Methane gases produced and used on the farm
Yes, there has been quite a bit of research done on harvesting methane from manure and food-processing waste. There is one dairy farm in Barry County that has an anaerobic digester (AD) already installed and operational. They collect methane and can either combust it in an engine to generate electricity, or they can scrub it (remove excess moisture and hydrogen sulfide) and pipe it into natural gas pipelines.
Right now, an AD is cost-effective only on larger farms that can afford to invest a few million dollars into them. There is research going on now to figure out a way to scale down this technology in a way that will still be economical to install and operate.
Depending on your questions, I might not be the right person to ask, but I can certainly put you in touch with someone who can answer your questions. I would suggest you give me a call or drop me an email. My phone number is 269-838-8265. My email is firstname.lastname@example.org.