Is it possible to get gas out of a liquid other than by boiling?

Still putting my solar device together and I'm still having some trouble getting the working fluid (ethanol) to boil. Almost there. I was wondering tho if there's not an easier way. Is it possible to by adding heat, make a gas dissolved in a fluid bubble out. Like if you heat up something like pepsi, get all the CO2 to gasify. And, how would you get the gas back in?

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shabaki8 years ago
well i know if you compress something hard enough the friction will heat it up (thats ow diesal engines run) so somme kind of compresser might help.. also if you need a way to et the as out without heat then electrical current mite be the way to go (such as electrify water to get o2 and hydrogen , run them past a few small turbines and let them mix to become water again)
SolarFlower_org (author) 8 years ago
I've tried some experiments heating and boiling carbonated drinks. The CO2 bubbles out very quickly with only a little heat added. Apparently 2 litres of liquid will contain about 4 litres of gas, which would be about what I'd need. But the main problems are: How do I get the gas back in? Some gas will reabsorb overnight, but I doubt it would be all of it. And how do I stop the CO2 from bubbling out too easily without increasing the pressure?
SolarFlower_org (author) 8 years ago
I'm using sunlight to boil a fluid, which produces bubbles, which drive a sort of inverse water wheel, which gives mechanical motion to the tracker for the collector. It's for keeping a parabolic dish or fresnel lens pointed directly at the sun, but needs to be something which can be easily and cheaply produced from mostly scrap so that anyone anywhere can make them. The working fluid can be anything as long as it's pretty easy to get and not too corrosive. Ethanol is good because it's so common and has a reasonably low boiling point. But maybe not quite low enough. Hexane would be great, but it's kinda hard to get and expensive. But the problem is that tho heating a liquid is easy, boiling it always takes a lot more energy (due to the enthalpic heat of vapourisation). So I'm wondering if there isn't a sneakier way to get the gas bubbles. Like, what would be ideal would be something like a softdrink. I heat it, the CO2 bubbles out, drives the device, the fluid cools, the CO2 redissolves back into the fluid. Repeat. I haven't tried heating a softdrink to see what happens, but I'm pretty sure it wouldn't work. So just wondering if there are any other fluids which would? (I'm kind of assuming there aren't, but if there was it woud solve all my current problems.)
I'd get an electric telescope mount designed for doing exactly this sort of thing: run it off solar energy. When you get the thing working properly, then consider trying to do it differently. From what you've said, this doesn't sound like something you'll get to work. Perhaps you could use a pair of gas-filled pistons which push against each other - the hotter one exerts more pressure and moves the device until they equilibrate to the same temperature? L
SolarFlower_org (author)  lemonie8 years ago
True, but these are things which have already been done, and have the problem of not really being easily fabricated and maintained. Maybe it'll work, maybe it won't. If it does tho it has the potential to save tens of thousands of lives and let people be completely solar self sufficient for less than $100. So I'm going to try to get it to work.
I meant to get one bit working at a time rather than trying to do everything at once, because there's more to this than just the tracking mechanism (if I remember correctly). L
SolarFlower_org (author)  lemonie8 years ago
Kind of, but not really. I guess the three components would be the tracker, the collector, and the light pipe. The last two will take some finessing but the physics is pretty straight forward and well known. (Touch wood.) And without the tracker there's not a lot of point in investing much time in them. This isn't a project to get myself solar, if that were the case I'd probably just go with something preexisting. The point is to design something which is of maximum benefit to others. So it needs to be as cheap and easy as poss. But, yes, I am kind of going about the design process a little wrong...
Maybe go with a tank of compressed air or wound up clock spring. Have a solar or battery powered solenoid valve to control the blasts of air for movement. You would have to fill up the tank every once in a while depending on its use and capacity. It may not be your idea of a solar powered only device though.
SolarFlower_org (author)  caitlinsdad8 years ago
I'd thought about that sort of thing, but really want something which can be set and forgot, not needing its energy source to be recharged manually. Plus I don't want anything electrical, as it ads extra hassle to the construction process.
lemonie8 years ago
An ultrasonic bath can help. Vaccum-filtration also works. Purging with helium is a good finisher. I don't think that you really have a problem with dissolved gas in ethanol, can you explain in detail what you're doing? Maybe post us a link to an unpublished Instructable? L
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