Process and system for producing dimethyl ether

A system for performing the synthesis of dimethyl ether (DME), comprising:

• (a) a first inlet (a1) and a second inlet (a2) for receiving a feedstock comprising H2 and COx, wherein x=1-2,
• (b) a reverse water gas shift reaction zone (b) for converting H2 and COx to H2O and CO, comprising an inlet (b1) for receiving a gaseous mixture, a catalyst bed (b2) comprising a reverse water gas shift catalyst and a water-selective adsorbent, and an outlet (b3) for discharging a gaseous mixture;
• (c) a separator (c) comprising an inlet (c1) for receiving the gaseous mixture originating from zone (b), means (c2) for separating the gaseous mixture into DME and a gaseous mixture comprising synthesis gas, an outlet (c3) for discharging the gaseous mixture comprising synthesis gas and an outlet (c4) for discharging DME;
• and
• (d) dimethyl ether production zone (d), comprising an inlet (d1) for receiving the gaseous mixture comprising synthesis gas originating from separator (c), a catalyst system (d2) capable of converting synthesis gas to dimethyl ether, and an outlet (d3) for discharging a gaseous mixture, wherein zone (d) is not a separation-enhanced DME synthesis (SEDMES) reaction zone;
• wherein the gaseous mixture entering the inlet (b1) comprises the gaseous mixture originating from zone (d), wherein the molar ratio of H2 to COx in the gaseous mixture is at least (x+0.8);
• wherein the inlet (a1) is in fluid connection with the inlet (b1) and the inlet (a2) is in fluid connection with the inlet (d1), the outlet (b3) is in fluid connection with the inlet (c1), the outlet (c3) is in fluid connection with the inlet (d1), and the outlet (d3) is in fluid connection with the inlet (b1).