Modeling and simulation of automotive urea production in Peru

Air quality concerns in Peru have prompted the implementation of EURO 4 regulations in 2018, with a planned upgrade to EURO 6 in 2026. These regulations seek to reduce nitrogen oxide (NO_x) emissions from diesel vehicles. Selective Catalytic Reduction (SCR) technology employing automotive urea (AdBlue®), offers a highly effective solution by reducing NO_x emissions by at least 90%. However, Peru does not produce automotive urea, and there is a lack of technical research on manufacturing. This study addresses this gap by focusing on modeling and simulating an automotive urea production plant in Peru using the process simulation software ProMax 6.0. The design and parameters were based on information from a BR&E document and from the Stamicarbon patent. Thermodynamic models were selected, considering the most suitable for each stage of the process. Pure water, dry air, and dry natural gas from Camisea, Peru, were considered as raw materials. Additionally, a net profit margin analysis was conducted to assess the operational profitability of the process. An alternative scenario involving the sale of CO₂ purified was also considered. The model predicts that 10.01 MMSCFD of natural gas are required to produce 528,000 L/year of AdBlue®, with a composition of 32.66% urea by weight. Regarding energy requirements, the study found that 1.582 kWh/kg of AdBlue® is needed for heating, 2.397 kWh/kg for cooling, and 0.486 kWh/kg for electricity. The natural gas requirement and the CO₂ intensity of the overall process are 0.137 kg of natural gas per kg of AdBlue and 0.336 kg of CO₂ per kg of AdBlue, respectively. Finally, the alternative scenario with CO₂ process purification resulted in a higher net profit margin (37.74%) compared to the non-CO₂ process purification scenario (34.75%).