Study on alkali metal vapor removal from coal gasification flue gases

A study on a dry type alkali sorbent has been conducted for the purpose of reducing the corrosion on gas turbine blades with alkali vapor in Direct Co al Fired. Turbines (DCFT) system using a Pressurized Coal Partial Combustor (PCPC). Kaolinite and zeolite were found to be very effective for capturin g the NaCl vapor. It is also found that coexistent gases such as H2O and H2 S promote the NaCl vapor capture on kaolinite whereas HCl gas suppresses it . The amount of Na captured on kaolinite is estimated to be around 30 mass % of kaolinite. From instrumental analysis of kaolinite using X-ray Photoel ectron Spectroscopy (XPS) and X-ray Diffraction (XRD), it is found that the Na is mostly captured on kaolinite by chemical adsorption and chemical rea ction.