How to compress & bottle BIO-Gas in cooking cylinders on a large scale ,i.e.min.1000 cylinders per day?

Question

Please give references of the experts and no silly answers as this is a sereous problem.

Answer 1

Any gas, bio gas or natural gas, is easily compressed, liquefied and placed in containers.  This technology has been around for decades.  Your problem is producing significant amounts in order to fill your 1000 cylinders a day.

Answer 2

That is the problem with all these alternative energy ideas. They work OK on a small scale but cannot be made to work on a large enough scale to compete with oil and natural gas.

Answer 3

I personally don't think it is economical - but I will give you the answer anyway as you asked.

Bio gas is approximately 60% methane and 40% co2 and traces of H2S (I guess you already know that). First, you might want to get rid of H2S as it will be corrosive - running the gas through iron shavings should do the trick.

second, you might want to get rid of the CO2 (it is going to take a lot of space - unless the pressure you ship the gas is much more than 50 atm, obviously depends on the temperature) - easy way will be to run it through lime solution but it is going to take energy to recycle lime (or you can compress the bio gas to a high enough pressure and low enough temperature and at the point when CO2 liquifies, try to get rid of it).

finally comes to the cylinders part. propane cylinders contain a lot of cooking gas the stuff inside is liquid. methane is pretty stubborn like hydrogen - you just can't compress it hard enough to liquify it unless the temperature is pretty low and stuff (just look at this page for methane properties: http://encyclopedia.airliquide.com/encyc...

So, well, you can just use any good piston based compressor, decide the pressure limits on the gas cylinders (propane tanks should be around 8-10 atm, safe limit as propane is supposed to liquify at this pressure, i think - you can find this from airliquide site also) - and supply cylinders filled with methane at this pressure. now, a 14 kg cylinder I use in india is probably around 25 liters inner volume and if you give me compressed methane of 250 liters, it is barely equalent to 0.2 liters of propane for me.

anyway... good luck - if you still want to pursue this path. feel free to ask me any questions as i have thought a lot about bio gas a few years ago and researched quite a bit.

[edit]

sorry, i was pretty pessimistic :-). research about CNG equipment - whatever works with CNG will work for biogas. just remember CNG tanks will operate at a much higher pressure than propane tanks. but if you go down this route, you can piggy back on whetever CNG has market (in india, you have autorickshaws running with CNG). but i still don't see much household use for CNG.

[Edit]

Other suggestion I have is to talk to the local utility company that supplies natural gas and see whether you can pipe your bio gas (purified of CO2 and H2S of course) to them - they can just use their existing natural gas distribution network. Then it would be just a matter of figuring out how to get gas into their infrastructure (will theoretically work if you have an incoming natural gas pipeline to your place as you can just use it to send it out also).