Waste To Energy

You could convert your MW to thermal equivalent, compensate for losses in generation, then divide by the energy density of the bio gas and multiply by weight of waste required to generate the necessary energy. Simple as pie!

That all depends on what kind of waste,plus a host of parameters starting with temperature, composition of the waste, plus what kind of bacteria you are using to digest the waste. Even something as simple as a controlled waste product like manure will vary depending on exactly what food the animals ate, season etc.

Biogas has a varying composition ratio. It is not as simple as saying so many pounds of a specific specie of wood will give you so many BTU of heat, If it was that easy everybody would be doing it.

Look up a company called Energy Flex Technology (EFT) they specialize in power production of what I think you are looking for. Or at least the amount of BDW for 1MW.

Good suggestion, and a very informative website. The company is now called FlexEnergy.

http://www.flexenergy.com/

Good luck with the project!

I think you should be considering the amount of waste input needed to generate one megawatt hour (MWh) not one megawatt (MW).

Suggest you refine your specifications to make a search practical. What waste material? How will the waste be sorted / graded and handled. Moisture content of the waste is critical to the digestion process. Land fill sites generally strive to control development of biogas because it could pose an explosion or fire risk however some land fill sites make use of this gas so they will handle the waste differently to promote the development of desirable biogas. In some places where the biogas is a desirable product, the waste is actually pre treated or sorted in order to optimize biogas production and minimize non essential solids. This is not to discourage you but to point out how you must define your parameters in order to get the desired product.

Once you get a usable biogas product you need to decide how you convert this into usable electric power. The most common method is using the biogas as a fuel in some kind of engine. Internal combustion engines will be mostly piston or turbine and Stirling engines are also good candidates for small scale external combustion.

You could also look at CHP plants where big boilers are used for steam generation to drive steam turbines. The waste heat can then be used for process or building heat.

5 -10 mW power plants are popular with isolated paper mills because the waste heat is usable for building heat as well as a production heat use. Drying the paper etc.

Every country has dozens of companies with decades of experience in this field.

Even in new, almost experimental technologies such as direct waste to energy production, there are companies setting up to exploit this. They are usually based on exploiting known industrial processes but perhaps not yet combined as a continuous process to deliver electrical power. Europe seems to be furthest along the development curve for this kind of business.

If you are thinking more along the line of DIY small scale for villages or homes try looking up John Fry or Jean Paine for ideas. Both developed and published information on a how to do it basis. Be prepared to spend money.

Some links you might find useful:

http://journeytoforever.org/biofuel_library.html

http://journeytoforever.org/biofuel_library/MethaneDigesters/MDToC.html