Technology
Induced Bed Reactor (IBR)
Oaktech is the exclusive UK and EIRE licensee of a state-of-the-art anaerobic digester known as the Induced Bed Reactor (IBR). Developed and already successfully implemented in the USA, IBR systems are designed to provide cost effective and reliable effluent treatment of organic material produced by the solid waste, farming and agriculture industries for farmers.
Energy from the anaerobic digester reduces or eliminates the need to purchase energy, surplus energy fed into the electric or gas grid provides income in the form of a feed in tariff, and the reduction in waste volume protects against rising landfill taxes and gate fees. IBR anaerobic digestion treatment serves to reduce the environmental impact of these waste streams whilst producing high quality soil amendments. IBR system shortens retention time to as low as 5 days, treats both liquid and solid feedstocks, decreases storage requirements, is more consistent and reliable, is easier to control, and produces more methane than other AD processes.
The IBR technology was originally developed to process dairy manure flush water – a waste that is difficult to treat owing to its content of abrasive particulate solids and the need for operational simplicity and reliability in use on the farm. The process is a flexible solution for the treatment of a wide range of feedstocks.
An aspect of bioreactor efficiency sometimes overlooked concerns the amount and quality of the residue that resists digestion (the digestate). With respect to amount, there is a reciprocal relationship between the production of methane and that of residual digestate.
The IBR method maximizes methane production while minimizing solid digestate production. Digestate produced by the process is highly stabilised and can add significant agricultural value when used as a biofertiliser.
The IBR System
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. IBR 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.
