CN104892339A - Method for preparing n-butane by using iso-butane - Google Patents

Abstract

The invention relates to a method for preparing n-butane by using iso-butane. The method comprises the following steps: A, providing a feeding gas flow a containing iso-butane of which the mass percentage is at least 80%; B, feeding the feeding gas flow a into at least one n-merization zone and enabling iso-butane to have n-merization reaction in the presence of a catalyst so as to obtain a product gas flow b; C, feeding the product gas flow b into at least one hydrogenation saturation zone for hydrogenation reaction to obtain a gas flow c; D, carrying out condensing separation the gas flow C at 0-40 DEG C to obtain a gas phase flow d1 and a liquid phase flow d2; E, feeding the liquid phase flow d2 into a first distillation zone so that low-boiling-point secondary components in the liquid phase flow d2 can be further separated so as to form a product flow e2 containing iso-butane and n-butane; and F, feeding the product flow e2 into a second distillation zone for separating iso-butane from n-butane so as to obtain a n-butane flow. The method disclosed by the invention is generally simple and controllable and has the advantages of high conversion rate, high yield and good economic benefit.

Description

A kind of method being prepared normal butane by Trimethylmethane

Technical field

The present invention relates to a kind of method preparing normal butane, be specially and utilize metal catalyst that positive for Trimethylmethane structure is turned to the production method of normal butane.

Background technology

Normal butane is a kind of important Organic Chemicals, is mainly used in the preparation of MALEIC ANHYDRIDE.In addition, also can through Oxidative Dehydrogenation butylene and divinyl; Acetic acid, acetaldehyde etc. is extracted through catalyzed oxidation; Through halogenation butyl halide; Through nitrated nitrobutane processed.

At present, the production method of normal butane generally with refinery's C-4-fraction for raw material, adopt partition method to obtain normal butane.A kind ofly from refinery C Four composition, the method for high purity normal butane of obtaining is separated as CN102690158A proposes, pretreated refinery C Four composition raw material hydrocarbon is sent into extraction tower, water wash column, using the mixing solutions of acetonitrile and water as extraction agent, by the alkene removing in raw material hydrocarbon, obtain butane; Then butane enters deisobutanizer, removes Trimethylmethane light constituent, obtains thick normal butane; Normal butane treating tower sent into by last thick normal butane, to remove heavy constituent, obtains highly purified normal butane.The patent CN102603454A of University Of Yantai proposes a kind of whole process and adds the method that extraction agent is separated Trimethylmethane, normal butane and butylene, extraction agent can adopt the mixed solvent of methylethylketone and n-formylmorpholine, with patent CN102690158A unlike, the method by extraction agent as under " light, heavy " order be separated successively and obtain Trimethylmethane, normal butane and butylene.This method is owing to adding extraction agent, and resolution between each component of C4 increases, but the whole process of extraction agent adds the equipment that result also in increases, the problems such as process cost increase.The patent 102351626A of TH Gases Co., Ltd. proposes a kind of method adopting fractionation by adsorption purification normal butane, the method take mixed c 4 as raw material, adopt three step absorption, sorbent material is respectively CaA, 13X molecular sieve, silica gel and 5A molecular sieve, be respectively used to except alkene, except Trimethylmethane, normal butane refine, after process, highly purified normal butane is stayed in Adsorption Phase by absorption, then molecular sieve heated or be aided with purging with nitrogen gas, make normal butane desorption, collect desorption gas and can obtain high purity normal butane product, product purity is 99.5 ~ 99.8%.The said firm also been proposed a kind of method adopting absorption-rectifying to combine purification normal butane afterwards, few for the production of amount, the normal butane production that purity requirement is higher.The core of these two kinds of methods is all fractionation by adsorption, can obtain highly purified normal butane, but sorbent material cost is high, and Production Flow Chart is complicated, is not suitable for scale operation normal butane.

