EUBCE 2026 - Oliver KRÖCHER - Biogas Up-grading by Flexible Power-to-Gas and Membrane Separation

Biogas Up-grading by Flexible Power-to-Gas and Membrane Separation

Short Introductive summary

Biogas-based power-to-X technology allows storing renewable electricity, while producing CO2-neutral products. This work investigates the conversion and upgrading of digestion-derived gas mixtures with focus on increasing the operational flexibility of the overall process. Compensation of fluctuations in the feed gases enable a better economic predictability of the processes and increase the product gas output. Based on flexible methanation and gas separation experiments with a commercial biogas upgrading module performed in a TRL 5 plant, a flexible upgrading concept using a permeation model was developed. It allows to swiftly switch between conventional membrane-based CO2 separation by a two-stage membrane unit and direct methanation of biogas and subsequent H2 recycling. A techno-economic analysis was performed on the flexible upgrading concept. The operation hours of the electrolyser were determined by applying a threshold to the electricity price distribution of the past years. The sensitivity on electricity cost (i.e. PtG operation hours) is clearly reduced with the flexible processes, resulting in a better economic predictability.

A. Gantenbein, PSI - Paul Scherrer Institut, Villigen PSI, SWITZERLAND
O. Kröcher, PSI - Paul Scherrer Institut, Villigen PSI, SWITZERLAND
T.J. Schildhauer, PSI - Paul Scherrer Institut, Villigen PSI, SWITZERLAND