Sustainable and cost‐effective process design for energy‐self‐sufficient ethyl lactate production from sugar mill feedstocks: a techno‐economic approach

Bio‐based ethyl lactate (EL) can replace several fossil‐derived products owing to its low toxicity, high solvent functionality, and environmental advantages. This study assesses the techno‐economic viability and greenhouse gas (GHG) reduction potential of producing EL from sugarcane A‐molasses and lignocelluloses in an energy self‐sufficient refinery annexed to an existing sugar mill. Nine biorefinery scenarios were simulated in Aspen Plus, using established first‐generation (1G) and second‐generation (2G) methods for ethanol (EtOH) production, combined with various neutralizing agents and separation/purification methods for lactic acid (LA) production. The goal was to eliminate gypsum co‐production as seen in the Corbion™ process. The most cost‐effective pathway used a 1 G‐based feedstock for EtOH and gypsum‐free LA production. Lactic acid and EtOH were converted to EL via catalytic reactive esterification distillation, followed by purification. This pathway yielded a minimum selling price (MSP) of $1664 t −1 , competitive with the market price of $1850 t −1 . The GHG emissions were reduced by 76%, with an emission factor of 1.36 kg CO 2 eq kg −1 EL, qualifying for a green premium discount, resulting in a revised MSP of $ 1498 t −1 . Operational expenditure decreased by 38% owing to reduced chemical use, and capital expenditure was 15% lower. Reactive esterification distillation‐based processes demonstrated 15% lower energy demand compared with conventional esterification routes. The combined 1G and 2G processes were not technically feasible. The ion exchange‐based LA production process demonstrates potential for further optimization and development toward cost‐effective, sustainable EL production.