Rhinoflux Demonstrates Power Generation from Wet Sewage Sludge

Rhinoflux Inc., a spinout from Kyoto University, has been selected by the Tokyo Metropolitan Government to demonstrate a new method of generating power from wet sewage sludge without combustion. The company will begin an 18-month field demonstration at a public infrastructure facility, converting the sludge into electricity and capturing 99.9%+ purity CO2.

This project addresses a significant challenge faced by wastewater utilities worldwide: the high moisture content of sewage sludge makes conventional energy recovery expensive. In Japan alone, approximately 2.34 million dry-solid tons (DS-t) of sewage sludge are generated annually. Despite a recycling rate of about 76%, energy recovery accounts for only around 10% of the total, while 23% still goes to landfill. The sewage sector emits approximately 3.38 million tons of CO2 equivalent each year, making it the largest single source of greenhouse gas emissions from municipal operations in the country.

Rhinoflux's Hydro Chemical Looping technology generates electricity through chemical reactions in an aqueous solution, eliminating the need for drying and pre-treatment stages. The company reports that its process is approximately two to four times more efficient than conventional biomass power systems. Additionally, the technology separates CO2 at 99.9%+ purity as an inherent output, requiring no additional purification equipment. This dual revenue stream from electricity and CO2 makes the technology more commercially viable.

The demonstration will run for a cumulative 2,400 hours of continuous operation, verifying performance across different types of sludge, primary, digested, and dewatered cake. The project aims to establish power output, CO2 recovery, sludge volume reduction, long-term operating stability, impurity management, interface conditions with existing plant processes, and safety and maintenance requirements. Rhinoflux CEO Alex Mazawa emphasized the importance of proving interface with existing equipment, safety, and long-term operation and maintenance in the field.

The company follows a five-stage development roadmap from laboratory to large-scale project. Having completed laboratory-scale continuous operation on multiple feedstocks in collaboration with water treatment equipment manufacturers and industrial biomass producers, Rhinoflux now enters field validation at public infrastructure. The on-site demonstration at a large-scale sewage treatment facility is scheduled for 2028, followed by the first commercial systems for municipal and industrial customers. Large-scale projects serving data centers, steel, chemicals, and utilities are planned for 2032 and beyond.

Through 2028, Rhinoflux aims to generate the evidence base required for public procurement decisions, making the technology more accessible to municipalities.

Rhinoflux Inc. was founded in April 2024 as a spinout from Kyoto University, developing Hydro Chemical Looping technology for converting wet biomass into electricity and high-purity CO2. The company is headquartered in Kyoto, Japan.