Feasibility of thermochemical conversion processes to convert sewage sludge into valuable products such as pyrolytic oil, synthetic gases and biochar is attracting great research interests. However, uncertainty in kinetics analysis and conversion modelling of sludge is considered as a significant barrier for accurate determination and understanding of its conversion pathways, kinetic parameters, and process optimisation. This is caused by the heterogeneity and complexity in composition of sludge since multiple thermal degradation reactions of different components occurred concurrently. Therefore synthetic sludge study is carried out to establish a component-based methodology to produce a representative tool for sludge conversion modelling and to address these issues. Synthetic sludge is formed based on an analytical survey on sludge samples collected from Water Reclamation Plants (WRPs) in Singapore and selective screening of model compounds. Dried sludge (CsY) collected from Changi Water Reclamation Plant (WRP) is used as a reference waste sample in this study. Thermochemical properties, multiple heating rates thermogravimetric analysis (TG-DTG), kinetics study, products evolution analysis, Fourier-Transform Infrared Spectroscopy (FTIR) spectra obtained from synthetic sludge and collected real sludge samples were analysed and compared. Acceptable representation with improved consistency was achieved with discrepancy identified for further improvement on composition analysis and model compounds selection. With this modifiable tool, synthetic sludge of controllable composition could then be applied in complex thermochemical process analysis as a representative compound to improve consistency of the results. Composition of sludge could also be manipulated as a control parameter to develop study on impacts of feedstock properties to the performance and optimisation of thermochemical conversion processes.

热化学转化工艺将污水污泥转化为有价值的产品（如热解油，合成气和生物炭）的可行性正引起人们极大的研究兴趣。但是，动力学分析和污泥转化模型的不确定性被认为是准确确定和了解其转化途径，动力学参数和工艺优化的重要障碍。这是由于污泥组成的不均匀性和复杂性引起的，因为不同组分的多个热降解反应会同时发生。因此，进行了合成污泥研究，以建立基于组件的方法，以产生用于污泥转化建模并解决这些问题的代表性工具。合成污泥的形成是基于对从新加坡水回收厂（WRP）收集的污泥样品进行的分析调查并选择性筛选模型化合物而形成的。从樟宜水回收厂（WRP）收集的干污泥（CsY）在本研究中用作参考废物样品。分析和比较了从合成污泥和收集的真实污泥样品中获得的热化学性质，多种加热速率热重分析（TG-DTG），动力学研究，产品演化分析，傅里叶变换红外光谱（FTIR）光谱。通过发现差异进一步改善组成分析和模型化合物选择，获得了具有改进一致性的可接受表示。有了这个可修改的工具，然后可以将可控制组成的合成污泥作为代表化合物应用于复杂的热化学过程分析中，以提高结果的一致性。污泥的组成也可以作为控制参数进行控制，以研究有关原料性质对热化学转化工艺性能和优化的影响。