Ba
a
Sulphur
b (wt%)
(mg/kg)
Ca
Pb
10.00
10000
Si
Mg
1000
1.00
100
K
Sb
0.10
10
0.01
1
Na
V
0
Conradson carbon
Total nitrogen
0.00
Zn
Mn
P
Al
Cr
Ni
Basic nitrogen
Fe
Cu
Figure 2a Contaminant contents in PDPO samples; 2b Heteroatom and concarbon contents in PDPO samples
deactivation and fouling, necessitating fre- quent regeneration or replacement of the catalyst. These effects make calcium a crit- ical contaminant to monitor and manage in FCC feedstocks. Based on the chemical determination of contaminants in alternative feed samples, a steady-state equilibrium catalyst (Ecat) metals calculator might be used to allow an understanding of potential catalyst deacti- vation effects.
Physical/chemical properties of VGO, PDPO A and PDPO B
Standard VGO
PDPO A
PDPO B
API (15°C)
22.9
26.0
37.1
Density, 15°C (g/cm³) Refractive Index, 60°C
0.916
0.898
0.838
1.5003
1.4720
1.4529
Sulphur (wt%)
0.09 0.23
0.01 0.04
0.13
Conradson carbon (wt%)
2.1
Table 1
of the catalyst particle, blocks feed molecule entry to the catalyst pore system and, therefore, affects the diffusion of feed or intermediate molecules to the active cracking sites (see Figure 3 ). In addition, calcium is known to contribute to zeolite Y destruction by catalysing the dealumination processes, leading to the collapse or degradation of the zeolite frame- work. This results in a loss of surface area, pore volume, and catalytic activity, significantly impairing the catalyst’s performance. The presence of calcium not only reduces cracking efficiency but also increases the likelihood of
To perform a techno-economic assessment, it is important to determine the crackability and yield structure effects of alternative feedstocks too. For this purpose, different scales of pilot plant equipment are available, such as fixed bed, fixed fluidised bed, and fully circulating riser pilot plants. An example of such an evaluation of catalytic testing results is described in the following discussion. Project scope Repsol is a leading multi-energy company that works to advance the energy transition using different technologies
60
70
a
b
50
68
40
30
66
20
64
10
0
62
0.30
0.40
0.50
0.60
0.70
Ecat CaO (wt%)
Figure 3a Cross-sectional SEM-EDX Ca mapping of Ca contaminated FCC Ecat sample; 3b Effect of Ecat CaO content on Ecat mass transfer resistance for Ecat samples
16
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