Front-end hydrogenation and absorption process for ethylene recovery

Patent · Tue Jun 15 00:00:00 EDT 1993

OSTI ID:6479307

Lam, W K; Mehra, Y R; Mullins, D W

A process is described for recovering ethylene from a cooled, sweetened, and compressed hydrocarbon (HC) gas stream containing hydrogen, methane, CO, ethane, ethylene, acetylene, and C[sub 3] and heavier HCs characteristic of ethylene plant cracked gas and/or a refinery off gas stream, the process comprising: (A) feeding the HC gas stream to a heat-pumped depropanizer and producing a bottom stream of C[sub 4+] hydrocarbons and an overhead stream of C[sub 3] and lighter HCs; (B) feeding overhead stream to a selective hydrogenation reactor to produce a reactor effluent stream containing reduced amounts of acetylene and diolefins; (C) feeding reactor effluent stream to a dehydrator; (D) feeding the dried effluent stream through at least one cooler and separating the stream into a vapor stream and a liquid stream that is recycled to the depropanizer; (E) feeding the vapor stream to an inter cooled and reboiled demethanizing absorber and producing a bottom stream of rich solvent containing most of the ethylene and heavier HCs and an overhead stream containing hydrogen, methane, CO, and the remainder of the ethylene and heavier HCs; (F) feeding overhead stream to a auto refrigerated recovery unit which is cryogenically cooled and producing an overhead stream of hydrogen, methane, and CO and a bottom stream containing substantially all of the ethylene and heavier HCs; (G) feeding the rich solvent of Step E to a solvent regenerator and obtaining a bottom stream of lean solvent which is recycled and an overhead HC stream of ethylene and heavier HCs; (H) combining the overhead HC stream of step G with said bottom stream from the recovery unit of step F and feeding this stream to a deethanizer which produces a bottom stream of propylene and heavier HCs and an overhead stream of ethylene and ethane; and (I) feeding the overhead stream of ethylene and ethane to a C2 splitter and producing a bottom stream of ethane and an overhead stream of ethylene.

• Assignee: Advanced Extraction Technologies, Inc., Houston, TX (United States); Kinetic Technology International Corp., San Dimas, CA (United States)
• Patent Number(s): US 5220097; A
• Application Number: PPN: US 7-836911
• OSTI ID: 6479307
• Resource Relation: Patent File Date: 19 Feb 1992
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
ETHYLENE
MATERIALS RECOVERY
HYDROCARBONS
SEPARATION PROCESSES
ACETYLENE
ADSORPTION
CARBON MONOXIDE
CHEMICAL EFFLUENTS
CRYOGENICS
DEHYDRATION
ETHANE
GASES
HYDROGEN
HYDROGENATION
METHANE
MOLECULAR WEIGHT
PETROLEUM REFINERIES
ALKANES
ALKENES
ALKYNES
CARBON COMPOUNDS
CARBON OXIDES
CHALCOGENIDES
CHEMICAL REACTIONS
CHEMICAL WASTES
ELEMENTS
FLUIDS
INDUSTRIAL PLANTS
MANAGEMENT
NONMETALS
NONRADIOACTIVE WASTES
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PROCESSING
SORPTION
WASTE MANAGEMENT
WASTE PROCESSING
WASTES
020400* - Petroleum- Processing