist for the conversion of sulfur dioxide to sulfuric acid. In this video, on brand with this channel, we try performing this oxidation by electrolysis.
@@Wavy_Gravy WTF is all this Chad/Gigachad stuff all about. In my day a Chad was someone who always took drink and drugs too far, he was the dude that started the party and then ended it halfway through by requiring an ambulance by showing off about how much more drink/drugs he consumed than everyone else before jumping off roof at a house with no swimming pool to land in....
@@BackYardScience2000 I'm pretty much of the belief that the 80's and 90's ruined language forever. Being ironic got too widespread and too many were too coked up to even understand irony, so slang sorta flipped polarity by accident! I think I qas already thinking about stuff in the context of "...back when things were normal..." by the late 90's. The internet was the new frontier, a wild west where freedom of information was the prime directive. Even the music we considered garbage back then, when compared to some of the shit these days, sounds like there was at least one modicum of talent involved! I think I've officially become an old fart now. I dunno when it happened or how it sneaked up on me, but it happened! I miss those days before I grew up and realised important shit was important!
I think NurdRage made some H2SO4 using electrolysis as well, but he was also using some bromine salts I think. Not the same method. P.S. Even though this was a failed experiment, I appreciate you uploading it. Most channels upload only the successful stuff, only a few upload failed experiments, which I think you can learn more from than just the successful ones.
I'm a big fan of that Nurdrage video! I'll definitely be trying the electrobromine process one day. I'm glad you like the unsuccessful stuff as well. Despite not yielding a positive result, these videos are just as much effort to make, and these kinds of comments assure me it's not all just wasted time! Haha.
@ScrapScience yeah. I think seeing failed experiments helps immensely when trying to replicate or learn from your (or any other channels) videos. So keep it up :)
Before the UK ban on H2SO4 above 15%, I had a homemade apparatus for this. It was a teflon lined compressed air tank I used. I'd quarter fill it with sulphur and water, fill the rest with compressed air (or oxygen which worked way better) til it was at about 8 or 9 psi, then I'd heat it very slowly til the pressure got to about 2× atmos, and throw the tank into my firepit til it went out (usually a couple of hours). Release the pressure incredibly slowly, the tank I had had a long tube added to above the liquids level, so I could vent the pressure without spraying H2SO4 everywhere. I've achieved over 90% H2SO4 in the past, though using a firepit means the temp wasn't consistent so the concentration wasn't either. I will add a disclaimer, I was in a very wide open space and didn't go near til it had cooled, explosions spraying concentrated H2SO4 are not only a risk, but actually very likely if the PTFE lining has flaws. The product did contain iron impurities, possibly from the regulator but equally possible that I overheated the PTFE and it let some through, but it was great for reactions where a bit of iron sulphate/oxide didn't matter, and was actually a benefit for reactions that require iron as a catalyst. Either way, only so it this way of you're too lazy to observe the reaction and have somewhere a sulphuric spray won't cause issues. It's dangerous AF but damn if it isn't easy!!! I tried a run with H2O2 in place of water but my weak 3% peroxide didn't seem to be reacting with the sulphur as much as the iron from the flawed cylinder.
@@IlusysSystems I was naive enough to think the PTFE lining would survive the heat, so I didn't think the iron would be too big of an issue. To be fair, it held out longer than it should have considering at one point the cylinder was getting close to cherry red!
@@Moritz___ It was from a small compressor, so probably about 60 litres. I don't know how thick the walls were but it was rated for about 9 bar IIRC, and I've actually tried to blow one up in the past and it was still holding at 21 bar before the compressor gave up.
Hey there Harry, I’ve been a subscriber to your channel since those halcyon high school days. I’ve derived much entertainment and enjoyment from watching your progress. Despite the less-than-stellar results in the current experiment, I found your analysis of the outcomes to be spot on and I truly admire your dogged determination to see the project through. I’ve learned 10X more from my failures and mistakes than from my successes. Also keep in mind that the destination is nowhere near as important as the journey. Good luck with your future experiments.
Thought you were going to use vandium pentoxide or other oxide passed through in a heated glass tube. Swap out the catalysis for nichkle oxide and sulfur dioxide for ammonia you git nitric acid ammonia than use the Nitric acid to oxidize the Sulfur dioxide to Sulfururic acid and form sodium nitrite from the NO2.
Maybe you could make a chamber with water in it and a Jacobs ladder in the top and you could pump air in the top and it would be converted into Nitrogen Dioxide by the ladder and that would dissolve into the water. Now hook up the sulfur dioxide generator to the the chamber and have the sulfur gas bubble slowly through the solution from the bottom, also while the Nitric dioxide is being made and dissolved, the nitric acid that is created would oxidize the sulfur dioxide into sulfuric acid. This method was experimented with in WW2. Any ways cool vid, keep up the great work.
You could try the Bunsen reaction, might be worth looking in to. I've not tried it but I'd do something like this: 2H2O + SO2 + I2 → H2SO4 + 2HI. Ideally by burning Sulphur to avoid HCl contamination. Decant the upper aqueous later and bubble air through it. 4 HI + O2 → 2 H2O + 2 I2 to remove traces of remaining HI. Extract the I2 from the acid with a non polar solvent. Bubble air through the HI/I2 liquid to regenerate I2, or try electrolysis. The Iodine can be made by electrolysis of KI. Concentrate the resulting acid after removing HI/I2, conc. Sulphuric can form Hydrogen Sulphide with Hydrogen Iodide.
Grab a quartz heater tube from an old space heater. Fill it loosely packed with vanadium pentoxide and slowly pass oxygen in excess plus SO2 while the tube is heated strongly. The SO3 vapor can be bubbled into water or crystallized as a solid. It forms long needle like crystals. ❤
if you do not have vanadium pentoxide, try other metal oxides- even iron oxide will do. these are catalysts and must be suspended on a carrier. Soak asbestos or mica in ferric chloride and use the dried mass as the catalyst. broken porcelain or boiling chips also will work. conversion will be around 40-50% for a single pass at 350-400C
"I have that popular video were I had to do a lot of work for small amount of sulfuric acid, so I decided to post another video where I am doing even more work for even less product!" Jokes aside - nice video, now I know how not to do it!
the music reminds me of the music used in a USA children's television show called, _"Mr. Rogers' Neighborhood"._ it ran for several decades, and the man responsible for almost everything in the show (Fred Rogers) is a much beloved educational television icon in the USA. he was awarded *_"Presidential Medal of Freedom"_* -- the highest possible civilian award -- for his contribution to children’s education initiatives. (for what it's worth, this comment is entirely meant as a compliment on your choice of music.)
Always interesting to see your attempts, if they work or not. For me, it was obvious, that your sulfur-burner couldn't work in that high tin can, while sucking off air from above, since there is just not enough oxygen coming around to burn it. You need a burner, that allows the air to flow in from below same time. Best thing would be a closed container, into that you can blow a regulated flow of air, with overpressure, so this would also make your vacuum-pump unnecessary. The method with HCl + NaHSO3 is way too expensive for producing just some diluted H2SO4, and doesn't make sense, as long as it can be bought right now instead, cheap, as HCl and perfectly clean. Also your setup with platinum electrode, expensive glass apparatus, doesn't match your channels name anymore, for my taste. The easiest method, I have in my mind for making H2SO4, is to oxidize Iron wool, or powder, or even better, Iron-oxide, to get some Iron-II-sulfate by air and over time and then to roast that stuff. But for now, I don't know the best method to produce the Iron-II-sulfate from just Water, Air, Iron and Sulfur (and time). But there must be a way, because that is, how it is generated naturally too, as a mineral. Another Idea is to just burn Sulfur to SO2, bubbled into some water and also bubble O3 from an Ozone-Generator into it, that would perfectly replace H2O2 without much costs and without the diluting-effect as well. And also it is way easier and cheaper, than to electrolyze the stuff with a platinum-electrode. Only Challenge I see in that, is to get the process that much effective, that no SO2 is wasted. Also H2SO4 can be made my reacting SO3 with Water. The most common source to make SO3 is gypsum, CaSO4, that decomposes to CaO and SO3 at 1450°C. This Temperature is challenging to achieve, but I think about to give it a try into a charcoal-fire, when I have the container, that is able to handle such temperatures.
For your next try, you could probably use a gas frit for the SO2, to increase the reaction surface. Just a little adjustment but maybe it'll do something. Nice video btw.
Maybe you could use two separate cells for the anode and cathode connecting them with a semi permeable membrane like in the sodium hydroxide video? I reckon this would be a decent way to minimize that elemental sulfur contamination. And run only SO2 through the anode so as to improve efficacy.
