Anaerobic digestion biogas upgrading using a two-stage membrane system under pilot-scale conditions.

In the present work, the construction, and operation of a pilot-scale biogas upgrading system is presented, employing 2 commercial polyimide (PI) membranes. The Upgrading system treats biogas produced via anaerobic digestion of the sludge, produced from the treatment of municipal wastewater in the facilities of Thessaloniki's Wastewater Treatment Plant. The goal of the separation unit is the production of high purity biomethane (>95%) for potential reuse in terms of energy.

Evaluation of polymeric membranes' performance during laboratory-scale experiments, regarding the CO separation from CH.

The present study evaluates the separation performance of a commercially available polymeric membrane, when employed for the upgrade of biogas to enrich CH from a simulated binary gas mixture. For this purpose, a laboratory-scale membrane set-up device has been designed and assembled, aiming to achieve the production of high purity biomethane (>95%) with simultaneous recycling and utilization of the (considered as) waste CO stream. The examined membrane is a polysulfone (PSF) hollow fiber (HF) one, applied in counter-current flow.