Techno-Economic Assessment of Natural Gas Combined Cycle Power Plants with Carbon Capture and Utilization

Carbon utilization in natural gas combined cycle (NGCC) power plants has attracted great attention due to necessary carbon reduction demands. In this study, NGCC power plants integrated with the carbon capture and utilization process (CCU) were developed: Case 2 (NGCC power plant with CO2 conversion on precarbon capture) and case 3 (NGCC power plant with CO2 conversion on postcarbon capture). Integrated process configurations were evaluated and compared with case 1 (NGCC power plant only with postcombustion carbon capture) in terms of technical (net power generation, natural gas consumption rate, syngas production rate, CO2 quantity released into the environment) and economic (total capital cost, total annual revenue, return on investment, payback period, and cash flow) performance. Here, case 2 represented the most environmentally friendly option with the lowest CO2 released. Besides, case 3 generated the highest amount of electricity due to a lower compression pressure demand for CO2 utilization than storage in case 1. The economic analysis indicated that the payback periods of cases 1, 2, and 3 were 9.2, 17.18, and 6.9, respectively. Case 3 was the best option under the least capital expenditure, operating expenditure, and the highest annual revenue. Additionally, case 2 was competitive in terms of low total capital cost as compared to case 1. Therefore, the suggested NGCC power plant processes with CCU are viable options for reducing CO2 emissions and improving the economics of NGCC power plants. In addition, the process may be used as a model for further CO2 utilization from flue gas released by gas power plants.

Automated summary

This study developed NGCC power plants integrated with CCU and compared them with a conventional NGCC power plant with postcombustion carbon capture. Case 2 showed the lowest CO2 emissions and Case 3 had the highest electricity generation due to lower CO2 utilization pressure. The economic analysis showed that Case 3 had the best performance in terms of capital and operating expenditures and annual revenue.