Does Composting Produce Methane, Heat, CO2, Biogas?


Perhaps you have wondered if composting produces methane, heat, CO2, or Biogas? If they do, are they harmful to the environment and people?  Can anything be done to reduce their effect if they are dangerous?

On average, composting does produce small amounts of heat as well as a mixture of methane and CO2 called biogas. All of these are produced due to the anaerobic reactions from bacteria and other organisms breaking the compost down.

To learn how exactly these gasses are produced and to find out the effect on the environment of each, keep reading below.

Does Composting Produce Methane?

Composting releases some methane gas, but the aerobic process used in composting is believed to reduce or prevent the release while the organic matter is being broke down. On the other hand, landfills use an anaerobic process that releases a more significant amount of methane into the atmosphere.

Composting not only reduces the amount of methane released from landfills but has other benefits too. One of those benefits includes the fact that farmers and other growers can use the compost in agricultural processes. Compost makes the soil healthier by replenishing nutrients removed during the growing process.

Composting improves the retention of soil fertilizers. Composting also improves soil structure and stimulates biological activity while helping to hold moisture in the soil. Compost helps reduce soil erosion and reduces the need for herbicides and pesticides, making the food healthier.

You can significantly reduce the rate of methane when using aerobic composting instead of anaerobic processes. There are several methods of composting to do this:

  • Open Pile
  • Static Pile
  • In-Vessel
  • Windrow
  • Vermicomposting

The things composted instead of ending up in a landfill help reduce emissions.

Here’s a helpful video about how to reduce methane when composting, with much more info below:

What is the Difference in Methane Emissions Between a Landfill and Composting?

To measure global warming, you look at how much heat over the next hundred years from one ton of a gas will absorb.

Methane has a global warming potential 28 to 36 times larger than CO2 or Carbon Dioxide.  Landfill’s gas emissions are about 50 percent methane and 50 percent CO2. Properly mixed compost bins will have oxygen introduced to the system, so they instead produce mainly CO2.

So, while a dump has the same amount of CO2 and methane going out, most of the emissions from composting are CO2 so it does affect the environment less. Much less, say, than your average yearly car’s emissions.

Is Heat Needed for Composting?

Heat helps break down vegetation much faster than a cold compost pile. Heating a compost pile is not talking about heat from the sun. Bacteria is one of the best ways to heat a compost pile. To heat your compost, you will need to make sure the conditions are right for bacteria.

It helps to turn your pile regularly. Add grass clippings or sawdust, or some other material to help prevent the oxygen from escaping out of the pile. Turning the pile mixes the pile-up and gets the oxygen moving in the pile. Nitrogen found in coffee grounds, grass clippings, and vegetable scraps will add nitrogen to the compost pile and help heat things up.

Add some brown materials to the pile. A good ratio is three parts brown to one part green. These materials could be dried grass or autumn leaves. Blood meal, bone meal, and corn gluten are beneficial things to add to your pile.

Your pile will need to have moisture to decompose correctly. You want it to be about as damp as a damp sponge. If it is raining too much and gets too wet, turn it to get the air in there to dry it out a bit. If needed, you can add more dry leaves or other brown materials to make it less wet.

Does Composting Release CO2?

Does composting release CO2? If so, how does it affect global warming and other factors that impact our planet?

As a whole, composting does release CO2. The CO2 does increase global warming, but whether you compost waste intentionally in a pile or it occurs naturally in the forest, anytime vegetation decomposes, there will be CO2 released into the air.

To learn more about how CO2 contributes to global warming, read below.

How Much CO2 is in a Ton of Compost?

While composting does produce CO2 emissions, it is considered carbon-neutral. It releases the same amount of CO2, whether decomposition is from a composting pile or natural composition in the forest. However, CO2 does help cause global warming.

There are 2167 pounds of CO2 in a tone of compost. This number is astounding when you think about it. Statistics show that Americans currently have a carbon footprint of 16 tons per person per year.

What Gas Does Composting Produce?

What gas does compost produce? Is it a recyclable gas? How can it benefit the planet?

Biogas, a mixture of mostly CO2 and methane, is produced during composting. It can then be used in heat production and electricity generation, and even fuel for cars. Potential “super-composters” could provide enough biogas to even power a home, in future.

To learn more about this new way to use composting to help reduce global warming and restore our planet read below.

What Can You Use Biogas and Compost to Do?

By reducing waste and composting, you can create renewable energy for your home. The process involved minimizes the time needed to compost your waste and turns it into useable fertilizer and Biogas.

You can use Biogas to cook your food or to heat your home. It can even be used for fuel for your car and to help create electricity. When using methane in this way, it no longer contributes to global warming.

Natural GasBiogas
1000 BTU per cubic foot600 BTU per cubic foot
80% methane55-65% methane, 30-35% CO2, hydrogen, nitrogen, and other impurities

 New technologies and processes are being developed every day to help us lower our carbon footprint.

To Conclude

While composting has some drawbacks from methane and CO2, it is still less harmful to the environment than landfills. Technology and inventions that allow methane and CO2 to be converted into Biogas can give us cleaner energy, reduce carbon footprint, and affect global warming over time.

Robert Sampson

I'm Robert Sampson and I live in Colorado where I spend a lot of time in the backyard with my family either grilling, playing games and sports, or working on a project to make our backyard a better place to be.

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