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US 4,215,231 AGranted
Co-production of ethylene and benzene
AssigneeUop LLC
InventorRobert F. Raymond
Life of this patent
Estimating the term…
Abstract
Ethylene and maximum benzene are co-produced via a combination process involving (1) thermal cracking, or pyrolysis, (2) aromatic hydrocarbon separation, or extraction, and, (3) dealkylation of alkyl-substituted aromatics to yield additional benzene. Unconverted feed paraffins are recycled to thermal cracking for additional ethylene and benzene production.
Claims14
A process for the co-production of ethylene and benzene from a hydrocarbonaceous feedstock which comprises:
- (a) charging said feedstock to a thermal cracking zone at conditions selected to convert paraffinic hydrocarbons into lower boiling, normally vaporous, hydrocarbons;
- (b) introducing the thermal cracking zone effluent into a first separation zone and separating a hydrogen-rich vaporous phase, ethylene, and a normally liquid phase containing aromatic hydrocarbons;
- (c) recovering the separated ethylene;
- (d) introducing said normally liquid phase into a second separation zone, concentrating the aromatic hydrocarbons therein, and separating unconverted non-aromatic hydrocarbons;
- (e) introducing said aromatic hydrocarbons into a third separation zone and separating benzene and alkylaromatic hydrocarbons therein;
- (f) recovering the separated benzene;
- (g) reacting said alkylaromatic hydrocarbons in admixture with at least a portion of said hydrogen-rich vaporous phase in a dealkylation reaction zone at conditions selected to convert said alkylaromatic hydrocarbons into benzene;
- and,
- (h) introducing the dealkylation zone effluent into said second separation zone in combination with the aforesaid normally liquid phase introduced thereto.
6 more elements
A process for the co-production of ethylene and benzene from a hydrocarbonaceous feedstock which comprises:
- (a) charging said feedstock to a thermal cracking zone at conditions selected to convert paraffinic hydrocarbons into lower boiling, normally vaporous hydrocarbons;
- (b) introducing the thermal cracking zone effluent into a first separation zone and separating a hydrogen-rich vaporous phase, ethylene, and a normally liquid phase containing aromatic hydrocarbons;
- (c) recovering the separated ethylene;
- (d) treating said normally liquid phase in admixture with a portion of said hydrogen-rich vaporous phase in a hydrotreating zone at hydrotreating conditions selected to saturate olefins and convert sulfurous compounds to hydrogen sulfide and hydrocarbons, separating hydrogen sulfide and recovering the hydrotreated normally liquid phase;
- (e) introducing said hydrotreated normally liquid phase into a second separation zone, concentrating the aromatic hydrocarbons therein, and separating unconverted non-aromatic hydrocarbons;
- (f) introducing said aromatic hydrocarbons into a third separation zone and separating benzene and alkylaromatic hydrocarbons therein;
- (g) recovering the separated benzene;
- (h) reacting with alkylaromatic hydrocarbons in admixture with at least a portion of said hydrogen-rich vaporous phase in a dealkylation reaction zone at conditions selected to convert said alkylaromatic hydrocarbons into benzene;
- and,
- (i) introducing the dealkylation zone effluent into said second separation zone in combination with the aforesaid hydrotreated normally liquid phase introduced thereto.
7 more elements
Dependencies are inferred from the claim text.