AD Support

Solution Strengths, Weaknesses and Critical Indicators

Anaerobic Digester Associated Technology:

NOTE: There are several technology types that are used as part of an integrated manure management system that includes an anaerobic digester and are not applicable to manure management in other cases. The impact of these technologies on the critical indicators are represented as those of an entire anaerobic digester system.

   

  • Long usable life and can be run reliably
  • Creates energy and generates environmental credits
  • Requires proper preparation of the feedstock
  • Requires other technologies for energy utilization
  • Requires other technologies for digestate handling
  • Proper feeding & system monitoring is required to avoid system downtime
  • Proven technology for odor control, GHG reduction and pathogen reduction

Overall Summary

 Primary Application

  • Dairy farms with over 500 cows or farms with meaningful organics for co-digestion.
  • Vacuumed/scraped manure, manure slurries, bedded pack that is diluted with digester effluent.

 Economic/Return on Investment Considerations

  • Economics are almost always a challenge; on a value of renewable energy basis, AD is hard to justify, at present received prices for electricity and gas.
  • AD does provide several non-monetary benefits to a farm (see below).

 Industry Uptake

  • 200 dairy-based U.S. installations and thousands worldwide.

Technology Maturity

  • Refined, standard designs available from multiple technology providers.

Primary Benefits

  • Odor reduction – 70 to 95% reduction of indicator acids.
  • Manure organic matter reduction – 35%.
  • Renewable electrical energy production – 2,000 kWh/cow possible each year.
  • Pathogen reduction – 90%+ elimination of fecal coliform organisms as a typical indicator pathogen.
  • Greenhouse gas emission reduction – amount varies by location and farm-specific, but reductions can be large, on the order of 67%+.
  • Nutrient preservation/transformation – key crop nutrients in manure are not consumed by AD and the nutrient form is more plant available than when not digested.
  • Contributes to society’s goal for organic landfill diversion – co-digestion easily achieved enhancing above benefits.

Secondary Benefits

  • Pre-treatment for tertiary treatments like ammonia stripping.
  • Renewable thermal heat production – 13,500 Btu’s/cow or more possible each year.
  • Less impact on water quality.
  • Increased crop yields possible.

How it Works

  • Raw or pre-treated manure is conveyed into a gas tight vessel on a regular basis (daily or more often) that operates at a set temperature (38 ⁰C in most cases).
  • Naturally occurring microbes in manure break solids down into energy-rich biogas.
  • Biogas is used to fuel engine-generators to make electricity or is cleaned to make a natural gas replacement.
  • Some of the produced gas, or heat produced by an engine-generator set is used to heat the digester making it a net energy production system.

 Pre-treatment and/or Post-treatment Required

  • Pre-treatment not required when organic material is used to bed stalls and/or when manure is not substantially diluted. Pre-treatment to remove bedding sand is required with sand-bedded stalls.
  • Pre-treatment may be used to remove excess moisture from influent from barns were hydraulic flushing is used.
  • Post-treatment not required but may be employed based on overall goals of the manure treatment system.

Limitations

  • Does not reduce volume.
  • Does not work well with raw manure containing bedding sand.
  • Does not work with highly diluted manure due to cost and heat demands for a large vessel.

Other Considerations

  • Currently, most systems are farmer managed, more consistent results may be achieved by dedicated operators.

Solutions Providers in order of 9-Point Scoring System

Streamline Innovations’ VALKYRIE® technology safely and effectively removes hydrogen sulfide (H2S) from your agricultural Biogas or Landfill Gas (LFG) stream without generating harmful byproducts. Removing H2S is a critical step in upgrading your Biogas or LFG stream to meet stringent pipeline specifications and upgrading to commercial Renewable Natural Gas (RNG).…
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IGS Energy’s comprehensive vertically integrated approach to the Renewable Natural Gas (RNG) industry means they construct, own, operate, and maintain anaerobic digesters and gas upgrading facilities that supply RNG and they transport the gas to injection facilities that they also own. They also own Compressed Natural Gas (CNG) stations that…
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CEM Engineering’s biogas/RNG services range from feasibility studies through to detailed design and construction. Their team has experience in conceptual design, feedstock testing, carbon intensity (CI) scores, equipment procurement, construction, and commissioning. With their teams years of combined experience in engineering, designing, and constructing biogas and RNG projects, they believe…
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Environmental assets now encompass the entire spectrum of traditional asset classes from venture capital, to private and public equity, to fixed income. Black Bear provides research and development of investments with positive environmental and financial returns. Black Bear provides environmental asset development, research, and advisory services in the following areas:…
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Peaks Renewables (Peaks) is working with six Maine-based, family-owned dairy farms to generate homegrown renewable natural gas. The Peaks facility is located at Flood Brother’s Farm in Clinton, Maine where the company broke ground early May of 2022. Once construction is completed, this facility is anticipated to produce approximately 130,000…
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Equipment Fabrication – Their vertically integrated manufacturing provides quality control, on-time delivery and cost efficiencies for equipment and components. To accomplish this they Fabricate and test equipment prior to site delivery for faster installation. They also offer customization of their equipment to meet your unique project requirements. Through this customization…
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Grainit provides an intelligent inventory management and documentation tool for farms and biogas plant owners. The solution offered is a data-driven innovation for biogas plant owners to handle and track all locations, suppliers, products, transportations and settlements that are involved in the production process. The system makes it possible to…
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The Mainspring Linear Generator – distinct from an engine, microturbine, or fuel cell – directly converts motion along a straight line into electricity using chemical energy. High Efficiency – Direct conversion of linear motion into electricity Mainspring’s linear generator is designed to enable high expansion of reacted gases and to…
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BAUER offers their customers complete flexibility. Their product offering ranges from simple compression systems, all the way to complete systems with drying, storage, priority, and sequencing. Their customers have the option to choose from several pre-engineered systems, designed for maximum value and shorter lead times, with a wide performance range…
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The BAUER GRU Bauer Compressors has recently been added to the Newtrient catalog. Newtrient will continue to work with Bauer Compressors to further refine the cost and performance information on their technologies and services. Newtrient will update this entry as more information becomes available and as new commercial dairy installations…
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