生物质气化过程中焦油的生成

总结了生物质气化过程中焦油的生成和分类,以及气化炉炉型、温度与氧量对焦油生成量和组成的影响规律。初级、二级和三级焦油是应用最为广泛的一种分类方法;不同炉型气化炉产气中焦油质量浓度从大到小依次为:上吸式流化床下吸式,分别在100,10,1g/m~3的量级,两段式等改进炉型在焦油控制上更有优势;上吸式气化炉焦油多为初级组分,下吸式则以无取代基的多环芳香烃等三级焦油为主,而流化床的焦油涵盖了二、三级焦油组分;温度的升高使得焦油量下降,且趋向于转化为化学结构更稳定的三级组分;氧量的增多对焦油的生成具有抑制作用。

Production of Tar during the Process of Biomass Gasification

In present work, results of investigations on production and classification of tar during biomass gasification process were summarized. The quantity and composition of tar produced by different types of gasifier were compared, and the effects of temperature and oxygen were gained as well. The classification of tar as primary, secondary and tertiary components is widely accepted and applied. For different types of gasifier, the quantity of tar produced varies： updraft （a level of 100 g/m3） 〉 fluid bed （a level of 10 g/m3） 〉 downdraft （a level of 1 g/m 3）. And improved types, like two-stage gasifier, have advantage in tar control. Primary tars are found to be the main part in updraft gasifiers, while in a downdraft gasifier it is tertiary components like non-substituent PAHs. As for fluid bed gasifiers, the syngas contains both the see- ondary and tertiary components. With the rise of temperature, tar decreases and tends to convert to tertiary components with more stable chemical structure. Oxygen is found to have inhibiting effect on tar formation.