Yep, maybe something like the hydrogen generator seen elsewhere made with a whisk and the right electrode material as wool or densely packed shavings? In the end it also may be an issue of the scale used by @ScrapScience. What about temperature ctrl? Is there a specific temperature range that will produce optimal results?
I‘m with @Dman6779 - this had a different goal than the one reached but on the other hand it shows how the requirements for each step need to be more specific and an acceptable range for each critical parameter defined and fulfilled. The failed experiment of one is inspiration for others. S can be found in brewing equipment shops too (as a salt to ensure yeast can handle apples and pears etc or in the form of sticks for „sanitising“ wooden barrels).
Harry.....I had a thought after watchig a video by Integza...he showed off a knife that has milions of pores in the metal that allowed the gas the blew threw (hydogen) to ignite without going out. It allowed the entire knife to flame and get red hot without going out...no matter how high he turned up the gas. my thought is if diffusing the SO2 gas inside the water flask would increase the concentration in a shorter time.
Hex I don't know if anyone has recommended this. But if you increase the initial sulfuric acid to 30-40% you can electrolyze at high current density (~70-80 A/dm3) to generate peroxydisulfuric acid, which hydrolyzes to hydrogen peroxide. (Theoretically, using a little potassium hydrogen sulfate can increase the efficiency.) Perhaps peroxydisulfuric acid can oxidise SO2 directly, but there is not much information on this The problem is that it takes a lot of sulphuric acid to get it started and increasing the concentration reduces the efficiency of the process. So either the reaction stops over time or the solution has to be diluted. Also, I know it's a bit extreme, but it is theoretically possible to react sulfur dioxide and oxygen directly with each other in an arc discharge without any other catalyst. This should in principle generate S2O7 which is the anhydride of peroxydisulfuric acid. Which then just needs to be absorbed in water and hydrolysed.
That's a very interesting idea! I'd be surprised if peroxydisulfate can't oxidise sulfur dioxide. The only thing I'm concerned about is the fact that peroxydisulfate is apparently a pretty tricky reaction to get right, and it is essential that platinum is used (I think lead(IV) oxide also works but I won't be touching that). I'd just find it a little bit difficult to call something an 'accessible reaction' if platinum is required, though I'm not completely averse to it. I mean, I used platinum in this video but the idea was to eventually move to graphite... Anyway, I'll hopefully be attempting the synthesis of peroxydisulfates at some point, though I've got no plans right now. It's been something I've wanted to try for a while, and this might be a nice thing to try alongside that. Thanks! An arc discharge reaction is definitely a thought too. I think I'd better start with some simpler reactions first though - maybe a Birkeland-Eyde reactor might be in order...
Thank you for sharing your experience. It is interesting how you apply science and I am especially happy to see you measure and qualify your results. I think you may have too little contact surface between the SO2 and 4% H2SO4 („standard“ ). Maybe use a bubble „stone“ or glass with a labyrinth?
I think this needs either a divided cell, or modifications to the anode/cathode surface area ratios. Since sulfur dioxide conversion to elemental sulfur was definitely an inefficiency, I think you'd see a difference from running in an anode chamber or reducing the cathode area available to reduce sulfur dioxide. Cathode material is another optimization that's available. This is just the data page on wikipedia, but it looks like the conversion of sulfur dioxide to bisulfate or sulfate is just a little more unfavorable than forming hydrogen (-0.16 V or so). That said, the overpotential for hydrogen formation on copper is -0.50 V, so it's possible reducing the sulfur dioxide on the cathode is the more favorable reaction. Platinum's overpotential for hydrogen formation is only -0.09 V, so using platinum for both the cathode and the anode may be the play if you don't divide the cell.
Yeah something like this sounds perfect. Although since elemental sulfur is produced on the cathode its probably going to be better to use a divided cell with some kind of permeable membrane to keep ions flowing also reducing the amount of gas that gets turned into elemental sulfur
Yeah, a divided cell is definitely the optimal route. If sulfur dioxide doesn't even touch the cathode to begin with, you don't have to be worried about surface areas and overpotential complications.
@@Relatablename exactly, if I wasn't preparing my house to sell I would run the experiment for myself. Unfortunately my lab is serving as a storage space right now lol.
SO2 plus oxygen blasted by UV works sort of. The SO3 formed will condense on the UV lamp absorbing the ozone lines. The problem can be solved by using a stronger UV source that makes enough heat to sublimate the SO3 off the light source.
@@ScrapScience I actually wonder if you literally modify a car battery since it contains seperators and lead anodes already. replace anode chamber with dilute sulfuric and inject SO2 slowly within them it would be probably viable. I also wonder about metal catalysts similar to nurdrage copper chloride process or maybe a halide catalyst like for the electrobromine process. You can use your MMO anodes for the electrobromine process since Ir-Ru is compatible with bromide electrolysis for the most part though Ir-Ta is preferred for non chloride salts.
Maybe a deep cycle battery would be a good way to go there... Though putting holes in a lead acid battery isn't generally my kind of thing. And yes, I've been thinking about metal catalysts too. The copper from Nurdrage's process is a definite option, but copper is probably too easy to plate out on the cathode (maybe an anion exchange membrane is required). I was thinking that iron sulfate might make a good catalyst for this, since Fe(III) would be generated on the anode and easily oxidise the SO2, forming a Fe(II)/Fe(III) cycle. Do highly acidic conditions damage MMO electrodes at all? I would have thought the high concentrations of HBr and H2SO4 would damage the titanium substrate at least. I've got no experience there though, so I'm probably wrong.
@@ScrapScience Ir-Ru MMO is stable usually up to 20% to 35% acid concentration depending on IrO2 content. Ir-Ta can handle up to 45% acid and PbO2 can handle up to 80%. HBr does damage titanium in high current density but it seems Ive seen people run Ir-Ru in bromate cells at lower pH and even a video of som1 making bromine with an Ir-Ru anode and a membrane cell. overall though Ir-Ta is preferred for any decent acid concentration as it can handle even very highly concentrated acids of both HCl and sulfuric. PbO2 is the best but as you said lead is not something you like working with.
assume electricity is free, and any source material is free, so the product is also free, so you dont really dont have to care about the "efficiency", its a gift in other words
Another way to prevent suck back is using a small pump, such as an aquarium pump, to impart a positive pressure in the apparatus. Also, without a scrubber between the SO2 generator and the reaction vessel, you will have contamination from the HCl that can form sulfur dichloride with the electrolosis. EDIT: Another method you can try is the metabisulfite method, in which metabisulfite is placed at the bottom of a beaker and 12.6 molar concentration hydrochloric acid is added. The resulting gas is bubbled through nitric acid, which will release brown/red vapors of nitrogen dioxide as the reaction proceeds. The completion of the reaction is indicated by the ceasing of the fumes. 3 SO2 + 2 HNO3 + 2 H2O → 3 H2SO4 + 2 NO
@@ScrapScience Yo can use a concentrated solution of sodium hydroxide as HCl readily reacts with it while allowing the SO2 to pass. (HCl + NaOH → NaCl + H2O). Other methods (that can be paired with the above in a two-step method) can use an amine-based solution using diethanolamine, methyldiethanolamine or aminoethoxyethanol (which would make it move complicated and less of a "scrap science"). Nevertheless, methyldiethanolamine is highly selective for HCl and can be effective in scrubbing systems.
The trouble with sodium hydroxide is that it also reacts with sulfur dioxide. In fact, I'm using sodium hydroxide here as the final washing bottle to prevent the release of SO2 into the atmosphere. Both HCl and SO2 are acidic gasses, so it's not generally possible to selectively absorb HCl with an alkaline solution. Amine-based solutions could be promising though, I'll look into it!
Well that's disappointing but I guess that's how these experiments go sometimes. Perhaps it would work in hydrochloric acid instead of sulfuric acid. H2SO4 will just produce O2 at the anode but HCl electrolysis would make chlorine and hypochlorous acid which could oxidize SO2 or sulfurous acid in solution to sulfuric acid. That way the oxidation isn't limited to the anode surface but the whole solution. There might also be less sulfur formation at the cathode because sulfurous acid in solution would be rather short lived.
Yeah, it's looking like some kind of homogeneous catalyst might be required for this oxidation. I've been thinking about using dissolved Fe(II)/Fe(III) as an 'electron transfer mediator' of sorts, but I'll add chlorine to the list of things that might work!
