典型粉末型吸湿性催化剂的雾室及静态检测

Fog Chamber and Static Detection of Typical Powdered Hygroscopic Catalysts

暖云催化剂在人工影响天气暖云催化降水和暖性云雾消除方面应用前景广阔,近年开发的各类新型材料有望在暖云催化中使用,但目前仍缺少效果理想的制剂配方,亟需在相同试验条件下对比各类吸湿性催化剂的性能。2023年5月在中国气象局云降水物理与人工影响天气重点开放实验室开展催化剂雾室及静态检测试验,评估9种典型粉末型吸湿性催化剂的消雾能力及吸湿特性。结果表明:无机盐类催化剂消雾所需时间最短,多孔复合材料催化剂效果也较好,而改性淀粉、分子筛、有机膨润土及钠基膨润土消雾效果不明显。在常温常湿环境下,CaCl_(2)的静态吸湿能力最强,其次是多孔复合材料,复合盐的吸湿性也较强,其他催化剂吸湿性不明显;在高湿环境下,膨润土类催化剂及分子筛吸湿性仍不佳,NaCl、多孔复合材料的吸湿能力明显高于其他催化剂。各种催化剂在雾室与静态检测试验的性能基本一致。

Catalysts for warm cloud seeding have significant potential for applications in warm cloud catalytic precipitation and fog elimination.In recent years,numerous innovative materials have been developed,each with the potential to be used in warm cloud catalysis.However,a universally recognized ideal formulation has not yet been established.It is necessary to conduct a scientific analysis on the performance of various hygroscopic catalysts under consistent experimental conditions.Therefore,9 types of typical powdered hygroscopic catalysts are collected,and experiments involving fog chamber and static testing of catalysts are conducted at CMA Key Laboratory of Cloud-precipitation Physics and Weather Modification in May 2023.Fog elimination capabilities and hygroscopic characteristics of various catalysts are comprehensively evaluated and compared.Results indicate that,under the same fog conditions,salt type catalysts demonstrate the shortest time to eliminate fog,and porous composite materials(PCM-100 and PCM-10)are also effective,while fog elimination effects of modified starch,molecular sieves,organic bentonite and sodium bentonite are not obvious after seeding.In static detection,under normal temperature and humidity conditions,CaCl_(2) exhibits the strongest static hygroscopicity,followed by porous composite materials such as PCM-100 and PCM-10.Composite salt catalysts exhibit strong hygroscopic absorption,whereas the static hygroscopic absorption capacity of other catalysts is not as pronounced.In high humidity conditions,bentonite and molecular sieve catalysts still do not exhibit moisture absorption characteristics.The hygroscopic abilities of CaCl_(2),PCM-100,and PCM-10 are significantly higher than those of other catalysts.The performance of various catalysts in the fog chamber experiment and static detection is basically consistent.Microstructures of various catalysts with strong hygroscopic properties do not show significant changes after 30 minutes.PCM-10 primarily exists in the form of liquid droplets after standing for 5 minutes and can continue to provide hydration.PCM-100 remains in irregular crystal form after 5 minutes and transforms into droplets after 30 minutes.CaCl_(2) absorbs moisture rapidly under the microscope,initially existing as liquid droplets for 5 minutes.Subsequently,there are no significant changes,primarily small droplets.Complex salts always form crystals,while the size of liquid droplets formed is larger.It should be noted that,although the hygroscopicity and the ability of fog elimination of various catalysts are important indicators,the dispersibility,corrosiveness and ease of preparation and storage of the catalyst are also important parameters of whether they can be used as efficient warm cloud catalysts.Follow-up research and evaluation of various catalysts will be conducted.