Renewable Energy Concept - Stirling Engine Composting

AI Thread Summary
The discussion centers on using heat generated from anaerobic composting to power a Stirling Engine, leveraging the high temperatures (120-160 degrees) found in the center of compost heaps. A gamma configuration with compressed helium as the working gas is proposed to enhance efficiency, alongside the necessity of a regenerator. Participants suggest measuring power output by pushing copper pipes through the compost to assess temperature changes in water flow. There is also mention of the potential for using the generated heat directly for heating purposes, as well as the methane produced during composting, which is already utilized in industrial applications. The thread emphasizes the need for calculations related to gas dynamics and torque to optimize the design.
Waggles
Messages
2
Reaction score
0
So I've got this crazy idea. To put it simply, to use the heat from anaerobic composting to power hot-air engine, specifically a Stirling Engine.

Based solely on my own reading, the center of a closed composting heap can reach anywhere from 120-160 degrees without killing the microorganisms required to produce methane. By water cooling the cold side of an engine, a temperature differential of >100F.

I imagine a gamma configuration with opposed/linear cylinders: hot cylinder down, cold cylinder up out of the heap. Compressed helium as the working gas will increase efficiency. And a properly built Stirling Engine requires a regenerator to further increase efficiency.

I'm the guy with the ideas, but I don't know how to do the complex gas equations, cylinder computations, electrical computations and etc. required to calculate the dimensions. As well as the necessary torque to run, say, an alternator.

Trying to upload concept sketches.
Any help would be much appreciated!
 

Attachments

  • 1495964304293790199471.jpg
    1495964304293790199471.jpg
    33.5 KB · Views: 790
  • 14959643371551813675428.jpg
    14959643371551813675428.jpg
    28.9 KB · Views: 716
Engineering news on Phys.org
Try working out how much power you can extract from a compost heap first. The simplest way would be to push some copper pipe through it and run some water through. You would need to know the flow rate and the temperature of the water going in and out. Leave it going for a few days to check you are measuring the long term rate.

Power = SHC * flow rate * (Tout - Tin)
where SHC is the specific heat capacity of water.

It might be better to use the hot water directly to heat your house/shower. Perhaps see..
https://www.hindawi.com/journals/ijce/2010/627930/
 
According to Google, compost generates heat at about 275 watts per cubic meter.

The other thing it generates is methane, which is already done on an industrial scale in landfills and sewage treatment plants. Usually, they just use the reactor heat to keep the waste warm for the microbes to do their jobs. If you cool it, you will at least need to insulate it to keep it warm.
 
Last edited:
Thanks for the replies, y'all. I'll extrapolate and ask a few more things when I can. Thanks again.
 
Thread 'Turbocharging carbureted petrol 2 stroke engines'
Hi everyone, online I ve seen some images about 2 stroke carbureted turbo (motorcycle derivation engine). Now.. In the past in this forum some members spoke about turbocharging 2 stroke but not in sufficient detail. The intake and the exhaust are open at the same time and there are no valves like a 4 stroke. But if you search online you can find carbureted 2stroke turbo sled or the Am6 turbo. The question is: Is really possible turbocharge a 2 stroke carburated(NOT EFI)petrol engine and...
I need some assistance with calculating hp requirements for moving a load. - The 4000lb load is resting on ball bearing rails so friction is effectively zero and will be covered by my added power contingencies. Load: 4000lbs Distance to travel: 10 meters. Time to Travel: 7.5 seconds Need to accelerate the load from a stop to a nominal speed then decelerate coming to a stop. My power delivery method will be a gearmotor driving a gear rack. - I suspect the pinion gear to be about 3-4in in...
Back
Top