APPLICATION OF THE NRTL EQUATION TO SELECTED VLE DATA FOR THE SIMULATION OF THE CONTACT SULFURIC ACID PROCESS

• Published in: Chemical engineering communications 1989-01, Vol.77 (1), p.25-41
• Main Authors: RICHARD, MICHAEL J., PIKE, RALPH W.
• Format: Article
• Language: English
• Subjects: Absorption; Flowsheeting; NRTL equation; Simulation; Sulfuric acid
• ISSN: 0098-6445; 1563-5201
• DOI: 10.1080/00986448908940171

The success of flowsheeting systems in modeling chemical processes is fundamentally dependent upon their ability to adequately represent the physical properties and thermodynamic quantities of the chemical system of interest. The nonideal H 2 SO 2 and H 2 O system poses particular difficulties both representing the physical properties and in modeling the adsorption-reaction step involved in the formation of sulfuric acid by the contact process. This paper proposes the use of suitable nonideal correlation equations such as Wilson and Renon's NRTL for the reduction of specially formulated VLE data to develop a correlation that overcomes the difficulties associated with calculating the mass and energy balances for this system. The approach presented here enables the user to make maximum use of the flowsheeting capabilities without adding user supplied subroutines. The results indicate improved agreement over previous modeling approaches for the calculation of the absorber energy balances in which the absorption-reaction step must be taken into account. The improvement is seen in closer agreement between plant and model outlet stream temperatures.