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Turning waste into a resource with cost-effective and sustainable technologies

At Fluence, we have more than 30 years of experience in the design, construction, and operation of waste-to-energy plants for a wide range of industrial and municipal clients. Our proprietary anaerobic treatment technologies process wastewater and sludge to produce biogas, which can be used to produce electricity and thermal energy, or which can be purified to produce biomethane for injection into the grid.

Our waste-to-energy technologies fall into three main categories:

  • Anaerobic treatment of wastewater containing a high concentration of soluble COD, including wastewater from breweries, paper mills, dairies, food processing plants, and pharmaceutical companies
  • Anaerobic digestion of sludge, particularly from slaughterhouses, fish processing plants, and rendering plants
  • Anaerobic digestion of solid waste, including biomass, food waste, manure, agricultural waste, and silage

The main benefits of using our waste-to-energy solutions to process wastewater and sludge include:

  • On-site production of energy, which can be used by the client to reduce a plant's electricity and gas consumption
  • Production of high-quality, treated effluents that meet the most stringent permitting requirements
  • Reduction of sludge volume by up to 90%, significantly reducing the amount bound for landfills
  • Production of a high-quality digestate that can be used by farmers as a fertilizer
  • Reduction of greenhouse-gas emissions
  • 100% reliability, and low operation and maintenance requirements

Every client is different, and, consequently, the biomasses they produce have different characteristics. Before designing a plant, we analyze the biomass in our laboratory to determine its capacity to produce biogas. Fluence engineers then evaluate the potential solution in business terms, calculating capital costs, operating cost reductions, and return on investment.

Market-Leading Waste-to-Energy Technologies

Our engineers have developed some of the most efficient and cost-effective waste-to-energy technologies on the market. Here are a few of our latest innovations in waste-to-energy.

Anaerobic digestion converts a large part of the organic carbon in biomass to biogas, but leaves the nitrogen content. In order to meet nitrogen permit limits, Fluence has developed a proprietary nitrification-denitrification process that doesn't require the addition of an organic carbon source. The process converts the nitrogen of the digestate into gaseous nitrogen without the use of chemicals, and without generating byproducts, allowing the client to reliably meet nitrogen discharge limits.
Fluence has also developed a proprietary nitrosation–denitrosation treatment process that can be used in cases of very limited residual COD or high ammonia load. Nitrosation partially converts ammonia in gaseous nitrogen using only two thirds of the energy required by nitrification-denitrification, and is three times faster.
Biogas Desulfurization
Biogas produced by the anaerobic treatment process can be rich in hydrogen sulfide, which is harmful to cogenerators and boilers. Hydrogen sulfide must be removed in a process called desulfurization before the biogas can be used.

Fluence engineers have developed a unique biogas desulfurization technology that doesn't use the common methods of blowing air into the digester dome or scrubbing the biogas with a caustic soda solution. Instead, it uses a synergic process involving the wet removal of the hydrogen sulfide coupled with an auto-regenerative system of the washing solution. This significantly lowers consumption of reagents, and subsequently, operating costs. Our solution is the most cost-effective on the market.

Converting Biogas to Biomethane
Biogas is approximately 60% to 70% methane. Specific regulations, particularly in Europe, provide economic incentives to industries to produce biomethane for injection into the grid. Fluence works with technology partners to provide a full turnkey solution for purifying biogas into biomethane.
Anaerobic MBR
At Fluence, our latest anaerobic digestion innovation has focused on anaerobic MBR, a combination of anaerobic digestion and membrane bioreactor technology, which concentrates solid digestate without the use of centrifuges or dissolved air flotation (DAF). This new application:

  • Can process a higher organic load than traditional technologies
  • Reduces the volume required for digesters
  • Provides better quality effluents
  • Uses less polyelectrolyte
  • Can be used to upgrade existing facilities


We’re here to help! Contact us to learn more about our solutions or to discuss your next project with our experts.


Featured Waste-to-Energy Case Studies

Reducing Sludge at a Fish Processing Plant

Fish processing produces an effluent particularly high in nitrogen and COD. A leading tuna processor in Ecuador wanted to add anaerobic digestion to its plant, but it had to be done without interrupting production. The successful renovation allowed the plant to meet environmental standards and reduce its sludge volume by 85%.

CSTR Anaerobic Digester for Bioplastics Manufacturer

When an Italian bioplastics manufacturer began using an innovative process to produce 1-4, Butanediol from a renewable source, it decided to buy and refurbish an existing plant. Using existing and new equipment, we devised three trains for primary treatment of well water, as well as treatment of effluent with a high organic load. The setup includes a continuous stirred tank reactor (CSTR) anaerobic digester to treat sludge and produce biogas, which is used to generate steam for production.

EFC Reactor Efficiently Handles Pharmaceutical Wastewater

Sandoz, a pharmaceuticals producer, wanted to add anaerobic digestion to its aerobic wastewater treatment plant, which had high energy consumption and sludge production. Without interrupting production, an anaerobic digester and a proprietary External Forced Circulation (EFC) reactor were added, producing a highly efficient and cost-effective solution.

Upgrade Helps Paper Producer Meet Environmental Standards

After a large Italian paper producer reduced its water use, pollutants in its effluent were concentrated, which made it hard to meet the parameters of its discharge permit. We refurbished the existing WWT plant, adding an EFC reactor and lamellar clarification. Sludge waste volume was reduced by 8 tons a day, use of electricity was reduced by 8,000 kilowatt-hours a day, and the effluent was brought up to permit standards.

Dealing With High-COD Slaughterhouse Waste

When a leading Italian food processor wanted to improve its wastewater treatment and lower sludge-disposal costs, anaerobic digestion and nitrification-denitrification were added to its treatment train to deal with COD-heavy slaughterhouse wastewater.

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