Anaerobic Digestion

BIOFerm provides a complete suite of anaerobic digesters to the North American market for varying types and amounts of feedstock. These turnkey systems include: continuously-stirred tank reactor (CSTR), plug-flow reactor (PFR), and dry fermentation (batch reactor).

Different types of biogas systems are better suited for different types of organic waste. Our industry experience has taught us that it is never a “one-size-fits-all” solution; we ensure our clients receive the system that best solves their organic waste and biogas needs.

Continuously-stirred tank reactor

6-15% Total Solids

Continuously-stirred tank reactor (CSTR) complete-mix anaerobic digester tanks utilize unique paddle mixers to ensure homogeneous mixing. Ideally operating in the 6-15% total solids (TS) range at mesophilic or thermophilic temperatures (project-dependent), a variety of feedstocks can be processed. Possible feedstocks include manure, biosolids, food waste, brewery waste, energy crops, and other low-solids organics. CSTR digester tanks are available in different sizes and can be combined, depending on tank size and expansions. CSTR applications include dairies, wastewater treatment plants, food processors, and more. CSTR can also be paired with the horizontal plug-flow digester, for processing higher solids feedstocks like wastewater sewage sludge, waste from food processors, breweries, and more.

Plug-flow reactor

12-25% Total Solids

The plug-flow reactor (PFR) digester with agitation is typically designed to operate in the mesophilic temperature range. The steel tank has a rectangular footprint and has a horizontal paddle mixer that runs the full length of the tank. The mixer is powered by planetary drive units both ends, and the tank is heated through the horizontal mixer shaft. Depending on the project, solid or liquid feeding systems are utilized. PFR is often combined with CSTR tanks.

DRY fermentation

25%+ Total Solids

Our dry fermentation digesters process high-solids organics, such as food waste, yard waste, and other stackable organics. Although feedstocks may vary in solids contents, the system typically operates within the 25%+ total solids (TS) range. During this batch-style digestion process (which requires no internal moving parts or pumpable waste stream), organics remain stationary inside the individual, rectangular fermentation chambers. Modular design allows the system to be scaled according to the feedstock amount available. Operating in the mesophilic temperature range, dry fermentation is ideal for municipalities, food processors, campuses, composters, etc.

Combined System

Anaerobic Digester + Biogas Upgrading

Utilize your facility’s byproduct or waste streams as feedstock for anaerobic digestion to produce biogas that is then upgraded to renewable natural gas (RNG). BIOFerm’s combined systems allow owners the ease of a single point of contact and wrapped contracts, as opposed to multiple contractors and conflicting technologies. Our facilities have integrated programming and similar equipment, allowing for streamlined operations.