Synthesis of oxymethylene dimethyl ethers (OME_n) via methanol mediated CO_x hydrogenation over Ru/BEA catalysts

Oxymethylene dimethyl ethers (OME_n) are attracting a lot of research interest but application in chemical industry is not yet practical due to a number of challenges. In this work, OME_n production is reported from methanol mediated heterogeneous catalytic CO_x hydrogenation over Ru catalysts. Highest yield was achieved over 3%Ru/BEA at 150 °C, 75 barg and H₂/CO₂ molar ratio of 3. Molecular sieve water adsorbent was used during CO₂ hydrogenation to remove water, which increased the selectivity towards OME_n. An investigation of reaction mechanism showed the dominancy of formaldehyde intermediate route over methyl formate route for 3%Ru/BEA catalyst. In present study, CO₂ hydrogenation provided the maximum OME₁ and OME₂ yields of 7.42 and 2.13 mmol/g_cat.L_MeOH, respectively at the above conditions.