Method of continuously separating c4-fraction

FIELD: petrochemical processes.

SUBSTANCE: invention relates to a method for continuously separating C4-fraction by extractive distillation using selective solvent on extractive distillation column, which method is characterized by a separation barrier disposed in extractive distillation column in longitudinal direction extending to the very top of the column to form first zone, second zone, and underlying common zone. Butanes (C4H10)-containing top stream is withdrawn from the first zone, butenes (C4H8)-containing top stream is withdrawn from the second zone, and C4H6 stream containing C4-fraction hydrocarbons, which are more soluble in selective solvent than butanes and butenes, is withdrawn from underlying common zone of column.

EFFECT: reduced power consumption and expenses.

15 cl, 2 dwg, 2 ex

 



 

Same patents:

FIELD: petrochemical processes.

SUBSTANCE: hydrocarbon mixture obtained by extractive distillation of C4-fraction using selective solvent, which mixture contains those C4-hydrocarbons, which are better soluble in selective solvent than butanes and butenes, is subjected to continuous separation. Mixture is supplied to first distillation column, wherein it is separated into top stream, containing 1,3-butadiene, propine, and, if necessary, other low-boiling components and, if necessary, water, and bottom stream containing 1,3-butadiene, 1,2-butadiene, acetylenes, and, if necessary, other high-boiling components. Proportion of 1,3-butadiene in bottom stream of the first distillation column is controlled in such a way as to be high enough to dilute acetylenes beyond the range wherein acetylenes can spontaneously decompose. Top stream from the first distillation column is passed to second distillation column, wherein it is separated into top stream, containing propine, and, if necessary, other low-boiling components and, if necessary, water, and bottom stream containing pure 1,3-butadiene.

EFFECT: simplified process and reduced power consumption.

4 cl

FIELD: petroleum processing and petrochemistry.

SUBSTANCE: in particular, invention aims at producing extraction dearomatized component from reformat of gasoline fraction, which component may be used in production of petroleum solvents such as hexane solvents. Process comprising countercurrent extraction of aromatic hydrocarbons with liquid selective extractant to separate dearomatized component (raffinate) and subsequent extractive rectification of resulting extract phase by distilling off aromatic hydrocarbons is characterized by that liquid selective extractant is diethylene glycol or triethylene glycol, countercurrent extraction is carried out at 125-140°C, extractive rectification is carried out using process steam in presence of saturated selective extractant wherein evaporation of water is performed with the aid of energetic steam, unsaturated selective extractant after extractive rectification and recycled gasoline are sent to extraction stage preliminarily using unsaturated selective extractant as heat carrier to generate process steam, and energetic steam condensate is used to heat recycled gasoline to 80-130°C.

EFFECT: enhanced process efficiency.

3 cl, 1 dwg, 1 tbl, 3 ex

FIELD: petroleum processing.

SUBSTANCE: separation of crude C4-fraction comprises rectification of C4-fraction containing butanes, butenes, 1,3-butadiene, and small amounts of other hydrocarbons, including C4-acetylenes, 1,2-butadiene, and C5-hydrocarbons, via extractive distillation using selective solvent. Crude C4-fraction is fed to middle part of first extractive distillation column and selective solvent is added to column above crude C4-fraction introduction point. Vaporous side stream containing C4-acetylenes together with 1,3-butadiene1,2-butadiene, C5-hydrocarbons, and selective solvent, wherein concentration of C4-acetylenes is below self-decomposition threshold, is withdrawn from the first distillation column from the point below crude C4-fraction introduction point. Top stream containing crude C4-fraction components, which are less soluble in selective solvent than C4-acetylenes, are withdrawn from upper part of the first extractive distillation column.

EFFECT: optimized order of process operations.

21 cl, 1 dwg

FIELD: industrial organic synthesis.

SUBSTANCE: crude 1,3-butadiene is recovered from C4-fraction by extractive distillation using selective solvent on column separated by a partition installed along longitudinal direction of the column to form first and second subzones and underlying common column zone. The column is connected to preswitched flush column. Distillation column operation is controlled by energy supply with the aid of lower evaporator and distribution of a series of theoretical plates within underlying common zone to create bottom stream therefrom consisting of purified solvent.

EFFECT: simplified process technology.

23 cl

FIELD: petrochemical processes.

SUBSTANCE: invention provides a process flow rate comprising at least (i) zone of extractive rectification in presence of polar extractant to produce distillate mainly containing butanes and butane(s); (ii) desorption zone wherein desorption of extractant gives stream containing mainly 1,3-butadiene and. as impurities, at least 2-butene(s) and acetylene hydrocarbons; and (iii) optionally rectification zone for mainly 1,3-butadiene-containing stream. In the latter, α-acetylene hydrocarbons are subjected to liquid-phase selective hydrogenation with hydrogen or hydrogen-containing mixture in presence of solid catalyst containing metal(s) exhibiting high activity in hydrogenation process, preferably non-precious metal(s) on solid support. Temperature is maintained within a range 5 to 75°C at contact time ensuring hydrogenation of no more then 6%, preferably no more than 2% of butadiene present. After hydrogenation, 1,3-butadiene is optionally additionally separated from impurities via rectification.

