Work

Biogas upgrading with PZ/MDEA: Pilot demonstration of absorber intercooling, cold solvent split and lean vapor compression

Year: 2025

Type: article

Abstract: The amine scrubbing technology enables upgrading of biogas to high purity biomethane. In this study, a mobile amine scrubbing pilot plant is upgrading industrially produced biogas utilizing a solvent consisting of 6 wt% piperazine (PZ) + 39 wt% methyldiethanolamine (MDEA). The aim of this study is to investigate the potential of three advanced process configurations: Absorber intercooling (IC), cold solvent splitting (CSS), and lean vapour compression (LVC), where CSS and LVC are used in combination. In base case operation, the PZ/MDEA solvent requires a specific reboiler duty (SRD) of 3.4 MJ per kg CO 2 . We find that IC increases the CO 2 content in the rich solvent by 20 % and reduces the specific reboiler duty (SRD) to 3.25 MJ per kg CO 2 . The SRD is further reduced to 2.8 MJ per kg CO 2 when combining IC with LVC and CSS. A ProMax model for the LVC system is used to quantify uncertainties and upscaling of the LVC system for PZ/MDEA. By including the compression work for the LVC, it is shown that the LVC configuration increases the overall energy consumption in the pilot scale experiments.

Source: Fuel

DOI: 10.1016/j.fuel.2025.135296