First of all, congratulations for the ideas and sharing your projects with the public. Thank you very much! I am an admirer of your content and I love seeing it, I remember that the production of sodium hypochlorite by electrolysis was something I also tried to do at home inspired by your content. I have a question in this proyect. Does the electrolysis of dilute sulfuric acid not produce H2 and O2? How selective is the platinum electrode against sulfur dioxide? Wouldn't that reduce the energy efficiency of the process greatly? I also think that what you proposed is interesting and excellent and the use of electrolysis in the oxidation of gases requires more study.
I'm super glad you like my content! To answer your questions, the oxidation of sulfur dioxide is significantly easier than the oxidation of water. While the electrolysis of dilute sulfuric acid does generally give hydrogen and oxygen, when we introduce sulfur dioxide to the mix, the anode should significantly prefer oxidising it to sulfate as opposed to oxidising water to oxygen. Obviously this didn't work as well as I'd hoped, but the idea is relatively sound. You're correct that there will always be a major source of energy inefficiency in the fact that we're letting the anode generate oxygen, but electricity is by far our cheapest reagent here, so it's of little consequence to the home experimenter.
the so2 will oxidise with oxygen in the solution so just bubbling air through the solution with the so2 should do it surely this is a method i would think would work
The reaction between sulfur dioxide and oxygen doesn't proceed at room temperature. Even with catalysts, extreme conditions are often required to get reasonable reaction rates.
Some soluble sulfate salt that preferribly creates an insoluble complex with oxalic acid may be an option. Mixing both in equimolar proportions in as little water as possible, then putting it into the fridge and decanting the liquid, followed by destillation the next day could be enough. I wonder if this also works with a 2:3 mixture of aluminium nitrate nonahydrate and oxalic acid in order to get some quick and dirty nitric acid, since aluminium oxalate is insoluble in water aswell. One thing to be aware of is that Oxalic acid is redox active, so there may be some concentration limit due to decomposition setting in. If that somehow wasn't an issue, then the oxalic axid could be molten (mp for the dihydrate is 101°C) or triturated with the target compound directly in order to get somewhat concentrated acid easily.
Copper Sulfate with Oxalic Acid is what I've seen. The properties of all the reagents seem just right. The melting idea seems super interesting but I could imagine that to be quite dangerous.
I didn't actually say it in the video here, but one of the reasons I'm trying this method is to avoid starting with a sulfate salt. I have other videos about converting sulfate salts into sulfuric acid, but if we can start with sulfur itself (which is a lot cheaper), it would be beneficial from a financial standpoint. Still though, definitely something to look into if the reagents can be found cheaply.
Maybe repeat the experiment, but instead of using a 4% solution of sulfuric acid in the beginning try using a ~50% one. Aparently this produces hydrogen peroxide once it undergoes electrolysis.
Could you use NO2 to do the oxidation step from SO2 to SO3? Perhaps this would be a way to make the Birkeland-Eyde reactor more efficient. "simply" put an adjustable air metering valve (they are cheap) on the intake of the BE reactor to give some control over the now-forked intake (assuming you go back to the burning sulfur/pull-thru setup). After the BE, you could use an air or water jacketed condenser to re-form the scrambled diatomic Nitrogen and Oxygen into some NO, which forms NO2 in contact with the remaining O2. From there, combine the SO2 and NO2 paths and run them into a chromatography reservoir for dwell time and visual appeal for friends and family. The unreacted NO2 should form HNO3+NO on contact with water, assuming it doesn't react with the SO2 to make SO3+NO on the way there (this makes contact time sort of a big deal). This is the point where you can get the bulk of your H2SO4 and HNO3 in the reaction flask. Any free O2 remaining, and the inevitable trace amounts of NO will oxidize back to NO2 and react in the gas wash stage, becoming weak but recoverable, HNO3. The HNO3 side products should be able to separate from the mix via distillation. Nitric acid boils at a far lower temperature than Sulfuric acid, so a Vigreux column should give a good separation of the two acids, preceded by fractionating the water/HNO3 mixture. You'd probably want to cool down and remove the Vigreux for distilling the H2SO4. Or, you could do it all in one distillation by attaching a vacuum source during the wide temperature deadzone, and then insulating everything, then insulating the insulation. With a light vacuum source, you can get the Sulfuric acid boiling point a bit under 300C, and with a strong vacuum source, you can get it down to a little over 200C. That's not bad, but your glass is likely to get stuck together, warranting the purchase of fancy combined function glassware (for fewer connections). ...or you could get bulk Sodium Percarbonate pretty cheap, in bulk. It is the active ingredient in Oxyclean, and various brewery/vintner food-safe sanitizers. It's 32.5% by weight H2O2, but in a powder form.
Nitric acid/NO2 is definitely an option for this type of reaction. In fact, they can actually act as catalysts to force the reaction between atmospheric oxygen and aqueous SO2 (so no NO2 is actually lost in the course of this reaction). A definite idea for the future. Thanks! The problem with sodium percarbonate is the fact that it's mostly sodium carbonate. Using this stuff directly will produce sulfate from SO2, but the basic nature of the sodium carbonate will cause the final product to be sodium sulfate (probably one of the most useless chemicals I can think of).
@@ScrapScience Thanks for the reply and confirmation of the idea. The part that involved the Sodium Percarbonate was not intended to be used directly, because of the obvious neutralizing effect of the carbonate. I kept that afterthought brief because I don't know how CO2 will affect the system. CO2 is likely to come from acid-forcing the carbonate to give up its O2 content. The Percarbonate side reaction would be from a flask with the powder, a vacuum port (for output), and a PE-Addition funnel to drip some liquid onto the powder to cause it to release the O2 (and CO2 biproduct). The vacuum port runs the O2 via hose to the cooled, pre-dwell-bulb gas flow from the Berkeland-Eyde NO generator. I don't know what liquid would be best for releasing the O2 from the Na-Percarbonate. I would default to Citric Acid (cheap, dry, doesn't stink, non-hazardous, known to cause NaPC to foam aggressively in my washing machine) dissolved in water. I suspect that it will put a lot of CO2 into the airflow, as well as some water vapor. I have no idea what effect the CO2 would have on the overall experiment. The effects are probably negligible, beyond Carbonic Acid pH offset. Since it would likely be a better idea to perform the distillation(s) before measuring the produced products, any CO2 should be a non-factor by that point, assuming it doesn't interfere with the process. Arguably, it may be better to place the air flow metering valve before the Pressure Equalizing Addition Funnel, and place this funnel/O2 generator setup before and inline with the BE reactor, in the hopes that the electric arc will also break the CO2 into O2 and ??, but I would be concerned about it making organic materials and tars. The post-cooling stage will have water, and it will become liquid acid, for sure. The physical arrangement of the system will benefit from ensuring the fewest gathering spots for this water/product loss to accumulate.
Oh, I see my error with the first comment about the Sodium Percarbonate. I smugly offered that as a source of H2O2, without thinking of a way to separate that from the carbonate afterward. Well... It can still produce O2 at an estimated cost of $0.03 per gram of O2 (best case scenario/if buying 10Lb bag of sodium parcarbonate + shipping in USA). I don't know if this is a good value for the additional NO-to-NO2 conversion efficiency, but it's more glass, and bubbles, fun adjustments to make, and calculations to calculate. Certainly worth the entertainment value for a home experimenter. :)
I didn't know you could make any sulfuric acid at all from just water and sulfur dioxide. Not a chemist but due to the sheer simplicity of your control test, would it be worthwhile to just bubble sulfur dioxide through water and recycle the sulfur dioxide that didn't react to make h2so4 and just do that over and over and over? Sort of like those homemade birkeland eyde nitric acid generator things? Also what would happen if you ran ozone from an ozone generator through the sulfur while burning it to try to make it give off so3? Probably wouldn't work but I've never seen anyone try it before.
The control test didn't actually generate any sulfuric acid. The hydrochloric acid that carried over from the sulfur dioxide generator just gave us a false positive, and it's likely that the electrolysis reaction gave us the same false positive too. An ozone reaction is definitely an option, but I'm not a fan of how long those reactions take and how low the efficiencies are. I might give it a go one day, but I don't have any plans right now
I was wondering if one could buy an ozone generator and modify it or adapt it so that the ozone it generates is bubbled into water, into which sulphur dioxide is simultaneously bubbled (via a SO2 generator)? If one was to try ozone as an oxidant, an all-glass aparatus and PTFE tubing (or glass tubing) would be required, as ozone is such a powerful oxidizer that it will quickly degrade rubber and most other polymers. PS: some of the portable home ozone generators I've looked at come with flexible tubing attached to an air stone (manufacturers suggested uses include germ removal on foodstuffs like fruit and veg; the idea is that you you place the fruit and veg into a bowl of water, then you bubble generated ozone into the water (through the tubing and airstone), which supposedly kills germs. These ozone generators could very easily be rigged up to chemistry apparatus, such as a SO2 generator!
