Towards a standardization of biomethane potential tests : A commentary
Inter-laboratory reproducibility of biomethane potential (BMP) is dismal, with differences in BMP values for the same sample exceeding a factor of two in some cases. Multiple national and international inter-laboratory studies show rather low reproducibility in measurement of BMP, with differences for the same substrate exceeding a factor of two in some cases despite the existence of well-known protocols. A large group of BMP researchers directly addressed this issue during a workshop held in Leysin, Switzerland, in June 2015. The workshop resulted in a new set of guidelines for BMP tests published in 2016. The work has continued with two international inter-laboratory studies and one additional workshop held in Freising, Germany, in 2018. The dataset generated by the two inter-laboratory studies were used to refine the validation criteria for BMP tests. Based on these new results, an update to the original guidelines is proposed.