Performance of a Vacuum Formed Chopped Ceramic Fiber Filter in a Reducing Environment Rajesh K. Ahluwalia (walia@anl.gov; 630-252-5979) Vincent J. Novick (vnovick@anl.gov; 630-252-6629) L. Zhang (fzhang@anl.gov; 630-252-6389) Manish P. Sutaria (manish_sutaria@qmgate.anl.gov; 630-252-5115) Jitendra P. Singh (jp_singh@qmgate.anl.gov; 630-252-5123) Argonne National Laboratory 9700 South Cass Avenue Argonne, IL 60439-4841 ABSTRACT A laboratory-scale apparatus has been used for unattended, long duration, continuous, flow-through testing of a vacuum formed chopped ceramic fiber filter under reducing conditions. Four candle specimens were exposed from 150 to 3550 h to 600 C gas containing 4% CO, 11% H , 2 12% CO , 14% H O, 59% N , 1 ppmv NaCl, 50 ppmv H S and 1000-2000 ppmw ash from a 2 2 2 2 transport reactor operated in gasification mode. A data base was established on pressure drop of the as-received and exposed filter as a function of face velocity and temperature. Tests were conducted to investigate the effects of back pulse parameters on filter regenerability. Results are reported on the critical reservoir pressure and pulse duration for maintaining a stable saw-tooth profile of pressure drop across the filter element. Data are obtained to characterize the effect of chemical and thermal aging on the apparent bulk density of the filter, pore size distribution, fast fracture strength and microstructure. It is suggested that the compliant filter undergoes a slow process of rigidization upon exposure to the test environment. INTRODUCTION Vacuum formed chopped ceramic fiber (VFCCF) filters made by Industrial Filter and Pump Manufacturing Company are being considered for high-temperature particulate removal applications in pressurized fluidized bed (PFBC) and integrated gasification combined cycle plants (IGCC). Compared to isostatically pressed silicon carbide filters, VFCCF candles (trade name Fibrosic) have stated advantages of lightweight construction, stable ceramic oxide materials, high temperature capability, shock and cracking resistance, and ease of surface treatment [1]. At 0.27-0.34 g/cc apparent density, VFCCF candles are 70-80% lighter than their SiC counterparts. The resulting weight saving translates into reduced stress on the flange of the candle filter and simplification of the design and construction of the tubesheet and supporting hardware. The fibers and binders are a blend of stable, pure ceramic oxides, primarily alumina and aluminosilicate materials rated for a maximum use temperature of 1400-1500 C. They do not exhibit significant physical changes, such as shrinkage, until a temperature of about 1260 C. The differences in the thermochemical properties between the binder and fiber are negligible because they are identical in composition. This results in