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Hairyloon

Pumping gas...

As you may know, I have been thinking about making gas for a while. One of the obvious problems is storing it and the obvious solution is to pump it into tanks.
This chap on Youtube is doing it with an ordinary garage compressor, which several people I've spoken to seem to think is a very dangerous prospect, what with electric motors, sparks and flammable gas.
I think the flammable gas is well enough sealed away from anything that would normally spark, but I thought I would seek a second opinion here...
dpack

a very dangeroos activity even with the right kit and safety trained staff

i recon a standard compressor made for air would be a big bang waiting to happen in a very impatient mood.

JUST DONT is my advice

im not sure how to get round this ,maybe a low pressure gasometer type store would be safer
dpack

ps i have worked with 2000psi hydrogen as well as oxy acetyline kit and compressed air at 2000 psi.

dangeroos stuff compressed gas
Hairyloon

I don't think I was planning to compress it that much.
dpack

any amount of compression ups the odds of a leak or internal bang if there is any contamination with air .

iirc the gas holders of old will fill with the pressure of production ie no pumps or compressors.

the modern stuff as in piper alpha et al uses high pressure compression to liquify the gas and is very dangeroos

if pumping is required maybe a bellows type thing (earthed against sparks and leak proof)would be a fairly safe way.a bit like a gas meter but pushing rather than pushed if you see what im getting at .
vegplot

The gas / oxygen mix has to be in the correct proportion to get a explosion or rapid burning even when pressurised so you'll need to scrub all oxygen from the mix before trying to compress it.

You'll also need to consider moisture. The drain valve at the bottom of the compressor isn't the way to do it either. Again scrub any moisture prior to compression. See diving tank compressor for method of scrubbing water from the gas.

Don't do it is very good advice but if it goes wrong we'll expect to see some pics.
Hairyloon

The gas / oxygen mix has to be in the correct proportion to get a explosion or rapid burning even when pressurised so you'll need to scrub all oxygen from the mix before trying to compress it.

If it is gas made by gasification, then I'd expect the oxygen to have been fairly effectively scrubbed by the combustion, and if the production is by anaerobic digestion, then if there is oxygen, then there will be no production.
Of course, there may be leaks subsequent...

Quote:
You'll also need to consider moisture. The drain valve at the bottom of the compressor isn't the way to do it either.

I can see that it is not desirable, but why would it be a big problem?
vegplot

1. Leaks are your enemy
2. Corrosion. See 1.
dpack

BANGS ARE ALSO YOUR ENEMY

see leaks as above

i have been reading about early and modern gas production and scrubbing the product between the retort and any subsequent pumping,storage ,distribution or use seems a very vital part of the process whatever the feed stock

see corrosion as above

see toxins and gumming up the works here

this game seems a bit iffy even for a hillbilly style wood gas engine
dpack

ps my second hound seems to manage to pump his gas by peristalsis and production pressure Laughing
Hairyloon

1. Leaks are your enemy
2. Corrosion. See 1.

That was what I thought, but I don't think corrosion will be quick enough to trouble the prototype, and as you've brought it up, it has put me in mind of a plastic beer barrel...
Mistress Rose

Didn't the old gas holders use water at the bottom as a seal?

I would advise against doing this too Hairyloon. I once saw the results of a house that had an explosion caused by natural gas. It was caused by a poorly sealed joint and when the gas/oxygen level reached the critical point it went bang. Luckily the only person injured suffered only superficial burns, but it didn't do the house a lot of good and wrecked the kitchen.
Falstaff

Difficult to envisage your system, but I expect your input to the compressor would be down some sort of pipe sealed to the unit so as to prevent the ingress of air ?

Oxygen is the killer here - and a purging mechanism must be employed, whether that be water or some inert gas, or a combination of the two. That purging mechanism must be adequate !

I don't see any reason to believe that a piston going up and down in a cylinder would either spark or provide enough compression to lead to a danger of "dieselling" - however without oxygen, neither of these apparent dangers can cause an ignition !

