Application of unloaded gas pipelines for the transportation of carbon dioxide in a gaseous state

<ns3:p>Assessment of the throughput and operating modes of existing unloaded gas pipelines when converting them to the transportation of carbon dioxide in a gaseous state.Application of mathematical modelling methods to obtain analytical dependences of the physical and thermodynamic properties of carbon dioxide on pressure and temperature in the range corresponding to its gaseous state in the pipeline. Establishment of the features of thermo-gasodynamic processes in the gas pipeline during the transition from pumping natural gas to transporting dioxide.It was established that the throughput of existing gas pipelines when pumping carbon dioxide in a gaseous state depends on the pressure and temperature at the beginning of the pipeline, the given pressure drop and environmental temperature conditions. For main gas pipelines operating at pressures higher than 3 MPa, to ensure the gaseous state of carbon dioxide, it is necessary to control the pressure and temperature along the pipeline's length and adjust, if necessary, the operating parameters that affect carbon dioxide transportation volumes.The next stage of the research is planned to investigate the influence of carbon dioxide properties on the regularities of the compression process in compressor stations of main gas pipelines.A method and software have been developed that enable the prediction of a gas pipeline's throughput and operating parameters when transporting carbon dioxide in a gaseous state without phase transitions. The influence of initial parameters and seasonal conditions on the throughput of the main gas pipeline, branch gas pipeline and high-pressure gas networks has been studied.Unlike most recent studies on the subject matter, the study considers an economically advantageous option for utilising existing unloaded gas pipelines to transport carbon dioxide in a gaseous state. The current state of the gas transportation system in Ukraine is considered.</ns3:p>