Use of Nickel Oxide as a Catalyst for Tar Elimination in a Chemical-Looping Reforming Reactor Operated with Biomass Producer Gas

作者：Berguerand Nicolas^*; Lind Fredrik; Israelsson Mikael; Seemann Martin; Biollaz Serge; Thunman Henrik

来源：Industrial & Engineering Chemistry Research, 2012, 51(51): 16610-16616.

DOI：10.1021/ie3028262

A secondary tar-cleaning process based on chemical-looping reforming (CLR) was investigated for upgrading biomass producer gas, derived from the Chalmers University of Technology 2-4 MW indirect gasifier. The experiments were conducted in a bench-scale CLR reactor using a manufactured nickel oxide (NiO) catalyst. Although Ni is a well-documented and efficient steam-reforming catalyst, it is susceptible to rapid deactivation under tar-rich conditions. The aim of this study was to explore the advantages of CLR as a gas-cleaning application, a process which offers continuous regeneration of the carbon deposits on catalysts. The tar-reforming performance of this Ni material and its influence on the gas composition and in particular its potential to increase the H-2/CO ratio, were studied. The system was tested at reforming temperatures that ranged from 700 to 880 degrees C and at oxygen concentrations of 1.0% and 2.2% in the inlet feed to regenerator section. The results confirm the strong ability of the catalyst to reform tars. Higher process temperatures dearly promoted tar conversion, with 96% overall conversion at 880 degrees C (99% if benzene is excluded), as compared with 45% conversion at 700 degrees C. The hydrogen production was favored when temperature was raised, though, a maximum ratio of H-2/CO of 2.2 was observed at 750 degrees C. Finally, no time-on-stream deactivation of the catalyst in the CLR was observed during the test, which lasted almost 7 h.

• 出版日期2012-12-26