EFFECT: simplified process.

13 cl, 3 dwg, 2 tbl, 10 ex

FIELD: petrochemical processes.

SUBSTANCE: process involves extractive rectification in presence of extractant mainly containing aliphatic N-alkylamide, while toluene is introduced into rectification column point disposed between extractant inlet and the top of column.

EFFECT: reduced loss of extractant with distillate.

6 cl, 3 dwg, 6 tbl, 6 ex

FIELD: petroleum processing and petrochemistry.

SUBSTANCE: catalysate of reforming of long gasoline fractions containing more than 2% benzene is separated by rectification into three fractions: light-boiling fraction containing mainly nonaromatic C4-C6-hydrocarbons and no more than 1%, preferably no more than 0.5%, benzene; high-boiling fraction containing mainly aromatic and nonaromatic hydrocarbons C7 or higher and no more than 1%, preferably no more than 0.5%, benzene; and benzene fraction boiling within a range of 70-95°C and containing no more than 0.1%, preferably no more than 0.02%, toluene and no more than 0.02% nonaromatic hydrocarbons with boiling temperature above 110°C. Benzene fraction is routed into benzene isolation process involving extractive rectification with polar aprotic solvent having ratio of dipole moment to square root of molar volume above 0.3 db/(cm3/g-mole)1/2, preferably above 0.4 db/(cm3/g-mole)1/2, and boiling temperature 150 to 250°C.

EFFECT: improved quality of benzene.

4 dwg, 2 tbl, 5 ex

FIELD: petroleum industry.

SUBSTANCE: process in carried out in column having divider arranging in longitudinal direction to form the first section, the second one and the third bottom joint section, wherein extractive scrubber is includes before divider.

EFFECT: simplified technology.

16 cl, 3 dwg

FIELD: petrochemical processes.

SUBSTANCE: C4-hydrocarbon fractions obtained by cracking and/or pyrolysis of hydrocarbon feedstock in presence of amine-type extractant are subjected to rectification additionally involving butylene-isobutylene fraction resulting from butylene-to-isobutylene isomerization and containing 30-70% butylenes, 25-65% isobutylene, and 3-8% butanes. Weight ratio of C4-hydrocarbon fractions to added butylene-isobutylene fraction is 1:(3-7).

EFFECT: increased separation efficiency.

3 ex

FIELD: petroleum processing and petrochemistry.

SUBSTANCE: C5-hydrocarbons with different degrees of saturation are separated by extractive rectification in extractive rectification column using dimethylformamide as extractant followed by desorption of pentenes or pentadienes therefrom and passing desorbed extractant to extractive rectification column. Part of hot desorbed extractant is subjected to liquid-phase mixing with starting hydrocarbons at vigorous stirring, after which resulting mixture is introduced into column in liquid form.

EFFECT: reduced power consumption.

2 dwg, 1 tbl, 5 ex

FIELD: petrochemical processes.

SUBSTANCE: hydrocarbon mixture obtained by extractive distillation of C4-fraction using selective solvent, which mixture contains those C4-hydrocarbons, which are better soluble in selective solvent than butanes and butenes, is subjected to continuous separation. Mixture is supplied to first distillation column, wherein it is separated into top stream, containing 1,3-butadiene, propine, and, if necessary, other low-boiling components and, if necessary, water, and bottom stream containing 1,3-butadiene, 1,2-butadiene, acetylenes, and, if necessary, other high-boiling components. Proportion of 1,3-butadiene in bottom stream of the first distillation column is controlled in such a way as to be high enough to dilute acetylenes beyond the range wherein acetylenes can spontaneously decompose. Top stream from the first distillation column is passed to second distillation column, wherein it is separated into top stream, containing propine, and, if necessary, other low-boiling components and, if necessary, water, and bottom stream containing pure 1,3-butadiene.

EFFECT: simplified process and reduced power consumption.

4 cl

FIELD: petroleum processing.

SUBSTANCE: separation of crude C4-fraction comprises rectification of C4-fraction containing butanes, butenes, 1,3-butadiene, and small amounts of other hydrocarbons, including C4-acetylenes, 1,2-butadiene, and C5-hydrocarbons, via extractive distillation using selective solvent. Crude C4-fraction is fed to middle part of first extractive distillation column and selective solvent is added to column above crude C4-fraction introduction point. Vaporous side stream containing C4-acetylenes together with 1,3-butadiene1,2-butadiene, C5-hydrocarbons, and selective solvent, wherein concentration of C4-acetylenes is below self-decomposition threshold, is withdrawn from the first distillation column from the point below crude C4-fraction introduction point. Top stream containing crude C4-fraction components, which are less soluble in selective solvent than C4-acetylenes, are withdrawn from upper part of the first extractive distillation column.

EFFECT: optimized order of process operations.

21 cl, 1 dwg

FIELD: industrial organic synthesis.

