Abstract The pyrolysis kinetics of two types of sewage sludge (municipal sludge and pharmaceutical sludge) were studied by thermogravimetry. The collected samples were pretreated and tested with nitrogen as carrier gas at different heating rates (10, 20, 30, and 40 °C/min) using a thermogravimetric analyzer. Model-free methods and master plots method were used to calculate the pyrolysis kinetic parameters of the samples. TG/DTG results showed that the thermal decomposition of the two types of sewage sludge may be divided into three stages (Dehydration, Decomposition, and Coking stage). The activation energies of the two kinds of sewage sludge were 366.58 KJ/mol (municipal sludge) and 268.36 KJ/mol (pharmaceutical sludge), respectively. The pyrolysis mechanism of two kinds of sewage sludge was discussed by the master plots method. The results showed that under a low conversion rate, the phase interface reaction model can better explain the pyrolysis mechanism of pharmaceutical sludge; under high conversion rate, the nucleation and growth model was more suitable. For municipal sludge, power law model was most suitable in the whole range. The pyrolysis characteristic of the samples was further studied. The results showed that the organic matter in sewage sludge can be decomposed into bio-oil and bio-gas at elevated temperatures and can be used as an attractive energy source.

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使用无模型和主图方法对污水污泥进行热解特性和动力学分析

摘要 采用热重法研究了两种污水污泥（市政污泥和制药污泥）的热解动力学。使用热重分析仪以不同的加热速率（10、20、30 和 40 °C/min）对收集的样品进行预处理和测试。采用无模型法和主图法计算样品的热解动力学参数。TG/DTG结果表明，两类污泥的热分解可分为三个阶段（脱水阶段、分解阶段和焦化阶段）。两种污水污泥的活化能分别为366.58 KJ/mol（市政污泥）和268.36 KJ/mol（制药污泥）。采用主图法讨论了两种污水污泥的热解机理。结果表明，在低转化率下，相界面反应模型可以更好地解释制药污泥的热解机理；在高转化率下，形核生长模型更适合。对于城市污泥，幂律模型在整个范围内最适合。进一步研究了样品的热解特性。结果表明，污水污泥中的有机物在高温下可分解为生物油和生物气，可作为一种有吸引力的能源。进一步研究了样品的热解特性。结果表明，污水污泥中的有机物在高温下可分解为生物油和生物气，可作为一种有吸引力的能源。进一步研究了样品的热解特性。结果表明，污水污泥中的有机物在高温下可分解为生物油和生物气，可作为一种有吸引力的能源。