Experimental research on the effect of CO on alkali metals' condensation characteristics

Integrated gasification combined cycle (IGCC) is one of the trends of clean coal power generation technology. However, that alkali metal vapors contained in the syngas which are generated from coal gasifier easily deposit on the surfaces of convectional syngas cooler (CSC) will not only lead to slagging, but also will cause high-temperature corrosion of gas turbine blades. An experimental facility was built to study the condensation characteristics of high temperature alkali metals contained in the syngas of the IGCC, and the effects of syngas and alkali metal components on the concretion process were obtained. The results show that the concreted temperature of alkali metal is between 620~720°C in the reductive atmosphere; the steam in the syngas has no effect on this concreted temperature; the higher the concentration of CO in the syngas, the lower the concreted temperature; if the concentration of CO keeps invariable, and the ratio of [Na⁺]/[K⁺] is lower, the concreted temperature is lower when both Cl^- and SO₄^2- exists than the case only Cl^- exists.