Document Type : Research Paper


1 Ph.D. Student, School of Chemical Engineering, College of Engineering, University of Tehran, Tehran, Iran

2 M.S. Student, School of Chemical Engineering, College of Engineering, University of Tehran, Tehran, Iran

3 Professor, School of Chemical Engineering and Institute of LNG, College of Engineering, University of Tehran, Tehran, Iran


Today, one of the challenging issues all over the world is the appropriate use of flare gases in oil, gas, and petrochemical industries. Burning flare gases having high heating value results in economic losses and the pollution of the environment. There are several methods to use flare gases; the heat and power generation, the production of valuable fuels, or the separation of more precious components are examples of these methods. In this study, a polygeneration system is designed and simulated for the coproduction of power, steam, methanol, H2, and CO2 from the flare gases in South Pars and Assaluyeh gas fields. The polygeneration system has advantages such as reducing greenhouse gases and the coproduction and sales of energy-related products. The polygeneration system for converting flare gases to energy and various products includes an acid gas removal unit, a synthesis gas production unit, a methanol synthesis unit, a hydrogen purification unit, a combined heat and power generation unit, and a CO2 capture unit. The purpose of this study is to conduct an economic evaluation of the polygeneration system and obtain the total capital cost, the operating profit, and the payback period of this process. The simulation results show that using 9690 kg/h of flare gases produces 8133 kg/h methanol, 653.7 kg/h hydrogen, 46950 kg/h nitrogen, 9103 kg/h CO2, 109850 kg/h medium-pressure steam, and 3.7 MW power. The economic evaluation results show that in the polygeneration system, the total raw material cost and the total utilities consumption cost are $193.8 and $1859.5 per hour respectively, and the total product sales and the total utility sales are $12941.8 and $2243.5 per hour respectively; also, the operating profit is $13132 per hour. Also, the equipment cost, the installation cost, the total capital cost, and the total operating cost are $29.7 million per year, $39.2 million per year, $71 million per year, and $27.9 million per year respectively; finally, the payback period is 1.5 years.


  • The polygeneration system has been used for converting flare gas to energy and various products such as power, steam, methanol, H2, and CO2;
  • A polygeneration system has lower raw material cost, utility cost, and operating cost than the corresponding single-product processes;
  • The total capital cost and the operating profit of the polygeneration system are $71 million and $115 million per year respectively, and the payback period is 1.5 years.


