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Figure 2 Product sulphur vs temperature for catalyst configurations tested at 80 barg
Figure 3 Product sulphur vs temperature for catalyst configurations tested at 120 barg
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Figure 4 Product nitrogen vs temperature for catalyst configurations tested at 80 barg
Figure 5 Product nitrogen vs temperature for catalyst configurations tested at 120 barg
• HDS activity has not been significantly impacted by the partial pressure of hydrogen for both CoMo and NiCoMo catalysts • HDS activity has been significantly impacted by the increase in partial pressure of hydrogen for NiMo catalyst. The product sulphur was reduced by about 100 ppmwt when the ppH2 (inlet) increased from 80 to 120 barg • Excel rejuvenated catalysts will allow low product sulphur levels to be maintained with high HDS compared to fresh in CFH applications to meet environmental regulations on gasoline, LCO sulphur content, and FCC unit sulphur oxides (SOx) emissions. Hydrodenitrogenation (HDN) activity Figures 4 and 5 show the CFH pilot plant testing and com- pare, side-by-side, the fresh HDN activities with their Excel rejuvenated state. The main outcomes were as follows: • Excel rejuvenated catalysts perform equivalent or better compared to their parent fresh catalyst for both pressures tested in terms of HDN activity • Excel rejuvenated NiMo (Catalyst 1) and CoMo (Catalyst 3) perform better than their parent fresh catalyst in terms of HDN activity for both pressures tested • HDN activity has been significantly impacted by the increase in hydrogen partial pressure for all catalysts tested
fresh counterpart/parent. To detect activity differences of less than 10% in a laboratory test, every aspect of the test – from reactor loading, temperature control, and equal feed distribution between reactors to product sample prepara- tion and analyses – needs to be carried out with utmost care to minimise all possible errors. One crucial factor requiring accuracy for comparing catalyst activities is to ensure a good mass balance throughout all the experiments being compared. In this case, mass balances for all catalysts com- pared were in the range of 99.5 ± 1%. Results and discussion The fresh and Excel rejuvenated catalysts were tested in parallel at various process conditions, focusing on the following parameters after the hydrotreating reaction: hydrodesulphurisation (HDS) activity, hydrodenitrogena- tion (HDN) activity, aromatic saturation and volume swell, hydrogen consumption, and C 5 + yield. Hydrodesulphurisation (HDS) activity Figures 2 and 3 show the CFH pilot plant testing and com- pare, side-by-side, the fresh HDS activities with its Excel rejuvenated state. The main outcomes were: • Excel rejuvenated catalysts perform equivalent to their parent fresh catalyst for both pressures tested
72
PTQ Q4 2022
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