No abstract

Process intensification leads to a substantially smaller process technology. In this work, we present a combination of an active microsize catalyst and an effective microstructured reactor technology for CO 2 methanation. The product of the reaction is renewable synthetic natural gas which can be injected into the existing gas infrastructure. The designed process was evaluated at pilot scale (37 kW electrolyzer) in a relevant environment using sewage biogas and a CO 2 waste stream as carbon sources. The desired gas quality was obtained in a 2step synthesis process at moderate pressure using a decreasing temperature profile (T = 275−475 °C) and water sequestration. Temperature profiles were adjusted by vaporizing water, compressed air, and heating cartridges. It was observed that pressure, carbon feedstock, and GHSV had an impact on the product gas quality. At the minimum pressure (P = 5 bar•g) for direct gas grid injection purposes, the process worked successfully at 31 500 h −1 using upgraded CO 2 and 37 500 h −1 using biogas. This represents a reduction of 4 times the volume of the commercial reference. Accordingly, the limits of CO 2 methanation process intensification were clearly crossed by the combination of reactor and catalyst miniaturization.

Conversion of intermittent renewable energy into synthetic fuels and chemicals is required to secure long‐distance transport and feedstock for chemical industry. Due to the fluctuating energy generation, process intensification and feed flexibility are essential. This contribution investigates the importance of feed flexibility on the buffer size with applying a 20:80 scenario of wind/solar energy generation. The degree of power and plant utilization are calculated. With the capability to accept a lower load bound of 17 % after only 10 min, a minimum tank capacity of only 1.3 h is calculated to avoid a fuel plant stop throughout a calendar year. Additional tank capacity for peak power compensation in the range of ∼10 h is beneficial for the utilization degree of power and under the prerequisite of a load‐flexible fuel plant.