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Different arrangements of variable‐speed turbo‐compressor units in a pipeline boosting station are investigated by estimating the exergy destruction and exergetic efficiency; a thermodynamic method for quantifying irreversibility. Fuel consumption is determined by using the performance curves of compressors and turbines that are unique for each turbo‐compressor. Exergy destruction values of eight possible configurations, including coolers, are estimated for a specific station and result in the following values: 2.932 kg s−1 fuel consumption, 132.13 MW exergy destruction, and 99.4 MW exergetic efficiency for the optimum configuration. The case study is focused on the transmission of sour gas through a 56 inch (1 inch=2.54 cm) pipeline. Corresponding state theory within a simple virial equation of state is used to determine the effect of H2S and CO2. The results show that the exergetic efficiency of each configuration depends on the operating conditions and number of compressors in use. The optimum configuration depends on the station delivery flow rate and its compression ratio.

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Transmission of natural gas with methane as the main constituent has been a subject of interest to industrial companies. Predicting hydrate formation conditions is important to prevent formation of methane hydrate in gas pipeline. Also, attention has been taken to account for capture and storage of pure methane. In this paper, a comprehensive comparison is performed between empirical correlations and different equation of state in van der Waals Platteeuw (VdW-P) thermodynamic model to determine the most accurate method of hydrate formation condition of methane. In addition, a novel, simple and accurate correlation is developed to predict methane hydrate formation temperature using genetic programming. Error analysis on a wide range of experimental data indicates that the new proposed correlation is superior over existing correlations and all VdW-P models with R 2 = 0.999.

This research aims to conduct an integrated energy and exergy evaluation of an acid gas recovery (AGR) plant. An effective simulation platform is developed and linked to a thermodynamic modeling approach. A newly developed amine blend, composed of methyl-di-ethanolamine (MDEA), di-ethanolamine (DEA), and piperazine (PZ), is utilized to absorb the acid gases. Based on the classical energy analysis, an energy loss of 70.79 MW and an energy efficiency of 90.29% are attained for each process component. Conventional exergy analysis is then conducted, and the sources of irreversibility are identified. The postprocessing is performed on the conventional exergy evaluation results using an advanced exergy method, to obtain a more realistic insight into the system's energy/exergy performance. It is concluded that stripper and absorber account for the maximum exergy destructions of 8.15 and 7.55 MW, respectively; this shows significant potential for operation improvement in these two key equipment. Also, it is concluded that 5.47 and 4.92 MW unavoidable exergy destructions occur in the stripper and absorber, respectively, which cannot be prevented. It is found from the advanced exergy analysis that the absorber, stripper, and heat exchanger with the greatest recoverable exergy amount (e.g., exergy rehabilitation ratio) exhibit substantial operation enhancement capability in comparison to the other process equipment. The overall exergy efficiency of the entire system is enhanced from 99.70 to 99.90%, when the technological constraints are abolished and the ideal condition governs. The results of avoidable/endogenous exergy destruction reveal high potential of the absorber (2.58 MW), stripper (2.18 MW), heat exchanger (0.74 MW), and valve (0.19 MW) in terms of operation improvement compared to the other process components. Based on the environmental analysis, a large amount of CO 2 emission (22.12 ton•day −1 ) can be prevented, when the process components are technologically upgraded.

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