The test setup consists of a gas cylinder (GC) containing synthetic flue gas, a thermally insulated high-pressure reactor (HPR) with a total volume of 1.9 ± 0.1 L, a separate cooling cycle (CC) with a Lauda IN 280 XT cryostat, a continuous operation line (COL), and a probe extraction line (PEL). The COL (dashed line in Fig. ) connects the reactor outlet to all valves and sensors used for continuous operation. For batch or semi-batch operation, the reactor outlet is closed using the ball valve BV-COL. In these operational modes, a gas lock (GL) formed by two ball valves on the PEL is positioned close to the HPR to extract tiny samples of gas for subsequent analysis. With a volume of only 1.84 ± 0.1 mL, extractions of less than 0.2 vol% of the gas contained in the reactor are possible, leaving the system practically unaffected.