Plug Flow Digester

A plug flow digester is a long narrow (typically a 5:1 ratio; 5 times as long as the width) insulated and heated tank made of reinforced concrete, steel or fiberglass with a gas tight cover to capture the biogas.


These digesters can operate at a mesophilic or thermophilic temperature. The plug flow digester has no internal agitation and is loaded with thick manure of 11 - 14 percent total solids.

This type of digester works well with a scrape manure management system with little bedding and no sand. Retention time is usually 15 to 20 days.