The main problem I have with using ozone as an oxidant is the abysmally low generation rate. Unless you can hook them up to pure oxygen, I haven't seen any cheap generators make any more than a few hundred milligrams per hour (though maybe I just don't know where to look for good ones). I mean, I'm no stranger to slow reactions, but producing only a couple of grams of sulfuric acid a day is difficult to justify. If I do end up getting one of those generators, I'll definitely look into it though. If it works well, maybe it can be scaled up...
if you would appreciate my demand would you make a video of how to make cacium carbide and i would like to make a hint on the method of preparation ,, by also using electricity for decreasing the energy required for the reaction ...... waiting for this ,, if you already have a video like that would be nice for you to tell me ,, and i'll search in your videos about that ,, thanks a lot /
i was searching about sulfuric acid production, aparently you can produce hydrogen sulfite(H2S) AND ammonia in small amounts using a biodigestor the thing is, H2S is soluble in water, and in theory, can react with the oxigen present, forming water and Sulfur could be cool make a video of a proof of concept: use H2S dillued in water and convert it in sulfuric acid
My thoughts exactly, you just need to stick a bit of cotton twisted into a wick into a pile of sulfur, and melt the sulfur a bit before lighting the wick.
Could you recycle the SO2? you have it bubble through more than once, or is that not as easy as it sounds I bet you couldn't do this with the selenium analogue 😅 if this creating small amounts of sulfur
Yeah, recycling gas from a single stream is a lot more difficult than it seems. At the very minimum, you need a gas pump and a reaction vessel designed to allow two isolated gas streams. It would be very nice if it were easy... And yes, haha, selenium chemistry is definitely beyond my level of knowledge and safety abilities.
It’s much easier to do this by simply electrolysing sodium chloride. I have a video about this here: th-cam.com/video/N45DlWLQ218/w-d-xo.htmlsi=8OvFCFhKTbQhnJkG
Ah I see, gotcha. Whilst it’s true that the electrolysis of bleach would be more energy efficient in producing sodium chlorate, there are some problems that make it more difficult than chloride electrolysis: Bleach is generally not very concentrated, so it’s very difficult to get a sodium chlorate product to crystallise out after you’ve performed the electrolysis. Additionally, bleach is only available as a solution, so it’s not generally possible to feed sodium hypochlorite into the cell as it runs. For these reasons, yes, I do strongly recommend the much simpler electrolysis of a sodium chloride solution.
Can you try lead chamber process. I get 70kg free sulfur powder. Burning sulfur mixed with 10% KNO3 in 5l can, I cant get any sulfuric acid. But why century ago it was industrial path, it must work.
That would likely work! There are a few options for what is effectively an 'electron transfer mediator' for this kind of process, and chloride/chlorine is one of them, I think... The only issue is that with the current setup, the chlorine may also react with the sulfur forming on the cathode, which would yield sulfur chlorides. This one might require a separated cell. Either way, I'll hopefully try something similar in the future at some point.
@@ScrapScience you could also make chlorine in one cell and mix it with sulfur dioxide and water it a diffrent container it should form HCl and H2SO4 which can be separated by distilation it is much harder and requires a lot of work but may work
I was wondering if it'll be possible to produce it via ionic bombardment. Basically using a large enough electric potential to ionize SO2 and accelerate it into a chamber of pure O2 before scrubbing. However, resulting solution might be contaminated with H2SO3.
warning for EU folks out there; >15% sulfuric acid is illegal to possess since 2022. glad to see those regulators up there making sure that everyone is safe!
Sorry, I'm not a fan of lead-based electrodes and I don't generally recommend their use due to the toxicity risk. I'm afraid you're going to have to look elsewhere on this one.
I have used lead anodes in the past, but I avoid them today for reasons of toxic contamination and the difficulty in dealing with waste. There are very few situations that a lead anode can be used directly (and even in these cases, it should be avoided for the reasons above). In the cases where you need an electrode of lead(IV) oxide on an inert substrate, it's just not worth the risk of getting lead poisoning or contaminating your workspace.
The separator in car batteries is generally nothing more than a porous diaphragm - not a proper membrane. Usually, it's just a fine mesh of fibreglass (or maybe a polymer?). They work great as electrolytic separators, but you might as well use a piece of finely woven fibreglass, as it will do exactly the same thing. Also, the idea of ripping apart a lead acid battery terrifies me, but if you can buy them separately then I suppose they're a great option if a diaphragm is all you need. In future videos where I require such a separator, I'll definitely be using something similar.
Sulphur dioxide shouldn't alter the pH until it reacts with the water to make H2SO4. If it's in solution it's H2SO4, doesn't it need to be interacting with water to even measure the pH???
@@y33t23 Dammit! I forgot about that as I'm still thinking about the method I've used to get SO4 instead of SO3. It was done at high pressure and temperature and worked beautifully. Very little unreacted sulphur remained and I've had up to 90% sulphuric acid from it (usually a bit lower, but still incredibly useful...). I hadn't even thought of the fact it wasn't under as much pressure because I'm so fixated on how well my bo mb prep worked. Edit: bo mb because YT has a habit of deleting my comments because of my username already, I don't need another commenting bloke because the bots misunderstood me!!!
Thanks for the scrummy summer drink recipe Harry
I just love unsuccessful attempt vids! I learn more from the fails AND i feel better about my own failures haha
The fact that you were making sulfuric acid in high school alone is impressive, no matter the output quality 👏
He also uploaded it to YT, Gigachad(murican chad not UK chad) activities.
@@Wavy_Gravy WTF is all this Chad/Gigachad stuff all about. In my day a Chad was someone who always took drink and drugs too far, he was the dude that started the party and then ended it halfway through by requiring an ambulance by showing off about how much more drink/drugs he consumed than everyone else before jumping off roof at a house with no swimming pool to land in....
@@Wavy_Gravy I'm from Scotland so UK standards aren't really applicable up here.
@@EddieTheHsame...
@@BackYardScience2000 I'm pretty much of the belief that the 80's and 90's ruined language forever. Being ironic got too widespread and too many were too coked up to even understand irony, so slang sorta flipped polarity by accident! I think I qas already thinking about stuff in the context of "...back when things were normal..." by the late 90's.
The internet was the new frontier, a wild west where freedom of information was the prime directive. Even the music we considered garbage back then, when compared to some of the shit these days, sounds like there was at least one modicum of talent involved! I think I've officially become an old fart now. I dunno when it happened or how it sneaked up on me, but it happened! I miss those days before I grew up and realised important shit was important!
I think NurdRage made some H2SO4 using electrolysis as well, but he was also using some bromine salts I think. Not the same method.
P.S. Even though this was a failed experiment, I appreciate you uploading it. Most channels upload only the successful stuff, only a few upload failed experiments, which I think you can learn more from than just the successful ones.
I'm a big fan of that Nurdrage video! I'll definitely be trying the electrobromine process one day.
I'm glad you like the unsuccessful stuff as well. Despite not yielding a positive result, these videos are just as much effort to make, and these kinds of comments assure me it's not all just wasted time! Haha.
It was the bromine sulfur route he used.
@ScrapScience yeah. I think seeing failed experiments helps immensely when trying to replicate or learn from your (or any other channels) videos. So keep it up :)
Always a delight to see a new video, and you've certainly come a long way from the early experiments!
Before the UK ban on H2SO4 above 15%, I had a homemade apparatus for this. It was a teflon lined compressed air tank I used. I'd quarter fill it with sulphur and water, fill the rest with compressed air (or oxygen which worked way better) til it was at about 8 or 9 psi, then I'd heat it very slowly til the pressure got to about 2× atmos, and throw the tank into my firepit til it went out (usually a couple of hours). Release the pressure incredibly slowly, the tank I had had a long tube added to above the liquids level, so I could vent the pressure without spraying H2SO4 everywhere. I've achieved over 90% H2SO4 in the past, though using a firepit means the temp wasn't consistent so the concentration wasn't either.
I will add a disclaimer, I was in a very wide open space and didn't go near til it had cooled, explosions spraying concentrated H2SO4 are not only a risk, but actually very likely if the PTFE lining has flaws. The product did contain iron impurities, possibly from the regulator but equally possible that I overheated the PTFE and it let some through, but it was great for reactions where a bit of iron sulphate/oxide didn't matter, and was actually a benefit for reactions that require iron as a catalyst.
Either way, only so it this way of you're too lazy to observe the reaction and have somewhere a sulphuric spray won't cause issues. It's dangerous AF but damn if it isn't easy!!!
