Multiscale Simulation-Guided Reaction Engineering for PdCu-Catalyzed Propylene Acetoxylation: From Reaction Mechanisms and Kinetic Modeling to Full-Process Design and Optimization

Abstract 1,4-Butanediol (BDO) is a critical high-value chemical for Spandex, biodegradable plastics, and lithium-ion battery materials, with allyl acetate (AAc) serving as its key upstream intermediate. The emerging direct hydroformylation route for BDO avoids toxic allyl alcohol and reduces energy consumption but requires ≥99% pure AAc. However, no industrial process for high-purity AAc has been reported, becoming a key bottleneck for BDO industry upgrading. This work adopted a multiscale simulation method integrating density functional theory (DFT), kinetic Monte Carlo (kMC), and process intensification/system integration. DFT calculations clarified the reaction mechanism of the key byproduct allylidene diacetate, whose formation is controlled by the C–O coupling of CH3COOCHCHCH2* and CH3COO*. Based on DFT results, kMC simulations were adopted to calculate the turnover frequency and space-time yield of allylidene diacetate and obtain its intrinsic kinetic equation. The intrinsic kinetic equations of the other six main and byproducts were obtained in the same way, which agree well with industrial data. On this basis, a high purity propylene based allyl acetate production process was developed via process intensification and system integration, which effectively separates allyl acetate from difficult to separate components such as water, acetic acid and aldehydes, with product purity above 99.9% to meet the strict feedstock requirements of direct hydroformylation. A heat integration strategy was proposed, reducing plant steam consumption by 30%. This work proposes a theoretical multiscale framework coupling DFT, kinetic Monte Carlo (kMC), process intensification and system integration. Based on series of computational predictions, this integrated tool may support the conceptual design of high-purity allyl acetate production flowsheet, and could serve as a feasible theoretical reference for the full-scale development linking catalytic reaction research and separation process optimization in chemical manufacturing.