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anaerobic digester

The Bright Future for Anaerobic Digestion Energy Production

Anaerobic digestion is a naturally occurring process in which microorganisms break down organic materials in the absence of oxygen. This process can be harnessed to produce what is called biogas, which contains approximately 60 percent methane and 40 percent carbon dioxide. Biogas is a renewable energy source that can be used by businesses or communities in a number ways, including to:

 

  • Power engines that produce electricity and/or heat
  • Fuel furnaces, boilers, or other devices like digesters
  • Meet the natural gas needs of homes and businesses
  • Power alternative fuel vehicles

 

How and where biogas can be used depends on how much it is processed after it is captured in the anaerobic digestion process. For example, steps are often taken to remove water vapor, carbon dioxide, and trace contaminants from biogas before it is used in some way to produce energy.

 

What Materials are Used to Produce Biogas and Ultimately Energy?

 

Biogas is created from the anaerobic digestion of organic materials. These materials can include just about anything that can trace its origin back to a living organism. For example:

 

  • Food scraps
  • Animal manures
  • Fat oil, and grease
  • Yard waste
  • Wastewater sludge
  • Industrial organic residuals

 

The general term for the material used in anaerobic digestion is biomass. In the digestion process, the biomass is heated to just under 100 degrees, which is the temperature at which bacteria and naturally occurring microorganisms are best able to break it down. The biomass then goes through four distinct stages: hydrolysis, acidogenesis, acetogenesis, and methanogenesis. The end result is biogas and some nutrient-rich solids and liquids.

 

Beyond Energy: Other Benefits of Anaerobic Digestion

 

Not only does anaerobic digestion produce energy, it provides other benefits as well. For example, it diverts material from landfills, turning what would have been waste into useful products. One of those products is what is called digestate, which can be used as a soil conditioner to increase nutrient levels and improve moisture retention.

Anaerobic digestion also helps reduce the release of methane into the atmosphere. Methane is a potent greenhouse gas that is produced naturally in landfills and manure lagoons. By making less material available in those areas, and capturing and using the methane that the material produces in a digester, anaerobic digestion plays a role in controlling methane emissions. Plus, the process provides an important outlet for the large volumes of manure produced in livestock operations.

Consequently, by some estimates, the biogas market is expected to grow by over 10 percent annually through 2022. To support that growth, many companies will be capitalizing on the engineering and project services of companies like APECS to design and build new anaerobic digesters and associated facilities.

 

Providing Project Services for One of North America’s Largest Anaerobic Digesters

 

As a leader in project services, design management, and owner’s representative services in the western U.S., we recently served as the owner’s representative for a client that is developing a waste-to-energy anaerobic digestion project. We have provided a variety of services including conceptual design, project siting, cost estimating, planning and entitlements, and project management.

One of the client’s goals is to produce biogas from the digestion of animal waste and other organic materials. The methane will be refined into renewable energy biofuels for use throughout the region. A second, equally important objective, is to reduce methane emissions in the area. And finally, the 100 percent recycled liquid and solid products will be useful for a number of purposes.

 

The Future of Biogas and Alternative Energy

 

While anaerobic digestion has been used for a variety of purposes for many years, new applications continue to be developed. For example, the U.S. Department of Energy is experimenting with ways to refine the chemical processes involved in digestion. It is believed that if they can stop the reaction at the right point, the material can be turned into gasoline, jet fuel, and other products.

Our full-service engineering and design firm can provide the project services needed to design and implement anaerobic digesters. We have 30+ years of experience helping our clients meet their engineering, design, project and portfolio management, capital planning, and environmental health & safety needs. Contact APECS, Inc. today to learn more about how we can help with your energy project.

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