Physical properties of SSG X2 vs SSG II
SOx breakthrough (2h s ulphation) @ 700˚C
1200
Physicals SA, m²/g A.I., w/w ABD, g/cm³
SSG II
SSG X2
(1000ppm SO + 1% O) switch to reactor
113
113
1000
1.1
1.3
800
0.85
0.85
APS, μm
92
95
600
400
Table 1
200
interaction also provided better particle sintering resist - ance, thereby improving the stability and activity of the additive over time. It is understood that cerium oxide par - ticle sintering leads to rapid deactivation of SOx reduction additives due to a reduction in the number of active sites available for Step 1: Oxidation.5 The new SOx reduction additive, SuperSoxGetter X2 (SSG X2), allows FCC unit operators across the globe to: Achieve the same SOx reduction using less additive; in other words, reduce their daily operating cost. v Expand their FCC unit operating window; in other words, improve their FCC unit margin. Laboratory physical properties analysis The new additive’s metal interaction with the support has been optimised without compromising its excellent physi - cal properties, as exemplified in Table 1 . These SOx reduc - tion additives exhibit low attrition and fines and possess a suitable particle size distribution, apparent bulk density (ABD), and surface area (SA), making them ideal for FCC applications. Sorption-desorption laboratory testing results Figure 1 presents a comparison of the SOx uptake and release capabilities of SSG X2 and SSG II using two dis - tinct benchtop-scale setups for evaluating SOx removal additives. Quartz reactors in a fixed fluid bed configuration were used to evaluate one-pass SOx uptake and release abilities. SOx pick-up was carried out by flowing a 1,000 ppm SO₂/1%O2/N₂ gas mixture over a sample after it had been heated in N₂ at 700ºC for 30 minutes. The efflu - ent gas was monitored by an IR analyser. Temperature- programmed sulphur release (TPSR) with reducing gas
0 0 1000 2000 3000 4000
5000
6000
7000
Time (s)
SSG II, fresh
SSG X2, fresh SSG II, steamed SSG X2, steamed
Temperature programmed s ulphur release
50 100 150 350 250 300 200 400
0
400
450
500
550
600
650
700
Temperature (˚C)
Figure 1 SOx breakthrough (top) and SOx release (bottom) profiles
Development of a novel SOx reduction additive Johnson Matthey’s work around SOx reduction additive performance highlighted the significant contribution of Step 1: Oxidation. Cerium oxide plays a crucial role in the selective oxidation of SO₂ to SO₃.⁷. Research revealed that a high number of active sites, active site reducibility, and active site stability improve additive performance. The development of an optimised metal dispersion and met- al-support interaction led to a significant increase in the number of active sites for oxidation compared to the cur - rent benchmark additive Super SoxGetter II (SSG II). Besides enhancing the efficiency of SO₂ to SO₃ oxida - tion, an optimised cerium dispersion and metal-support
One - pass 2h SOx uptake, wt%
TGA-SOx 9th cycle SOx uptake, wt%
10.00 15.00 20.00 30.00 25.00 35.00 40.00
0.00 0.20 0.40 0.60 0.80 1.20 1.00 1.40 1.60
SSG II Std SSG X2
SSG II
SSG X2
+42%
+19%
+32%
+50%
1.43
35.04
1.33
1.20
28.00
1.01
24.64
18.70
0.00 5.00
Fresh, wt%
Steamed, wt%
Fresh, wt%
Steamed, wt%
Figure 2 Laboratory performance ranking of SSG X2 and SSG II
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PTQ Q3 2024
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