CleanWorld closes the loop on organic waste.

CleanWorld’s BioDigester is a thermophilic, high-rate, high-solid digestion system, with a three-stage design. It is especially engineered with food waste in mind, including agricultural residues, commercial food processing waste, and restaurant and supermarket food scraps.


High-solids: CleanWorld’s BioDigesters efficiently digest a high-solid waste stream (up to 50% solids) without requiring substantial preprocessing and with minimal added water. The system can handle de-packaging and sorting, so organic waste streams that include cans, bottles, plastic-wrapped foods, and other contaminants can be used.

High-rate: CleanWorld’s proprietary high-rate digester design uses continuous—rather than batch—processing, allowing for rapid waste throughput. This technology has a higher organic loading rate, shorter hydraulic feedstock retention time (approximately 20 days), and a longer solids retention time to maximize bacterial populations and solids digestion in the system. High-rate processing reduces retention times by up to 50% over other systems, which means smaller tanks, a smaller system footprint, and lower site costs, allowing for economical applications in a wide range of industries.

Three-stage processing: By dividing the anaerobic digestion process into three stages, CleanWorld’s BioDigesters provide the optimum environment for the bacteria used in each stage of processing. This means more complete digestion of waste, resulting in higher energy production and greater carbon reductions compared with single stage digesters

Sacramento BioDigester

Taken when the Sacramento SATS BioDigester first opened: this project is negative carbon!

Thermophilic: CleanWorld’s AD systems operate at thermophilic temperatures (122-140º F), in contrast to most AD systems, which operate at mesophilic temperatures (86-104° F). Operating at higher temperatures results in faster processing and reduces the size of the digester required. In addition, it destroys pathogens in the waste, making the residual materials safe for use as compost and organic soil amendment products.

Energy usage: The low parasitic load of CleanWorld BioDigesters increases system energy efficiency in comparison with traditional power-hungry, high-liquid AD systems. The tanks and pipes are well insulated to minimize heat loss. In most cases, no additional energy is required to operate the digester because all of the digester’s energy needs can be met by the heat and power it produces.

Construction: CleanWorld’s AD design combines the use of low-cost manufacturing and assembly techniques with a standardized, modular design that makes possible economically viable AD systems. Simplified assembly, reduction of labor, and the elimination of complicated on-site construction minimize up-front costs and speed construction. A CleanWorld BioDigester can be operational in as little as four to six months. The modular design also improves serviceability and enables easy scale-up when waste processing needs increase.

Monitoring: Advanced instrumentation and control systems allow remote monitoring and control of the digester by PC, tablet, or smartphone, improving operational efficiency while reducing staffing needs and operating costs. The system provides real-time data trending; historical data is collected as well and analyzed to produce reports for monitoring system performance and detecting trends.

Sample Projects

Sacramento SATS BioDigester (CNG project) 

UC Davis READ BioDigester (Electricity Project)







ribbon cutting UC Davis BioDigester Earth Day

 UC Davis Renewable Energy Anaerobic Digester (READ) 50 tons a day/5.9 million kWh per year of green electricity