The method that above method and some other patent domestic provide is and adopts physical separation method to produce normal butane from mixing carbon point component, its shortcoming is inevitably to produce a large amount of byproduct Trimethylmethane, butylene etc., this will greatly increase storage, the transportation cost of enterprise, have a strong impact on the overall economic efficiency of enterprise.Liaoning proposes one with carbon four for raw material with the patent CN203269811U of beneficial petrochemical industry company limited, the a series of complex reaction such as superimposed, dehydrocyclization, aromatization, dehydrocyclization is there is under conditions of non-hydrogen, produce light aromatic hydrocarbons and heavy aromatics, the method of by-product normal butane simultaneously, but the emphasis of this method does not lie in normal butane product, build the aromatization device of bulky complex to produce normal butane and be not suitable for the downstream unit of supporting normal butane.US Patent No. 4191845 provides a kind of method of being closed C_4 hydrocarbon Hydrogenation normal butane by insatiable hunger, first raw material is carried out hydrogenation, then be separated and obtain normal butane, Trimethylmethane then on the metal catalyst of traditional platinum or palladium 238 DEG C, under 2.0MPa reaction generate normal butane.This method solve above-mentioned by-product Trimethylmethane problem, but the method operates under lesser temps and pressure, lower temperature of reaction makes the low conversion rate of Trimethylmethane, and only 30%, which results in a large amount of Trimethylmethane circulations, add energy consumption, and lower reaction pressure makes reaction product and the increase that is separated of hydrogen, add the loss of butane, in addition, if make reaction carry out at higher temperatures and pressures, the better catalyzer of performance must be adopted; In addition, the normal butane purity that the method generates is only 95mol%, be mainly used in refining art, cracking increasing output of ethylene and propylene, this normal butane has no idea to meet the raw materials for production needs of the normal butane downstream chemical product such as MALEIC ANHYDRIDE, butylene, divinyl, acetic acid, butyl halide, nitrobutane; Moreover the method is inappropriate using the higher C 4 olefin of added value as raw material production normal butane economically.

The concrete meaning that in the present invention, positive structure relates to is:

Positive structure: refer to the structure of change isoparaffin and do not change its elementary composition and molecular weight, it being converted into the process of normal paraffin.

Summary of the invention

The technical problem to be solved in the present invention is for the deficiencies in the prior art, and provide the positive structure of a kind of Trimethylmethane to prepare the method for normal butane, the method income is high, transformation efficiency is high, do not have by product.

for achieving the above object, concrete scheme of the present invention is:

Prepared a method for normal butane by Trimethylmethane, it comprises the following steps:

A) the feed stream a at least comprising mass percent 80% Trimethylmethane is provided;

B) feed stream a is fed at least one positive structure region, and under catalyst action, make Trimethylmethane that the reaction of positive structureization occurs, thus obtain the product gas flow b comprising Trimethylmethane, normal butane, methane, ethane, propane, propylene, iso-butylene, 1-butylene, 2-butylene, hydrogen;

C) product gas flow b is fed at least one hydrotreated lube base oil region and carry out hydrogenation catalyst reaction, make iso-butylene, 1-butylene, 2-butylene, propene thus obtain comprising the air-flow c of Trimethylmethane, normal butane, methane, ethane, propane and hydrogen;

D) condensation separation air-flow c at 0-40 DEG C, obtains comprising the vapor phase stream d1 of the lower boiling secondary components such as hydrogen, methane, ethane, propane and comprising the liquid phase stream d2 of methane, ethane, propane, normal butane, Trimethylmethane;

E) liquid phase stream d2 is fed the first distillation zone to be separated the lower boiling secondary component such as methane, ethane, propane in liquid phase stream d2 further and to be formed and comprise the product stream e1 of methane, ethane, propane and Trimethylmethane and comprise the product stream e2 of Trimethylmethane and normal butane;

F) stream e2 is fed after-fractionating region, separation Trimethylmethane and normal butane are formed and comprise Trimethylmethane stream f1 and normal butane stream f2, Trimethylmethane stream f1 circulation are fed back to positive structure region simultaneously.

