Technology

PEG anaerobic digestion systems are designed to be the most compact and highly efficient high-solids digesters in the industry. Using patented IBR (Induced Bed Reactor) technology developed by Utah State University, PEG designs and builds modular waste to energy systems that expand with increased production for the commercial food and beverage industries worldwide. PEG offers systems in various ranges, each starting with a base platform system including all controls and infrastructure necessary for immediate use and expansion. As production and associated waste increase, system operators are be able to add additional IBR digestion tanks to the base platform in a seamless and pre-engineered format. All systems are prefabricated and transported to the site via commercial transport, for immediate setup and operation. PEG’s systems are vertically designed to minimize footprint, with IBR tank arrays erected on concrete pads or appropriate surfaces for skid mounted systems.

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IBR Technology:

The patented IBR technology represents a unique class of anaerobic digesters (AD) where both the efficient processing of high solid’s waste streams is maximized, and the system footprint is minimized. Anaerobic digestion is a naturally occurring process where micro organisms and bacteria breakdown and digest organic materials and produce biogas as a byproduct. When controlled in a modern bioreactor such as the IBR, the environment and conditions for microbial activity are optimized and maintained creating an energy generating biological system. The methane (CH4) rich biogas that is produced by the micro organisms is an alternative to natural gas once it’s been conditioned to remove background gasses and moisture. This now Renewable Natural Gas (RNG) can be used to supplement natural gas use in boilers or combusted in electrical generating equipment. Though various companies produce AD systems, not all are the same in the way they carry out the anaerobic process. Differences in system footprint size and processing duration/efficiency define the various types of AD technologies in the global market place.  The key difference between IBR technology and all other digester systems is the decoupling of Solid’s Retention Times (SRT) and Hydraulic Retention Times (HRT). This feature alone sets the IBR technology in it’s own class of AD systems being compact in size and highly efficient at processing high solids waste streams.

SRT & HRT Explained:

SRT is a measure of how long organic solids will remain in the AD digester to be broken down by microbes to produce biogas. The longer solids remain, the more broken down they become, and the more biogas is generated. HRT on the other hand is the length of time it takes water to pass through the system. The water is needed to keep the solids in a slurry suspension, but does not contribute to the production of biogas. So the water is inert and passive as it passes thought the digester. SRT and HRT in Complete Mix systems: In all other types and designs of anaerobic digestion systems, the HRT and SRT are always equal, meaning that as new hydrated waste material in pumped into the system, digested material is pushed out. Because these systems are completely mixed and stirred at all times, as material in forced out, so are beneficial microbes and a mixture of digested material that varies in how long it was actually in the tank. To combat this problem, complete mix systems are designed to hold very large amounts of material and rely on longer HRT times of 20-30 days. These systems are very large, and require a more spacious footprint.

Uncoupling SRT and HRT:

IBR Out Performs: The uniqueness of the IBR is the decoupling of HRT and SRT, doing so dramatically reduces system footprint while decreasing HRT to 5 days or less. The patented IBR design creates an environment where solids and microbes are retained, while water is allowed to passively move through. The patented septum incorporates an opening and auger assembly creating positive resistance to hold the solids and microbes below the aperture. Digested solids and liquid flow past the auger to the upper chamber where final digestion is completed before exiting the system. With these features as well as several others, the IBR has been proven to process waste streams with up to 15% solids loading while processing this material in 5 days or less. Due to this substantial reduction in HRT, a typical IBR system is approximately 1/4th to 1/5th the size of competitive systems while processing the identical amount of waste in less time. This offers system owners the reduced footprint while maximizing energy production of processing waste on-site. Because there are no mixing motors, only the 1 RPM passive auger, the parasitic load of energy needed to operate the IBR is less than 10% of its output including biogas used in the temperature control system.

Building on Performance:

The IBR systems offered by PEG are designed to fit a wide range of industrial and commercial clients. By building it’s systems as modular and expandable, PEG offers it’s clients a solution for growth as their production output and waste streams increase. By adding more IBR tanks to the base platform system, operators can quickly expand without costly on-site construction and interruptions to production. Varying ranges of system size’s cover different waste outputs associated with various industries. For ease of installation, all systems are prefabricated and shipped to the client using conventional transport services. Please contact PEG for more information about waste to energy processing potential for your industry. Learn More About PEG Anaerobic Digestion Systems (PDF)»