Ammonia capture with biogas purification from anaerobically digested poultry litter

• Main Authors: Kulow, A. (Author), Lansing, S. (Author), Lupitskyy, R. (Author), Moss, A. (Author), Witarsa, F. (Author)
• Format: Article
• Language: English
• Published: John Wiley and Sons Ltd 2021
• Subjects: ammonia; Ammonia; ammonium chloride; Ammonium chloride; anaerobic digestion; Anaerobic digestion; Article; biogas; Biogas; Biogas purifications; biomass; carbon dioxide; Carbon dioxide; Chemical industry; Chlorine compounds; Desulfurization; Effluents; hydrogen; hydrogen sulfide; Hydrogen sulfide; methane; nitrogen; Nitrogen; Novel design; Nutrients; Organic nitrogen; pH; poultry; poultry litter; Poultry litter; purification; reactor design; recovery; Scrubber systems; Scrubbers; Scrubbing systems; separation; Stripping (removal); Sulfur compounds; Total ammonia nitrogens
• Online Access: View Fulltext in Publisher

 BACKGROUND: Poultry litter (PL) has a high solid and organic nitrogen content that is converted into NH3 during anaerobic digestion (AD), requiring the dilution of PL influent prior to AD. With nutrients extracted from the AD effluent, the water could be reused for influent dilution or for other purposes, while creating a designer nutrient product from the PL matrix. The study goal was to determine the effectiveness of an ammonia (NH3)-stripping and scrubbing system to remove and capture NH3 from anaerobically digested PL. After NH3 stripping, a novel, patent-pending dual-vessel NH3-scrubber system was designed to simultaneously capture the stripped NH3 while producing higher quality biogas through partial removal of non-combustible carbon dioxide (CO2) and corrosive hydrogen sulfide (H2S). RESULTS: The stripping reactor reduced total ammonia nitrogen (TAN) by 84.6–90.4% when loaded with an ammonium chloride solution or screened PL digestate after 4 h, while the scrubber captured 73.3–76.2% of the stripped NH3 when proxy biogas streams (59–60% CH4, 40% CO2) with two H2S concentrations (0.1 or 1% H2S) were used. The scrubber reduced CO2 and H2S concentrations in the biogas by 3.9% and 23–29%, respectively. CONCLUSION: The study demonstrated a novel NH3 stripping-and-scrubbing system that successfully reduced TAN in anaerobic digestate, captured the stripped NH3, and reduced CO2 and H2S concentrations in biogas. The novel design can be used to increase the adoption of AD for PL by providing a useful NH3 fertilizer, wastewater with less NH3, and a biogas stream with less H2S. © 2020 Society of Chemical Industry (SCI). © 2020 Society of Chemical Industry (SCI)