I tried a run with H2O2 in place of water but my weak 3% peroxide didn't seem to be reacting with the sulphur as much as the iron from the flawed cylinder.
That's metal AF.
Even more metal is adding H2O2 to sealed contained when you know there is iron that can react
Damn that sounds scary!
how big was the container and how thick were the walls to keep a high number of psi inside
@@IlusysSystems I was naive enough to think the PTFE lining would survive the heat, so I didn't think the iron would be too big of an issue. To be fair, it held out longer than it should have considering at one point the cylinder was getting close to cherry red!
@@Moritz___ It was from a small compressor, so probably about 60 litres. I don't know how thick the walls were but it was rated for about 9 bar IIRC, and I've actually tried to blow one up in the past and it was still holding at 21 bar before the compressor gave up.
theres a ban ? oh i shouldnt be buying litres of 96% acid then ooops not like i been stashing it knowing that
His neighbours be like, "he's making meth again"
I first found your channel through that video! Thrilled to see a "new version"!! Keep at it my man!
We must support this Chanel 😊❤🎉
An awesome experiment. I look forward to future videos on this subject.
Hey there Harry, I’ve been a subscriber to your channel since those halcyon high school days. I’ve derived much entertainment and enjoyment from watching your progress. Despite the less-than-stellar results in the current experiment, I found your analysis of the outcomes to be spot on and I truly admire your dogged determination to see the project through. I’ve learned 10X more from my failures and mistakes than from my successes. Also keep in mind that the destination is nowhere near as important as the journey. Good luck with your future experiments.
Very kind words mate. I really appreciate your interest in my content. Failures are definitely the most educational of results!
Thought you were going to use vandium pentoxide or other oxide passed through in a heated glass tube. Swap out the catalysis for nichkle oxide and sulfur dioxide for ammonia you git nitric acid ammonia than use the Nitric acid to oxidize the Sulfur dioxide to Sulfururic acid and form sodium nitrite from the NO2.
You are doing well, keep up the good work.
Sorry it didn't work out; but out of failure comes new knowledge! Thanks for sharing, dude!
Maybe you could make a chamber with water in it and a Jacobs ladder in the top and you could pump air in the top and it would be converted into Nitrogen Dioxide by the ladder and that would dissolve into the water. Now hook up the sulfur dioxide generator to the the chamber and have the sulfur gas bubble slowly through the solution from the bottom, also while the Nitric dioxide is being made and dissolved, the nitric acid that is created would oxidize the sulfur dioxide into sulfuric acid. This method was experimented with in WW2. Any ways cool vid, keep up the great work.
I might be building a Birkeland-Eyde reactor at some point in the future (probably a long while away), so I'll be sure to look into this. Thanks!
You could try the Bunsen reaction, might be worth looking in to. I've not tried it but I'd do something like this: 2H2O + SO2 + I2 → H2SO4 + 2HI. Ideally by burning Sulphur to avoid HCl contamination. Decant the upper aqueous later and bubble air through it. 4 HI + O2 → 2 H2O + 2 I2 to remove traces of remaining HI. Extract the I2 from the acid with a non polar solvent. Bubble air through the HI/I2 liquid to regenerate I2, or try electrolysis. The Iodine can be made by electrolysis of KI. Concentrate the resulting acid after removing HI/I2, conc. Sulphuric can form Hydrogen Sulphide with Hydrogen Iodide.
Great video! I would love to see you improve on this method in another video.
Thanks! Hopefully I'll get around to it at some point. I've got the design for a better cell, but can't make any guarantees, haha.
@@ScrapScience Take your time :) and keep making whatever awesome projects you'd like!
I liked the first setup, burning sulphur. You should use a more open container, not the high-wall beaker. Nice aspirator-setup!
Grab a quartz heater tube from an old space heater. Fill it loosely packed with vanadium pentoxide and slowly pass oxygen in excess plus SO2 while the tube is heated strongly. The SO3 vapor can be bubbled into water or crystallized as a solid. It forms long needle like crystals. ❤
if you do not have vanadium pentoxide, try other metal oxides- even iron oxide will do. these are catalysts and must be suspended on a carrier. Soak asbestos or mica in ferric chloride and use the dried mass as the catalyst. broken porcelain or boiling chips also will work. conversion will be around 40-50% for a single pass at 350-400C
"I have that popular video were I had to do a lot of work for small amount of sulfuric acid, so I decided to post another video where I am doing even more work for even less product!"
Jokes aside - nice video, now I know how not to do it!
Yeah haha, that's pretty much exactly what happened. A perfect summary of this whole situation in a single sentence.
the music reminds me of the music used in a USA children's television show called, _"Mr. Rogers' Neighborhood"._ it ran for several decades, and the man responsible for almost everything in the show (Fred Rogers) is a much beloved educational television icon in the USA. he was awarded *_"Presidential Medal of Freedom"_* -- the highest possible civilian award -- for his contribution to children’s education initiatives.
(for what it's worth, this comment is entirely meant as a compliment on your choice of music.)
Always interesting to see your attempts, if they work or not.
For me, it was obvious, that your sulfur-burner couldn't work in that high tin can, while sucking off air from above, since there is just not enough oxygen coming around to burn it. You need a burner, that allows the air to flow in from below same time. Best thing would be a closed container, into that you can blow a regulated flow of air, with overpressure, so this would also make your vacuum-pump unnecessary.
The method with HCl + NaHSO3 is way too expensive for producing just some diluted H2SO4, and doesn't make sense, as long as it can be bought right now instead, cheap, as HCl and perfectly clean.
Also your setup with platinum electrode, expensive glass apparatus, doesn't match your channels name anymore, for my taste.
The easiest method, I have in my mind for making H2SO4, is to oxidize Iron wool, or powder, or even better, Iron-oxide, to get some Iron-II-sulfate by air and over time and then to roast that stuff.
But for now, I don't know the best method to produce the Iron-II-sulfate from just Water, Air, Iron and Sulfur (and time). But there must be a way, because that is, how it is generated naturally too, as a mineral.
Another Idea is to just burn Sulfur to SO2, bubbled into some water and also bubble O3 from an Ozone-Generator into it, that would perfectly replace H2O2 without much costs and without the diluting-effect as well. And also it is way easier and cheaper, than to electrolyze the stuff with a platinum-electrode. Only Challenge I see in that, is to get the process that much effective, that no SO2 is wasted.
Also H2SO4 can be made my reacting SO3 with Water. The most common source to make SO3 is gypsum, CaSO4, that decomposes to CaO and SO3 at 1450°C. This Temperature is challenging to achieve, but I think about to give it a try into a charcoal-fire, when I have the container, that is able to handle such temperatures.
Thanks as always for dispelling the impression that people can or will succeed on the first try!
For your next try, you could probably use a gas frit for the SO2, to increase the reaction surface. Just a little adjustment but maybe it'll do something. Nice video btw.
Yes!
Maybe you could use two separate cells for the anode and cathode connecting them with a semi permeable membrane like in the sodium hydroxide video? I reckon this would be a decent way to minimize that elemental sulfur contamination. And run only SO2 through the anode so as to improve efficacy.
Yeah, that's the plan if I end up revisiting this.
@ScrapScience sounds fun! Please do upload even if its a failure as im sure all of us armchair chemists combined could help
Yep, maybe something like the hydrogen generator seen elsewhere made with a whisk and the right electrode material as wool or densely packed shavings?
In the end it also may be an issue of the scale used by @ScrapScience.
What about temperature ctrl? Is there a specific temperature range that will produce optimal results?
I‘m with @Dman6779 - this had a different goal than the one reached but on the other hand it shows how the requirements for each step need to be more specific and an acceptable range for each critical parameter defined and fulfilled.
The failed experiment of one is inspiration for others.
S can be found in brewing equipment shops too (as a salt to ensure yeast can handle apples and pears etc or in the form of sticks for „sanitising“ wooden barrels).
Harry.....I had a thought after watchig a video by Integza...he showed off a knife that has milions of pores in the metal that allowed the gas the blew threw (hydogen) to ignite without going out. It allowed the entire knife to flame and get red hot without going out...no matter how high he turned up the gas. my thought is if diffusing the SO2 gas inside the water flask would increase the concentration in a shorter time.
You should try using an ozone generator tube to oxidize the gas in high voltages, I'd think SO2 would not reduce in these conditions
Hex I don't know if anyone has recommended this. But if you increase the initial sulfuric acid to 30-40% you can electrolyze at high current density (~70-80 A/dm3) to generate peroxydisulfuric acid, which hydrolyzes to hydrogen peroxide. (Theoretically, using a little potassium hydrogen sulfate can increase the efficiency.)
