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June 11, 2025
Bion’s Ammonia Recovery System was conceived from a need to capture and upcycle the ammonia released when an anaerobic digester is used to produce biogas from livestock manure. Ammonia loss from digester effluent (digestate) is a significant environmental problem and a waste of the nitrogen resource. Bion determined that a high-performance organic nitrogen fertilizer was the highest value byproduct that could be produced from the ammonia. Bion set out to develop a platform to produce the fertilizer reliably and at the lowest possible cost, while maintaining its organic integrity.
The ARS uses evaporation to isolate the ammonia from the waste stream and its suspended solids. A certain amount of water must be evaporated along with the ammonia. After the combined vapor is condensed, the ammonia is in a ‘clean’ solution that can now be concentrated in a distillation column without fouling the column with suspended solids from the digestate. Once concentrated, the ammonia solution enters a diffusion tank where it is partially stabilized with CO2 (also from the waste stream) to produce Bion’s organic nitrogen fertilizer products.
Bion engaged Buflovak, a New York engineering firm, to assist with ARS development, due to their focus on evaporation, distillation, and separation processes. Their involvement began in 2019, with an early pilot system, followed by design and fabrication of the small commercial scale ARS at Fair Oaks, Indiana (FO), that commenced operations in summer 2023. FO system startup was followed by approximately 18 months of operations and optimization that were recently completed.
ARS optimization at FO and the Technology-Optimization Report were completed with guidance from Buflovak, based on data collected and analyzed by Bion from operations at FO. The Buflovak engineering team that was integrally involved during ARS development provided input throughout the optimization phase and participated in a final review of the report. All comments and suggestions provided by the Buflovak team were incorporated in the report. The Buflovak engineering team is available to discuss the report and its conclusions.
Bion did not build the demonstration facility to determine if the ARS would ‘work’. Evaporation and distillation are well-understood principles and used in many industrial processes. Bion built Fair Oaks to determine optimal design and operating conditions at small commercial scale, before committing to the risks of full-scale design and deployment. Details of the FO initiatives and results, including data tables, are contained in the full Technology-Optimization Report, which is available under Confidentiality Agreement. The Report’s Conclusions follow this Summary.
As shown in the Report’s Conclusions, the ARS has demonstrated it is stable, reliable, and scalable (with further operational improvements expected at full scale). The ammonia recovery platform is now ready for the final design process of a full-scale commercial system.
ARS Economics
An evaluation of system economics was not an objective of the FO optimization. However, the substantial operational improvements we achieved directly impact our modeled system economics and fertilizer production costs. Early financial models were developed from a Budgetary Proposal prepared by Buflovak for a commercial system Bion was evaluating. Our modeling estimates were cautious, in keeping with our historically conservative approach. We anticipated significant improvements in system performance at the FO facility. Design and operational enhancements, coupled with larger scale, contributed to the steady-state operations needed to minimize capex and opex. Key improvements that were accomplished during optimization at FO:
- Reduced the amount of water required to be evaporated along with the ammonia.
Reducing this ratio was the biggest driver of the reductions we achieved in modeled opex and capex. As detailed in the report, the optimized ARS at FO required 33% less water to be evaporated from the waste stream than was previously modeled.
OPEX: Thermal energy for evaporation was the largest component of overall opex at ~32%. The 33% decrease in evaporation results in a 10% reduction in overall opex.
CAPEX: The ARS was sized/modeled to process 100,000 gallons per day of digestate. FO demonstrates the same system will actually process 150,000 gpd (and recover the 50% more nitrogen/ fertilizer it contains at the same cost). Impact on project capex will vary with system sizing, but capex will be lower than earlier modeling indicated.
- Minimized foaming events that increase opex and can lead to costly system shutdowns.
Increased scale, coupled with design and operational improvements, largely eliminated unexpected foaming events that were previously modeled at 15% of overall opex.
- Maintained continuous steady state operations.
The system proved to be stable and reliable, as demonstrated throughout the Report. Steady flow conditions are the cornerstone of an efficient process. In the case of Bion’s ARS, it will ensure digestate treatment and fertilizer production at the lowest possible cost.
Actual results at Fair Oaks indicate opex for a full-scale commercial system will be about 25% lower than previously modeled. These savings directly offset the cost per pound to produce Bion’s nitrogen fertilizer. Overall capex will be significantly reduced, too, but to what degree is less predictable since the relationship between capex and system capacity is not linear (as it is with energy and opex). Further, capex measured on a per unit of waste treated- or fertilizer produced-basis will be significantly lower than previously modeled. We expect to see additional improvements in system performance and efficiency as it is further scaled up to full commercial capacity, with corresponding improvements to both capex and opex.
