In order to combat global warming, the reduction of greenhouse-gas emissions is required. The performance of gas turbines is enhanced by raising the operating temperature. With the growing number of high-efficiency combined-cycle power generation systems available, the demand for liquefied natural gas (LNG) has increased as the fuel. This LNG has a variable composition and differs depending on the production regions. However, the demand for sharing common facilities using the LNG is increasing. Additionally, it is desirable to utilize blast-furnace gases generated from steelworks in high-efficiency combined generation facilities. Considering such environmental backgrounds, this paper discusses technologies that enable the use of various types of fuels for stable combustion with high-temperature and low-pollution conditions.