Methanol synthesis catalyst manufacturing using the green solid-state method

In this research study, methanol synthesis catalysts were manufactured with various mole ratios of metal carbonates (zinc, copper and aluminum carbonate) and ammonium hydrogen carbonate via a green solid-state method that employed a ball mill apparatus. Some parameters for the catalyst preparation, such as Al mole percent, Cu/Zn mole ratio, rotations milling speeds and aging time, were optimized to obtain the maximum catalyst activity. The prepared catalysts were compared with the best quality industrial catalyst under the same temperature and pressure condition in a titanium tabular fixed bed reactor. This novel method has many advantages in comparison to the conventional method. The main advantage of the solid-state method is that the methanol synthesis catalyst can be produced without using solvent. Furthermore, this new method reduces operating costs due to the elimination of the filtration and washing steps. Methanol synthesis catalytic activity was maximized at an optimized mole ratio of Cu/Zn of 1.9234 and an Al mole percent of 8 at the maximum grinding speed (450 rpm) during an aging time of 30 min, which showed higher activity (240 gCH3OH/kg cat.h) in comparison with an industrial catalyst sample (218 gCH3OH/kg cat.h). The production of a green catalyst, which requires less water and results in higher catalyst activity, can be widely used for methanol synthesis catalytic applications.