A slightly more complex arrangement could possibly be engineered using perhaps TWO of those beer barrels. One as the terminal storage vessel and the other as a receiver/compressor. This could be filled with water and gas allowed to enter, displacing the water through a valve arrangement at the bottom. Once the barrel is fille3d with gas, the water could be forced back in, compressing the gas and eventually driving it along a line connected to the top of the barrel into the storage vessel usnig the principles of Hydraulics.

http://hyperphysics.phy-astr.gsu.edu/hbase/pasc.html

The provision of the compressing force could be by using a compressor running air, or possible by simply using mains water pressure !
Hairyloon

Didn't the old gas holders use water at the bottom as a seal?
Not just the old ones, I think they still do that, but there is a limit to how much pressure you can contain that way.

Quote:
I would advise against doing this too Hairyloon. I once saw the results of a house that had an explosion caused by natural gas. It was caused by a poorly sealed joint and when the gas/oxygen level reached the critical point it went bang.

That would have been because of a leak rather than gas under pressure, it isn't really relevant to this discussion, unless you are advising me simply not to mess with gas...
Falstaff

Just went and watched your link HL ! Cool Then went for a bit of a tour

I particularly liked this one :-

https://www.youtube.com/watch?v=1p34rZeRPoM

It seems so simple, just a charcoal kiln basically and using the waste to inflate a receiver (Love the receiver !) Then pumping up a bottle (PERHAPS ?)

The gas coming out of that tube of his seems like good stuff - He says "Hydrogen" - Can it really be done as simply as that ?
Falstaff

Oops Embarassed mark

For serious storage of gas it is essential it is not only stored so that the gas cannot spark or be exposed to sparks- but that it is also properly shield from any possible fire generated by other causes unrelated to the gas .

I cannot believe you are thinking about storage in plastic barrels which would melt/burst and release their contents in even quite a gentle domestic fire!

Also I have been home brewing for countless years - and know what I'm doing in keeping airtight seal - but from time to time leaks happen! With plastic and steel barrels! it's a FACT OF LIFE! I don't know where you get the confidence they will not happen to you!

There are quite strict regulations on the storage of fuel especially when it is not stored in underground tanks which are desirable.

If you live in leasehold or rented property it is probable that you are in breach of your lease or tenanted property.

If its your own property you still need to check building and planning regulations for fuel storage.

You will probably also invalidate your house insurance in case of a fire related or unrelated to the project if anything did happen unless you get it specifically covered!

If you have near neighbours just don't go there full stop! - else you will be the neighbour from hell!

This sort of project is best for those living out alone in the desert!

But if you do get tempted please put on a live feed so we don't miss the actions cos the camera has been destroyed if it all goes BANG!
dpack

the voice of reason there,well put mark tahir

I have nothing to add except that I have seen the results of a fireball type explosion; a kid in our class was experimenting making home made rocket fuel and blew up his mum's garage and suffered burns so severe that when he eventually was allowed back to school (after 22 odd skin grafts) he had to wear what looked like an elastoplast mask over what remained of his face, he had no functioning fingers and his nose, ears, eyelids and lips no longer existed.

I hope he did OK after school, always wondered about him.
dpack

ps

i have not only used high pressure and flammable/oxidising gasses, i was a nitration chemist for a year or so.

i would rather mess about with naps in a reaction i have not tried before than work with gasses Wink
onemanband

After reading this thread I shall cross "wood gasification" off my list of future projects Sad

*puts steam engine back onto list
Falstaff

Just make sure you don't even speak of it ! Mad dpack

a direct feed from the gas production to an engine with maybe a small res to balance the flow conducted outside ,up a mountain away from your house ,away from my house , should perhaps be a possible way to produce work from wood in a safe manner.

or

big engineering ,folk like shane to keep you clean and safe and compete with the frackers is the other option .

domestic production and compression seems a recipe for horror probably sooner rather than the other option.
Hairyloon

conducted outside ,up a mountain away from your house ,away from my house , should perhaps be a possible way to produce work from wood in a safe manner.
That is part of the need for compression: there is not many useful things I can do with gas up a mountain. If I can bottle it and bring it home, then there are a lot more possibilities.
dpack

maybe use the energy to charge batteries rather than filling gas bottles Question

or even making liquid wood distillates ,methanol or whatever as a fuel for storage
mark

I'm with dpack on this if you go this route it is better
- separate and store liquid fuel fractions - use the gas to immediately to generate electricity to store , or heat water, make steam , power machines etc ..

but really just make sure you educate yourself more on safety matters ..

the pioneers of energy production like most pioneers learnt the safety lessons the hard way ..no need to repeat the bad bits!
Shane

Mark's 4:55pm post from yesterday sums it up nicely. Don't do it. Compressed gases are dangerous enough as it is, even when they're not flammable.