Step B of the present invention) described in positive structure react in condition specific as follows and carry out: 1, in positive structure region, positive structureization reaction is carried out under limited amount hydrogen existence condition, to reduce the coking rate of catalyzer, simultaneously for the temperature in balanced reactor catalyst bed; In the hydrogen total content provided in the present invention and feed stream a, the mol ratio of Trimethylmethane content is 1-3:1, preferred 1.2-2:1.Wherein the presentation mode of hydrogen can be less than 20 %(molar percentages for pure hydrogen or containing light paraffins) mixing hydrogen stream; 2, in positive structure region, its reaction is temperature 200 DEG C-700 DEG C, and working pressure is carry out under the hydro condition of 2-5MPa; 3, the catalyzer used in the positive structure region of the present invention comprises carrier and live body component, and wherein carrier is the mixing of one or more refractory oxides, and active constituent is the VIII transition element composition of one or more periodic table of elements; Its lifting capacity is mass percent 0.01 ~ 5%; One or more wherein in carrier preferential oxidation zirconium, zinc oxide, aluminum oxide, silicon-dioxide, titanium dioxide, magnesium oxide, lanthanum trioxide, cerium oxide; The preferred platinum of active constituent and/or palladium.In order to improve the performance of catalyzer, be also added with acidic components and auxiliary agent in the catalyzer that the present invention relates to, the preferred muriate of acidic components is to keep acid, and its lifting capacity is mass percent 0.01 ~ 5%.One in auxiliary agent preferential oxidation cerium, stannic oxide, zinc oxide, vanadium oxide, lanthanum trioxide, chromic oxide, ferric oxide, zirconium white, manganese oxide, its lifting capacity is mass percent 0.01 ~ 5%.In the present invention, the geometrical shape of catalyzer can be such as spherical or cylindrical.

In the present invention, positive structureization reaction can adopt fixed bed, moving-bed, fluidized-bed to carry out; Feed stream a can up, the descending or mode of radial flow contact with the bed of granules of catalyst.The reactor that positive structureization reaction adopts can be separate unit, also can be multiple stage.Bed number in reactor is 1-2 layer.

The present invention further improves and is, step C) described in hydrogenation catalyst reaction temperature 50-250 DEG C, carry out under reaction pressure 50-200 kPa condition, the described hydrogen total content provided and in feed stream a Trimethylmethane content than for 1-3mol:1mol, and the presentation mode of hydrogen can be less than 20 %(molar percentages for pure hydrogen or containing light paraffins) mixing hydrogen stream; In this reaction process, catalyzer is any applicable hydrogenation catalyst, the nickel-base catalyst of preferential oxidation alumina supporter, and the geometrical shape of catalyzer can be spherical or cylindrical.In the present invention, hydrogenation catalyst reaction can adopt fixed bed, moving-bed, fluidized-bed; Stream can up, the descending or mode of radial flow contact with the bed of granules of catalyst.

In order to control the temperature of charge entering hydrogenation reaction region, the present invention also can arrange water cooler before hydroconversion reaction zone.

The present invention further improves and is, be provided with step G): by step e) in the stream e1 that obtains be separated further, obtain containing 20-40%(mass percent) the streams g3 of Trimethylmethane, and streams g3 is recycled to the first distillation zone, improve transformation efficiency of the present invention further.

As the preferred embodiments of the present invention, the lock out operation of the first distillation zone adopts and carries out in lightness-removing column, and the tower top of lightness-removing column adopts cryogenic condensation mode, and the temperature of condensation is 5 ~ 30 DEG C, adopt interchanger or segregation and fractionation system to carry out condensation operation, lightness-removing column tower top pressure is 0.7 ~ 1.2MPa.

As the preferred embodiments of the present invention, the lock out operation in after-fractionating region carries out in butane tower, and butane tower also can be able to adopt single tower to operate for double tower.

As the preferred embodiments of the present invention one, the feed stream a in the present invention derives from liquefied petroleum gas (LPG), and its concrete steps are as follows:

A11) liquefied petroleum gas (LPG) (LPG) stream is provided;

A12) from above-mentioned LPG stream, remove propane and C4-hydrocarbon and C5+ hydrocarbon, obtain the stream comprising normal butane and Trimethylmethane;

A13) from the stream comprising normal butane and Trimethylmethane, take out normal butane and obtain comprising the incoming flow a of Trimethylmethane.

