what's inside a methanol synthesis reactor with green hydrogen h2
Channel: VOLKS-ELECTROLYZER
Date: 2023-12-08

https://v-electrolyzer.de/

Methanol production
Hydrogen for Methanol
Power to X
Carbon capture


Methanol use
Combustion
Methanol Fuel Cell

DMFC: Direct Methanol FC
A special form of PEMFC is the DMFC, in which methanol is fed to the anode in liquid or vapor form. The principle is shown in Fig. 6.9.
Atmospheric oxygen is supplied to the cathode. A proton-conducting polymer membrane is used as the electrolyte, which always requires water for the conduction mechanism. This requires moistening via the supplied material flows or by back-diffusion of product water from the cathode to the anode. In most cases, a liquid methanol-water mixture is fed to the anode. However, this requires precise dosing of the mixture concentration via a dosing pump. The charge transport takes place via H+ ions. One problem is the so-called methanol crossover. Methanol diffuses from the anode to the cathode side and mixes with oxygen at the cathode surface. The undesired methanol oxidation reduces the performance and thus the efficiency of the cell. CO2 is produced as waste gas at the anode. Reaction
Anode: CH3OH + H2O ! CO2 + 6 H+ + 6 e Oxidation/electron donation
Cathode: 3/2 O2 + 6 H+ + 6 e! 3 H2O Reduction/electron absorption
Overall reaction CH3OH + 3/2 O2 2 H2O + CO2 Redox reaction
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The main advantages of the DMFC are a direct conversion of the fuel methanol and a simple system design because, in contrast to the conventional PEMFC, no complex humidifier unit is required. DMFCs are mostly used for small applications at low power levels up to about 1 kW and in the portable range up to a maximum of 5 kW. The DMFC has a good lifetime and is easy to refuel. The efficiency is relatively low, a problem is the permeation of methanol, CO2 is produced as exhaust gas.
 
Fig. 6.9 DMFC principle