화학공학소재연구정보센터
Industrial & Engineering Chemistry Research, Vol.59, No.36, 16052-16058, 2020
High-Temperature Attrition of Nano CaO-Based CO2-Reactive Adsorbents in the Calcium Looping Process
The high-temperature attrition behavior of nano CaO-based CO2-reactive adsorbents was studied during multiple calcium looping (CaL) processes with a carbonation temperature of 600 degrees C and a calcination temperature of 800 degrees C using a fluidized bed reactor. The effect of the cyclic run number and the presence of steam on attrition were analyzed under a given fluidization number. The features of the hot attrition revealed that the attrition of the adsorbents occurred mainly in the first 15 cycles, and the maximum average single attrition loss reached about 3.6% in the first five cycles. With the CaL run number increasing, the average single attrition loss decreased, was basically stable below 0.5% between 20 and 60 cycles, and was less than 0.2% during 60-90 cycles. Moreover, because of the presence of steam, the attrition loss increased by about 8.9% in the calcination stage while attrition loss only increased by 2.8% in the carbonation stage. The particle size distribution, scanning electron microscopy, and energy-dispersive spectrometry tests showed that the attrition was mainly due to the surface flaking, and the high-temperature steam made adsorbent particles more prone to cracking. Additionally, attrition mainly occurred in the calcium-rich area, which was the weak point of the mechanical strength of the adsorbents.