Ramsey/Washington Recycling & Energy (R&E) is continually expanding its efforts to minimize waste generated in the community, while recovering value from waste that arrives at the R&E Center. Through R&E, the counties are increasing investments in waste reduction, reuse and recycling. Examples include:
With a focus on recovering value from waste and opportunities presented by new technology, the counties’ plans also include upgrading the Recycling & Energy Center:
When Ramsey and Washington counties were considering purchase of the Recycling & Energy Center, they focused on how the facility could best serve as part of an effective solid waste management system well into the future. In doing so, they adopted the following guiding principles for design of the waste and recycling system:
Considerable research and evaluation has shaped the development of the R&E waste management system:
Ramsey/Washington Recycling & Energy is partnering with Dem-Con HZI Bioenergy, LLC to use a process called anaerobic digestion to recover value from food scraps and other organic materials. Anaerobic digestion turns food scraps into renewable energy and soil nutrients, while reducing the amount of material sent to landfills and incinerators.
Food scraps collected through the Food Scraps Pickup Program, along with organic materials recovered at the Ramsey/Washington Recycling & Energy Center, will be processed at a new anaerobic digestion facility in Louisville Township in Scott County.
Anaerobic digestion is a natural process that uses microorganisms to break down food scraps in an environment without oxygen.
Inside a large, airtight tank called a digester, microorganisms break down the food scraps and produce two valuable products: biogas and digestate. The biogas is captured and processed to create renewable natural gas. The digestate is processed to create biochar and other useful products that can improve soil health.
Anaerobic digestion has been used successfully in Europe for decades. While the technology is relatively new to our region, it provides a proven way to manage large amounts of food scraps while recovering energy and other resources.
Food scraps make up about 28% of the trash generated by residents in Ramsey and Washington counties. Separating food scraps from the trash gives us an opportunity to recover their value instead of sending them to landfills or incinerators.
Anaerobic digestion provides a large-scale solution for processing food scraps collected from homes and other sources.
When food scraps break down in landfills, they produce methane, a powerful greenhouse gas. Anaerobic digestion captures the biogas produced as food scraps break down and puts that gas to use.
The result is renewable energy produced from materials that would otherwise be discarded. The biogas produced at this new facility will be upgraded to renewable natural gas to be used in homes, businesses and vehicles.
Anaerobic digestion also produces digestate, a nutrient-rich mixture of solids and liquids. At the new facility, the digestate will be processed into biochar, which has a variety of potential uses, including soil improvement, filtration and environmental remediation. Biochar stores carbon, and the process of making biochar and use of biochar in remediation have shown promise in reducing per- and polyfluoroalkyl substances (PFAS) – a class of toxic chemicals that are notoriously difficult to manage.
Food scraps are collected.
Residents separate food scraps through the Food Scraps Pickup Program. Other organic materials are recovered at the Ramsey/Washington Recycling & Energy Center.
Materials are transported to the facility.
The organic materials are transported to the Dem-Con HZI Bioenergy facility in Louisville Township in Scott County.
Microorganisms break down the food scraps.
The materials are placed in large, airtight tanks without oxygen. Microorganisms break down the organic material over the course of approximately one to two weeks.
Biogas is captured.
The breakdown process produces biogas, a renewable source of energy. The biogas is processed into renewable natural gas for use as an energy source.
The remaining material becomes a soil health resource.
The remaining material, called digestate, is processed to create biochar and other potentially useful products that can help with soil health.
Anaerobic digestion is one piece of a larger approach to managing food scraps.
The first priority is always to prevent food waste whenever possible. For food scraps that are generated, communities can use a variety of approaches, including backyard composting, local composting facilities and anaerobic digestion. Together, these approaches make better use of the resources contained in our food scraps.
Ramsey/Washington Recycling & Energy has partnered with Dem-Con HZI Bioenergy, LLC to build and operate the regional anaerobic digestion facility.
This public-private partnership brings together Minnesota waste management expertise and international anaerobic digestion technology.
Dem-Con Companies is a third-generation family business with decades of experience managing waste and recycling facilities in Minnesota. Dem-Con partnered with Kanadevia Inova, formerly known as Hitachi Zosen Inova, an international provider of anaerobic digestion technology with nearly 100 digesters operating in North America and Europe.
The facility is designed to process up to 75,000 tons of organic material each year.
The facility is located in Louisville Township in Scott County and is currently under construction. Construction is anticipated to be completed at the end of 2027, with production of renewable natural gas and biochar beginning once the facility is operational.
The anaerobic digestion project has received financial support from several state and federal sources, including: