Kamal, Sumit

A known conventional route to produce methyl pentenone (MPO), a perfumery intermediate used in the fine chemical industry, is through the aldol condensation of acetaldehyde with methyl ethyl ketone (MEK) using an acidic catalyst such as H2SO4. However, the use of homogeneous catalysts makes the overall process inefficient because of multiple side reactions, lower yield, and corrosion. In this work, we emphasized the use of commercially available reusable heterogeneous cation exchange resin Amberlyst-15 as a catalyst to develop the experimentally validated process to improve the MPO yield and to develop the production strategy for MPO production at the industry scale (i.e., 4 TPD) using aspen plus in batch mode. Among different affecting parameters, the semibatch mode of acetaldehyde addition in the batch reactor was found to be the most effective way to improve the MPO selectivity up to 92% from 70% while using batch mode of reaction. The BatchOp model was used to simulate the batch and semibatch reactor operation, and the BatchSep model was used to develop the downstream separation strategy for using batch distillation. The effects of recycling only a pure MEK vs MEK-H2O azeotrope mixture over reaction performance and MPO selectivity were investigated. Overall, the standard operating procedure for MPO production using semibatch mode to achieve nearly 92% MPO selectivity using reusable heterogeneous catalyst Amberlyst-15 and MPO recovery of 95% at the purity of 99% using batch distillation is developed. © 2025 American Chemical Society.

Hydrogen is considered as one of the promising green energy alternatives to non-renewable fuels to accommodate the ever-increasing demand for energy resources. The growing application of hydrogen at its ‘technical grade, i.e., 99.999% pure’ in the fuel cell and as blending with natural gas in the gas grid has enormously increased the demand to produce extremely pure hydrogen for all practical purposes. Ammonia, being easy to liquefy, and store, and with high hydrogen content (17.6% w/w) chemicals, is considered as one the important carbon-free sources of hydrogen. Among different existing technologies, membrane reactors have been extensively explored mainly because of the feasibility of simultaneously decomposing ammonia using a catalyst and in-situ separate hydrogen using a membrane. Conventionally, packed bed membrane reactors (PBMR) are extensively explored for the process of ammonia decomposition. However, catalytic membrane reactors (CMR) are considered as advanced membrane reactors mainly because of the constraint of diffusional mass transfer resistance and temperature non-uniformity in PBMR. The application of materials such as Ruthenium (Ru) based catalysts and Palladium (Pd) based inorganic membranes are extensively explored owing to their high performance. However, their industrial application is constrained due to the high price, limited availability, and the brittle nature of the Pd-membrane. In this chapter, the recent developments in the technologies for catalytic membrane reactor-based hydrogen production from ammonia are discussed. A comprehensive insight on the material selection for catalyst and membrane preparation, reactor design, and its coupling with sustainable processes of solar energy will be elaborated.