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US 10,208,259 B2Granted
Aliphatic cracking and dealkylation with hydrogen diluent
AssigneeUop LLC
InventorsAvram M. Buchbinder, Stanley J. Frey, Hayim Abrevaya, Falaah Falih
Life of this patent
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Abstract
A naphtha cracking feed stream is taken, heated and passed to a cracking reactor. Hydrogen is added to the cracking reactor to mitigate catalyst deactivation. The aliphatic compounds are selectively cracked and at least a portion of the alkyl groups on the aromatic compounds are selectively dealkylated in the presence of a cracking catalyst to produce a cracked effluent stream comprising aromatic compounds and cracked olefins.
Claims20
A process for making aromatics comprising:
- providing a cracking feed stream boiling in the naphtha range comprising aromatic compounds and aliphatic compounds, wherein at least a portion of the aromatic compounds contain alkyl groups;
- passing the cracking feed stream at a temperature of at least 500° C. to a cracking reactor comprising a cracking catalyst including a zeolite with a maximum pore diameter of greater than 5 Angstroms at a pressure of no more than about 345 kPa (absolute);
- adding at least about 60 mol % hydrogen to the cracking reactor to preserve the cracking catalyst against deactivation;
- and
- selectively cracking the aliphatic compounds and selectively dealkylating the alkyl groups on the aromatic compounds in the presence of the cracking catalyst in the cracking reactor under cracking conditions to cracked olefins and aromatic compounds in a cracked effluent stream.
2 more elements
A process for making aromatics and light olefins comprising:
- reforming a naphtha stream in a reforming unit under reforming conditions to produce a reformer effluent stream comprising aromatic compounds and aliphatic compounds, wherein at least a portion of the aromatic compounds contain alkyl groups;
- taking a cracking feed stream from the reformer effluent stream;
- heating the cracking feed stream to at least 500° C. and passing the cracking feed stream at a temperature of at least 500° C. to a cracking reactor comprising a catalyst including a zeolite having pore size greater than 5 Angstroms and a zeolite silica to alumina molar ratio of greater than about 250;
- providing at least about 50 mol % hydrogen to the cracking reactor to preserve the cracking catalyst against deactivation while maintaining the hydrogen partial pressure in the cracking reactor is between about 62 kPa (9 psia) and about 345 kPa (50 psia);
- and
- selectively cracking the aliphatic compounds and selectively dealkylating the alkyl groups on the aromatic compounds in the presence of the cracking catalyst in the cracking reactor under cracking conditions to cracked and dealkylated olefins and the aromatic compounds in a cracked reformer effluent stream, wherein the cracked olefins comprise at least one of ethylene, propylene, and butylene.
3 more elements
A process for making aromatics comprising:
- taking a cracking feed stream boiling in the naphtha range comprising aromatic compounds and aliphatic compounds, wherein at least a portion of the aromatic compounds contain alkyl groups;
- heating the cracking feed stream to at least 500° C. and passing the cracking feed stream at a temperature of least 500° C. to a cracking reactor comprising a cracking catalyst including a zeolite with having a pore size greater than 5 Angstroms and a zeolite silica to alumina molar ratio of greater than about 250;
- providing at least about 60 mol % to about 90 mol % hydrogen to the cracking reactor to preserve the cracking catalyst against deactivation;
- selectively cracking the aliphatic compounds and selectively dealkylating the alkyl groups on the aromatic compounds in the presence of the cracking catalyst in the cracking reactor under cracking conditions to cracked olefins and aromatic compounds in a cracked effluent stream wherein a weight ratio of olefins to paraffins of C4− hydrocarbons is at least 1 in the cracked effluent stream.
1 more element
Dependencies are inferred from the claim text.