Optimal Process Synthesis of Pesticide Production Considering Variable Demands and Raw Material Prices.

In pesticide manufacturing, the handling and storage of hazardous chemicals are routinely performed under extreme conditions. Demand variability, particularly short-term and seasonal shifts, can exacerbate safety risks by increasing the need for extended storage of dangerous intermediates. Temporal and seasonal fluctuations in product demands as well as dynamic market prices of raw materials can greatly affect the cost-effectiveness, operational efficiency, and safety of pesticide production. To address these challenges, we present a superstructure flowsheet optimization approach for the selection of optimal processing routes to produce glyphosatethe world's most widely used herbicideunder varying feedstock costs and product demand profiles. A hierarchical, bilevel superstructure representation allows for adjusting the fidelity of design while enabling simultaneous design and planning of pesticide production processes. We apply the approach for designing a glyphosate plant for meeting time-varying demands in the San Joaquin Valley of California. The results show that varying demand profiles significantly influence process design, affecting both the selection of chemical routes and storage requirements. Additionally, dynamic feed pricing introduces complex trade-offs, highlighting the need for an integrated approach toward future expansion to include both safety and economic considerations.