Perhaps peroxydisulfuric acid can oxidise SO2 directly, but there is not much information on this
The problem is that it takes a lot of sulphuric acid to get it started and increasing the concentration reduces the efficiency of the process. So either the reaction stops over time or the solution has to be diluted.
Also, I know it's a bit extreme, but it is theoretically possible to react sulfur dioxide and oxygen directly with each other in an arc discharge without any other catalyst. This should in principle generate S2O7 which is the anhydride of peroxydisulfuric acid. Which then just needs to be absorbed in water and hydrolysed.
That's a very interesting idea! I'd be surprised if peroxydisulfate can't oxidise sulfur dioxide.
The only thing I'm concerned about is the fact that peroxydisulfate is apparently a pretty tricky reaction to get right, and it is essential that platinum is used (I think lead(IV) oxide also works but I won't be touching that). I'd just find it a little bit difficult to call something an 'accessible reaction' if platinum is required, though I'm not completely averse to it. I mean, I used platinum in this video but the idea was to eventually move to graphite...
Anyway, I'll hopefully be attempting the synthesis of peroxydisulfates at some point, though I've got no plans right now. It's been something I've wanted to try for a while, and this might be a nice thing to try alongside that. Thanks!
An arc discharge reaction is definitely a thought too. I think I'd better start with some simpler reactions first though - maybe a Birkeland-Eyde reactor might be in order...
Thank you for sharing your experience. It is interesting how you apply science and I am especially happy to see you measure and qualify your results.
I think you may have too little contact surface between the SO2 and 4% H2SO4 („standard“ ). Maybe use a bubble „stone“ or glass with a labyrinth?
I think this needs either a divided cell, or modifications to the anode/cathode surface area ratios. Since sulfur dioxide conversion to elemental sulfur was definitely an inefficiency, I think you'd see a difference from running in an anode chamber or reducing the cathode area available to reduce sulfur dioxide. Cathode material is another optimization that's available. This is just the data page on wikipedia, but it looks like the conversion of sulfur dioxide to bisulfate or sulfate is just a little more unfavorable than forming hydrogen (-0.16 V or so). That said, the overpotential for hydrogen formation on copper is -0.50 V, so it's possible reducing the sulfur dioxide on the cathode is the more favorable reaction. Platinum's overpotential for hydrogen formation is only -0.09 V, so using platinum for both the cathode and the anode may be the play if you don't divide the cell.
Yeah something like this sounds perfect. Although since elemental sulfur is produced on the cathode its probably going to be better to use a divided cell with some kind of permeable membrane to keep ions flowing also reducing the amount of gas that gets turned into elemental sulfur
Yeah, a divided cell is definitely the optimal route. If sulfur dioxide doesn't even touch the cathode to begin with, you don't have to be worried about surface areas and overpotential complications.
How is finding a low temperature method for making elemental sulphur not useful?
Very informative! Thank you as always!
Yeah that's actually a pretty big deal. He should test the product to confirm that the solid is in fact sulfur and not a slurry of metal oxides.
@@Relatablename exactly, if I wasn't preparing my house to sell I would run the experiment for myself. Unfortunately my lab is serving as a storage space right now lol.
Mix sulpher with water and heat under pressure in a stainless steel wessel 😂
Another way is to blast with UV🎉
Yeah, I'm going to be staying well clear of pressurised reactions, lol.
This sounds like if the average londoner designed a reaction scheme 😂
@@ScrapScience But they're the most fun, how else would you simulate reactions on Venus ?
SO2 plus oxygen blasted by UV works sort of. The SO3 formed will condense on the UV lamp absorbing the ozone lines. The problem can be solved by using a stronger UV source that makes enough heat to sublimate the SO3 off the light source.
Really interesting even with the not so great result, perhaps it is worth trying the hydrogen peroxide method?
Lead anodes work better than Pt in this case. Also coat cathode in a layer of gypsum to stop reduction by making a selective pem coating.
I think I might be a little paranoid about lead anodes... they still scare me.
@@ScrapScience I actually wonder if you literally modify a car battery since it contains seperators and lead anodes already. replace anode chamber with dilute sulfuric and inject SO2 slowly within them it would be probably viable. I also wonder about metal catalysts similar to nurdrage copper chloride process or maybe a halide catalyst like for the electrobromine process.
You can use your MMO anodes for the electrobromine process since Ir-Ru is compatible with bromide electrolysis for the most part though Ir-Ta is preferred for non chloride salts.
Maybe a deep cycle battery would be a good way to go there... Though putting holes in a lead acid battery isn't generally my kind of thing.
And yes, I've been thinking about metal catalysts too. The copper from Nurdrage's process is a definite option, but copper is probably too easy to plate out on the cathode (maybe an anion exchange membrane is required). I was thinking that iron sulfate might make a good catalyst for this, since Fe(III) would be generated on the anode and easily oxidise the SO2, forming a Fe(II)/Fe(III) cycle.
Do highly acidic conditions damage MMO electrodes at all? I would have thought the high concentrations of HBr and H2SO4 would damage the titanium substrate at least. I've got no experience there though, so I'm probably wrong.
@@ScrapScience Ir-Ru MMO is stable usually up to 20% to 35% acid concentration depending on IrO2 content. Ir-Ta can handle up to 45% acid and PbO2 can handle up to 80%. HBr does damage titanium in high current density but it seems Ive seen people run Ir-Ru in bromate cells at lower pH and even a video of som1 making bromine with an Ir-Ru anode and a membrane cell. overall though Ir-Ta is preferred for any decent acid concentration as it can handle even very highly concentrated acids of both HCl and sulfuric. PbO2 is the best but as you said lead is not something you like working with.
@@ScrapScience I still think modifying an old car battery would probably work out well since its basically prebuilt and has everything.
Also maybe using ammonium sulfate to generate ammonium persulfate, using that to oxidize so2
assume electricity is free, and any source material is free, so the product is also free, so you dont really dont have to care about the "efficiency", its a gift in other words
you are doing the think that i love the most in my life ,,, so i think we will be a good friends ,, or you can say i'll be the best fan of you
How about ozone? Also to get sulfur to burn well use a fiber glass wick as if it was a candle, even a piece of charcoal could work as a wick.
Another way to prevent suck back is using a small pump, such as an aquarium pump, to impart a positive pressure in the apparatus. Also, without a scrubber between the SO2 generator and the reaction vessel, you will have contamination from the HCl that can form sulfur dichloride with the electrolosis.
EDIT: Another method you can try is the metabisulfite method, in which metabisulfite is placed at the bottom of a beaker and 12.6 molar concentration hydrochloric acid is added. The resulting gas is bubbled through nitric acid, which will release brown/red vapors of nitrogen dioxide as the reaction proceeds. The completion of the reaction is indicated by the ceasing of the fumes.
3 SO2 + 2 HNO3 + 2 H2O → 3 H2SO4 + 2 NO
Do you have any ideas for a scrubber that would remove HCl but allow the SO2 to pass?
@@ScrapScience Yo can use a concentrated solution of sodium hydroxide as HCl readily reacts with it while allowing the SO2 to pass. (HCl + NaOH → NaCl + H2O). Other methods (that can be paired with the above in a two-step method) can use an amine-based solution using diethanolamine, methyldiethanolamine or aminoethoxyethanol (which would make it move complicated and less of a "scrap science"). Nevertheless, methyldiethanolamine is highly selective for HCl and can be effective in scrubbing systems.
The trouble with sodium hydroxide is that it also reacts with sulfur dioxide. In fact, I'm using sodium hydroxide here as the final washing bottle to prevent the release of SO2 into the atmosphere. Both HCl and SO2 are acidic gasses, so it's not generally possible to selectively absorb HCl with an alkaline solution.
Amine-based solutions could be promising though, I'll look into it!
make a "lamp" with fiberglass wick and small open container, probably work to do the SO2
Well that's disappointing but I guess that's how these experiments go sometimes. Perhaps it would work in hydrochloric acid instead of sulfuric acid. H2SO4 will just produce O2 at the anode but HCl electrolysis would make chlorine and hypochlorous acid which could oxidize SO2 or sulfurous acid in solution to sulfuric acid. That way the oxidation isn't limited to the anode surface but the whole solution. There might also be less sulfur formation at the cathode because sulfurous acid in solution would be rather short lived.
Yeah, it's looking like some kind of homogeneous catalyst might be required for this oxidation. I've been thinking about using dissolved Fe(II)/Fe(III) as an 'electron transfer mediator' of sorts, but I'll add chlorine to the list of things that might work!
I think nafion may just make it work, it may have a higher potential to reduce the s02 than to oxidize it.
