AC on Methan from biodigester

Hi.
I have built a bio digester that is highly efficient, and i have excess gas, especially in summer.
So im looking for a way of utilizing the excess in cooling my house.
Does anybody knows about an "off the shelf" product or a way of converting a common appliance to an biogas powered one?
Cheers.

If you had a propane a/c you possibly could convert that to use biogas instead of propane.  

There is no way that I know of to convert an electric appliance to use gas.

It would be fun to know if any of our members could explain how to convert an electric appliance though to me there is just no way.

I would suggest looking at what "common appliances" you own to try that.

The YouTubes where some people try to show how it works use a appliance that used some sort of gas originally.

Anne Miller wrote:If you had a propane a/c you possibly could convert that to use biogas instead of propane.  

There is no way that I know of to convert an electric appliance to use gas.

It would be fun to know if any of our members could explain how to convert an electric appliance though to me there is just no way.

I would suggest looking at what "common appliances" you own to try that.

The YouTubes where some people try to show how it works use a appliance that used some sort of gas originally.

I have looked everywhere and so far didnt find any gas powered AC. If anyone here familiar with something like that i would be very happy

Natural gas (methane) wouldn't be suitable as the working fluid (refrigerant) in a cooling system, since it doesn't phase change from gas to liquid at suitable temperatures/pressures. (Propane can be used as a refrigerant, and that creates some confusion when searching for information.)

Propane is commonly used as the heat source for RV refrigeration. There are also propane powered RV air conditioners, though they seem pricey. There's no reason why methane couldn't provide the heat source.

I suggest you use different search engines (e.g. duckduckgo.com) and search for "propane air conditioner" and "natural gas air conditioner".  

Anne Miller wrote:If you had a propane a/c you possibly could convert that to use biogas instead of propane.  

There is no way that I know of to convert an electric appliance to use gas.

It would be fun to know if any of our members could explain how to convert an electric appliance though to me there is just no way.

I would suggest looking at what "common appliances" you own to try that.

The YouTubes where some people try to show how it works use a appliance that used some sort of gas originally.

Very old refrigerators used natural gas. The system was based on ammonia evaporation. Natural gas was used to power the cycle.
The process is outlined clearly on the following web site.

https://www.energy-concepts.com/_pages/absorption_process.htm#:~:text=The%20basic%20operation%20of%20an,vapor%20to%20desorb%20the%20solution.

If you can't find one, they aren't too hard to build if you can braze copper pipe and have a vacuum pump and some clean ammonia.

Edit: Readers may be surprised to learn that one of the first patents of this technology was awarded to Albert Einstein.

Douglas Alpenstock wrote:Natural gas (methane) wouldn't be suitable as the working fluid (refrigerant) in a cooling system, since it doesn't phase change from gas to liquid at suitable temperatures/pressures. (Propane can be used as a refrigerant, and that creates some confusion when searching for information.)

Propane is commonly used as the heat source for RV refrigeration. There are also propane powered RV air conditioners, though they seem pricey. There's no reason why methane couldn't provide the heat source.  

To help others understand how refrigeration works, I ask my dear hubby how a propane fridge works. He says the propane is used to heat ammonia just like the electricity is used to heat ammonia.

Propane refrigerators are fairly common as the Amish have used them for many years as has the recreational vehicle industry.

I doubt that the Amish use air conditioning, though I don't know.

I know it is an easy fix to change a natural gas cooking stove over to propane, though the manufacturer may have made the cooking stove interchangeable, I don't know.

I bought an old RV to part out as a way to get a propane fridge and generator for research. I later bought a Servel brand propane fridge. Then... life got in the way.

Years ago, a chemist in the biomass industry told me that biogas was only about 50% methane. Lots of Nitrogen mixed in there as well. So, converting from propane to biogas may e tougher than first glance.

My propane fridge was used in a hunting camp (no electricity). Very efficient as far as gas consumption but not good to recover if the door is opened for very long. In other words, it takes a long time to chill the fridge.

Todd Turner wrote:Years ago, a chemist in the biomass industry told me that biogas was only about 50% methane. Lots of Nitrogen mixed in there as well. So, converting from propane to biogas may e tougher than first glance.

Yes, that is very true. It's a low grade fuel. I suppose that could be compensated for with higher flow.

Aside: Landfill gas is also low grade fuel. When I was doing work in the electrical generation industry, they piped in gas from a nearby landfill to a natural gas power plant. People thought it was great, using landfill gas to generate electricity. Talking to the engineers, it turns out the landfill gas was so low grade, with moisture and impurities, that they were incinerating it using natural gas to prevent methane release to atmosphere. It was only years later that they installed specially designed engines to handle the landfill gas and actually generate power.