Economic evaluation of Ethyl lactate production via reactive distillation at different concentrations of lactic acid

Abstract

Ethyl lactate is a green solvent made from agricultural crops, making it more environmentally friendly than petrochemical solvents. The product is obtained via esterification of lactic acid with ethanol over Amberlyst-15 acid catalyst in a reactive distillation column.

In commercial-scale production of ethyl lactate, this work designs production processes at two concentrations of lactic acid (50 and 85 wt.%) and two ethanol feed temperatures (25 and 85 °C). Highly concentrated lactic acid can result in adverse effects, such as increased oligomers and reduced desired products, making a comprehensive simulation of the production process necessary to evaluate energy consumption, economics, and CO2 emissions.

The simulation results show that the ethyl lactate production process at 85 wt.% of lactic acid and 25 °C of ethanol feed temperature is the best scenario, with a net present value of 176 million USD, internal rate of return of 74.6%, payout period of 3.41 years, specific energy consumption of 2.60 kWh/kg L1E, and CO2 emissions of 1.91 kg CO2-eq/kg L1E. This process is more energy-efficient and has lower CO2 emissions compared to producing ethyl lactate at 50 wt.% of lactic acid.