Main Subjects

Abd, A. A., Naji, S. Z., and Barifcani, A., Comprehensive Evaluation and Sensitivity Analysis of Regeneration Energy for Acid Gas Removal Plant Using Single and Activated-Methyl Diethanolamine Solvents, Chinese Journal of Chemical Engineering, Vol. 28, No. 6, p. 1684–1693, 2020.
Al-Malah, K. I. M., Aspen Process Economic Analyzer (APEA), Aspen Plus, p. 523–64, 2016.
Amran, U. I., Ahmad, A., and Othman, M. R., Kinetic Based Simulation of Methane Steam Reforming and Water Gas Shift for Hydrogen Production Using Aspen Plus, Chemical Engineering Transactions, Vol. 56, p. 1681–1686, 2017.
Behroozsarand, A. and Zamaniyan, A., Simulation and Optimization of an Integrated GTL Process, Journal of Cleaner Production, Vol. 142, p. 235–257, 2017.
Calderón, A. J. and Pekney, N. J., Optimization of Enhanced Oil Recovery Operations in Unconventional Reservoirs, Applied Energy, Vol. 258, p. 3–21, 2020.
Chen, L., Xu, Q., Gossage, J. L., and Lou, H. H., Simulation and Economic Evaluation of a Coupled Thermal Vapor Compression Desalination Process for Produced Water Management, Journal of Natural Gas Science and Engineering, Vol. 36, p. 442–453, 2016.
Dwiyantoro, B. A. and Saungweme, F. W., Analysis of an Optimum Method for Power Generation Using Flare Gas from Oil Refinery Plants, in AIP Conference Proceedings, Vol. 2187, No. 1, P. 020035, AIP Publishing LLC, 2019.
Fallah, T., Belghaieb, J., and Hajji, N., Analysis and Simulation of Flare Gas Recovery in Oil and Gas Producing Company. Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, Vol. 115, p. 1–7, 2019.
Fisher, D. and Wooster, M. J., Multi-decade Global Gas Flaring Change Inventoried Using the ATSR-1, ATSR-2, AATSR and SLSTR Data Records, Remote Sensing of Environment, Vol. 232, p. 15–32, 2019.
Gallucci, F., Fernandez, E., Corengia, P., and Van Sint Annaland, M., Recent Advances on Membranes and Membrane Reactors for Hydrogen Production, Chemical Engineering Science, Vol. 92, p. 40–66, 2013.
Ghasemzadeh, K., Jafari, M., and Basile, A., Theoretical Study of Various Configurations of Membrane Processes for Olefins Separation, International Journal of Membrane Science and Technology, Vol. 4, P. 1–7, 2017.
Hajizadeh, A., Mohamadi-Baghmolaei, M., Azin, R., Osfouri, S., and Heydari, I, Technical and Economic Evaluation of Flare Gas Recovery in A Giant Gas Refinery, Chemical Engineering Research and Design, Vol. 131, p. 506–519, 2018.
Hamidzadeh, Z., Sattari, S., Soltanieh, M., and Vatani, A., Development of a Multi-objective Decision-Making Model to Recover Flare Gases in A Multi Flare Gases Zone, Energy, Vol. 203, P. 117–132, 2020.
Hashemi Fard, K. and Shafiee, M., Recovering Gas Flares From the 12th Gas Phase of the South Pars Gas Refinery, Advanced Journal of Chemistry-Section A, Vol. 3, No. 1, P. 49–57, 2020.
Hoo, P. Y., Hashim, H., and Ho, W. S, Opportunities and Challenges: Landfill Gas to Biomethane Injection into Natural Gas Distribution Grid Through Pipeline, Journal of Cleaner Production, Vol. 175, p. 409–419, 2018.
Hydrogen Fuel Price, Retrieved from Https://Www.Hydrogen.Energy.Gov/Pdfs/Htac_Dec18_06_ Munster.Pdf, (7 October, 2020).
Jafari, M., Ashtab, S., Behroozsarand, A., Ghasemzadeh, K., and Wood, D. A, Plant-wide Simulation of an Integrated Zero-Emission Process to‎ Convert Flare Gas to Gasoline, Gas Processing Journal, Vol. 6, No. 1, p. 1–20, 2018.
Jafari, M., Ghasemzadeh, K., Yusefi Amiri, T., and Basile, A, Comparative Study of Membrane and Absorption Processes Performance and Their Economic Evaluation for CO2 Capturing from Flue Gas, Gas Processing Journal, Vol. 7, No. 2, p. 37–52, 2019.
Kang, J. Y., Kim, T. S., and Hur, K. B., Comparative Economic Analysis of Gas Turbine-based Power Generation and Combined Heat and Power Systems Using Biogas Fuel, Energy, Vol. 67, p. 309–318, 2014.
Khademi, M., Behzadi Forough, A., and Khosravi, A., Techno-economic Operation Optimization of A HRSG in Combined Cycle Power Plants Based on Evolutionary Algorithms: A Case Study of Yazd, Iran, Energy Equipment and Systems, Vol. 7, No. 1, p. 67–79, 2019.
Liu, H., Qu, J., Pan, M., Zhang, B., Chen, Q., and He, C., Design and Optimization of Small-scale Methanol Production from Sour Natural Gas by Integrating Reforming with Hydrogenation, International Journal of Hydrogen Energy. Vol. 45, No. 59, P. 34483–34493, 2019.
Luqman, M., Bicer, Y., and Al-Ansari, T., Thermodynamic Analysis of an Oxy-Hydrogen Combustor Supported Solar and Wind Energy-based Sustainable Polygeneration System for Remote Locations, International Journal of Hydrogen Energy, Vol. 45, No. 5, p. 3470–3483, 2020.
Mesbah, M., Jafari, M., Soroush, E., and Shahsavari, S., Mathematical Modeling and Numerical Simulation of CO2 Removal by Using Hollow Fiber Membrane Contactors, Iranian Journal of Oil & Gas Science and Technology, Vol. 6, No. 4, p. 80–96, 2017.
Methanex Posts Regional Contract Methanol Prices for North America, Europe and Asia, Retrieved From Https://Www.Methanex.Com/Our-business/Pricing (7 October, 2020).
