[Music]
Hi everyone, welcome back to Cody's Lab
So today I'm going to be building a methane digestor
I'm going to be starting with this here, which I built for
one semester of college a few years ago
to digest food waste
and it was working
as you can see, it's a little digestor thing here
But somebody eventually ended up stuffing it with leaves and shut it right down, so
Yeah, I ended up getting it
And there it is
And I'm going to be improving the design
See, I was heating it
with some wire
this is a nichrome wire
I just wrapped some nichrome wire around it like that
And
I actually was running 120V AC through there, so
Yeah, that's obviously going to need to be fixed
And also
As you can tell
It is now very cold
It's the middle of winter
Of course it's always the middle of winter when I decide I want to work on something like this
So I'm going to have to insulate it rather well
and possibly even put it inside the garage, so
That's the plan
So I have set it up over here in the corner of the garage by this door
It'll hold the door shut, but
the idea is that I'll move it outside of this door during summer when it's warm enough
But, since it's winter, we'll have to heat it
I'm thinking this is what I'll use to heat it, this is an aquarium heater
it has a thermostat in it
I'll turn it up to 94° F
Now, I thought about just sticking it in there, then making a seal, and just adding it inside the barrel, but
I've decided that that's a little too simple
It's not going to work all that well, because the heat transfer would be terrible
So I've decided to produce this contraption over here
and then it'll be inside of this
The idea is that this will be filled with water
the water will be warm
and it'll want to rise
it'll come up here through this tube
and go down, through this, through this coil here
and then
all this other coil here, just to dissipate heat, put it in different places inside the barrel
That way I can transfer the heat around much more efficiently
Yeah, this pipe will be down inside of there
and this part will be open to the air
and I'll be able to just pull this out
whenever I need to
And, I don't know if you've noticed this
But there's a little disk here
which is movable
Now the idea with this
is that I can take a magnet, stick it in here
and I can move this back and forth
and agitate the slurry
As you can see
And that's
It might work
but that's the idea
So this is the fill tube
This is where I'm going to be putting the material into the chamber
Just a bit down in there
All the way in the bottom
There we go, so I'm going to put material down into this hole here
It has to come up high like this, so I can generate a little bit of pressure
This way the fluid
has to get pushed up a large distance
Before the thing blows
stuff all over the place
The heater is going to go in
just like this
And this is going to come in right there
I'm going to stick this one down there
and match those up
I'm going to fill this up with some cold water
and test for leaks
So this didn't work at all; it leaked like crazy, and the hot water wouldn't flow through it
so I've decided to cut that all out and replace it with something a little simpler
I put some dye into the water to make sure the thermal siphon was working
It seems that it was, but unfortunately as the tubing heated up it twisted and kinked itself off
So I've fixed my kinked hose problem
and what I did was I actually cut the pipe off
and I wound the hose around it
You know, out here where I could actually work with it and then I just stuck the whole thing down in there
and put a coupler, and fixed it back up
Yeah, I think it's working now
I got my little infrared thermometer here
So the room temperature is about 40°F
and the side of the barrel is somewhat warmer
a few degrees there
This is
around 90°
which is what you'd expect, because the heater's on
The pipe down in there
Is definitely warm
but this is what I definitely want to know is
Is this warm over here
And it is, so it's working
Excellent
The temperature inside the barrel is
It's still kind of cold because there's ice down at the bottom
Yeah, I probably ought to get that out of there
although the dye probably won't hurt the bacteria at all
But I still need to get it out of there so I can get this pipe to go all the way down
But yeah
I just got to seal these pieces here
I'll use some acrylic or something to seal those up
And then
probably as early as tomorrow morning
I'll be able to fill this up with material
Which is good, because I've got plenty of rabbit poop
Alright, so it's the next day
It looks like my glue has cured and locked the pipes into place
Excellent
Now I've decided to leave the dye inside the tank
Mostly because it's a food-grade dye and it's probably not going to hurt the bacteria
But also I forgot to leave the heater on last night
and it never melted, so
It's still stuck to the bottom of the pot
The bacteria is very sensitive, but it's not like that's antibacterial soap or anything
My first methane generator
I was using a five gallon bucket and I had it full of horse and cow manure
and it was working, it was making gas
and I was bubbling the gas through a dish of soapy water
so I could collect the bubbles, and I'd light them on fire and it would burn the gas because it would float upwards
And I was showing it to my mom, and I was pushing down on the bucket to get the gas to come out
because I'd already been playing with it
When I released the bucket
it sucked the soapy water back into the chamber
And
As you can imagine antibacterial soap doesn't play well with bacteria so it just outright killed it
So, definitely keep anything like that out of here, but
I think the dye will be fine
So there's the rabbit droppings that I'm planning to put inside of the chamber
These guys over here, my partridges, they're making a lot of noise
You might have been able to hear them in a couple of my recent videos
Their droppings can also be used for this
but it's a little bit high in nitrogen, and
It might be best to mix in with some other organic material to get it to compost better.