The only way to store a decent amount of energy in a reasonable volume with gas is to liquefy it or compress it to very high pressure, neither of which should be attempted by amateurs, and certainly not anywhere near a residential area (Google "vapour cloud explosion").

With regards to leaks, if you're pressurising, gas will escape rather than oxygen entering the process. Unless you're investing in the latest fire & gas systems, you will not detect a leak until it's found an ignition source (which it will). Even a small leak will continue to accumulate on a cold, still day until you have significant inventory ready to ignite as soon as somebody drives past.
Falstaff

I think it's important to note that gas containers are usually kept outside, away from buildings and in a locked mesh enclosure, for obvious reasons.

Also, I see now that those boys on you tube were compressing to 10 bar for storage in LPG bottles.

Apart from any other risk, I'd be quite unhappy pressurising a plastic container up to 150 lbs/sq in.
Mistress Rose

Basically Hairyloon, I was saying, as the others have; Don't mess with gas. Hairyloon

Also, I see now that those boys on you tube were compressing to 10 bar for storage in LPG bottles.
Did you spot the chap filling an air bed?

Quote:
Apart from any other risk, I'd be quite unhappy pressurising a plastic container up to 150 lbs/sq in.

Again, I wasn't planning to go that high.
mark

I'd be unhappy pressuring plastic with anything flammable to anything above air pressure !

My beer barrels only work with beer cos they have a safety release valve which works by releasing the gas inside - not such a problem with CO2 or nitrogen but flammable gas!

It is dangerous enough experimenting with this stuff but can be justified I think if you have the knowledge and will spend the money and do it properly ..

But if you want to run it regularly as a domestic fuel supply you need to upgrade your standards massively ! I think it can be done but it will cost big time!
Hairyloon

I'd be unhappy pressuring plastic with anything flammable to anything above air pressure !
Oh, I don't know: look at fizzy pop bottles. Wink
But seriously, the plastic barrel was just a passing thought.
Quote:
It is dangerous enough experimenting with this stuff but can be justified I think if you have the knowledge and will spend the money and do it properly ..

But if you want to run it regularly as a domestic fuel supply you need to upgrade your standards massively ! I think it can be done but it will cost big time!

Thinking it through first, experimenting second.
Only then do we need worry about the domestic supply.
But on that score, why is a bottle of gas that I have filled significantly more dangerous than the one that Calor has filled?
Even if I filled it to the same pressure, I would be filling it with a much less energetic gas.
vegplot

why is a bottle of gas that I have filled significantly more dangerous than the one that Calor has filled?

They have..

Quality control
Expertise
Knowledge
Skill
Science
Engineering
Process management
Process control

to name but a few.
Nick

why is a bottle of gas that I have filled significantly more dangerous than the one that Calor has filled?

They have..

Quality control
Expertise
Knowledge
Skill
Science
Engineering
Process management
Process control

to name but a few.

Insurance.
A grip on reality.
tahir

A grip on reality.

Why would that be necessary?
Hairyloon

why is a bottle of gas that I have filled significantly more dangerous than the one that Calor has filled?

They have..

Quality control
Expertise
Knowledge
Skill
Science
Engineering
Process management
Process control

to name but a few.
Perhaps, but the bottom line is that the gas is either safely in the bottle, or it is not.
Hairyloon

A grip on reality.

Why would that be necessary?
Exactly so. I've never needed it before now.
vegplot

Camera. You need a web connected video camera. It's absolutely essential you do this before anything else is in place and publish its address.

Either we're going to watching something duller than dull or it's going to be briefly very entertaining.
Falstaff

Also, I see now that those boys on you tube were compressing to 10 bar for storage in LPG bottles.
Did you spot the chap filling an air bed?.

Certainly did ! He said he was using that as a receiver and pumping from there into Lpg canisters.

He was the one with the micro charcoal burner setup and catching the waste from that into that airbed.

Then showed it burning in a stove and running a VW Beetle car !

Really quite impressive - IF it was not a fake ! I suppose Scientific method would demand that the experiment be repeated to see if the results could be repeated. Seemed simple enough.



