Research Of Imitation Of Separating FCC Catalyst From FCC Slurry By Filtering

A small size backwashing filter is built in the laboratory. With this device, the filter of slurry and the progress of regenerating of filter element are simulated and analyzed using water and FCC catalyst as simulating media. A series of experiments are carried on to figure out how filtering rate, viscosity of slurry and the percentage of catalyst powder in the slurry affect filtration pressure drop and filtration efficiency; and how different concentration, diameter, species, size distribution, of filter aid, and the proportion of filter aid and hole diameter of filter element affect filtration pressure drop and filtration efficiency.Experiments show that, as the concentration of catalyst powder increases, the ascending speed of filtration pressure first decrease then getting bigger. Thus there is a best concentration of catalyst which gives the smallest ascending speed of filtration pressure. After adding large diameter FCC catalyst as filter aid into the simulation system, the ascending speed of filtration pressure drop decreased markedly; filtration efficiency became higher; after backwashing, the original value of pressure drop of filter element reduced. As more filter aid are added into slurry, the ascending speed of filtration pressure drop reduces first then increases. When the percentage of filter aid in slurry is 10%, which is the best concentration of filter aid in this experiment, the ascending speed of pressure drop comes to a minimum. Three types of filter elements with different hole diameters are analyzed in this experiment and find out the best diameter of filter aid for each element. Different hole diameters correspond different best diameter of filter aid; that means there is a most proper proportion among hole diameter, diameter of filter aid and catalyst powder. Another way of adding filter aid is also analyzed in this experiment, which is adding two different size of filter aid simultaneously, and determined the proportion of concentration of these two filter aid and diameter for each filter aid. Slurry concentration can also affect on filter aid effect. The bigger the slurry concentration, the more inconspicuous the filter aid effect is.