A growing number of modern waste and wastewater facilities have the capability to also generate clean, renewable energy. These facilities use anaerobic digestors to transform waste into biogas, creating a cost-effective alternative to fossil fuels.
In most cases, the decomposition of organic waste generates greenhouse gases such as methane and carbon dioxide. Both are powerful greenhouse gases and a major contributors to climate change. Rather than allowing greenhouse gases to escape, specially designed waste-to-energy facilities capture these gases, turning a myriad of waste materials into an energy source that minimizes climate and environmental impacts.
How Anaerobic Digestion Systems turn Waste into Biogas
Biogas is a mixture of gases (methane, carbon dioxide, hydrogen sulfide, and siloxanes) produced by anaerobic bacteria as they decompose organic matter. Anaerobic digestion systems produce the biogas within sealed enclosures that prevent oxygen from contacting waste materials. The waste products that can most readily be converted into biogas include food scraps, oils, greases, and sludge. In addition to providing a rich energy source, the residual solid waste can be an excellent fertilizer (think compost!).
Quick Facts about Biogas
- According to the Environmental and Energy Study Institute (ESI), as of 2017, there were slightly more than 2,200 waste to energy plants in the United States equipped to generate biogas. However, the organization estimates that the potential exists for six times as many such facilities.
- All organic waste materials can potentially produce biogas. However, animal waste, along with fibrous material such as wood, are difficult for anaerobic digesters to process.
- Biogas reduces greenhouse emissions from motor vehicles by approximately 90% when compared with petroleum.
- The ESI estimates that the full implementation of biogas as an energy source can create as many as 350,000 jobs.
- In addition to dramatically reducing the emission of harmful greenhouse gases, biogas limits our dependence fossil fuels.
- Renewable energy sources, including biogas, accounted for approximately 17% of total energy consumption in the U.S in 2018.
- Like all waste to energy facilities, plants that boast anaerobic digestion systems must consider a range of factors before construction. These factors include environmental impacts, biological characteristics, site selection, political considerations, community concerns, and other logistics which vary from site to site.
- Anaerobic digestors must be closely monitored for optimum efficiency.
- The most efficient biogas-producing waste to energy plants must rely on the expertise of environmental engineering consultants such as HSA Golden, with proven track records in waste to energy design and construction.