I think ive read something about making sulfiric acid by bubbling ozone through water with sulfur in it
You should check it out
First of all, congratulations for the ideas and sharing your projects with the public. Thank you very much! I am an admirer of your content and I love seeing it, I remember that the production of sodium hypochlorite by electrolysis was something I also tried to do at home inspired by your content. I have a question in this proyect. Does the electrolysis of dilute sulfuric acid not produce H2 and O2? How selective is the platinum electrode against sulfur dioxide? Wouldn't that reduce the energy efficiency of the process greatly? I also think that what you proposed is interesting and excellent and the use of electrolysis in the oxidation of gases requires more study.
I'm super glad you like my content!
To answer your questions, the oxidation of sulfur dioxide is significantly easier than the oxidation of water. While the electrolysis of dilute sulfuric acid does generally give hydrogen and oxygen, when we introduce sulfur dioxide to the mix, the anode should significantly prefer oxidising it to sulfate as opposed to oxidising water to oxygen. Obviously this didn't work as well as I'd hoped, but the idea is relatively sound. You're correct that there will always be a major source of energy inefficiency in the fact that we're letting the anode generate oxygen, but electricity is by far our cheapest reagent here, so it's of little consequence to the home experimenter.
Thank you very much for the response and for continuing to teach.@@ScrapScience 💪💪💪
the so2 will oxidise with oxygen in the solution so just bubbling air through the solution with the so2 should do it surely this is a method i would think would work
The reaction between sulfur dioxide and oxygen doesn't proceed at room temperature. Even with catalysts, extreme conditions are often required to get reasonable reaction rates.
ok fair enough what are the catalysts used i assume exotic@@ScrapScience
Some soluble sulfate salt that preferribly creates an insoluble complex with oxalic acid may be an option. Mixing both in equimolar proportions in as little water as possible, then putting it into the fridge and decanting the liquid, followed by destillation the next day could be enough. I wonder if this also works with a 2:3 mixture of aluminium nitrate nonahydrate and oxalic acid in order to get some quick and dirty nitric acid, since aluminium oxalate is insoluble in water aswell.
One thing to be aware of is that Oxalic acid is redox active, so there may be some concentration limit due to decomposition setting in. If that somehow wasn't an issue, then the oxalic axid could be molten (mp for the dihydrate is 101°C) or triturated with the target compound directly in order to get somewhat concentrated acid easily.
Copper Sulfate with Oxalic Acid is what I've seen. The properties of all the reagents seem just right. The melting idea seems super interesting but I could imagine that to be quite dangerous.
I didn't actually say it in the video here, but one of the reasons I'm trying this method is to avoid starting with a sulfate salt. I have other videos about converting sulfate salts into sulfuric acid, but if we can start with sulfur itself (which is a lot cheaper), it would be beneficial from a financial standpoint.
Still though, definitely something to look into if the reagents can be found cheaply.
Try with nitric acid instead of weak sulfuric. You'll get sulfurous acid that can be oxidised by electrolysis or oxygen 🤔
I caught a fresh scrap science drop!
Maybe repeat the experiment, but instead of using a 4% solution of sulfuric acid in the beginning try using a ~50% one. Aparently this produces hydrogen peroxide once it undergoes electrolysis.
Could you use NO2 to do the oxidation step from SO2 to SO3? Perhaps this would be a way to make the Birkeland-Eyde reactor more efficient. "simply" put an adjustable air metering valve (they are cheap) on the intake of the BE reactor to give some control over the now-forked intake (assuming you go back to the burning sulfur/pull-thru setup). After the BE, you could use an air or water jacketed condenser to re-form the scrambled diatomic Nitrogen and Oxygen into some NO, which forms NO2 in contact with the remaining O2. From there, combine the SO2 and NO2 paths and run them into a chromatography reservoir for dwell time and visual appeal for friends and family. The unreacted NO2 should form HNO3+NO on contact with water, assuming it doesn't react with the SO2 to make SO3+NO on the way there (this makes contact time sort of a big deal). This is the point where you can get the bulk of your H2SO4 and HNO3 in the reaction flask. Any free O2 remaining, and the inevitable trace amounts of NO will oxidize back to NO2 and react in the gas wash stage, becoming weak but recoverable, HNO3. The HNO3 side products should be able to separate from the mix via distillation. Nitric acid boils at a far lower temperature than Sulfuric acid, so a Vigreux column should give a good separation of the two acids, preceded by fractionating the water/HNO3 mixture. You'd probably want to cool down and remove the Vigreux for distilling the H2SO4. Or, you could do it all in one distillation by attaching a vacuum source during the wide temperature deadzone, and then insulating everything, then insulating the insulation. With a light vacuum source, you can get the Sulfuric acid boiling point a bit under 300C, and with a strong vacuum source, you can get it down to a little over 200C. That's not bad, but your glass is likely to get stuck together, warranting the purchase of fancy combined function glassware (for fewer connections).
...or you could get bulk Sodium Percarbonate pretty cheap, in bulk. It is the active ingredient in Oxyclean, and various brewery/vintner food-safe sanitizers. It's 32.5% by weight H2O2, but in a powder form.
Nitric acid/NO2 is definitely an option for this type of reaction. In fact, they can actually act as catalysts to force the reaction between atmospheric oxygen and aqueous SO2 (so no NO2 is actually lost in the course of this reaction). A definite idea for the future. Thanks!
The problem with sodium percarbonate is the fact that it's mostly sodium carbonate. Using this stuff directly will produce sulfate from SO2, but the basic nature of the sodium carbonate will cause the final product to be sodium sulfate (probably one of the most useless chemicals I can think of).
@@ScrapScience Thanks for the reply and confirmation of the idea.
The part that involved the Sodium Percarbonate was not intended to be used directly, because of the obvious neutralizing effect of the carbonate. I kept that afterthought brief because I don't know how CO2 will affect the system. CO2 is likely to come from acid-forcing the carbonate to give up its O2 content.
The Percarbonate side reaction would be from a flask with the powder, a vacuum port (for output), and a PE-Addition funnel to drip some liquid onto the powder to cause it to release the O2 (and CO2 biproduct). The vacuum port runs the O2 via hose to the cooled, pre-dwell-bulb gas flow from the Berkeland-Eyde NO generator.
I don't know what liquid would be best for releasing the O2 from the Na-Percarbonate. I would default to Citric Acid (cheap, dry, doesn't stink, non-hazardous, known to cause NaPC to foam aggressively in my washing machine) dissolved in water. I suspect that it will put a lot of CO2 into the airflow, as well as some water vapor.
I have no idea what effect the CO2 would have on the overall experiment. The effects are probably negligible, beyond Carbonic Acid pH offset. Since it would likely be a better idea to perform the distillation(s) before measuring the produced products, any CO2 should be a non-factor by that point, assuming it doesn't interfere with the process.
Arguably, it may be better to place the air flow metering valve before the Pressure Equalizing Addition Funnel, and place this funnel/O2 generator setup before and inline with the BE reactor, in the hopes that the electric arc will also break the CO2 into O2 and ??, but I would be concerned about it making organic materials and tars. The post-cooling stage will have water, and it will become liquid acid, for sure. The physical arrangement of the system will benefit from ensuring the fewest gathering spots for this water/product loss to accumulate.
Oh, I see my error with the first comment about the Sodium Percarbonate. I smugly offered that as a source of H2O2, without thinking of a way to separate that from the carbonate afterward.
Well... It can still produce O2 at an estimated cost of $0.03 per gram of O2 (best case scenario/if buying 10Lb bag of sodium parcarbonate + shipping in USA). I don't know if this is a good value for the additional NO-to-NO2 conversion efficiency, but it's more glass, and bubbles, fun adjustments to make, and calculations to calculate. Certainly worth the entertainment value for a home experimenter. :)
I didn't know you could make any sulfuric acid at all from just water and sulfur dioxide. Not a chemist but due to the sheer simplicity of your control test, would it be worthwhile to just bubble sulfur dioxide through water and recycle the sulfur dioxide that didn't react to make h2so4 and just do that over and over and over? Sort of like those homemade birkeland eyde nitric acid generator things?
Also what would happen if you ran ozone from an ozone generator through the sulfur while burning it to try to make it give off so3? Probably wouldn't work but I've never seen anyone try it before.
The control test didn't actually generate any sulfuric acid. The hydrochloric acid that carried over from the sulfur dioxide generator just gave us a false positive, and it's likely that the electrolysis reaction gave us the same false positive too.
