The filtration efficiency for separating liquid paraffin (or water) from a slurry consisting of 25 wt.% spherical alumina in a Slurry Bubble Column Reactor (SBCR) comprised of a cylindrical tube of 10 cm diameter and 150 cm length was studied. Various differential pressures (ΔP) were applied to two separate tubular sintered metal stainless steel filter elements with nominal pore size of 4 and 16 μm. The experimental results disclosed that the rate of filtration increased on applying higher differential pressure to the filter element, albeit this phenomenon is limited to moderate ΔPs and for ΔP more than 1 bar is neither harmful nor helpful. The highest filtration rates at ΔPs higher than 1 bar were 170 and 248 ml/min for 4 and 16 μm, respectively. Using water as the liquid in slurry, the rate of filtration was enhanced fourfold, which clearly reveals the impact of viscosity on filtration efficiency. In all situations, the total amount of particles present in the filtrate part never exceeded a few parts per million (ppm). The statistical analysis of the SEM images of the filtrate indicated that by applying higher pressure difference to the filter element the frequency percent of larger particle size increases. The operation of filter cake removing was performed with backflashing of 300 ml of clean liquid with pressures of 3-5 bar of N2 gas.

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