Effect of regeneration conditions on the emission of HCN in FCC regeneration process

Ju, Feng; Zhao, Xinyi; Luan, Hui; Lin, Jueying; Xiu, Guangli; Ling, Hao

doi:10.1016/j.cej.2020.124484

Cited by 11 publications

(3 citation statements)

References 13 publications

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“…The oxygen content is usually less than 0.5%. Most of the hydrogen and carbon on the coke react in this zone, which inhibits the formation of NO x and favours the formation of N 2 and of more reduced S and N species such as COS, H 2 S, NH 3 and HCN (Babich et al, 2005;Ju et al, 2020). From Table 4 and Table 5, NO x emission factors of U3 is the among three modes, which are 1.74 kg NO x /t coke burn and 0.151 kg NO x /t throughput, respectively.…”

Section: Effect Of Regeneration Process On Factorsmentioning

confidence: 99%

“…This also con rms that full regeneration will produce more NO x . Previous research (Ju et al, 2020) has shown that pyridinic nitrogen (N-6), pyrrolic nitrogen (N-5), and quaternary nitrogen (N-Q) are the main precursors of nitrogen -containing species, including NO, NH3 and HCN etc., during FCC regeneration, different regeneration conditions, such as regeneration temperature and oxygen concentration, could cause these nitrogen-containing compounds to transform into each other. In addition, due to partial regeneration, it produces less NO x , and there is no CO boiler downstream, resulting in that NH 3 , HCN and other gases cannot be converted to NO x under conditions of high temperature, excess oxygen, and long residence time, and eventually lead to lower NO x emissions in U1.…”

Section: Effect Of Regeneration Process On Factorsmentioning

confidence: 99%

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Study on emission factors of FCC flue gas pollutants in petroleum refineries

Luan

Xiu

et al. 2022

Environ Sci Pollut Res

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Fluid Catalytic cracking (FCC) unit is one of the means to lighten heavy oil in re neries, and its regenerated ue gas is also the main source of air pollutants from re nery. However, it is not clear about the type and amount of pollutants discharged from FCC units. The emissions of regenerated pollutants in the stack ue gases of three typical FCC units in China were investigated in this study, including a partial regeneration unit without a CO boiler (U1), a partial regeneration unit with a CO boiler (U2) and a full regeneration unit (U3). Different monitoring methods were used to analyze the concentration of sulfur dioxide (SO 2 ) and nitrogen oxides (NO x ), and the results showed that Fourier Transform Infrared Spectroscopy (FTIR) monitoring results of SO 2 and NO x are approximately 10 times and 5 times larger than that of the Continuous Emission Monitoring System (CEMS) data, respectively. Also, the contents of characteristic pollutants such as NH 3 , C 6 H 6 , HCN, C 8 H 8 , C 2 H 4 , CH 4 and CO were also monitored by FTIR, and the emission factors based on coke burn-off rate and throughput were investigated. The pollutants in U1 exhibited relatively higher contents with the NH 3 , HCN and C 6 H 6 of 116.99, 71.94 and 56.41 mg/Nm 3 in ue gas, respectively. The emission of regenerated pollutants in U2 and U3 are signi cantly different from U1. Regeneration processes (including coke properties, operating modes and presence or absence of CO boilers) affected pollutants emission factors in varying degree. At last, reasonable emission factors based on the different FCC regeneration processes contributes to the prediction, assessment and control for the pollutants emission.

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Section: Effect Of Regeneration Process On Factorsmentioning

confidence: 99%

Section: Effect Of Regeneration Process On Factorsmentioning

confidence: 99%

Study on emission factors of FCC flue gas pollutants in petroleum refineries

Luan

Xiu

et al. 2022

Environ Sci Pollut Res

Self Cite

View full text Add to dashboard Cite

show abstract

“…The oxygen content is usually less than 0.5%. Most of the hydrogen and carbon on the coke react in this zone, which inhibits the formation of NO x and favours the formation of N 2 and of more reduced S and N species such as COS, H 2 S, NH 3 and HCN (Babich et al, 2005;Ju et al, 2020). From To sum up, the emission factors of FCC unit regeneration pollutants need to be distinguished from the types of coke properties, regeneration modes, and pollutant control devices.…”

Section: Effect Of Regeneration Process On Emission Factorsmentioning

confidence: 99%

Study on Emission Factors of FCC Flue Gas Pollutants in Petroleum Refineries

Luan¹,

Wu²,

Xiu³

et al. 2021

Preprint

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Fluid Catalytic cracking (FCC) unit is one of the means to lighten heavy oil in refineries, and its regenerated flue gas is also the main source of air pollutants from refinery. However, it is not clear about the type and amount of pollutants discharged from FCC units. The emissions of regenerated pollutants in the stack flue gases of three typical FCC units in China were investigated in this study, including a partial regeneration unit without a CO boiler (U1), a partial regeneration unit with a CO boiler (U2) and a full regeneration unit (U3). Different monitoring methods were used to analyze the concentration of sulfur dioxide (SO2) and nitrogen oxides (NOx), and the results showed that Fourier Transform Infrared Spectroscopy (FTIR) monitoring results of SO2 and NOx are approximately 10 times and 5 times larger than that of the Continuous Emission Monitoring System (CEMS) data, respectively. Also, the contents of characteristic pollutants such as NH3, C6H6, HCN, C8H8, C2H4, CH4 and CO were also monitored by FTIR, and the emission factors based on coke burn-off rate and throughput were investigated. The pollutants in U1 exhibited relatively higher contents with the NH3, HCN and C6H6 of 116.99, 71.94 and 56.41 mg/Nm3 in flue gas, respectively. The emission of regenerated pollutants in U2 and U3 are significantly different from U1. Regeneration processes (including coke properties, operating modes and presence or absence of CO boilers) affected pollutants emission factors in varying degree. At last, reasonable emission factors based on the different FCC regeneration processes contributes to the prediction, assessment and control for the pollutants emission.

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Non-Destructive characterisation of coke deposit on FCC catalyst and its transient evolution upon Air-Firing and Oxy-Fuel regeneration

Tang

et al. 2022

Chemical Engineering Journal

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Effect of regeneration conditions on the emission of HCN in FCC regeneration process

Cited by 11 publications

References 13 publications

Study on emission factors of FCC flue gas pollutants in petroleum refineries

Study on emission factors of FCC flue gas pollutants in petroleum refineries

Study on Emission Factors of FCC Flue Gas Pollutants in Petroleum Refineries

Non-Destructive characterisation of coke deposit on FCC catalyst and its transient evolution upon Air-Firing and Oxy-Fuel regeneration

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