Electronic Thesis and Dissertation Repository

Thesis Format



Master of Engineering Science


Chemical and Biochemical Engineering


Zhu, Jingxu


Group A powders are widely utilized in the industry because of the great quality of fluidization, which can be affected by the fine content. This project investigates the feasibility that employing the fine powders (≤ 20 μm) as additives to further improve the fluidization ability of Group A powders. Three additives, Coal-15, GB-6, and SiO2-5 are added into FCC-76, based on various volume fractions. The minimum fluidization velocity (Umf), bed expansion ratio (BER), and dense phase expansion ratio (DER) are tested to evaluate the quality of fluidization. Coal-15 can slightly improve the fluidization quality. High content of GB-6 can make the mixture obtain some characteristics of Group C/A powders. While after adding 13.5% SiO2-5, BER and DER separately enhance 19.4% and 10.3%, besides, there is a 28.8% decrease in Umf. The improvement of Group A powders on the fluidization has potential industrial values, especially in improving the gas-solid reaction conversion.

Summary for Lay Audience

In daily life, many items are solid particles, such as soybeans, flour, and rice. Solid particles that I am studying are smaller than soybeans but larger than flour and they are around 76 microns. In the industry, there is a technology named fluidization and just like its name, this technology is related to the fluid. Solid particles can have many properties of real fluid by continuously injecting upward gas. One of the reasons that fluidization technology is widely used for gas-solid reactions is great gas-solid contact. The research found that fine powders (less than 20 microns) have significant effects on the fluidization quality. My works try to utilize the fine powders as additives to improve the fluidization ability. After mixing with fine powder additives, for example, SiO2-5, the contact between gas and solid can be greatly improved. Fine powder additives have great potential in the industry because high gas-solid contact could improve the reaction efficiency.