PSI - Issue 36

Ye. Kryzhanivskyy et al. / Procedia Structural Integrity 36 (2022) 370–377 Ye. I. Kryzhanivskyy et al. / Structural Integrity Procedia 00 (2021) 000 – 000

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and stress corrosion cracking (Kryzhanivs’kyi and Nykyforchyn (2011), Poberezhny et al. (2019 b), Zvirko et al. (2016, 2019, 2021). The transit of natural gas through GTS of Ukraine in January-September 2021 amounted to 32.7 billion cubic meters, which is 17.2% less than for the same period in 2020 (39.5 billion cubic meters). Thereby present trend of transition of natural gas from Russia to the EU doesn’t seem to be optimistic for utilizing the facility of GTS by its direct purpose. However, certain elements of the GTS can be excluded to perform alternative tasks (GTS operator (2021), Zapukhliak et al. (2019)). Upon that previously operated gas distribution pipelines will provide transportation of captured greenhouse gases from enterprises to main gas pipelines. Significant volumes of captured gas can be stored in excluded parts of underground gas storage facilities or depleted natural gas or oil deposits. Today, there are 22 active projects in the world to implement CCS technology, out of which 15 are to be under operation and 7 are in preparation for implementation. In total, these 22 projects will reduce only 0.1% of CO 2 emissions. In terms of the number of implemented CCS projects, the leadership is kept by the USA (Obergassel et al. (2016)). Captured CO 2 can also be used effectively in extinguishing fires, increasing oil and gas recovery of wells, being used as a raw material in the chemical and pharmaceutical industries, and more. Thus, hazardous greenhouse gas will be converted into raw materials for the relevant industries. This will keep the GTS of Ukraine in working order and, if necessary, use it for its direct purpose (Chudyk et al. (2019), Pinka and Marcin (2004)). 2. Research problem To form main principles of utilizing decommissioned sections of main gas pipelines to deliver to the place of disposal of carbon dioxide, in particular: 1. During the transportation of captured mixture of gases through main gas pipelines made of highly tightened carbon steel probable corrosion processes and even plugging the pipeline cross-section caused by appearing impurities in the CO 2 stream, namely: H 2 O and H 2 S. Transportation of a mixture of CO 2 with H 2 O can lead to liquefaction of water particles and their accumulation at the lowest points of the pipeline (Grudz et al. (2009)). The presence of aggressive components, such as H 2 S, in the transported medium also causes corrosion damage of the steel pipe resulting from electrochemical corrosion and hydrogen embrittlement (Osadchuk et al. (2014), Maruschak et al. (2016), Zvirko et al. (2016, 2019, 2021), Poberezhny et al. (2019a, 2019b). Therefore, special in-pipe repair technologies should be used to protect the inner surface of pipelines from corrosion during the transportation and storage of carbon dioxide (Doroshenko et al. (2019)). 2. Main gas pipelines can be filled with CO 2 up till a pressure value not exceeding, and for some sections even less than 75 atm, which is regulated by the wall strength of long-term operated steel pipes. The transition of CO 2 to the supercritical phase appears upon that. So, it is necessary to gain regularities of gas-dynamic parameters trends in length and time of CO 2 when it is injected into the decommissioned main gas pipelines for the following transportation. It is also necessary to set up the time required to inject CO 2 into the pipeline, the optimal value of the average pressure for transportation and temporary storage of CO 2 in the volume of main gas pipelines, and choose the optimal modes of managing these processes from the point of theoretical studies and the experience of other countries in CO 2 transportation (Harkin et al. (2017)). 3. Research methodology In the process of transporting the captured carbon dioxide through the main gas pipelines there is a need to resolve many scientific problems, in particular, the development of methodology for effective implementation of each particular stage of the carbon dioxide transportation process including preparation of captured carbon dioxide for transportation, pressurizing, dewatering, filling in and discharge from the pipeline (Liu et al. (2015), Zucker and Biblarz (2019)). The research focuses on solving two strategic tasks: 1) assessment of the amount of carbon dioxide that can be stored in the cavity of the pipeline; 2) determining the time of filling the pipeline and the rate of pressure increase. To solve these problems, a mathematical model was created based on the fundamental equations of gas dynamics for the isothermal flow in the pipeline in partial derivatives (Zucker and Biblarz (2019)): - equation of gas motion: