The Study on Porosity Controllable Filter Material for the Integrated Gasification Combined Cycle

Abstract

The porous ceramic filter material is the most effective filter materials in the integrated gasification combined cycle. The porous silicon nitride due to its higher mechanical strength, as well as good corrosion resistance, is considered as a promising material in the integrated gasification combined cycle, and it were prepared directly though the SiO2 and α-Si3N4 through carbothermal reduction - pressureless sintering in nitrogen. There was a great lot weight loss in this reaction, so it was expected to create the high porosity materials. The rod-like β-Si3N4 grains and uniform pores were formed through changing the content of α-Si3N4, SiO2 and C. So high-performance and porosity controlled porous silicon nitride filter material was obtained. With an increasing in the α-Si3N4 content, the weight loss, the linear shrinkage, and the porosity decreased, the flexural strength increased accordingly. The porous silicon nitride filter material with addition of 50wt% α-Si3N4 showed a higher aspect ratio β-Si3N4 grains and better mechanical properties .