IBR Technology


Andigen Ags IBR anaerobic digester provides robust handling all types of animal, municipal and industrial organic waste. The IBR’s modular format allows scaling from small to large operations.

Examples of cost effective volumes for treating waste with an IBR system are shown below:



The Induced Bed Reactor system is comprised of a series of independent above ground tanks or cells with the appearance of a classic farm silo. IBR systems are modular and scalable, allowing the digester to grow incrementally with the needs of the user without major alterations to the existing facility. Andigen digesters are fully automated with a user friendly control system. The IBR design is simple, extremely reliable and requires minimal energy to run a largely passive operation.

A high rate digester results in a lower material storage requirement. Combined with a vertical column design, the IBR footprint is much smaller than needed by other anaerobic digesters. With a small footprint, IBR tanks are generally housed in an insulated, environmentally controlled building for a more consistent operation and protection from the elements.

Using the above ground, small diameter cell approach, the IBR offers greater modularity than alternative in-ground systems or very large complete mix tanks. Completed IBR tanks are delivered to the user site for fast and simple installation, and can be moved to another location later if ever needed. When maintenance is required, a single tank can be taken off line without affecting the overall system that if free to continue operation without interruption. The IBR’s operation is mechanically simple with lower maintenance requirements and less energy consumption.


Andigen offers IBR digester systems consisting of pre-engineered anaerobic digesters including uniquely designed tanks, influent and effluent control mechanisms, biogas conditioners, heat exchangers, sensors and electronic monitoring equipment.

IBR Support Systems: Andigen can assist the user with the acquisition and installation of related infrastructure including building enclosures, influent holding and mixing tanks, and electrical generating and gas storage equipment

IBR System Monitoring and Control: As an ongoing service, Andigen remains linked to operating systems electronically in order to remotely monitor performance and make adjustments as needed to insure successful operation.


Unique features of Induced Bed Reactor (IBR) create a super rich concentration of digesting bacteria that greatly improves the performance of the system.

The UASB/IBR system is uses reactor tanks that may be placed above or below ground.

The animal waste (influent) is typically heated before it enters the tank to maintain the mesophillic temperature range in the reactor.

The IBR digester is designed to handle influent with a solids content of from 2 to 10%.

The influent enters the lower part of the tank and gradually moves upward through the super rich bacteria blanket where digestion and gas production occurs.


Methane gas production is directly related to solids destruction.  Digesters with comparable solids destruction levels will produce comparable levels of methane gas measured in BTU’s.  The actual gas volume produced by a digester will vary somewhat with the concentration of methane in the gas.  Digesters producing 50% methane gas (500 BTUs per cubic foot) must produce a higher gas volume than a digester producing 65% methane gas (650 BTUs per cubic foot) in order to achieve the same energy output (total BTU’s).

Not all digestible waste streams are equal in terms of the potential for methane gas production, and not all organic waste streams are suitable for anaerobic digestion by themselves.  Animal manure is well suited for digestion by itself or as an excellent buffer for other waste streams that are too acidic or basic for processing on their own but that have high energy potential.  By adding high energy substrates to animal waste in the correct proportion, methane gas production can be enhanced significantly.  The Andigen system is well suited for the controlled addition and digestion of supplemental substrates.


Methane gas from an anaerobic digester can often be used as a direct replacement for natural gas.  It is typically necessary to make a simple modification to natural gas burners in order to accommodate the lower BTU content of biogas from digesters.  Compatibility is enhanced when digesters produce gas with a higher BTU content and lower H2S content as in the Andigen system.  When direct utilization of biogas is employed, a fraction of the BTUs produced must be used to heat the digestion process.  On average this would be less than 1/4th of the energy, depending on the climate.

Biogas is also suitable for use in a combustion engine generator.  The high BTU content and low H2S content make the gas from the Andigen digester well suited for this application.  The actual kilowatt production is directly related to solids destruction as reflected in BTUs generated by the digester as methane gas, and the efficiency of the engine generation system.

When an engine generator is used, waste heat is also available from three sources, engine cooling water, engine exhaust and radiant heat.  These heat sources are more than enough to heat the digester.  On average, over 60% of the total of engine waste heat is available for other uses.


No variables are left to chance with the Andigen IBR digester. The entire IBR system is housed in a small building where optimal operating temperatures are maintained year round in any climate.