An ozone reaction is definitely an option, but I'm not a fan of how long those reactions take and how low the efficiencies are. I might give it a go one day, but I don't have any plans right now
I was wondering if one could buy an ozone generator and modify it or adapt it so that the ozone it generates is bubbled into water, into which sulphur dioxide is simultaneously bubbled (via a SO2 generator)? If one was to try ozone as an oxidant, an all-glass aparatus and PTFE tubing (or glass tubing) would be required, as ozone is such a powerful oxidizer that it will quickly degrade rubber and most other polymers.
PS: some of the portable home ozone generators I've looked at come with flexible tubing attached to an air stone (manufacturers suggested uses include germ removal on foodstuffs like fruit and veg; the idea is that you you place the fruit and veg into a bowl of water, then you bubble generated ozone into the water (through the tubing and airstone), which supposedly kills germs. These ozone generators could very easily be rigged up to chemistry apparatus, such as a SO2 generator!
The main problem I have with using ozone as an oxidant is the abysmally low generation rate. Unless you can hook them up to pure oxygen, I haven't seen any cheap generators make any more than a few hundred milligrams per hour (though maybe I just don't know where to look for good ones). I mean, I'm no stranger to slow reactions, but producing only a couple of grams of sulfuric acid a day is difficult to justify.
If I do end up getting one of those generators, I'll definitely look into it though. If it works well, maybe it can be scaled up...
@@ScrapScienceIt's worth remembering that the other byproduct of air corona discharge is nitrogen oxides, so win-win either way.
if you would appreciate my demand would you make a video of how to make cacium carbide and i would like to make a hint on the method of preparation ,, by also using electricity for decreasing the energy required for the reaction ...... waiting for this ,, if you already have a video like that would be nice for you to tell me ,, and i'll search in your videos about that ,, thanks a lot /
Good video. When you will publish the video about magnesium?
Probably in a month or two. I still need to edit it.
what about using a borosilicate check-valve to prevent suckback?
i was searching about sulfuric acid production, aparently you can produce hydrogen sulfite(H2S) AND ammonia in small amounts using a biodigestor
the thing is, H2S is soluble in water, and in theory, can react with the oxigen present, forming water and Sulfur
could be cool make a video of a proof of concept: use H2S dillued in water and convert it in sulfuric acid
You can burn sulfur easily if you make candle of it.
My thoughts exactly, you just need to stick a bit of cotton twisted into a wick into a pile of sulfur, and melt the sulfur a bit before lighting the wick.
Sulphuric or nitric making is a winner.
What about making sulfurous acid this way, then running ozone from a chinese ebay ozonator through it?
Could you recycle the SO2? you have it bubble through more than once, or is that not as easy as it sounds
I bet you couldn't do this with the selenium analogue 😅 if this creating small amounts of sulfur
Yeah, recycling gas from a single stream is a lot more difficult than it seems. At the very minimum, you need a gas pump and a reaction vessel designed to allow two isolated gas streams. It would be very nice if it were easy...
And yes, haha, selenium chemistry is definitely beyond my level of knowledge and safety abilities.
@ScrapScience I love the glass aspirator pump.
Revisiting h2so4 videos because I've realised I can't buy sulfuric battery acid in uk any more
I like your style but I shudder when I see nitrile gloves. How come your hands don't sweat? I can't wear gloves like that
Yeah, they suck. I only wear them when absolutely necessary.
They're not nice, but I don't find them too bad I suppose.
Can you try electrolysing sodium hypochlorite to obtain sodium chlorate?
It’s much easier to do this by simply electrolysing sodium chloride. I have a video about this here: th-cam.com/video/N45DlWLQ218/w-d-xo.htmlsi=8OvFCFhKTbQhnJkG
@@ScrapSciencei've already watched it but if u think that's easier than electrolysing bleach then that sounds good
Ah I see, gotcha.
Whilst it’s true that the electrolysis of bleach would be more energy efficient in producing sodium chlorate, there are some problems that make it more difficult than chloride electrolysis:
Bleach is generally not very concentrated, so it’s very difficult to get a sodium chlorate product to crystallise out after you’ve performed the electrolysis. Additionally, bleach is only available as a solution, so it’s not generally possible to feed sodium hypochlorite into the cell as it runs.
For these reasons, yes, I do strongly recommend the much simpler electrolysis of a sodium chloride solution.
@@ScrapScience thank you so much bro for the infos
I read on science madness that platinum can be poisoned by sulfur oxide. Is that OK for the platinum anode?
It should be protected by the current passing through it. Also, isn't it mostly platinum catalysts that have trouble with sulfur?
I'm honestly not sure. The platinum still looks and acts as it did before, so I imagine this isn't a problem for bulk platinum surfaces.
Can you try lead chamber process. I get 70kg free sulfur powder. Burning sulfur mixed with 10% KNO3 in 5l can, I cant get any sulfuric acid. But why century ago it was industrial path, it must work.
Bro...
Burn sulfur with oxy hydrogen torch?
What if you added some hcl the chlorine from electrolysis can oxidize it to H2SO4 and make hcl that will get electrolized
That would likely work! There are a few options for what is effectively an 'electron transfer mediator' for this kind of process, and chloride/chlorine is one of them, I think...
The only issue is that with the current setup, the chlorine may also react with the sulfur forming on the cathode, which would yield sulfur chlorides. This one might require a separated cell.
Either way, I'll hopefully try something similar in the future at some point.
@@ScrapScience you could also make chlorine in one cell and mix it with sulfur dioxide and water it a diffrent container it should form HCl and H2SO4 which can be separated by distilation it is much harder and requires a lot of work but may work
I was wondering if it'll be possible to produce it via ionic bombardment. Basically using a large enough electric potential to ionize SO2 and accelerate it into a chamber of pure O2 before scrubbing. However, resulting solution might be contaminated with H2SO3.
Try ozone, it will work. I think.
warning for EU folks out there; >15% sulfuric acid is illegal to possess since 2022.
glad to see those regulators up there making sure that everyone is safe!
Hello! Can you please make video on making PbO2 anode? Like plating.
Sorry, I'm not a fan of lead-based electrodes and I don't generally recommend their use due to the toxicity risk. I'm afraid you're going to have to look elsewhere on this one.
@@ScrapScienceI have seen some videos where you used lead anode, so you already got some experience. Does it contaminate electrolyte too much?
I have used lead anodes in the past, but I avoid them today for reasons of toxic contamination and the difficulty in dealing with waste. There are very few situations that a lead anode can be used directly (and even in these cases, it should be avoided for the reasons above). In the cases where you need an electrode of lead(IV) oxide on an inert substrate, it's just not worth the risk of getting lead poisoning or contaminating your workspace.
This isn't to say that lead-based electrodes are always a terrible idea, but it's just that I'm not comfortable working with them any more.
Hey harry what if you use the separating element in car batteries as membrane? Think it will be cheaper
The separator in car batteries is generally nothing more than a porous diaphragm - not a proper membrane. Usually, it's just a fine mesh of fibreglass (or maybe a polymer?). They work great as electrolytic separators, but you might as well use a piece of finely woven fibreglass, as it will do exactly the same thing. Also, the idea of ripping apart a lead acid battery terrifies me, but if you can buy them separately then I suppose they're a great option if a diaphragm is all you need.
In future videos where I require such a separator, I'll definitely be using something similar.
2NaHSO4=H2SO4+Na2SO4
Vanadium Pentoxide - a catalyst - used as a glaze for pottery
It's really cool how many metal oxides you can get from pottery suppliers
Everybody wants to have sulfuric acid.
Especially in Europe.
So many documented and undocumented ways to make it honestly why even bother regulating it.
im in uk i just buyy it is so cheap even after ban 5 pounds for a litre
sorry ten pounds
@@unlockeduk
I found you can still buy old ph lowering agent from private sellers in 14kg canisters.
Thats about 49% sulfuric.
0,2% Increase, Ahhhh, not suuuuper good yield...
Sulphur dioxide shouldn't alter the pH until it reacts with the water to make H2SO4. If it's in solution it's H2SO4, doesn't it need to be interacting with water to even measure the pH???
So2 reacts with water to h2so3 instead of h2so4
@@y33t23 Dammit! I forgot about that as I'm still thinking about the method I've used to get SO4 instead of SO3. It was done at high pressure and temperature and worked beautifully. Very little unreacted sulphur remained and I've had up to 90% sulphuric acid from it (usually a bit lower, but still incredibly useful...). I hadn't even thought of the fact it wasn't under as much pressure because I'm so fixated on how well my bo mb prep worked.
Edit: bo mb because YT has a habit of deleting my comments because of my username already, I don't need another commenting bloke because the bots misunderstood me!!!
Don’t stop lying!¡!
its as if sulfuric acid is one of the most important acid
Thank god in America we can get it relatively pure from ace hardware