Localized Temperature Control in Microchannel Reactors Using Bimetallic Thermally-Actuated Valves

The smaller physical dimensions of microchannel reactors result in substantial reductions in capital and operating cost. However, microreactor control is challenging because of the difficulty of implementing distributed measurement devices and actuators. Using an autothermal catalytic plate reactor coupling steam-methane reforming and methane combustion as a test case, we propose a novel temperature control method using bimetallic strips that function as thermally actuated valves to regulate fluid flow in the microchannels. Bimetallic strips convert temperature variations into mechanical displacement, and by proper placement in the reactor channels, they can function as valves that close and open with temperature changes. We discuss the necessary design decisions and show through simulations that the thermally actuated valves contribute to an inherently safer design of microchannel reactors. We demonstrate that they can compensate for unequal flow distribution to the microchannels and successfully reject disturbances that would otherwise result in hotspots that could damage the reactor structure.