Environmental impact and thermodynamic comparative optimization of CO2-based multi-energy systems powered with geothermal energy

Olusola Bamisile; Dongsheng Cai; Michael Adedeji; Mustafa Dagbasi; Yihua Hu; Qi Huang

doi:10.1016/j.scitotenv.2023.168459

Environmental impact and thermodynamic comparative optimization of CO2-based multi-energy systems powered with geothermal energy

Sci Total Environ. 2024 Jan 15:908:168459. doi: 10.1016/j.scitotenv.2023.168459. Epub 2023 Nov 12.

Authors

Olusola Bamisile¹, Dongsheng Cai², Michael Adedeji³, Mustafa Dagbasi³, Yihua Hu⁴, Qi Huang⁵

Affiliations

¹ College of Nuclear Science and Automation Engineering, Chengdu University of Technology, Chenghua District, Chengdu, Sichuan P.R., China; Centre for Environmental Policy, Faculty of Natural Science, Imperial College London, United Kingdom; Sichuan Industrial Internet Intelligent Monitoring and Application Engineering Technology Research Center, Chengdu University of Technology, Chenghua District, Chengdu, Sichuan P.R., China. Electronic address: o.bamisile@imperial.ac.uk.
² College of Nuclear Science and Automation Engineering, Chengdu University of Technology, Chenghua District, Chengdu, Sichuan P.R., China; Sichuan Industrial Internet Intelligent Monitoring and Application Engineering Technology Research Center, Chengdu University of Technology, Chenghua District, Chengdu, Sichuan P.R., China. Electronic address: caidongsheng@cdut.edu.cn.
³ Energy Systems Engineering Department, Cyprus International University, Haspolat-Lefkosa, via Mersin 10, Turkey.
⁴ Electrical Engineering Department, Kings College London, United Kingdom.
⁵ College of Nuclear Science and Automation Engineering, Chengdu University of Technology, Chenghua District, Chengdu, Sichuan P.R., China; Sichuan Industrial Internet Intelligent Monitoring and Application Engineering Technology Research Center, Chengdu University of Technology, Chenghua District, Chengdu, Sichuan P.R., China.

PMID: 37963538
DOI: 10.1016/j.scitotenv.2023.168459

Abstract

The continuous increase in global population and energy demands has enhanced the use of fossil fuels. The evident climate change effect in recent years has brought about the necessity to reduce fossil fuels. Hence, there exists an aggregate problem of meeting energy demands and reducing carbon emissions. Renewable energy sources have been proffered as the probable solution; however, multi-energy systems are effective options/alternatives to solving this problem. In recent literature, geothermal energy has been proposed as a renewable energy source that can continuously meet energy demands. However, there exists a significant gap in literature about the most viable temperature range for geothermal energy applications in multi-energy systems. In this study, two innovative CO₂-based systems namely, high-temperature geothermal multi-energy system (HTGMES) and low-temperature geothermal multi-energy system (LTGMES) are designed, modelled, analyzed, and compared using a thermodynamic approach. While the HTGMES is modelled to predominantly use CO₂ as a working fluid, a novel modified absorption system is integrated with the LTGMES. The two systems are modelled to produce electricity, cooling/refrigeration effect, space heating, hydrogen, and hot water. The energy, exergy environmental, exergy destruction, and exergoeconomic methodology is used to evaluate the performance of the innovative GMESs. Also, multi-objective optimization of the HTGMES and the LTGMES is carried out in a bid to minimize the total product unit cost and maximize overall exergy efficiency. The environmental impact analysis of the proposed system is presented considering CO₂ mitigation. The results from analyses showed that the overall energetic and exergetic efficiencies in steady state are 44. 22 % and 33.5 % for the HTGMES and 45.40% and 32.9 % for the LTGMES. The optimized LCOE, LCOC, and LCOH based on the total unit cost are 0.0573 $/kWh, 0.1833 $/kWh, and 11.59 $/kg for the HTGMES; 0.0323 $/kWh, 0.0032 $/kWh, and 11.9$/kg for the LTGMES. Furthermore, the optimized exergetic performance showed that the LTGMES can achieve as high as 64.54 % and 40.96 % energy and exergy efficiency.

Keywords: Energy/exergy analysis; Environmental analysis; Geothermal fuel; Multigeneration system; Optimization.