Can Common Gas Stoves Work from Methane?

Natural Gas is mostly methane. Problem is what gases that you get from the decomposition of waste may not be just methane and some may be a hazard with an open flame like a kitchen stove. These gases need to be separated.

I thought there was a best case, gases separated, and then a good enough case, use what you get. I guess now what I am looking for is a standardized gas separator, that would go inline from the gas generator to the farmhouse line. > Forgive me if I ought to have put this in Commercial Space.

Hi Trans

don't know much about it but need more information, as you do. In China they use anything that can be collected and they are doing just fine. Lets split some hairs and get down to what is feasable, Ky.

there is no seperator available, it takes loads of heat and mass transfer equipment. The problem is pressure. the gases from waste must be pressureized in order to flow to the stove and pass through the cotrol system. Not much pressure, but some.

The digester will need to be a sealed unit so the gases can build up pressure. If air gets mixed in, then you have a sealed up digester that is a bomb. SO, you must purge out the air.

In China, they don't care about controlling the flames and small explosion now and then is the norm. In the US, a small explosion and uncontrolled flame sends in the lawyers. A burnt pinky is worth $100,000, I'm not going to risk designing your system with a $100,000 penalty tag, nor should you risk it.

Go to a professional that will get a safe design, the cost of which makes the net gas produced cost more than plain ol natural gas.

Isn't it a case of changing the diameter of the nozzles depending on the gas used: methane, propane, butane? The size of the flames will change according to the nozzle/gas arrangement.

Biogas from anaerobically digested waste (human or animal) is about 65 to 70 percent methane and the difference (30 to 35 percent) is carbon dioxide. There is also some moisture in the gas as water vapor. There are trace amounts of hydrogen sulfide and other gasses. The small fraction of hydrogen sulfide in the gas maybe good since it will enable you to smell the gas in the event of a gas leak. Most gas companies add an odorous sulfide based compound to be able to smell the gas since methane is odorless. Biogas is often used in boilers without any type of cleaning other than the removal of condensate water in so called "drip pots or drip traps". Since the fraction of methane is less with biogas than pipe-line gas one has to use more gas to generate the same heat value. In boilers the nozzle is ussualy larger than the nozzle used for natural gas. In some systems the lines are blended to maintain the same btu value without having to change nozzels.

OK, this might be a dumb question, but if methane is odorless, well, what is the smell we always attribute to methane (i.e. when driving past a dump)? Is that also what you speak of, where the methane itself is odorless, but the other factors from decomposition create the smell?

Read the mail to which you replied.

we add ethyl mercaptane to make natural gas have an odor.

methane is odorless. that is a result of anerobic digestion. at the dumps you are smelling ammonia from the aerobic digestion.

Hey trans,

here's a link for you. The guy converted one burner of his propane stove. If the jet is for natual gas it looked like he was just interested in air flow control for a good flame.

http://www.youtube.com/watch?v=W2SMQGUuY3g&feature=related

I'm making a digester my self, but I'm using round 500 gallon concrete septic tanks. Was looking at chicken waste since chiken house businesses are abundant here where I live in South East Texas. Would like cow and horse waste, want to come up with a good collector system other than a shovel, lol. Lazy I guess, just love something you use with a tractor.

I've collected some solar panels and wind generator. This time I'm using my methane for my boiler to run my homemade steam engine that runs permanent magnet alternators to charge my batteries, catch you later.

Jerry

I was of the belief that a flammable gas will burn when the air to fuel mixture is correct. Knowing that there were probably about 100 different jet sizes for Holley carburetors, could you adapt a fixed air flow, and change jet sizes until you achieve a ratio that would burn. Once a base is established, you should be able to vary the flame output by moving the air and fuel flow at the same rate.

WARNING. Do your test work outside, with an established flame burning to prevent the build up of flammable gasses.

If you want to try this, let me know.

if it is a natural gas stove, yes it can. the line pressure from a properly working methane digester is just about right for a stove. without storage and compression, though, the heat generated will probably be less. a good digester works at 1 PSI. a natural gas stove works at between 7 to 11 inches of water pressure. 1 PSI = 2.306 feet of water at 32 degrees F. that means that you need to reduce the pressure from a normally working digester down to about one quarter to one third of a PSI