Effect of Fines Content on Fluidity of FCC Catalysts for Stable Operation of Fluid Catalytic Cracking Unit

Abstract

Effect of fines content (weight % of particles with diameter less than 45 μm) on bed fluidity was determined to get a base for good fluidization quality in the fluid catalytic cracking (FCC) unit. The fines content in equilibrium FCC catalysts (Ecat) from commercial units were controlled by adding or removing the fines to simulate commercial situation. To get the fluidity values (Umb/Umf) of seven different FCC catalysts (2 Ecats and 5 fresh catalysts) and their mixture, minimum fluidization velocity (Umf) and minimum bubbling velocity (Umb) were measured in a fluidized bed reactor (0.05 m ID). The fluidity decreased with loss of fines content and increased with increments of makeup of fresh catalysts or additive with the controlled fines content. The fluidities of catalysts increase with increases of normalized particle diameter variation by the fines addition. The obtained fluidities have been correlated with the fines contents and the catalyst and gas properties. The proposed correlation could guide to keep good catalyst fluidity in the FCC unit.

Preparation of MWCNT Microbeads for the Application of Bed Materials in a Fluidized Bed Heat Exchanger

“…Repose angles of the raw CNT and the microbeads were measured by the method of ASTM C1444 [20]. Fluidization characteristics such as minimum fluidization velocity were determined in a fluidized bed cold model reactor (0.05 m ID) where pressure drop across the bed was measured with varying air velocity [3]. The details of the cold model reactor can be found elsewhere [3].…”

“…Fluidization characteristics such as minimum fluidization velocity were determined in a fluidized bed cold model reactor (0.05 m ID) where pressure drop across the bed was measured with varying air velocity [3]. The details of the cold model reactor can be found elsewhere [3]. Figure 3 showed macroscopic and SEM images of the prepared CNT microbeads samples of case I and case II.…”

“…Figure 6 shows the ∆P/L variation with gas velocity for determining the minimum fluidization velocity (U mf ), which is the most important parameter associated with design and operation of the fluidized bed [31]. The pressure drops (∆Ps) across the bed increased linearly due to the friction loss and the kinetic energy loss, and reached a constant value corresponding to apparent weight of the bed materials [1,3]. However, the CNT powders experience an unusual variation of the ∆P with increasing gas velocity due to physical entanglement and strong aggregation phenomena between powders, and show unique fluidization behavior due to the van der Waals force [7,32].…”

“…The fluidized bed has been in existence as a reactor type using the fluidization technology for more than a century. The fluidized bed reactors have been utilized for fluid catalytic cracking, combustion, heat or mass transfer such as gas-solid heat exchange and solid coating [2,3]. Recently, nanoparticles with high specific area and reactivity have played an important role in various powder-based process areas.…”

Modeling of a Catalytic Cracking in the Gasoline Production Installation with a Fuzzy Environment

“…Available information is sometimes uncertain that is person's (person making decisions-PMD, expert) knowledge (experience, intuition, judgment). Effective formalization of uncertain information representing knowledge of experts on CES may be obtained based on methods for expert evaluations and fuzzy set theory (FST) [10][11][12][13].…”