Direct conversion of syngas to DME as a green fuel in a high pressure microreactor: Influence of slurry solid content on characteristics and reactivity of washcoated CuO-ZnO-Al2O3/HZSM-5 nanocatalyst

Micro-channels of a stainless steel micro-reactor were successfully washcoated with Cu-ZnO-Al2O3/HZSM-5 nanocatalyst slurry with different concentrations (10, 20 and 30 wt.%). The 20 wt.% catalyst slurry exhibits uniform coating, good adherence, almost no cracks and homogenous dispersion of copper and zinc. Trend of weight gain during 10 soaks in catalyst slurry was very slow for 10 wt.% but got faster for 20 wt.% and 30 wt.%. The performance of microreactor package with different slurry concentrations were evaluated in direct synthesis of DME. The microreactor regardless of slurry concentration exhibits better reactivity in feed conversion and DME yield in comparison to fixed-bed reactor. Among three different slurry concentrations washcoated on microchannels, 20 wt.% nanocatalyst slurry has the best reactivity in DME synthesis.