Thermo economic evaluation of oxy fuel combustion cycle in Kazeroon power plant considering enhanced oil recovery revenues

Ehsan Torabnejad¹, Ramin Haghighi-Khoshkhoo², Niloufar Sarabchi³

(1. Research & Development Office, MONENCO Iran Consulting Engineers, Tehran, Iran;
2. Faculty of Mechanic and Energy Engineering, Shahid Beheshti University, A.C., Tehran, Iran;
3. Faculty of Mechanical Engineering, University of Tabriz, Tabriz, Iran)

Abstract:Oxy fuel combustion and conventional cycle (currently working cycle) in Kazeroon plant are modeled using commercial thermodynamic modeling software. Economic evaluation of the two models regarding the resources of transport and injection of carbon dioxide into oil fields at Gachsaran for enhanced oil recovery in the various oil price indices is conducted and indices net present value (NPV) and internal rate of return on investment (IRR) are calculated. The results of the two models reveal that gross efficiency of the oxy fuel cycle is more than reference cycle (62% compared to 49.03%), but the net efficiency is less (41.85% compared to 47.92%) because of the high-energy consumption of the components, particularly air separation unit (ASU) in the oxy fuel cycle. In this model, pure carbon dioxide with pressure of 20×10⁵ Pa and purity of 96.84% was captured. NO_X emissions also decrease by 4289.7 tons per year due to separation of nitrogen in ASU. In this model, none of the components of oxy fuel cycle is a major engineering challenge. With increasing oil price, economic justification of oxy fuel combustion model increases. With the price of oil at $ 80 per barrel in mind and $ 31 per ton fines for emissions of carbon dioxide in the atmosphere, IRR is the same for both models.

Key words:oxy fuel combustion; CO₂ capture; combined cycle; enhanced oil recovery; NO_X reduction