2. Methods
The microchannel reactor comprises a plurality of process microchannels containing the catalyst, transferring heat from the process microchannels to a heat exchanger, and removing the product from the microchannel reactor. The heat exchanger comprises a plurality of heat exchange channels adjacent to the process microchannels. The heat exchange channels are microchannels. The unstructured mesh of the microchannel reactor is illustrated schematically in Figure 1 in which the reactor comprises a plurality of process microchannels transferring heat from the process microchannels to a heat exchanger. The term microchannel refers to a channel having at least one internal dimension of height or width of up to about 2.0 millimeters. The microchannel has a diameter of 0.7 millimeters and length of 50.0 millimeters. The other dimension of height or width may be of any dimension. Fluid flows through the microchannel along the length of the microchannel. The process microchannel has an entrance and an exit and at least one heat exchange zone adjacent to the process microchannel. The heat exchange zone comprises a plurality of heat exchange channels, and the heat exchange channels extend lengthwise at right angles relative to the lengthwise direction of the process microchannel. The length of the heat exchange zone is less than the length of the process microchannel. The width of the process microchannel at or near the process microchannel exit is greater than the width of the process microchannel at or near the process microchannel entrance.