Apart from any other risk, I'd be quite unhappy pressurising a plastic container up to 150 lbs/sq in.

Again, I wasn't planning to go that high.

I never for one moment thought you were - you were perfectly clear that this setup was a brainstorm endeavour for consideration of a prototype.

I'm sure that the possible downside of plastic would have been realised and discussed calmly in the course of considering the design options.
Nick

why is a bottle of gas that I have filled significantly more dangerous than the one that Calor has filled?

They have..

Quality control
Expertise
Knowledge
Skill
Science
Engineering
Process management
Process control

to name but a few.
Perhaps, but the bottom line is that the gas is either safely in the bottle, or it is not.

The bottom line, maybe. But what about all the working out, of getting it there. That might be where the issue lies. I agree with VP. I think you should push ahead full steam, but set up a webcam first.
vegplot

Take your gas filled air bed with you...

mark

Its perfectly safe

Hairyloon

I'd read that that was caused by an engine fire and sustained by a general burning of the fusilage. The fact that it was topped by a huge bag of explosive gas made it very spectacular, but didn't really contribute so much to the casualties.

Slightly surprised that nobody'sa mentioned the joys of carbon monoxide yet...
mark

or the hairyloon specific risks...

Hairyloon

That, I like.
Who's the artist?
mark

I found it in a photoshop contest for fire animals on http://www.pxleyes.com/ Hairyloon

Perhaps, but the bottom line is that the gas is either safely in the bottle, or it is not.

The bottom line, maybe. But what about all the working out, of getting it there. That might be where the issue lies.
Certainly it is. My point there is that if you have a domestic setup* which is designed to take a bottle of gas, then (subject to your normal checks), you can assume that everything that side of the valve is working safely.
Quote:
I agree with VP. I think you should push ahead full steam...

Ooh no, steam is nasty dangerous stuff. Wink

{*OK, so I don't: I'm planning to burn it in some kind of lashed together CHP effort, but that's beside the point. Wink}
vegplot


{*OK, so I don't: I'm planning to burn it in some kind of lashed together CHP effort, but that's beside the point. Wink}

Will you need help selling tickets?

Wear protection. Coveralls treated with a salt, say potassium nitrate, has good preservative properties.
dpack

the gas industry had to start somewhere and via some mistakes("MISTAKES") have procedures and kit that minimizes the risks of repeating the HUGE BANGS

im not saying small scale gas should not be done but i am saying there is a lot of scope for tragedies or extreme embarrassment.

i recon i would personally go down the steam engine route for wood to motion but that also has a variety of risk factors ,rules n regs for good reasons etc etc .
Hairyloon

i recon i would personally go down the steam engine route for wood to motion but that also has a variety of risk factors ,rules n regs for good reasons etc etc .
Gasification to directly feed an infernal combustion engine is pretty well established and seems straightforward enough.
dpack

direct feed does seem fairly simple to do with no more risk than using petrol ,maybe less thinking about it . Hairyloon

direct feed does seem fairly simple to do with no more risk than using petrol ,maybe less thinking about it .
Bigger risk from carbon monoxide than with petrol. Less risk of fire and explosion... as long as the gasifier is secure.
Hairyloon

Take your gas filled air bed with you...


There is an obvious volumetric limitation to that, but are you persuaded by the safety considerations?

How about a really big airbed and a lot of hydrogen in the mix?
Tow it home with a robot piloted drone. Wink
Mutton

A general cylinder safety note from my years in a lab

1. Always store a cylinder of gas upright and chained in place - that way if the valve at the top goes, the cylinder tries to bury itself into the ground rather than whizzing around. Bear in mind a cylinder whizzing around one ground has a hell of a lot of mass and there are instances of them smashing through brick walls.

