Example Ethane to Acetic Acid

Although the direct oxidation of ethane to acetic acid is of increasing interest as an alternative route to acetic acid synthesis because of low-cost feedstock, this process has not been commercialized because state-of-the-art catalyst systems do not have sufficient activity and/or selectivity to acetic acid. A two-week high-throughput scoping effort (primary screening only) was run on this chemistry. The workflow for this effort consisted of a wafer-based automated evaporative synthesis station and parallel microfluidic reactor primary screen. If this were to be continued further, secondary scale hardware, an evaporative synthesis workflow as described above and a 48-channel fixed-bed reactor for screening, would be used. 

Methyl Red dye and (b) integrated intensity vs. acid amount on absorbent plate calibration curve. 

C02 was not significant because the absorption capacity for acetic acid that condenses on the plate is much greater than for C02. The mass spectrum of the reactor exhaust did not exhibit peaks other than those associated with ethane, C02, acetic acid, and a CO (and/or C2H4 cracking fragment of ethane). 

Acrylonitrile is commercially produced from propylene by a molybdate-based catalyst that has been optimized to produce a yield of around 80% acrylonitrile. Utilizing a less-expensive feedstock, the selective ammoxidation of propane to acrylonitrile has significant potential in reducing acrylonitrile production cost. The work-flow for this chemistry consisted of a primary scale evaporative synthesis station and 256-channel parallel screening reactor using a proprietary optical-based detection method. For the initial work shown here, secondary screening was done on a six-channel fixed-bed reactor. 

Reaction conditions for the Massively Parallel Microfluidic Reactor were a feed of 6% C3H8, 7% NH3, 17% 02, and 70%, a reaction temperature of 420°C, and a residence time of 0.4 s. Integrated responses from the detection plate spots were non-linear and a calibration curve was generated from standards to quantify acrylonitrile content in the detection plate spots (Fig. 3.18). 

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