M
icrochannel Reactor Technology

 
Microchannel chemical processing technology is an emerging field with applications in most industrial processes due to excellent mixing, controlled reaction environment, and energy efficiency. This technology offers improvements in existing processes and will enable new processes to become cost effective. Of particular interest is the reformation of hydrocarbons to hydrogen for fuel cell applications, the upgrading of natural gas to high value liquids, and the conversion of carbon dioxide to useful products which do not contribute to global warming.
 
The basic MEI microchannel reactor design is based on the flow between parallel platelets coated with catalyst. The large aspect ratio of the channel provides extensive surface area in a small volume. Microchannel reactors were developed based on ceramic substrates as well as metal substrates. In both types of reactors, multiple layers coated with catalytic material are bonded, forming a monolithic structure. An added benefit of a layered pattern is the ability to easily scale up or down by adjusting the number of layers. This provides great flexibility in the design if desired production capacity is changed, without the need to redesign the reactor (as it would be the case in a tubular reactor).
 
Makel Engineering has developed techniques to deposit various catalysts directly into the microchannel layers, including catalysts for methane reformation, carbon monoxide and dioxide methanation, water gas shift reaction, and preferred oxidation of carbon monoxide. The result is a thin layer of catalyst (order of hundreds of microns) that does not generate significant pressure drop, and is not susceptible to settling, a problem common to packed beds.
 
MEI’s ceramic-based reactors use laser machined ceramic platelets to form the reactor structure. Catalyst is applied to the laser machined ceramic, providing a robust catalyst that is not susceptible to settling and does not increase pressure drop of the system. Due to they inert nature, ceramic substrates are compatible with most reaction media, even at high temperatures. They also enable incorporation of printed patterns for heaters and temperature sensors.
 
MEI’s metal-based reactors use etched metal platelets to form the reactor structure. Catalyst is applied to the etched platelets by a method similar to that used for ceramic platelets. Multiple layers are bonded forming the microchannel reactor. The metal-based reactors have better mechanical properties, such as being tolerant to vibration and thermal cycling, compared to ceramic-based reactors. Incorporation of auxiliary components such as heat exchangers, manifolds, condensers, which are usually metal-based, is facilitated as well.