2. Never use a cylinder as a roller or anything other than a cylinder - valve damage and metal fatigue.

And not quite the same thing - but I am reminded of the taxi driver during the petrol crisis who filled a plastic dustbin with petrol.
http://news.bbc.co.uk/1/hi/uk/1220240.stm

Not all plastics are the same - different solvents dissolve different plastics.
Falstaff

How on earth do you run a motor on Woodgas - without carrying a tank of it ? Confused Mistress Rose

Those cars were run on either hydrogen or town gas. Hairyloon

How on earth do you run a motor on Woodgas - without carrying a tank of it ? Confused
You have a portable gasifier and make it on the hoof. It is nothing new: they did it during the war.
Shane

Bit like this, you mean?

dpack

proper "not quite mad max" kit

a charcoal fueled steam wagon would be another transport/haulage alternative.until to the axle weight laws changed in the 1930's they were quite common and with a modern materials etc the chassis , box and pistons could be light so they could be made quite sporty.

it is hard to beat petrol/nitromethane for power and silly speeds but a 60 mph plodder fueled with wood heated steam seems plausible

wood to gas to turbine to electric to batteries to leccy motor has a loss at every stage

wood to liquid fuel to internal combustion engine driving vehicle seems worth looking into.iirc there is a way to distill trees into a fuel that will run a cossack or a t34 or a 1940's russian lorry .

the chap cracking wood distillates on youtube seems to have started playing with such things

i recon home compressed gas is really too dangeroos to learn as you go
Hairyloon

proper "not quite mad max" kit
"As sane as the next Max" kit. Wink
Hairyloon

a charcoal fueled steam wagon would be another transport/haulage alternative.until to the axle weight laws changed in the 1930's they were quite common and with a modern materials etc the chassis , box and pistons could be light so they could be made quite sporty.
I'm told it was quite a close run thing that could've gone either way: if we'd put as much effort into developing external combustion engines as we've put into the infernal ones, then they'd probably have comparable performance... if they don't anyway: I've read some promising stuff on modern steam...
dpack

big oil = a few easy bought brown chaps and a few technicians

big coal= lots of local dirty pink chaps with unions

a few well placed peeps did the maths and we have the results (refs available )

the tech could go either way but is probably evens for joules per mile or whatever the common units should be Laughing
Shane

iirc there is a way to distill trees into a fuel that will run a cossack or a t34 or a 1940's russian lorry.
Yep - it's called the Fischer–Tropsch process. Invented in Germany and further developed by the Nazis during WWII to produce liquid fuels to run their war machine. It works by gasifying a feed stock, producing "syngas" and then converting that into liquid fuels. Same process is used all over the world today for various gas-to-liquids plants, with Shell and Sasol being two of the biggest players, each having their own proprietary technology.
dpack

ah ha ,with that type of strategy at least the fuel storage and transport is similar to petrol etc and all the risks of gasses are contained in the production facility

i sort of remember a strait distillation to a liquid fuel for brutally simple engines but i might be wrong
Hairyloon

You can "distill" methanol out of wood. That is another experiment that is on the agenda...
But methanol is not nice, and I don't think it's great as a fuel either: if the experiment is successful, I'll probably use it in biodiesel.
Falstaff

You can "distill" methanol out of wood. That is another experiment that is on the agenda...
.

Didn't we decide somewhere that you can't "distil" anything without a licence and a 400gallon still ?
Hairyloon

You can "distil" methanol out of wood. That is another experiment that is on the agenda...
.

Didn't we decide somewhere that you can't "distil" anything without a licence and a 400gallon still ?
We decided you cannot distil spirit, but you can distil methanol. HMRC use a different word for it, I forget what.
Plus I think it is not a true distillation (hence quote marks), but a pyrolytic decomposition.
dpack

i recon it might be that and birch trees im thinking of

if methanol would come off as a product along with (or before ?)birch tar (waterproofer ,medicine etc ) and leave charcoal for smoke free cooking that would be ideal for sticking two up to the einsatzgruppen in the forests of Byelorussia,

methanol is a reasonable fuel for robust internal combustion engines (fuel of choice for some speedway bikes )
Hairyloon

methanol is a reasonable fuel for robust internal combustion engines (fuel of choice for some speedway bikes )
Dreadful mpg, nowhere to fuel up and no easy way to dual-fuel, whereas I'm led to believe that gas will burn in almost any engine without much modification.
But now we are talking at cross purposes again: I think we'd established that for vehicular use, gasification on the hoof was the way to go...
Shane

One big downside with methanol, especially for the amateur producer, is that it burns with an almost invisible flame, so it can be very difficult to tell that it's on fire except by observing the effects (or getting caught in them). Mistress Rose

