Hey /sci/
I want to construct a biogas plant. If there are any chemical engineers here whom could help me it'd be great.
I'm looking to do something like this:
https://www.youtube.com/watch?v=9kKRdlAFuZw
How save would something like this be ?
Can I just throw humps of of shit and other organic waste materials inside of it? Will it produce clean burning methane ? Or will other harmful gasses be created ?
Also, can I use the slurry for fertilization of my organic garden ?
Thanks
Do you own a farm or have a way of generating some considerable amount of manure to fermentate? If you don't it won't be profitable and you'd better buy some gas.
The composition of biogas is more or less 35% CO2 and 65% methane but small amounts of H2S are also generated. The CO2 is anoying because it will cause the biogas to burn much less the pure methane. But the H2S is really toxic and when you burn it it also generates toxic fumes. But the amount of toxic fume shouldnt be a lot.
The slurry can be used for fertilization perfectly and will work as good as the manure but i don¡'t think it's worth the work.
>>7749186
I've done this before, but I'm a high school drop out and glorious retired NEET. Thankfully, this is very seat-of-your-pants type stuff, so long as you have general safety knowledge about exploding gases and hydrogen sulfide.
You can make a biogas plant on any scale, fyi. That is the best thing about them. Mine were all in the 5 to 10 gallon range. I did all of them on that scale because it is far easier to design and much cheaper to make. These things are exceedingly simple. Once you have small scale ones completed you can move onto whatever size you want that you can afford.
All of this is from memory, but no you don't just toss in stuff and hope for the best. There's a general mixture of solids and cellulose-based materials you need to use along with manure/feces. Getting it started is slow if you don't have a batch to get the microbes from to inoculate it with. But, once it is up and running after about 6 months everything will be pretty smooth going. The percentages of animal and plant wastes are often times a bit of a recipe.
I highly suggest you frequent online forums dedicated to this DIY tech.
>>7749457
Continued, my text from an old /diy/ thread some time ago,
>Will it produce clean burning methane ? Or will other harmful gasses be created ?
Biogas may be improved by filtering it through limewater (Calcium hydroxide) to remove carbon dioxide, iron filings or iron powder to absorb corrosive hydrogen sulfide and calcium chloride to extract water vapor, in that order.
Make Limewater by mixing 1tsp of lime with 1 gallon of water. Shake for two minutes, let sit for 24 hours, filter until clear through coffee filters.
Calcium chloride is used for melting ice like in, "Qik Joe's Ice Melt". Scrubbing the biogas helps prevent corrosion of your equipment. There are many methods you can use to scrub it that I didn't list, so do some research.
After you have it cleaner (if you decide to clean the gas, which you don't technically need to do), you simply run it through a compressor that can compress flammable gasses. The amount of pressure you want in the tanks will determine the expense of both the tanks and the compressor. The higher the PSI the more cost they will be. Storage in this manner is common, but on a DIY scale it can be expensive in the short run, but pay for itself in the long run. For instance, you can use the biogas as the fuel to power the compressor's engine. You can use it to help maintain the temperature for the biogas generator tanks and use it for creating electricity.
If india constructed biogas tanks, they could become completely energy independent.
>>7749458
Continued...
>Also, can I use the slurry for fertilization of my organic garden ?
Yes, however, I highly recommend you pasteurize the fertilizer before using it directly on any plants. You can avoid the need for pasteurizing it if you are putting it on a field that won't be planted over winter (2-3 months fallow). Both will destroy harmful pathogens that can make your plants sick and make you sick.
Now, one EXTREMELY IMPORTANT thing about the biogas methane. The Hydragen sulfide is ETREMELY DEADLY. Do not fuck around with it. Do not sniff it, do not allow fumes to build up in any enclosed location. NEVER EVER EVER enter a large biogas methane digestor while it is still active and has not been 100% ventilated.
1 single sniff of high concentrations can knock you and and kill you. Lower concentrations will make you pass out after a couple breaths then you die. At lower concentrations would lose the ability to smell. If that last one ever happens, you need to get the fuck out of where ever you are and get fresh air.
Oh, and of course there's explosion prevention. Always maintain proper handling procedures for that. Same as with home natural gas.
>>7749462
They already do. They are the leading nation in "GOBAR gas" proliferation, just not very high tech like the Germans are.
>>7749465
>>7749462
Thats pretty cool
>>7749468
Biogas will make India the 21st century superpower.
