Simulation And Optimization Of The Dual-pressure Nitric Acid Production Process

Nitric acid is important inorganic acid, which is widely used in chemical industry,fertilizer, fuel, medicine and textile and so on. The nitric acid industry plays a key role innational economy, defense industry and aerospace. After a long-term development, nitricacid production process updated constantly. In fact, the process has great promotion spacein the aspect of the saving energy and reducing the emission of NOx.This paper summarizes the advantages and disadvantages of the process and choosesthe most advanced dual-pressure process for research. With the aid of the flowsheetsimulation software, the nitric acid absorption process was simulated. The absorber modelwas established firstly because the absorption tower is the key equipment. The operationconditions were optimized based on the mathematical model.The cold-hot streams are complex and the more heat exchange equipments wererequired in nitric acid process. This paper analyses and optimizes the heat exchangenetworks by using the pinch analysis method. The cold and hot streams were matchedreasonably after the absorption tower was optimized. The optimization results wereanalyzed.Nitric acid absorber model can well reflect the actual simulation in nitric acidproduction. The optimization plan has great instruction significance to nitric acidabsorption operation. Heat exchange network is analyzed by using pinch analysis method.A new process was put forward based on the original process. The new network reduces thesteam and cooling water consumption, and achieves the purpose of energy conservation.