What is a BMP test?
The Biochemical Methane Potential (BMP) test is a batch experiment used to determine the maximum methane potential and biodegradability of an organic substrate. During the test, the substrate is mixed with an anaerobic bacteria culture (the inoculum), normally retrieved from an active digester. Optimal conditions for the completion of the process (temperature, mixing, nutrients, pH, alkalinity) must be ensured for the whole duration of the experiment.
Biogas, mainly composed of methane and carbon dioxide, is produced during the testing period due to the anaerobic degradation of organic contents of the substrate. Carbon dioxide (acidic gas) can be removed by chemical absorption with alkaline chemicals/chemical solutions: the methane generated from the substrate is then measured and referred to the mass of volatile solids or to the chemical oxygen demand (COD) of substrate added in the test vessel, which is called the biochemical methane potential of the substrate.