Nourmohamadi Taemeh, A., Shariati, A., and Khosravi Nikou, M. R., Analysis of Energy Demand for Natural Gas Sweetening Process Using A New Energy Balance Technique, Petroleum Science and Technology, Vol. 36, No. 12, p. 827–834, 2018.
Peters, M. S., Timmerhaus, K. D., and West, R. E., Plant Design and Economics for Chemical Engineers, Vol. 4, 1968.
Poelhekke, S., How Expensive Should CO2 be Fuel for the Political Debate on Optimal Climate Policy, Heliyon, Vol. 5, No. 11, p. 129–141, 2019.
Radzuan, M. A., Syarina, N. A., Rosdi, W. W., Hussin, A. H., and Adnan, M. F., Sustainable Optimization of Natural Gas Sweetening Using A Process Simulation Approach and Sustainability Evaluator. Materials Today, Proceedings, Vol. 19, p. 1628–1637, 2019.
Rahimpour, M. R., Jamshidnejad, Z., Jokar, S. M., Karimi, G., Ghorbani, A., and Mohammadi, A. H., A Comparative Study of Three Different Methods for Flare Gas Recovery of Assaluyeh Gas Refinery, Journal of Natural Gas Science and Engineering, Vol. 4, p. 17–28, 2012.
Rahmandoost, E., Roozbehani, B., and Maddahi, M. H., Experimental Studies of CO2 Capturing from the Flue Gases. Iranian Journal of Oil & Gas Science and Technology, Vol. 3, No. 4, p. 1–15, 2014.
Roh, K., Lim, H., Chung, W., Oh, J., Yoo, H., Al-Hunaidy, A. S., and Lee, J. H, Sustainability Analysis of CO2 Capture and Utilization Processes Using a Computer-Aided Tool, Journal of CO2 Utilization, Vol. 26, p. 60–69, 2018.
Roohollahi, G. and Ehsani, M., An Investigation into the Effect of Hydrotalcite Calcination Temperature on the Catalytic Performance of Mesoporous Ni-Mgo-Al2O3 Catalyst in the Combined Steam and Dry Reforming of Methane, Iranian Journal of Oil & Gas Science and Technology, Vol. 8, No. 4, p. 64–84, 2019.
Saidi, M., Application of Catalytic Membrane Reactor for Pure Hydrogen Production by Flare Gas Recovery as A Novel Approach, International Journal of Hydrogen Energy, Vol. 43, No. 31, p. 14834–14847, 2018.
Seidi, M., Khezeli, M., Bayati, B., and Najafi, E., The Selection of Amine Solvent in Gas Treating Process Considering Physical and Process Criteria Using Multiple Criteria Decision-Making Techniques: A Case Study of Ilam Gas Treating Company, Iranian Journal of Oil & Gas Science and Technology, Vol. 8, No. 3, p. 73–88, 2019.
Sharif Dashti, S., Shariati, A., and Khosravi Nikou, M. R., Sensitivity Analysis for Selection of an Optimum Amine Gas Sweetening Process with Minimum Cost Requirement, Asia‐Pacific Journal of Chemical Engineering, Vol. 10, No. 5, p. 709–715, 2015.
Shayan, M., Pirouzfar, V., and Sakhaeinia, H., Technological and Economical Analysis of Flare Recovery Methods, and Comparison of Different Steam and Power Generation Systems, Journal of Thermal Analysis and Calorimetry, Vol. 139, No. 4, p. 2399–2411, 2020.
Snytnikov, P. V., Potemkin, D. I., Uskov, S. I., Kurochkin, A. V., Kirillov, V. A., and Sobyanin, V. A., Approaches to Utilizing Flare Gases at Oil and Gas Fields: A Review, Catalysis in Industry, Vol. 10, No. 3, p. 202–216, 2018.
Unlu, D. and Hilmioglu, N. D., Application of Aspen Plus to Renewable Hydrogen Production from Glycerol by Steam Reforming, International Journal of Hydrogen Energy, Vol. 45, No. 5, p. 3509–3515, 2020.
Wilkinson, S. K., Van De Water, L. G. A., Miller, B., Simmons, M. J. H., Stitt, E. H., and Watson, M. J., Understanding the Generation of Methanol Synthesis and Water Gas Shift Activity Over Copper-Based Catalysts–A Spatially Resolved Experimental Kinetic Study Using Steady and Non-Steady State Operation Under CO/ CO2/H2 Feeds, Journal of Catalysis, Vol. 337, p. 208–220, 2016.
Younessi Sinaki, S., Atabi, F., Panjeshahi, M. H., and Moattar, F., Post-Combustion of Mazut with CO2 Capture Using Aspen HYSYS, Petroleum Science and Technology, Vol. 37, No. 20, p. 2122–2127, 2019.
Zadakbar, O., Abbassi, R., Khan, F., Karimpour, K., Golshani, M., and Vatani, A., Risk Analysis of Flare Flameout Condition in A Gas Process Facility, Oil & Gas Science and Technology–Revue D’ifp Energies Nouvelles, Vol. 66, No. 3, p. 521–530, 2011.
Zadakbar, O., Khan, F., and Imtiaz, S., Development of Economic Consequence Methodology for Process Risk Analysis, Risk Analysis, Vol. 35, No. 4, p. 713–731, 2015.
Zadakbar, O., Vatani, A., and Karimpour, K., Flare Gas Recovery in Oil and Gas Refineries, Oil & Gas Science and Technology-Revue De L'ifp, Vol. 63, No. 6, p. 705–711, 2008.
Ziyarati, M. T., Bahramifar, N., Baghmisheh, G., and Younesi, H., Greenhouse Gas Emission Estimation of Flaring in A Gas Processing Plant: Technique Development, Process Safety and Environmental Protection, Vol. 123, p. 289–298, 2019.
Zoeir, A., Tabatabaei Nejad, A., and Khodapanah, E., Impact of H2S Content and Excess Air on Pollutant Emission in Sour Gas Flares, Iranian Journal of Oil & Gas Science and Technology, Vol. 8, No. 1, p. 1–10, 2019.
Zolfaghari, M., Pirouzfar, V., and Sakhaeinia, H., Technical Characterization and Economic Evaluation of Recovery of Flare Gas in Various Gas-processing Plants, Energy, Vol. 124, p. 481–491, 2017.