Understanding particle adhesion of sewage sludge incineration ash at high temperatures: Effect of physical characteristics

• Published in: Journal of the Energy Institute 2024-08, Vol.115, p.101691, Article 101691
• Main Authors: Ito, Masahiro, Tone, Koichiro, Horiguchi, Genki, Koseki, Takami, Kamiya, Hidehiro, Okada, Yohei
• Format: Article
• Language: English
• Subjects: Particle adhesion; Particle size; Powder bed porosity; Sewage sludge incineration ash
• ISSN: 1743-9671
• DOI: 10.1016/j.joei.2024.101691

Ash particle adhesion at high temperatures in thermochemical processes is a serious problem, and adhered ashes cause operational problems for processing plants, resulting in inefficient and unstable operation. A major mechanism of adhesion is the formation of a liquid phase due to melting of the ash components with low melting points, which results in a liquid bridge force, which is an attractive force. Therefore, the chemical characteristics of the ashes have been carefully studied to understand the adhesion phenomenon. However, each ash is also characterized by its physical properties such as particle size and packing ability. In this study, we focused on the physical characteristics of sewage sludge incinerated ashes collected from commercial incineration plants and carefully examined their relationship to adhesion. We found good correlations between particle size or porosity of the powder bed and adhesiveness at both ambient temperature and 800 °C. Understanding particle adhesion based on physical characteristics is simpler than considering complicated chemical characteristics and is useful for predicting particle adhesion at high temperatures. [Display omitted] •Physical properties of sewage sludge ashes examined their relationship to adhesion.•A good correlation was observed between the tensile strength and physical properties.•Particle size and porosity of powder bed were important factors affecting adhesion.•Strong correlation was observed between particle size and tensile strength at 800 °C.•Physical characteristics can be used to understand ash adhesion at high temperatures.