The government could pay people to deliver their shit to biogas plants for some cash, it'd really clean up their streets and their country.
>>7749460
With that amount of livestock, yard waste biomass, kitchen scraps, and your own black water you should be able to easily supply yourself with all the gas you need. Of course this depends on what you are using it for.
People use biogas methane for cooking, heating water/home, and fuel for generators and vehicles. Keep in mind that some people use it raw and some people actually scrub it as described in my post here >>7749458 Using it raw means it will burn a little less efficient and there will be a bit more wear and tear on your gear.
It is still quite amazing how much usable gas you get from what seems to be so little input. There are a few online calculators for this too.
http://www.biowattsonline.com/
>>7749474
Thanks I will read more into it and start collecting the stuff I need. This sci post was just as an introduction. I'll definitely remember the hydrogensulfide thing and learn more about the best ways to get rid of it. I also need to check with my local government if this shit is even allowed, but I think it is.
>>7749487
>I also need to check with my local government if this shit is even allowed, but I think it is.
I found that often times they have never even heard of it nor have regulations for it. What you need to do is look at regulations for the use and storage of Natural Gas. Those things should be what would apply to you. If you need to talk to someone face to face about it, you should probably have all the related research materials with you to show them. Especially, peer reviewed papers and diagrams/photos of working same-scale plants you want to make. Just remember, authorities in charge will simply say "no" to anything they do not already know about as course of protecting themselves. The better informed they are the more likely you'd be allowed to get a permit or related thing for larger scale production larger than a 55-gallon drum.
Since you seem like you are in a somewhat rural area you probably wont' have trouble, but in a city it may fall under zoning laws and nothing you can do would be allowed. If the answer is "no" and you are serious about this, then start lobbying for it via education of local officials and citizens.
Also, as an added precaution, you can also add flashback arrestors inline with your equipment and/or burners. Like those used for flammable welding/cutting gases. While you shouldn't even need these, it will add peace-of-mind.
I love threads like these, but they are really best suited for >>>/diy/
>>7749469
its a retarded meme you poltard
https://en.wikipedia.org/wiki/Biogas
>In the 1985 Australian film Mad Max Beyond Thunderdome the post-apocalyptic settlement Barter town is powered by a central biogas system based upon a piggery. As well as providing electricity, methane is used to power Barter's vehicles.
>"Cow Town", written in the early 1940s, discuss the travails of a city vastly built on cow manure and the hardships brought upon by the resulting methane biogas. Carter McCormick, an engineer from a town outside the city, is sent in to figure out a way to utilize this gas to help power, rather than suffocate, the city.
>>7750193
> In fact, one cow can produce enough manure in one day to generate 3 kilowatt hours of electricity
That's like 1/5 to 1/3 of my electric bill usage per day. Waste from 5 cows would be the max I'd need.
>>7750203
What about the solids themselves, can't they be further processed and sanitized to become fuel briquets?
https://en.wikipedia.org/wiki/Dry_animal_dung_fuel
It might produce even more energy than the gas for all you know. There must be stats somewhere.
>>7750212
No, the leftovers are used as high nitrogen fertilizer.
you could also use the produced heat to warm water in an isolatet container with many tube windingsshould rech 50° after a few weeks
source /DIY/ or /out/
>>7751324
>poopy vegetable water
>>7751324
No you can't do it that way. You must actually heat the biomass in order for it to create biogas efficiently. Normally, you heat it with something else then when the biogas is generating you switch to gas heat to maintain its temps.
The thing you are thinking of is aerobic digestors which involves oxygen and produce lots of heat. Which can be used exactly as you are talking about.
The biogas methane generators are anaerobic digestors which only work properly in the absence of oxygen and do not produce heat like the other does.
>india is drowning in cows
>it tuns out their shit is an amazing source of fuel
It's like poetry. Poo will be your savior, india
aThere's evidently a huge amount of methane gas being wasted by sheep and possibly also cows. I wonder if there's a way to siphon off this methane when the animals are at least in a building?
http://www.sciencedirect.com/science/article/pii/S1658077X13000131
http://news.nationalgeographic.com/news/2002/05/0509_020509_belch.html
>Enteric fermentation is methane produced as part of the normal digestive process of animals, such as cows and sheep. It is primarily released in the form of burps.
>The 45 million sheep and 10 million cattle in New Zealand make for a lot of burped methane—about 90 percent of that country's methane emissions, according to government figures.
