含硫生物质气化气催化燃烧性能研究

Catalytic Combustion of Sulphur-Bearing Gasified Biomass

制备了Pt和Pd负载LaAl_(11)O_(19)整体式催化剂,借助XRD和BET对其进行了表征,同时考察了催化剂作用下模拟生物质气化气的燃烧特性及气化气中加入H2S对可燃成分催化燃烧的影响。结合失活样的XPS、SEM和FTIR表征结果,初步分析催化剂硫中毒的机理。结果表明,制得催化剂活性优良,明显降低了可燃成分的起燃温度,低温下Pd的活性优于Pt。Pd和Pt在抗硫中毒性上是不同的,催化剂失活是通过生成的表面硫酸盐覆盖活性位,失活后有一定的再生性。

Precious metal based catalyst Pd/LaAl11O19 and Pt/LaA111019 were prepared and characterized by means of XRD and BET. Then washcoated on cordierite monoliths and tested in a bench scale reactor with a synthetic low-heating value fuel that resembles the gas from gasification of biomass, besides 0.005% hydrogen sulphide were added to the fuel to investigate the influence of sulphur on the catalytic combustion. Combined the characterization results of XPS, SEM and FTIR after the activity tests, a preliminary analysis of the mechanism for the sulfur poisoning of the catalysts were deduced. The results show excellent catalytic activity for the catalysts which significantly reducing the ignition temperature of combustible ingredients, the low temperature activity for Pd was superior to Pt. Besides all samples were deactivated to some extent by addition of sulphur, although poisoning effect varied depending on the active phase. The poisoning processes mainly through the formation of sulfate which deposition on the surface composition, then covered the active site resulting a decrease in catalytic activity.