Study of distances of effects (explosion, thermal, toxic) of the main scenarios of biogas purification and methane injection units. Study report

Within the context of development of future biogas purification units (located downstream of methanization and biogas production units), it is interesting to be able to assess, from the first design stages, the main accidental consequences with respect to envisaged installations, in order to select the locations of future installations, technologies to be chosen, and the main safety constraints to be taken into account. Thus, this study reports the calculation of distances of different effects (explosion, thermal effects, toxic dispersion) of major accidental scenarios for these units. These distances have been calculated from installation operation data provided by two manufacturers of two biogas purification processes developed by Flowtech and by Air Liquide which will probably prevail during the years to come (water-based washing, selective permeation). After a recall of risks related to methane and to biogas, the report proposes an overview of the status of development and technologies of biogas purification processes (absorption, adsorption, permeation, cryogenics). It identifies scenarios for the two selected processes, and reports the assessment of potential hazards for three scenarios.