Challenges in part load operation of biogas-based power-to-gas processes (part I)

Direct methanation of biogas enables the storage electrical energy in carbon-neutral (bio-)methane and subsequent injection into national gas distribution grid. The intermittent availability renewable electricity, as well varying nature production by e.g. anaerobic digestion, necessitate enhanced operational flexibility such a Power-to-Gas process intermediate buffer storage. This work provides experimental data dynamic part load operation TRL 5 plant with upgrading to grid-ready biomethane. Full recycling unreacted H 2 could be achieved commercial membrane (Evonik SEPURAN ® Green). Using real biogas, sequence levels down 45% full capacity were tested. Stable demonstrated grid limitations fulfilled after equilibration system. Additionally, an idealised PtG chain was simulated focus on sensitivity analysis hours. It shown that increasing hydrogen decreases number start-up shut procedures plant. using equally sized electrolyser unit, allowing only during emptying tank leads longer activity phases while reactor filling had negative effect.