International Scientific Journal


Natural gas is typically transported for long distances through high pressure pipelines. Such pressure must be reduced before the gas distribution to users. The natural gas lamination process, traditionally adopted for this scope, may determine hydrate formation which may damagingly affect the system operation. Therefore, in order to avoid such circumstance, a suitable gas preheating is required. On the other hand, the available pressure drop can be recovered through a turbo-expansion system in order to provide mechanical energy to drive electricity generators. In this case a higher gas preheating is necessary. This paper presents a detailed simulation model capable to accurately analyse this process as well as the traditional decompression one. Such new model, implemented in a computer tool written in MATLAB, allows one to dynamically assess the energy, economic and environmental performance of these systems, by also taking into account hourly energy prices and weather conditions. Two turbo-expansion system layouts are modelled and simulated. In particular, the gas preheating is obtained by considering two different scenarios: gas-fired heater or solar thermal collectors. Another novelty of the presented dynamic simulation tool is the capability to take into account the time fluctuations of electricity feed-in and purchase tariffs. Finally, a suitable case study relative to a gas decompression station located in South Italy is also presented. Here, a remarkable primary energy savings and avoided CO2 emissions can be obtained through the examined turbo-expansion systems vs. traditional decompression ones. Results show that the economic profitability of the investigated novel technology depends on the available gas pressure drops and flow rates and on the produced electricity use.
PAPER REVISED: 2018-03-12
PAPER ACCEPTED: 2018-03-13
CITATION EXPORT: view in browser or download as text file
  1. ***, BP Statistical Review of World Energy, 2016,
  2. Neseli, M. A., et al., Energy and Exergy Analysis of Electricity Generation From Natural Gas Pressure Reducing Stations, Energy Conversion and Management, 93 (2015), Mar., pp. 109-120
  3. ***, Directive 2003/55/EC, European Parliament and of the Council of 26 June 2003, 2003
  4. Bisio, G., Thermodynamic Analysis of the Use of Pressure Exergy of Natural Gas, Energy, 20 (1995), 2, pp. 161-167
  5. Poživil, J., Use of Expansion Turbines in Natural Gas Pressure Reduction Stations, Acta Montanistica Slovaca, 9 (2004), 3, pp. 258-260
  6. Nazir Unar, I., et al., Estimation of Power Production Potential from Natural Gas Pressure Reduction Stations in Pakistan Using ASPEN HYSYS, Mehran University Research Journal of Engineering & Technology, 34 (2015), 3, pp. 1-8
  7. Borelli, D., et al., Energy Recovery From Natural Gas Pressure Reduction Stations: Integration with Low Temperature Heat Sources, Energy Conversion and Management, 159 (2018), Mar., pp. 274-283
  8. Greeff, I. L., et al., Using Turbine Expanders to Recover Exothermic Reaction Heat—Flow Sheet Development for Typical Chemical Processes, Energy, 29 (2004), 12-15, pp. 2045-2060
  9. Mirandola, A., et al., Full Load and Partial Load Performance of Poly-generation Systems with Gas Expanders and Internal Combustion Engines, Proceedings, 24th Intersociety Energy Conversion Engineering Conference, Washington, D. C., USA, 1989
  10. Farzaneh-Gord, M., et al., Feasibility of Accompanying Uncontrolled Linear Heater with Solar System in Natural Gas Pressure Drop Stations, Energy, 41 (2012), 1, pp. 420-428
  11. Farzaneh-Gord, M., et al., Employing Geothermal Heat Exchanger in Natural Gas Pressure Drop Station in Order to Decrease Fuel Consumption, Energy, 83 (2015), Apr., pp. 164-176
  12. Ghezelbash, R., et al., Performance Assessment of a Natural Gas Expansion Plant Integrated with a Vertical Ground-coupled Heat Pump, Energy, 93 (2015), Part 2, pp. 2503-2517
  13. Badami, M., et al., A Biofuel-based Cogeneration Plant in a Natural Gas Expansion System: An Energetic and Economic Assessment, Applied Thermal Engineering, 118 (2017), May, pp. 52-61
  14. Mehdi Taleshian, J., et al., Modeling Turbo-expander Systems, SIMULATION, 89 (2013), 2, pp. 234-248
  15. ***, Solar Keymark Certification, UNI EN 12976-2, 2017
  16. Kakac, H. L. S., et al., Heat Exchangers: Selection, Rating, and Thermal Design, CRC Press, Boca Raton, Florida, USA
  17. ***, Italian GSE (Manager Energy Service)
  18. ***, Turbinde S.r.l.,
  19. Buonomano, A., et al., Experimental Analysis and Dynamic Simulation of a Novel High-temperature Solar Cooling System, Energy Conversion and Management, 109 (2016), Feb., pp. 19-39

© 2018 Society of Thermal Engineers of Serbia. Published by the Vinča Institute of Nuclear Sciences, Belgrade, Serbia. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International licence