NaturTech Composting Systems Inc., based in St. Cloud, Minnesota, installs turnkey in-vessel composting systems that process materials such as grass clippings, biosolids and food scraps. Depending on the feedstocks and desired end use, the system can produce compost, green mulch for agricultural applications or alternative daily cover for landfills. NaturTech systems are currently used by military bases, municipalities, contractors, landfills and topsoil producers.
The system utilizes modified roll-off containers as vessels that can easily be transported and unloaded. The containers are coated to prevent corrosion and can also be insulated for operation in colder climates. (Developed and tested in the heart of Minnesota, they can withstand freezing cold weather.)
The starter system consists of four containers and a biofilter that can process between 3.5-18 tonnes/day depending on the product. The modular design allows a facility to easily expand as more materials are diverted from landfill disposal.
A computerized process control system regulates and monitors the composting process, including air pressure, airflow and temperature data. Two blowers are used; one delivers air to the bottom of each container and another draws air out of the top and forces it through a biofilter. In colder climates, this airflow system can be reversed. A built-in modem enables remote monitoring and adjustment. Leachate is contained and collected for either reuse or disposal in a sanitary sewer system. The computer also tracks and stores all process data so it can be reported to regulatory agencies.
Craig Benton is vice president of NaturTech Composting Systems Inc., based in Seattle, Washington.