Innovative technology generates energy from wine production
AnAerobic waste stream technology helps wine producer regulate flow, improve operating costs and produce renewable energy.
By Daniel J. Hagen
The Canandaigua Wine Company lowered operating costs and regulated sporadic waste flow with a new waste stream treatment technology from the US company AnAerobics, Inc., which produces renewable energy.
Schematic of the AnAerobic MFT wastewater treatment system
Prior to AnAerobics' installation, extreme variations in wastewater flows and organic load discharges slowed down production at the wine production facility. In addition, the cost for electricity, sludge disposal and chemical requirements made the CWC process incredibly expensive. CWC treated the plant's wastewater using an aerobic, extended aeration activated sludge system that provided relatively reliable, yet lengthy and costly treatment. The aerobic system consisted of two one-million-gallon aerobic pretreatment tanks and two 115,000-gallon activated sludge tanks. This system represented over 2.3 million gallons of aerobic treatment capacity that required in excess of 400 horsepower.
Waste streams from wine production contain soluble, highly biodegradable organic components, so pretreatment is required prior to discharge to avoid costly sewerage surcharge fees and maintain regulatory compliance to local, state, and federal specifications. The CWC system generated an average of 650,000 gallons of sludge per month, which required expensive disposal fees. Chemicals were added daily, which increased costs.
Overall, the winery needed a treatment system that could treat wastewater flows in a more consistent, less costly way that could also support increasing future volumes of production.
AnAerobics applied its patented Mobilized Film TechnologySM (MFT), a wastewater treatment technology based on more than 25 years of research at Cornell University (New York, USA), to solve CWC's problems and help meet regulatory requirements. CWC recognised that anaerobic treatment had the potential to substantially lower pretreatment costs and improve production at their facility.
AnAerobics designed, financed and installed a two-module anaerobic MFT system that began operating in parallel with the existing aerobic facility in 1997. The MFT system had a footprint of 40-ft by 40-ft, compared to the 260-ft by 200-ft footprint of the original aerobic system. In 2001, AnAerobics expanded capacity of the MFT system by 50% to handle increasing volumes of wastewater resulting from CWC production expansion.
AnAerobics' treatment includes biological and mechanical processes. The biological element relies on methanogenic bacteria that attach to inert media and form a deep bed within enclosed reactors. Mechanically, the reactors are driven by the MFT process control system to move wastewater through the bed, ensuring a constant high-rate flow over an enormous surface area of living organisms. Minimal chemical additions and pre-heating are required to maintain a robust, resilient bacterial community.
AnAerobics' MFT is the first successful full-scale application of the expanded bed biological treatment process. The bulk of the reactor volume is occupied by the bed of small-diameter carrier media to which the biomass attach and grow. Wastewater is distributed across the bottom of the bed inducing up-flow through the bed. Solids, such as digested biomass or sludge, settle and collect in a small layer on top of the bed and are removed. Finally, the gas produced from the consumption of the organic matter by the organisms is captured and either used to power the reactor and/or delivered to the production plant, significantly reducing the plant's energy requirements by offsetting natural gas use. Wastewater is discharged from the MFT system after achieving 98% to 99% removal rates.
Eventually, the MFT system completely replaced the aerobic system at CWC. Although influent flow and load variation was often extreme for CWC, installation of AnAerobic's treatment technology has stabilised performance even though production has dramatically increased.
In addition, the MFT system has reduced overall power consumption to 60 horsepower at the facility. Considering the plant's increased production, an average 288,000 kWh of electricity would have been needed per month with the old aerated treatment system. But, with MFT, the monthly electrical usage of the pretreatment system (including all unit processes) was 92,200 kWh a month, saving a total of 196,000 kWh.
Sludge disposal costs were lowered as sludge production was reduced by approximately 90% after installation of the MFT system, which helped CWC comply with wastewater discharge regulations more easily and cost-effectively.
AnAerobics' system has been successfully operating at the CWC winery for more than six years. AnAerobics' solutions, offered as a service with no capital or equipment costs, are in operation at several major food and beverage companies around the world. The MFT solution can also be used to treat high-strength waste streams generated in municipalities and in many other industries, including pharmaceutical, petrochemical and pulp and paper.
Daniel J. Hagen is senior vice president of business development for AnAerobics Inc., based in Canandaigua, New York.