Looking Forward
Our third-gen Ammonia Recovery System is ready for deployment now, but our 30-plus years of commitment to innovative organic waste treatment solutions will continue. Our fourth-generation technology development is already underway. Our goal is to dramatically reduce capital and operating costs, recover more clean water for reuse or discharge into local waterways or aquifers, and create solutions for the unique challenges faced by industrial sources, that our patents cover since 2024.
California trends toward requiring ammonia solutions and clean water recovery from dairy/livestock production could expand to other parts of the country. We are positioned to provide verified solutions for future water and/or nutrient regulations the industry may face for its impacts to ground- and surface- water.
Bion’s legacy ‘Separate and Aggregate’ strategy applies today, more than ever, to waste and wastewater treatment. Seeking solutions for a circular economy, reducing supply chain waste, and improving the sustainability of both food and energy production are what drive Bion’s technology development and opportunities.
Recovering Resources | Preventing Pollution
Following are Conclusions from Bion’s ARS Technology-Optimization Report. The full report can be obtained from Bion under NDA.
Conclusions
Steady State Operation – Exceeded project expectations by developing optimized operating procedures that will not require continuous use of defoamer under typical operating conditions. With the high cost of the OMRI certified defoamer, this will result in substantial cost savings. The identified design modifications to the control program, level sensors and flow control equipment will further simplify full-scale operation and ensure routine steady state operation.
Multi-Effect Testing – Successfully completed under baseline throughput operating conditions. No operational upset when we varied and maximized pressure and temperature transitions as Bion utilized the modified steady state operating procedure to keep foam production down. Foam suppression is the critical component: spontaneous foam generation that contacts the heat exchanger fouls the surface, significantly reduces energy reclamation efficiency, and requires system shutdown and cleaning. Maintaining steady state is the key to reclaiming 60% – 70% of the energy and minimizing operational cost, and this was accomplished. Run data incorporated into Buflovak design model showed consistency with expected design values.
Water/Ammonia Evaporation/Volatilization Ratio – Provided favorable results as multiple single effect runs, and multiple multi-effect runs produced data indicating a 90%+ ammonia volatilization rate with a water evaporation rate of 30% – 35% under worst case digestate conditions. Requiring 33% evaporation of the bulk water, as compared to the 50% initially anticipated, translates to a savings of 33% of the original expected heating and cooling energy cost.
Concentrated Distillate Product/Liquid AB Solution – The concentrated ammonium-N product will help minimize costs as it is less expensive to produce and will eliminate the capital cost of the crystallization equipment needed to produce ammonium bicarbonate crystals. The excess CO2 from the biogas upgrading system can still be used to help stabilize the concentrated solution at concentrations low enough to prevent crystal precipitation. The use of this option should be determined in conjunction with the wholesale partner who ultimately purchases the concentrated solution. Steady state-run data with targeted column control yielded a minimal pressure increase in the system and subsequent minimal loss of undissolved ammonia vapor or dissolved ammonia in the distillation column wastewater as the critical operational parameters were determined. This was consistent with the most recent single-effect and multi-effect production runs.
Design and Scaling – Routine steady state operation of the integrated system has been established with the current system. The relative hydraulic retention times, throughput, and surface area relationships from the steady state production runs are comparable to expected performance from the initial design and applied to the scaled design. In other words, the design is functioning and providing sufficient data to provide design criteria for scaling to larger operations. Despite the challenging nature of the digestate utilized at Fair Oaks, with its varying solids content, low flow rates, high fine solids content during the critical multi-effect runs, and low ammonium-N concentrations in the digestate – the system was able to find operating points to continue operation, which is a testament to the system’s flexibility and reliability, as well as applying it to the scaled design. Scaling Bion’s technology will reduce many of the challenges discussed above. Higher flow rates are expected to enhance a number of operational efficiencies, including access to a wider array of equipment options with reduced clogging risks, while achieving enhanced cost efficiencies.
Next Steps at Fair Oaks – Fair Oaks will continue to be a valuable asset for Bion as we move on to design and construct the next project elsewhere. Bion plans to continue to utilize the system to push the throughput and evaporation limits of the digestate, eliminating system risk and enhancing operational efficiencies. These steps will highlight opportunities to reduce system sizing without sacrificing operational costs, consistent with standard engineering development practices. The first full-scale production system will inherently have added capacity safeguards to accommodate variations in the makeup of the influent feedstock and subsequent AD output. Ideally, this process goal would be run in conjunction with the final design process for the initial full-scale project, in order to perform targeted runs that reflect influent and operating conditions specific to that project.