Solid particle size distribution in inlet liquid immediately after shaking
Solid particle size distribution in outlet liquid immediately after shaking
25.0
20.0
Particle size (nm)
(%)
Particle size (nm)
(%)
339.3 388.6 445.1 509.8 583.9 668.7
0.189 0.700 1.387 1.443 0.824 0.397 0.200 0.096 1.851 92.913
1318.2 1509.9 1729.4 1980.8 2268.7 2598.5 2976.3
0.240 0.620 1.075 1.636 2.000 2.225 2.431 2.734 3.812 6.818
15.0
10.0
766
5.0
877.3
3409
5122.3
3904.5 4472.1 5122.3
6000
0.0
16.805 59.605
6000
Particle size (nm)
Table 2
Table 3
Figure 2 PSD of suspended (nm) solids in inlet liquid to Universal Filter
From Table 2 and Figure 2, it appears that larger particles of mainly 6,000 nm in size were settled out of the inlet liq- uid 30 minutes after being shaken, and only the particles with a size of 7-30 nm remained suspended in the liquid. The outlet liquid sample was also shaken with an ultra- sound vibrator for a few minutes to break up any lumps or coagulates of the solid particles. PSD of one portion of the shaken outlet liquid sample was immediately measured with the laser particle analyser Horiba LB550. The PSD analysis is presented in Table 3 . Another portion of the shaken outlet liquid sample was allowed to settle for 30 minutes before analysing the PSD. However, no 7-30 nm or any other size particles were detected in the outlet liquid. These results imply that the Universal Filter was capable of completely removing 7-30 nm particles from the inlet liquid. To further confirm the effective removal of nm-size par - ticles using the Universal Filter, samples of solid slurry collected (simultaneously with the liquid samples) were dispersed in hexane solvent under ultrasound shaking. Most large particles were settled from the solvent 30 min- utes after shaking and were not counted since the focus was on the ‘nm’ particle size distribution. PSD of the sus- pended particles in the solvent was then measured with the laser particle analyser Horiba LB550. The PSD is plot- ted in Figure 3 . From the PSD curves in Figures 2 and 3 and the compar- ative PSD measurements as shown in Table 4 , it appears that 7-30 nm particles in the inlet coal tar liquid, which do not settle from the liquid 30 minutes after shaking, matched well with 7-30 nm particles collected in the solid slurry sample. This means 7-30 nm solid particles in the inlet stream were effectively removed by the Universal Filter. Comparing Tables 2 and 3, the PSD of solid particles was 339.3 to 877.3 nm in inlet liquid versus 1,318 to 4,472 nm in outlet liquid (both measured immediately after shak- ing). It is obvious that the particles in the inlet liquid were much smaller than those in the outlet liquid. This is because the smaller particles in the inlet liquid were preferentially removed by the filter. Particles with a size of 6,000 nm are
excluded because they may be the lumps or coagulates of the solid particles. Important conclusions from material balances XRF analysis and direct PSD analysis of the inlet and outlet liquid streams: After 45 days of continuous on-stream operations without regeneration (backwashing), the Universal Filter removed as high as 97.6% of the solid particles from the coal tar liquid stream to the HDS reactor. Universal Filter demonstrated effective removal of FM, DM, and paramagnetic solid particles, such as Fe, S, Mn, Al, Cr, Mo, Ni, Cl, and Cu, from the coal tar liquid stream. Universal Filter completely removed 7-30 nm particles from the inlet liquid because no 7-30 nm particles were detected in the outlet liquid after 30 minutes of settling after being shaken. Also, 7-30 nm particles in the inlet coal tar
25.0
20.0
15.0
10.0
5.0
0.0
Particle size (nm)*
Figure 3 PSD of nm solids in accumulated slurry of Universal Filter
89
PTQ Q1 2023
www.digitalrefining.com
Powered by FlippingBook