How Do Industrial Composting Systems Work?an outdoor windrow composting system

How Do Industrial Composting Systems Work?

Industrial composting refers to the large-scale composting processes used to treat organic waste, typically from municipal, agricultural, or commercial sources. Various methods have been developed to handle the large quantities of waste produced and to expedite the composting process.

The goal of each method is the same; to aid the composted items in biodegrading. This is so it can be used productively or at least disposed of in more planet friendly ways, instead of merely contributing to the planet’s waste. Let’s take a look at some of the methods science has come up with to make the most out of our compostable refuse:

  1. Windrow Composting: This method involves piling organic matter into long rows known as windrows. The rows vary in height across facilities. The rows are periodically turned to aerate the material, accelerate the composting process, and ensure uniform decomposition. This is done using front-end loaders or tractors in smaller operations or dedicated specialized machinery in large scale operations. This method is suitable for large volumes of organic waste, such as yard waste and agricultural residues.

  2. Aerated Static Pile Composting: Organic waste is piled over a network of pipes that deliver air to the compost to ensure aerobic decomposition. It's a method commonly used for treating mixed yard and food waste. With this method, the compost is not turned manually, but relies on the network of pipes to aerate the material. It can take up less space than windrow composting and requires less labor as there is no need for people and machinery to turn the compost. However, setting up the pipes is a large investment and the method does require a power source.

  3. In-vessel Composting: This method uses a drum, silo, concrete-lined trench, or similar equipment to control environmental conditions and optimize the composting process. The vessel allows for better control over temperature, moisture, and aeration. It's faster than many other methods and is often used for food waste, bio-solids, and other organic materials. This method can be done in both small and large operations.

  4. Tunnel Composting: In this method, waste materials are placed in a closed tunnel. The environment inside the tunnel (temperature, humidity, and aeration) is controlled to expedite the composting process. After an initial phase in the tunnel, the compost is typically further matured in open-air facilities.

  5. Rotary Drum Composting: The compost material is placed inside a rotating drum. As the drum turns, the material is mixed and aerated, speeding up the composting process.

    (There are now options to perform a variation of this method at home by using a compost tumbler. Small scale gardeners and farmers can buy a tumbler for their compost, or even make their own using, for example, a 50-gallon drum.)

  6. Vertical Composting Units: These are multi-story, bin-like systems where organic materials are added to the top and mature compost is removed from the bottom. As materials decompose, they move downwards through the bin, making the process continuous. This is a more advanced and large-scale operation than what we can do at home, but the basic idea of removing the mature compost from the bottom and adding more material to the top is the same.

  7. Plug Flow Systems: These systems move composting material through a rectangular chamber using a combination of gravity and mechanical systems. The environment in each section of the chamber can be controlled to optimize different phases of the composting process.

The above are just some of the methods for industrial composting that can be used at both small and large scale operations. The type of industrial composting method chosen often depends on the type and volume of organic waste, space limitations, desired processing time, and budget constraints. Each method has its own advantages and challenges, so careful consideration is taken to ensure that the chosen process is overall beneficial.