ZHANG Zhe1，2，XIAO Weiting2，HE Yufei1，3*，YAN Zihan4，LI Dianqing1，3，ZHAO Xiaodong2
( 1. State Key Laboratory of Chemical Resource Engineering， College of Chemistry， Beijing University of Chemical Technology， Beijing 100029， China；2. Liming Research & Design Institute of Chemical Industry Co. ， Ltd. ， Luoyang 471000， China；3. Quzhou Institute for Innovation in Resource Chemical Engineering， Quzhou 324000， China；4. State Key Laboratory of Heavy Oil Processing， College of Chemical Engineering and Environment，China University of Petroleum， Beijing 102249， China )
Objective The three-phase fluidized bed is extensively employed in chemical industry due to its low mass transfer resistance，uniform temperature distribution， and maximized contact between catalysts and reactants. The attrition resistance of catalysts is a crucial parameter due to the severe collisions between catalyst particles and the inner walls of reactors， as well as among the particles themselves. However， existing attrition resistance tests are typically conducted in gas-solid two-phase environments，and the catalysts are also applied in the similar system. Therefore， designing a new method which simulates a three-phase fluidized bed is both academically and practically significant.
Methods In this paper， deionized water was introduced as the liquid phase to transform the traditional gas-solid two-phase attrition test into a gas-liquid-solid three-phase test. Attrition tests were conducted on pristine samples and samples that were prescreened to remove fines under 20 μm or 45 μm to determine the influence of sample pre-screening on test results. An orthogonal test was designed to evaluate the contributions of gas flow volume （6 to 8 L/min）， sample mass （20. 0 to 30. 0 g）， and water volume （100 to 140 mL） to the attrition index. The combination of levels that resulted in the highest attrition index from the orthogonal test was proposed as the optimal test condition for the new method， and its repeatability was evaluated. Attrition tests with durations ranging from 0. 5 to 2. 5 h were conducted to study the time-profile characteristics of microspherical materials in gas-liquid-solid three-phase fluidization.
Results and Discussion In traditional tests， fines collected in the filtering flask often contain intact microparticles， which are mistakenly calculated as attrited fines， leading to systematical bias. Additionally， fines with diameter below 20 μm in the sample can interfere with attrition test results for the same reason and should therefore be pre-screened. With these improvements， the fines collected in the novel method were solely those generated during the attrition test. The orthogonal test showed the relative significance of different factors in the following order： gas flow volume > sample mass > water volume， with the first factor positively correlated with the result and the last two negatively. The highest attrition index was observed when using 20. 0 g of the sample，100 mL of water， and a gas flow volume of 8. 0 L/min. To evaluate the repeatability of the new attrition test method， three batches of samples were tested， with five parallel experiments for each sample. The relative standard deviation ranged from 3. 48% to 4. 46%， indicating good reliability. Attrition test results over time corresponded well with the Gwyn model， indicating that the attrition mechanism in the three-phase fluidized bed was similar to that in the gas-solid two-phase system.
Conclusion A novel method for evaluating attrition resistance of microspherical materials used in three-phase fluidized beds was established. To more precisely reflect attrition resistance in real three-phase reactors， fines with diameter below 20 μm should be removed. The orthogonal test showed that gas flow volume had the most significant influence on attrition. The repeatability of the test was confirmed， with a relative standard deviation of less than 5%， indicating good reliability. The new method can be used to determine the attrition resistance of different materials used in three-phase reactors， which has important practical applications.
Keywords：microspherical material； attrition resistance； gas-liquid-solid three-phase fluidization
Get Citation:ZHANG Z， XIAO W T， HE Y F， et al. An attrition index test method for microspherical materials in gas-liquid-solid three -phase fluidization［J］. China Powder Science and Technology，2024，30（4）：94−103.
Received:2024-04-02. Revised:2024-06-14, Online:2024-06-27。
Funding Project:国家重点研发计划青年科学家项目，编号：2022YFA1506200；国家自然科学基金项目，编号：22078007；河洛青年创新创业人才项目（2022年度）
First Author:张哲（1988—），男，高级工程师，博士生，研究方向为：催化剂研发及产业化，E-mail： zhgzhe@126. com
Corresponding Author:
贺宇飞（1988—），男（满族），教授，博士，博士生导师，研究方向为：催化剂反应工程，E-mail： yfhe@mail. buct. edu. cn
李殿卿（1962—），男，教授，博士，博士生导师，研究方向为：无机功能材料与催化新材料，E-mail: lidq@mail.buct.edu.cn
DOI：10.13732/j.issn.1008-5548.2024.04.009
CLC No:TB4； TQ016.1 Type Code:A
Serial No:1008-5548（2024）04-0094-10
