SBSA Participates in Unique Biosolids Treatment Demonstration

The South Bayside System Authority (SBSA), a wastewater facility serving more than 200,000 residents and businesses in southern San Mateo County, is working with BioForceTech to demonstrate:

·        Drying biosolids through an aerobic respiration mediated by bacteria already present in the biosolids.

·        Pyrolysis of dried biosolids, which allows producing a syngas with high energy content.

·        Oxidation of the produced syngas with consequent recovery of energy.

            The testing of this new technology at SBSA is expected to last through the summer of 2014.

            At the moment, BioForceTech is just flaring the syngas, but the ultimate use for it is additional heat or some sort of power generation – options are under study.

            The demonstration project is on SBSA’s biosolids, which are the nutrient-rich organic materials resulting from the treatment of sewage “sludge."

            For several years, biosolids have been disposed in various ways: incineration, landfill, deep injection or land applied as fertilizer. Many of these options are no longer available and SBSA is looking to the future for long-term biosolids disposal options that are not only cost effective, but also beneficial to the environment around us.

            SBSA currently contracts private entities to haul biosolids to San Joaquin, Contra Costa, and Santa Clara counties for disposal into a landfill, composting or at a land application site. SBSA is interested in expanding its options for disposal of biosolids, including the beneficial use of biosolids as a fuel source. The use of dried biosolids as an energy source (“bio-fuel”) is one of the newest and more highly-anticipated markets for biosolids in the United States. Biosolids have a heat value in the range of 6,000 to 7,000 Btu/lb and can provide more economical, environmentally-friendly, and sustainable fuel than bituminous coal.

            SBSA entered into the demonstration project, which began in late October 2012. According to its founders, BioForceTech was formed to solve the problem of biosolids treatment. To achieve this goal, ​​a team of experts in the fields of biotechnology, business administration, and energy, mechanical, and software engineering was created.

            Removing moisture from biosolids is a task that historically involves a large cost of energy. BioForceTech studied a combined system that allows the evaporation of water from organic matter using the thermal energy of microbiological reactions. The process is completely additive-free, and doesn't require any external source of thermal energy other than the return heat captured from the pyrolysis process.

            “Pyrolysis” is a thermochemial degradation process that works without oxygen.
The pyrolysis can convert solid matter into a gaseous fuel, leaving the most pollutants in the produced ash. This type of process can obtain a conversion at relatively low temperature (600 °C) in the absence of flame. The BioForceTech reactor has been designed with a system that allows the transportation of the biosolids regardless of the materials physical conditions (example: higher or lower levels of humidity), making it a more flexible process.

            The pyrolysis process combined with the biological evaporation considerably reduces the emissions of polluting molecules in the atmosphere. The system installed directly into the area of the sewage treatment plant eliminates the pollutants emitted from transportation, improving the efficiency of the overall processes in environmental terms.

            SBSA is owned by the cities of Redwood City, San Carlos, Belmont, and the West Bay Sanitary District, which serves Menlo Park, Atherton and portions of Woodside and Portola Valley.

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