Measuring attrition properties of calcium looping materials in a 30 kW pilot plant

• Published in: Powder technology Vol. 336; pp. 273 - 281
• Main Authors: Alonso, Mónica, Arias, Borja, Fernández, José Ramón, Bughin, Olivier, Abanades, Carlos
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 01.08.2018; Elsevier BV
• Subjects: Abrasion; Attrition; Calcium; Calcium looping; Carbon dioxide; Carbon sequestration; Chemical composition; Circulating fluidized bed; CO2 capture; Comminution; Diameters; Fruits; High temperature; Limestone; Mechanical properties; Performance indices; Pilot plants; Sorbents; Circulating fluidized bed; Limestone; Calcium looping; CO2 capture; Attrition
• ISSN: 0032-5910; 1873-328X
• DOI: 10.1016/j.powtec.2018.06.011

The attrition of CaO-based solids operating in calcium looping (CaL) post-combustion CO2 capture systems is an important factor to consider when limestones are selected as sorbent precursors. In this work, four commercial natural limestones with similar chemical compositions but with very different mechanical properties were tested in a 30kWth calcium looping pilot plant. The main attrition mechanisms that act upon the limestones (i.e. fragmentation, decrepitation and abrasion) were identified on the basis of the evolution of their particle size distributions during the start-up and the first calcination of each batch. Great differences in the performance of the selected limestones were observed, which confirms the suitability of the experimental procedure employed for sorbent screening purposes in these high-velocity, high-temperature pilot plants. Several attrition indexes reported in the literature were tested to conclude that the Total Particle Generated Index (TPGI) and the Maximum Diameter of Particles Generated (MDPG) indexes are the most useful for quantifying attrition phenomena and rank limestones. [Display omitted] •Attrittion mechanims were studied in a fluidized bed pilot plant with and without calcination•The study of the PSDs allowed abrasion, fragmentation and decrepitation mechanism to be identified•Attrition Indexes defined by Gwyn and by Forsythe/Hertwig did not describe well the observed changes in the PSDs•TPGI and MDPG indexes, which consider elutriated and non-elutriated solids,were shown to be suitable