Monitoring of Ammonia in Biogas

Abstract

Ammonia content is an important factor, which has to be considered when optimizing the processes in a biogas plant. A measurement system for a continuous monitoring of ammonia has been constructed, which can be placed in the gas room above the digester. The monitoring is based on the measurement of the electrical impedance. In this system, a condensate is generated on the surface of an interdigital electrode so that the whole stray field is covered by the condensate. For determining the ammonia content, impedance spectroscopy of these drops is performed. The ammonia of the biogas causes a decrease in the impedance in comparison to a pure aqueous condensate. A first evaluation of this measurement system using artificial slurries has been performed.

Operational Parameters of Biogas Plants: A Review and Evaluation Study

“…Portable GC-MS (gas chromatography-mass spectroscopy) [239] CH 4 emissions from pressure relief valves of an agricultural biogas plant Flow velocity and temperature sensors [240] Ammonia in biogas Impedance measurement of biogas condensate in the gas room above the digester [241] Dissolved active trace elements in biogas Total reflection X-ray fluorescence spectroscopy in dried digester slurry [238] H 2 S in biogas Gas responsive nano-switch (copper oxide composite) [242] Microbial communities depend on the substrate combinations Sequencing of the 16S rRNA, biodegradable feedstock samples from eight different biogas plants [243] Controlling gas pressure in the digester Programmable logic controller (PCL) [244] Ammonia in biomethane The currently available technologies do not enable the monitoring of all operational parameters of the biogas plant. Therefore, samples have to be collected from the biogas plant and analyzed in individual facilities (off-line monitoring) [142].…”

Physical Validation of a Residual Impedance Rejection Method during Ultra-Low Frequency Bio-Impedance Spectral Measurements

“…The basic feature of this method is that it can be adapted extremely well to issues other than those listed above. Adapting this technology to specific needs (by, e.g., replacing a reference element or adding new hardware elements) provides an opportunity to adapt it to measurements related to environmental [ 43 , 44 ] and biotechnological [ 45 , 46 ] research.…”

Investigating Methane, Carbon Dioxide, Ammonia, and Hydrogen Sulphide Content in Agricultural Waste during Biogas Production

“…An elevated nitrogen concentration results in an overabundance of ammonia synthesis during the decomposition of proteins and urea. An excessive amount of ammonia can elevate the pH level and generate a harmful setting for methanogens, limiting their functioning [21]. High levels of ammonia (ammonia toxicity) could affect the functioning of methanogens, the microorganisms that produce methane.…”

“…Occasionally, the introduction of exogenous carbon or nitrogen supplies can assist in modifying the C/N ratio. For instance, the act of incorporating straw or sawdust, which are carbon sources, into substrates that are high in nitrogen [21].…”

“…At high concentrations, ammonia can be toxic to the microorganisms responsible for breaking down organic matter. This leads to a slowdown or even a halt in the anaerobic digestion process, reducing biogas yield [21]. Therefore, monitoring and controlling ammonia levels are crucial for optimising biogas production efficiency.…”