As the preferred embodiments of the present invention two, the Raw material processing containing butane that in the present invention, incoming flow a is obtained by carbon after ether four is formed, and concrete steps are:

A21) raw material containing butane is provided;

A22) utilize step e) in lightness-removing column remove iso-butylene, 1-butylene, 2-butylene and other unsaturated hydrocarbons in above-mentioned material, obtain the stream containing normal butane and Trimethylmethane;

A23) utilize step F) in butane tower be separated normal butane thus formed Trimethylmethane stream namely formed comprise 80%(mass percent) the feed stream a of Trimethylmethane.

Compared with prior art, the beneficial effect of technical scheme of the present invention mainly has the following advantages:

1. the direct material can produced using butane as normal butane, improves the economic value added of butane;

2. the high utilization rate of butane raw material, does not have the Trimethylmethane of by-product, and factory is without the need to arranging Trimethylmethane products pot and huge head tank group, and handling and traffic unit also greatly can reduce scale;

3. can the normal butane of production purity >=98.5, can be used for the normal butane downstream chemical product such as production MALEIC ANHYDRIDE, butylene, divinyl, acetic acid, butyl halide, nitrobutane;

4. adopt the novel positive structure catalyzer of Trimethylmethane, this catalyzer can carry out the reaction of positive structureization at higher temperatures and pressures;

5. positive structureization reaction is carried out at higher temperatures, is conducive to the transformation efficiency improving Trimethylmethane, reduces the internal circulating load of Trimethylmethane, reduce plant energy consumption;

6. positive structureization reaction is carried out at a higher pressure, is conducive to reacted separation performance, improves the rate of recovery of butane-component, reduce material consumption;

7. the high utilization rate of raw material, does not have the Trimethylmethane of by-product, and factory is without the need to arranging Trimethylmethane products pot and huge head tank group, and handling and traffic unit also greatly can reduce scale.

The method that the present invention relates to makes Trimethylmethane be converted into normal butane by Trimethylmethane being fed positive structure step; The productive rate of the positive structureization of Trimethylmethane normal butane processed is increased by hydrogenation step; Make the Trimethylmethane complete reaction in raw material by unconverted Trimethylmethane is recycled to positive structure step, further increase the transformation efficiency of Trimethylmethane; Its method is overall simply controlled, and transformation efficiency is high, and output is high, and economic benefit is better.

figure of description

Fig. 1 is the schema that embodiment one relates to;

Fig. 2 is the schema that embodiment two relates to.

Embodiment

Below in conjunction with the accompanying drawing in the embodiment of the present invention, be clearly and completely described the technical scheme in the embodiment of the present invention, obviously, described embodiment is only the present invention's part embodiment, instead of whole embodiments.Based on the embodiment in the present invention, those of ordinary skill in the art, not making the every other embodiment obtained under creative work prerequisite, belong to the scope of protection of the invention.

embodiment one

The present embodiment relates to liquefied petroleum gas (LPG) stream and prepares feed stream a and prepare normal butane two parts by feed stream a.

First part: adopt liquefied petroleum gas (LPG) stream to prepare feed stream a, comprise the following steps:

A11) liquefied petroleum gas (LPG) stream is provided;

A12) adopt multiple conventional rectification tower, in the first rectifying tower, C4-hydrocarbon can be isolated from tower top; In Second distillation column, at the bottom of tower, isolate C5+ hydrocarbon thus obtain comprising the stream of normal butane and Trimethylmethane;

A13) butane tower is adopted from above-mentioned stream, to be separated normal butane and to obtain comprising the feed stream a of Trimethylmethane.

Second, as shown in Figure 1, prepare normal butane by the feed stream a comprising Trimethylmethane:

1. provide the feed stream a comprising Trimethylmethane, the Trimethylmethane content comprised in feed stream a is by percent mass hundred more than 80%, and preferably 95 more than %, comprise the Trimethylmethane of 96% in feed stream a in the present embodiment.