In theory it should be possible to obtain methanol, other alcohols low boiling point organic liquids, wood tar and charcoal. Would need very careful pyloric decomposition and collection of all the fractions at the right temperature though. Good for very small quantities, or industrial amounts, but difficult in the middle without more investment than it is worth. Hairyloon

I'm thinking to insulate a big steel drum and roast it as hard as possible: see what comes off.
I've also wondered about doing it at reduced pressure to lower the bp of the volatiles. That was one reason for asking about puming gas, although that one had slipped my mind.
Mistress Rose

Don't think you need to insulate the drum, and no need to reduce the pressure. Methanol has a low enough boiling point anyway; it is breaking down the wood enough to obtain the various chemicals that needs heat, and not sure how reduced pressure will affect that. Hairyloon

Don't think you need to insulate the drum, and no need to reduce the pressure. Methanol has a low enough boiling point anyway; it is breaking down the wood enough to obtain the various chemicals that needs heat, and not sure how reduced pressure will affect that.
I was thinking of the reduced pressure distillation for the methanol recovery from biodiesel, so I'm planning to set the kit up anyway, but it was a passing thought in respect of the pyrolysis.
I think you'll waste a lot of heat if you don't insulate: it is bad enough on a straightforward distillation.
Mistress Rose

You need to be able to control the temperature and we certainly don't have any trouble keeping the temperature up on the kiln. The main problem is to ensure it doesn't overheat anywhere. Hairyloon

What happens if you overheat it?
The difference is that you are trying to make charcoal, which you do by burning or boiling off everything else: it doesn't matter how much of the eelse that you burn to keep it hot enough.
Whereas I am trying to harvest the eelse, and I think I'll be needing to use an external heat source: every joule that escapes is a joule that I'll have to replace.
dpack

would a kiln drum inside a slightly bigger(insulated) drum that is heated in a rocket stove style by a combustion chamber with a choke valve to control the airflow and a chimney to drive the airflow be a place to start ?

if the "remains" in the pyrolosis drum is charcoal that could be at least part of the fuel for the next batch

ps another option might be a "hot tube" (or tubes)in a drum of woodchips again powered like a rocket stoveand insulated on the outside

i recon play about at the 25 to 50 ltr scale and see what works then refine method then try bigger ,too small will have too many heat losses etc

50 gall oil drum scale might be a better experimental size

clay is cheap and mixed with fibreglass makes fairly a good fire cement for filling gaps etc
Mistress Rose

If it gets too hot the metal of the kiln glows red and distorts; we are talking about those sorts of temperatures. Using a retort kiln, which is pretty well what Dpack is talking about, you can in theory take the gasses you are producing and cool them to use the various chemicals coming off. The only time we have ever had problems with getting the temperature high enough was when we were trying to make wood tar and we had a container that was about a foot or so cube. it just wasn't really large enough to hold the heat, and it wasn't made so we could increase the pressure as we should have done.

To break down wood by pyrolysis needs quite a high temperature, and even with no or very little air, you are still talking about things getting pretty hot once it get going. The initial burn is usually carried out using wood to get the whole thing up to temperature.
dpack

the "tubes"thing i tried to describe is a bit like a steam engine boiler but with woodchip where the water would be .

having thought about it the problem of removing the residue from between tubes might require a bit of experimentation and planning to work well.

another slightly different option would be to pipe the hot combustion gasses( balanced or slightly reducing flame)directly through the wood chip a bit like air into a forge fire in a box

i want to play now ,but i cant see it being popular in a city terrace yard
Hairyloon

the "tubes"thing i tried to describe is a bit like a steam engine boiler but with woodchip where the water would be .
Yes, I had had a similar idea.

Quote:
having thought about it the problem of removing the residue from between tubes might require a bit of experimentation and planning to work well.

The residue /should/ be charcoal. It shouldn't be too hard to tip out if the drum is not too big. Few big tubes rater than many small ones.

Quote:
another slightly different option would be to pipe the hot combustion gasses( balanced or slightly reducing flame)directly through the wood chip a bit like air into a forge fire in a box

Instinctively, I feel that would not work, but logically, I cannot think why not.

Quote:
i want to play now ,but i cant see it being popular in a city terrace yard

If you've got a condensor on the exhaust, then you shouldn't be producing much smoke... perhaps also bubble it through something? I was thinking biodiesel soap: see if anything reacts with anything.
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