Black liquor gasification process with direct causticization using TiO2 is considered as a promising technology for the black liquor recovery in the future.In this study,laboratory-scale pyrolysis and steam gasification experiments with direct causticization using TiO2 for wheat straw alkaline black liquor were performed in a thermo gravimetric analyzer and a tube furnace,respectively.Effects of TiO2 on the pyrolysis and steam gasification characteristics were discussed based on the products analysis.Results showed that thermo gravimetric behaviors along with releasing patterns of CO2 and CO of the black liquor were changed when the pyrolysis temperature was higher than 550 ℃ after adding TiO2.In the presence of TiO2,swelling and agglomeration were prevented during the pyrolysis process.