2. feed stream a is fed at least one positive structure region, and under catalyst action, make Trimethylmethane that the reaction of positive structureization occurs be converted into normal butane, thus obtain the product gas flow b comprising Trimethylmethane, normal butane, methane, ethane, propane, propylene, iso-butylene, 1-butylene, 2-butylene, hydrogen;

Be specially: in the positive structure reactor of Trimethylmethane, Trimethylmethane reacts and obtains normal butane on positive structure catalyzer, generates iso-butylene, 1-butylene and 2-butylene simultaneously, and also forms a small amount of methane, ethane, propane and propylene.Because structureization reaction positive in the present embodiment carries out under limited amount hydrogen existence condition, therefore also there is unconverted Trimethylmethane and hydrogen in the reacted product gas flow b of positive structureization.

In the present embodiment, positive structure catalyzer comprises carrier, active constituent, acid composition and auxiliary agent.Carrier is made up of refractory oxides or mixed oxide, carrier is preferably one or more mixing in zirconium white, zinc oxide, aluminum oxide, silicon-dioxide, titanium dioxide, magnesium oxide, lanthanum trioxide, cerium oxide, in the present embodiment, selective oxidation aluminium is as carrier, and lifting capacity is mass percent 91%; Described active constituent comprises one or more VIII transition elements, and its lifting capacity is mass percent 2%; Preferred platinum and/or palladium, select platinum in the present embodiment.Be chosen as muriate in described acidic components embodiment to keep acid, its lifting capacity is mass percent 4%; One in described auxiliary agent selective oxidation cerium, stannic oxide, zinc oxide, vanadium oxide, lanthanum trioxide, chromic oxide, ferric oxide, zirconium white, manganese oxide, its lifting capacity is mass percent 3%; The geometrical shape of positive structure catalyzer is the centre of sphere.

In the present embodiment, positive structure reactor adopts fluidized-bed reactor, arranges beds 1-6 layer in reactor.In positive structure reactor, internal temperature is at 200 DEG C-700 DEG C, and working pressure is carry out under the hydro condition of 2-5MPa, and weight hourly space velocity (WHSV) is 0.5 ~ 2 h ^-1.

In the present embodiment, positive structureization reaction is carried out under limited amount hydrogen existence condition, to reduce the coking rate of catalyzer, simultaneously for the temperature in balanced reactor catalyst bed, described in the hydrogen stream that provides in hydrogen total content and feed stream a the mol ratio of Trimethylmethane content be 1-3:1; , in the present embodiment, mol ratio is 1.5:1.The hydrogen provided can be less than 20 %(molar percentages for pure hydrogen or containing light paraffins) mixing hydrogen stream, be pure hydrogen in the present embodiment;

In the present embodiment, the positive structureization reaction carried out under these conditions, can make to comprise the positive structure of Trimethylmethane of in the feed stream a of Trimethylmethane 50%.

3. product gas flow b is fed at least one hydrotreated lube base oil region and carry out hydrogenation catalyst reaction, make iso-butylene, 1-butylene, 2-butylene, propylene carry out hydrogenation reaction;

This reaction is in hydrotreated lube base oil reactor, and butylene obtains normal butane and Trimethylmethane with hydrogen reaction on hydrogenation catalyst.In above-mentioned reaction, alkene is converted into alkane, thus defines the product gas flow c comprising Trimethylmethane, normal butane, methane, ethane, propane and hydrogen.

In hydrogenation catalyst process, adopt general hydrogenation catalyst, such as zirconium white, zinc oxide, aluminum oxide, silicon-dioxide, titanium dioxide, magnesium oxide, lanthanum trioxide, cerium oxide etc., active metal component can be the VIII transition element of one or more periodictables, such as alumina supporter nickel-base catalyst.The geometrical shape of catalyzer is cylindrical.

In the present embodiment, hydrotreated lube base oil reactor adopts separate unit fixed bed, and the catalyst bed number of plies in reactor is 1-2 layer.Catalytic inner temperature of reaction in hydrogenation zone is usually at 50-250 DEG C, and preferred 50-150 DEG C, the present embodiment selects 120 DEG C.In the present embodiment, the working pressure of hydrogenation zone is lower than positive structure region, and be 50-200 kPa, preferred 60kPa, 80kPa, gas hourly space velocity selects 0.5-2 h ^-1.In hydrogenation zone, in the hydrogen stream provided hydrogen total content and in feed stream a Trimethylmethane content than for 1-3mol:1mol, in the present embodiment, select 1.5 mol/1mol, with the hydrogen hydrocarbon phase in positive structure region with.

