污水污泥流化床空气气化焦油的燃烧特性

利用热重分析法，研究了气化温度（650、750和850℃）和污泥性质对污泥流化床气化焦油燃烧特性的影响变化规律。结果表明：6种污泥气化焦油的燃烧过程均分为轻质有机物挥发和燃烧、重质有机物分解和燃烧以及微量残炭燃烧3个阶段；其中第一阶段失重率均明显高于第二阶段，且第一阶段和第二阶段的失重率随气化温度的升高而分别呈现为升高和降低的变化趋势。来自于活性污泥法工艺未消化污泥气化焦油在第一阶段的失重率高于消化污泥的，而A2/O工艺未消化污泥气化焦油在第一阶段的失重率则低于消化污泥的。6种气化焦油的机理函数不完全相同，但反应级数均在1~2.5之间，且第一阶段的表观活化能均低于30 kJ·mol-1。污泥流化床空气气化焦油的着火点和表观活化能均比其固定床空气气化焦油的低。

Combustion properties of tars from air gasification of sewage sludge under fluidized bed

The influence of the gasification temperature (650, 750 and 850℃) and sewage sludge nature on the combustion properties of tar from the air gasification of sewage sludge under fluidized bed were studied by thermogravimetric analysis. The results showed that the combustion processes of the six different gasification tars, which were obtained from the four kinds of sludge gasification under different temperatures, can be divided into the same three stages:the volatilization and combustion of light organic compounds, the decomposition and combustion of heavy organic compounds, and the combustion of trace residue carbon. The mass loss percentages of the six tars in the first stage were always higher than that in the second stage, and the mass loss percentages in the first and second stages increased and decreased respectively with the increase of gasification temperature. In the first stage, the mass loss percentages of the gasification tar of the indigestion sludge from the activate sludge process was higher than that of the digestion sludge, but the opposite phenomenon happened for the gaisification tar of the indigestion and digestion sludge from the A2/O process. The mechanism functions of the six gasification tars were unlike each other, but their reaction orders were in the range of 1 to 2.5, and their apparent activation energy in the first stage was always lower than 30 kJ·mol-1. The ignition point and apparent activation energy of the sludge gasification tar under fluidized bed were lower than that under fixed bed.