But just to start, I'm going to use the rabbit droppings
Because it's almost got the perfect mixture
So I've got a five gallon homer bucket here
This will be just my measuring device
I'm going to take some scoops of rabbit droppings
Just like this
Now, this is mixed in with some of their bedding
some wood pellets, that's actually going to help, it going to add carbon
and I think it's actually got the carbon to nitrogen ratio perfect at this point
So, I'm only going to add in
until the bucket's about a third the way full
Maybe a little bit more
Just like this
Now I'm going to fill the rest up with water
I want to get my solids down to only about 30%
any higher and I'll just end up with a huge amount of foaming
and it could cause the chamber to explode if it plugs up the gas relief
So
It might need a little bit more water
but you guys get the idea
Let's get this mixed up into a slurry
This also makes it easier to move around
And yeah, here we go
Let's get this dissolved up
So I'm just using tap water for this
or, I guess in this case "tub" water
Ideally I'd need rainwater, because it doesn't contain chlorine, but
all my rainwater sources are currently frozen, so I'm going to have to use this
but in order to make it so it doesn't kill out the bacteria
I'm going to add some of this dechlorinating mixture that's used for fish
I find it works really well for getting rid of chlorine
it doesn't hurt the bacteria
so, a cap of that in there
Just fill it up with tub water
Also this way I can add it warm
So it doesn't take so long to heat up the chamber
Okay, so here's the first load of rabbit droppings
I'm just going to load this in through the service hole
because it's going to be faster this way
I probably mentioned this before, but this material I'm adding has the perfect carbon to nitrogen ratio
So
it's going to be perfect for growing the bacteria
but also it contains some of the bacteria that I need
Cow manure would contain more
but rabbit droppings does actually contain it
Human waste or just plain food scraps are not going to contain
are not going to contain as much of the bacteria, if it contains it at all
Most humans don't actually produce the correct bacteria to produce methane
So
Fortunately I've got a little spill pad here, so I can just clean this up when I'm done
Yeah
Everything's looking good; I'm going to continue loading this
So there's all the rabbit droppings in place
Now it's not quite all the way full, I've left a little bit of room so that I can add more stuff if I need to
And also
If this decides to foam up it's got some room before it tops out
You can see here that the stir thing does work
Excellent
Let's pull that out of there
So now I'm going to put this cover plate on there
As you can see it's clear so that I can actually see through it and see what's going on inside of there
The actual digestor is complete
You can see I've got a tube coming up here
I'm going to run it through water and then that way I can bubble the gasses and keep it sealed
There's definitely no soap in here
This is not the prettiest, but it'll work
As you can see I've got the chamber sitting on some stacks of carpeting
And I'm wrapping it in some R-19 insulation, so
I'm going to get this well insulated so that that the heater doesn't have to run so much
The aquarium heater itself has a thermostat that shuts off at 93° F
which is actually a little cold; I'd rather it shut off at about 100°
But it should work. As long as this chamber is above 80° it should make methane
If it isn't able to stay warm enough, you can see that I have another thermostat here
So I can plug in another heater if I need to
and I'll use this thermostat to regulate the temperature of the actual barrel
Alright, I'm going to finish the insulation
So from now on I'm going to add material up to this funnel right here
As you can see, you pour water in and it displaces air
That's kinda cool, that means its sealed properly
Once the digestion process is underway and I've got a robust bacteria population
Then what I can do is add maybe a pint or so of material every day
and
Take the material out over here
And just have sort of a continuous feed system going on
but it's going to be a while before that's up and running
Well there it is. It's finished
At least to the point where all I've got to do now is wait
It could take up to a week or more just to
have the bacteria consume the oxygen that's inside the chamber
So it'll be at least that long before this becomes an anaerobic environment
So I think what I'm going to do is I'm actually going to cut the video
Make this a two parter
I'm going to make you guys come back in a month or so, when this is producing gas
So if you guys are watching in the year 12,018
You should just be able to click a link right here and it'll take you to the second video
where this thing's actually making gas
In fact, by then there should be probably several more videos on the subject
Unlucky enough to be watching this at the time that I'm publishing this video, then you're gonna have to wait, so
it might be a good idea to subscribe to me and
when the second video comes out in a month or so, you can watch it then
So, until then, I'll see you next time