Anaerobic digestion process monitoring system and anaerobic digestion process monitoring method

An anaerobic digestion process monitoring system which predicts a production amount of biogas to be produced from a fermented liquid obtained by acclimating anaerobic microorganisms inside a digestion tank with organic waste fed into the digestion tank, and monitors a state of an anaerobic digestion process, the anaerobic digestion process monitoring system comprising:

• a first sensor which measures a feeding amount of the organic waste into the digestion tank and outputs a measurement result as load data;
• a second sensor which measures at least pH and an electrical conductivity of the fermented liquid inside the digestion tank, as a property, and outputs a measurement result;
• a process observation circuitry to accumulate the load data and at least the pH and the electrical conductivity;
• a preprocessing circuitry to calculate a concentration of an organic acid and a concentration of ammonia nitrogen from the load data, the pH, and the electrical conductivity, using a first estimation model constituted of at least a correlation formula between the concentration of the organic acid in the fermented liquid inside the digestion tank, and the load data and the pH, and a correlation formula between the concentration of the ammonia nitrogen in the fermented liquid inside the digestion tank, and the load data and the electrical conductivity, acquired before system introduction or in a given learning period after system introduction;
• and
• a gas production amount prediction circuitry to predict a biogas production amount prediction value, from at least the load data, the pH, the electrical conductivity, and the concentration of the organic acid and the concentration of the ammonia nitrogen calculated by the preprocessing circuitry, using a second estimation model constituted of at least a correlation formula between the biogas production amount, and the load data, the pH, and the concentration of the organic acid in the fermented liquid inside the digestion tank, and a correlation formula between the biogas production amount, and the load data, the electrical conductivity, and the concentration of the ammonia nitrogen in the fermented liquid inside the digestion tank, acquired before system introduction or in a given learning period after system introduction, wherein
• the state of the anaerobic digestion process is monitored using the concentration of the organic acid and the concentration of the ammonia nitrogen calculated by the preprocessing circuitry, and the biogas production amount prediction value predicted by the gas production amount prediction circuitry.