UNI-MB - logo
UMNIK - logo
 
E-viri
Celotno besedilo
Recenzirano
  • Combination of double and s...
    Sun, Zhixue; Bongole, Kelvin; Yao, Jun; Wang, Yueying; Mboje, James; Seushi, Kadria; Jiang, Chuanyin; Wang, Tong

    International journal of energy research, April 2020, Letnik: 44, Številka: 5
    Journal Article

    Summary The rise in global temperature due to an unceasingly increase in non‐condensable gases (NCG) prompts more development of safe and economical CCUS (Carbon Capture Utilization and Storage) technologies. Carbon dioxide (CO2) sequestration with heat mining in deep enhanced geothermal systems (EGSs) is one of the promising methods to reduce CO2 emitted to the atmosphere. In this study, a cyclic alternation of pressures at the injection and production wells is applied in an EGS for heat mining together with CO2 deposit. Simultaneous alternation of the injection and production pressures can significantly increase the amount of CO2 sequestrated compared to applying a fixed pumping or withdrawing pressures at the injector and producer respectively. At the injection well, alternation in pumping pressures at high frequency (small interval of days) increased CO2 sequestration rate. Reducing the pumping frequency resulted in the lowering of the total amount of CO2 sequestrated, lesser than using a fixed pumping pressure. The alternation in pumping frequency has a direct relationship to the CO2 sequestration rate. The frequency of the injection and production pressures refers to the interval in days of the interchange in pressure between high to a low value and vice‐versa. Furthermore, simultaneous alternation of pressures at the injection and production wells respectively (double cyclic method) improved geothermal heat extraction efficiency, thus higher performance for both geothermal and CO2 sequestration projects. This paper showed that pressure alternation at the injection and/or production well improves the cumulative amounts of CO2 sequestration and heat mining rate. The frequency of pressure variation affects the extent of CO2 deposit. Pressure alternation at higher frequency had more potential in depositing large volumes of CO2 into the geothermal reservoir. Therefore the frequency of pressure alternation at the injector or producer wells is proportional to CO2 sequestration rates.