SUBSTANCE: crude 1,3-butadiene is recovered from C4-fraction by extractive distillation using selective solvent on column separated by a partition installed along longitudinal direction of the column to form first and second subzones and underlying common column zone. The column is connected to preswitched flush column. Distillation column operation is controlled by energy supply with the aid of lower evaporator and distribution of a series of theoretical plates within underlying common zone to create bottom stream therefrom consisting of purified solvent.

EFFECT: simplified process technology.

23 cl

FIELD: petrochemical processes.

SUBSTANCE: invention provides a process flow rate comprising at least (i) zone of extractive rectification in presence of polar extractant to produce distillate mainly containing butanes and butane(s); (ii) desorption zone wherein desorption of extractant gives stream containing mainly 1,3-butadiene and. as impurities, at least 2-butene(s) and acetylene hydrocarbons; and (iii) optionally rectification zone for mainly 1,3-butadiene-containing stream. In the latter, α-acetylene hydrocarbons are subjected to liquid-phase selective hydrogenation with hydrogen or hydrogen-containing mixture in presence of solid catalyst containing metal(s) exhibiting high activity in hydrogenation process, preferably non-precious metal(s) on solid support. Temperature is maintained within a range 5 to 75°C at contact time ensuring hydrogenation of no more then 6%, preferably no more than 2% of butadiene present. After hydrogenation, 1,3-butadiene is optionally additionally separated from impurities via rectification.

EFFECT: simplified process.

13 cl, 3 dwg, 2 tbl, 10 ex

FIELD: petroleum industry.

SUBSTANCE: process in carried out in column having divider arranging in longitudinal direction to form the first section, the second one and the third bottom joint section, wherein extractive scrubber is includes before divider.

EFFECT: simplified technology.

16 cl, 3 dwg

FIELD: organic chemistry, chemical technology.

SUBSTANCE: invention relates to technology for isolation and purification of butadiene prepared by thermal cracking of hydrocarbons followed by removing heavy by-side products from crude butadiene flow after the selective hydrogenation of undesirable impurities. The flow outgoing from the reaction zone of the selective hydrogenation is fed into evaporator with fraction zone for extraction of butadiene wherein this zone is sprayed with the raffinate flow from the zone of butadiene extraction. From the evaporator the vapor phase containing butadiene with reduced concentration of by-side products is removed and fed to the stage for isolating the concentrated liquid phase comprising heavy by-side products of the reaction. Butadiene-containing vapor phase is recovered to the zone for extraction of butadiene. The fraction zone comprises from 3 to 7 theoretical plates. The temperature in evaporator is maintained in the range from 27°C to 93°C under the pressure value from 375 to 790 kPa. Invention provides the improved technology in preparing the purified butadiene.

EFFECT: improved method for treatment.

5 cl

FIELD: petrochemical processes.

SUBSTANCE: 1,3-butadiene is obtained via catalytic dehydrogenation of n-butylenes at 580-640°C and essentially atmospheric pressure while diluting butylenes with water steam at molar ratio 1:(10-12) and supplying butylenes at space velocity 500-750 h-1. Catalyst is composed of, wt %: K2O 10-20, rare-earth elements (on conversion to CeO2) 2-6, CaO and/or MgO 5-10. MoO3 0.5-5, Co2O3 0.01-0.1, V2O5 0.01-0.1, and F2O3 the balance. Once steady condition is attained, dehydrogenation is carried out continuously during all service period of catalyst.

EFFECT: increased yield of 1,3-butadiene and process efficiency.

2 ex

FIELD: catalysts of selective hydrogenation of alkynes of C4 fractions.

SUBSTANCE: proposed catalyst contains 1-30 mass-% of copper used as first active component, 0.001-5 mass-% of palladium used as second active component, at least 0.001-6 mass-% of one metal selected from Al, Pt, Pb, Mn, Co, Ni, Cr, Bi, Zr and Mo as co-catalyst; the remainder being one carrier selected from aluminum oxide, silicon dioxide and titanium oxide. Method of production of catalyst includes impregnation of carrier calcined preliminarily with solutions of active components depending on their content in catalyst. Alkynes are removed from C4 fractions enriched with alkynes by means of selective hydrogenation with the use of said catalyst.

EFFECT: enhanced selectivity and stability of catalyst.

31 cl, 2 tbl, 13 ex

The invention relates to methods for production of 1-butanol (options), 1,3-butadiene and high-octane fuel from ethanol

The invention relates to the field of polymers butadienestyrene

FIELD: catalysts of selective hydrogenation of alkynes of C4 fractions.

SUBSTANCE: proposed catalyst contains 1-30 mass-% of copper used as first active component, 0.001-5 mass-% of palladium used as second active component, at least 0.001-6 mass-% of one metal selected from Al, Pt, Pb, Mn, Co, Ni, Cr, Bi, Zr and Mo as co-catalyst; the remainder being one carrier selected from aluminum oxide, silicon dioxide and titanium oxide. Method of production of catalyst includes impregnation of carrier calcined preliminarily with solutions of active components depending on their content in catalyst. Alkynes are removed from C4 fractions enriched with alkynes by means of selective hydrogenation with the use of said catalyst.

EFFECT: enhanced selectivity and stability of catalyst.

31 cl, 2 tbl, 13 ex

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