Natural gas density measurements and the impact of accuracy on process design
The liquefaction of natural gas is an energy intensive process, requiring at least 5% of the energy associated with methane's lower heating value. Key to estimating and optimizing these energy requirements are process simulations which rely upon calculated thermophysical properties of the natur...
| Main Authors: | , , , , , , , |
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| Format: | Journal Article |
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2021
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| Online Access: | http://purl.org/au-research/grants/arc/IC150100019 http://hdl.handle.net/20.500.11937/85085 |
| _version_ | 1848764712798388224 |
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| author | Al Ghafri, S.Z.S. Jiao, F. Hughes, T.J. Arami-Niya, Arash Yang, X. Siahvashi, A. Karimi, A. May, E.F. |
| author_facet | Al Ghafri, S.Z.S. Jiao, F. Hughes, T.J. Arami-Niya, Arash Yang, X. Siahvashi, A. Karimi, A. May, E.F. |
| author_sort | Al Ghafri, S.Z.S. |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | The liquefaction of natural gas is an energy intensive process, requiring at least 5% of the energy associated with methane's lower heating value. Key to estimating and optimizing these energy requirements are process simulations which rely upon calculated thermophysical properties of the natural gas. In particular, the prediction of thermophysical properties of natural gas mixtures at pressure-temperature conditions close to the mixture's critical point or cricondenbar is challenging but important as often natural gas processes operate close to these conditions. In this work, we present a comprehensive study of two natural gas related systems: (CH4 + C3H8 + CO2) and (CH4 + C3H8 + C7H16) with n-heptane fractions up to 15 mol%. High accuracy measurements of densities, at temperatures from 200 K to 423 K and pressures up to 35 MPa are presented. The extensive experimental data collected for these mixtures were compared with the GERG-2008 equation of state, as implemented in the NIST software REFPROP. The relative deviations of the measured densities from those calculated using the GERG-2008 model range between (−2 to 4)% for all mixtures, presenting a systematic dependent on mixture density and n-heptane content. Finally, a case study is presented that probes the impact of the accuracy of density on the pinch point in a simulated LNG heat exchanger. An uncertainty in the density of 1% is shown to cause significant 30% reduction in the minimum approach temperature difference, suggesting that accurate thermophysical property calculations are key to reducing over-design of processing plant. |
| first_indexed | 2025-11-14T11:23:43Z |
| format | Journal Article |
| id | curtin-20.500.11937-85085 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T11:23:43Z |
| publishDate | 2021 |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-850852023-07-20T03:17:35Z Natural gas density measurements and the impact of accuracy on process design Al Ghafri, S.Z.S. Jiao, F. Hughes, T.J. Arami-Niya, Arash Yang, X. Siahvashi, A. Karimi, A. May, E.F. The liquefaction of natural gas is an energy intensive process, requiring at least 5% of the energy associated with methane's lower heating value. Key to estimating and optimizing these energy requirements are process simulations which rely upon calculated thermophysical properties of the natural gas. In particular, the prediction of thermophysical properties of natural gas mixtures at pressure-temperature conditions close to the mixture's critical point or cricondenbar is challenging but important as often natural gas processes operate close to these conditions. In this work, we present a comprehensive study of two natural gas related systems: (CH4 + C3H8 + CO2) and (CH4 + C3H8 + C7H16) with n-heptane fractions up to 15 mol%. High accuracy measurements of densities, at temperatures from 200 K to 423 K and pressures up to 35 MPa are presented. The extensive experimental data collected for these mixtures were compared with the GERG-2008 equation of state, as implemented in the NIST software REFPROP. The relative deviations of the measured densities from those calculated using the GERG-2008 model range between (−2 to 4)% for all mixtures, presenting a systematic dependent on mixture density and n-heptane content. Finally, a case study is presented that probes the impact of the accuracy of density on the pinch point in a simulated LNG heat exchanger. An uncertainty in the density of 1% is shown to cause significant 30% reduction in the minimum approach temperature difference, suggesting that accurate thermophysical property calculations are key to reducing over-design of processing plant. 2021 Journal Article http://hdl.handle.net/20.500.11937/85085 10.1016/j.fuel.2021.121395 http://purl.org/au-research/grants/arc/IC150100019 http://creativecommons.org/licenses/by-nc-nd/4.0/ fulltext |
| spellingShingle | Al Ghafri, S.Z.S. Jiao, F. Hughes, T.J. Arami-Niya, Arash Yang, X. Siahvashi, A. Karimi, A. May, E.F. Natural gas density measurements and the impact of accuracy on process design |
| title | Natural gas density measurements and the impact of accuracy on process design |
| title_full | Natural gas density measurements and the impact of accuracy on process design |
| title_fullStr | Natural gas density measurements and the impact of accuracy on process design |
| title_full_unstemmed | Natural gas density measurements and the impact of accuracy on process design |
| title_short | Natural gas density measurements and the impact of accuracy on process design |
| title_sort | natural gas density measurements and the impact of accuracy on process design |
| url | http://purl.org/au-research/grants/arc/IC150100019 http://hdl.handle.net/20.500.11937/85085 |