Patent ID: 8747805

Claim:
A process for conducting an equilibrium limited chemical reaction in a microchannel reactor to convert a reactant composition to a desired product, the microchannel reactor comprising a microchannel reactor core comprising a first reaction zone and a second reaction zone, each reaction zone comprising a plurality of process microchannels and a plurality of heat exchange channels, the process microchannels and heat exchange channels being aligned in layers, the first reaction zone being operated at a first reaction temperature, the second reaction zone being operated at a second reaction temperature, the first reaction temperature being higher than the second reaction temperature, the heat exchange channels containing a heat exchange fluid that flows in a direction that is cross-current relative to the direction of the flow of fluid in the process microchannels, the desired product comprising methanol or dimethyl ether, the reactant composition comprising CO and H 2 , the process comprising: (A) determining the equilibrium conversion value for a primary reactant in the reactant composition at the first reaction temperature and at the second reaction temperature, the primary reactant being CO; (B) flowing the reactant composition in the first reaction zone in the microchannel reactor at the first reaction temperature in contact with a first catalyst to form an intermediate product composition, the intermediate product composition comprising the primary reactant and the desired product, the contact time of the reactant composition and intermediate product composition with the first catalyst in the first reaction zone being in the range from about 10 to about 500 milliseconds, the approach to equilibrium for conversion of the primary reactant in the first reaction zone being from about 5% to about 99%, and exchanging heat between the process microchannels in the first reaction zone and the heat exchange channels in the first reaction zone to maintain the temperature within the first reaction zone at the first reaction temperature; and (C) flowing the intermediate product composition from the first reaction zone in the second reaction zone in the microchannel reactor at the second reaction temperature in contact with a second catalyst to form the desired product, the contact time of the intermediate product composition and product with the second catalyst in the second reaction zone being in the range from about 10 to about 500 milliseconds, the approach to equilibrium for conversion of the primary reactant in the second reaction zone being from about 5% to about 99%; and exchanging heat between the second reaction zone and the heat exchange channels in the second reaction zone to maintain the temperature within the second reaction zone at the second reaction temperature, the second catalyst being the same as or different than the first catalyst.