Common use of SULFUR Clause in Contracts

SULFUR. There are several concerns relative to the levels of sulfur contained in the fuel gas supply. Many of these are not directly related to the gas turbine but to associated equipment and emissions requirements. These concerns include but not limited to: 1. Hot Gas Path Corrosion Typically, use of sulfur bearing fuels will not be limited by concerns for corrosion in the turbine hot gas path. Experience has shown that oxidation/corrosion rates are not significantly affected by fuel sulfur levels up to about 1% sulfur. Hot corrosion of hot gas path parts is controlled by specifying the fuel alkali levels to values shown in table 2. This controls the extent of alkali sulfate formation, which is the salt responsible for hot corrosion. Unless sulfur levels are extremely low, alkali levels are usually limiting in determining hot corrosion of hot gas path materials. For low Btu gases, the fuel contribution of alkali metals at the turbine inlet is increased over that for natural gas, and the alkali limit in the fuel is therefore decreased.