Enter the temperature of hydrogenation zone to control air-flow b, the present embodiment arranges water cooler in hydrogenator.

In embodiments, the conversion of olefines that can make to comprise in the feed stream b of C4 alkene 99% is alkane.

4. condensation separation air-flow c at 0-40 DEG C, obtains comprising the vapor phase stream d1 of the lower boiling secondary components such as hydrogen, methane, ethane, propane and comprising the liquid phase stream d2 of methane, ethane, propane, normal butane, Trimethylmethane;

In embodiments, in order to save energy, in the present embodiment, condensing mode adopts multistage cooling, preferred 2-3 level cooling.By condensing equipment, air-flow c is cooled to 0 ~ 40 DEG C in this programme, in this example be 20 DEG C, the material that the boiling points such as normal butane, Trimethylmethane, propane are higher is condensed into liquid, the lower boiling secondary components such as hydrogen, methane, ethane, propane are still then gas, isolate above-mentioned gas and liquid formation vapor phase stream d1 and liquid phase stream d2, wherein in vapor phase stream d1, hydrogen content reaches 70 ~ 90 %, by mole very.Above-mentioned isolated vapor phase stream d1 can directly or purify after for positive structure reaction or hydrogenation reaction, also can be transported to other application, such as, for producing electric energy in fuel cell.

5. liquid phase stream d2 is fed the first distillation zone to be separated the lower boiling secondary component such as methane, ethane, propane in liquid phase stream d2 further and to be formed and comprise the product stream e1 of methane, ethane, propane and Trimethylmethane and comprise the product stream e2 of Trimethylmethane and normal butane;

In the present embodiment, the first distillation zone is carried out in lightness-removing column, and lightness-removing column has 20 ~ 50 pieces of theoretical stages, and column plate pattern can be bubble plate, floating valve tray, sieve plate, also can adopt structured packing or random packing.

The tower top of lightness-removing column adopts cryogenic condensation mode, condensing temperature controls as being 5 ~ 30 DEG C, to reclaim more Trimethylmethane, interchanger or segregation and fractionation system is adopted to carry out condensation operation, lightness-removing column tower top pressure is 0.7 ~ 1.2MPaA, full tower pressure drop is 20 ~ 50kPa, and column bottom temperature is 80 ~ 90 DEG C, and trim the top of column is than >=3; Cryogenic condensation mode adopts the direct condensation of salt cooler, and the heating medium of reboiler at the bottom of lightness-removing column can be low-pressure steam, hot water, thermal oil.

By aforesaid operations, at the bottom of the tower of tower, discharge the stream e2 comprising Trimethylmethane and normal butane, stream e2 contains normal butane and the Trimethylmethane of 90-99 quality %.The stream e1 comprising methane, ethane, propane and Trimethylmethane is discharged at the tower top of tower.

In the present embodiment, segregation fractionating column is adopted to be separated further stream e1, at liquid phase stream g1, the basic gas phase stream g2 be made up of ethane, methane that overhead extraction is made up of propane substantially.The propane of stream g1 usually containing 40-70 quality %; Discharge the valuable stream g3 comprising Trimethylmethane in the bottom of tower, and stream g3 is recycled to the first distillation zone.

6. stream e2 is fed after-fractionating region, separation Trimethylmethane and normal butane are formed and comprise Trimethylmethane stream f1 and normal butane stream f2, Trimethylmethane stream f1 circulation are fed back to positive structure region simultaneously.

Be specially: the product stream e2 from the Trimethylmethane at the bottom of lightness-removing column and normal butane is sent into butane tower.Butane column overhead obtains the Trimethylmethane stream f1 containing mass percent 95 ~ 99 %, and obtain the normal butane stream f2 containing mass percent 95 ~ 99 % at the bottom of tower, in normal butane stream f2, Trimethylmethane content is 0.1 ~ 1%.Butane tower can adopt single tower to operate, and when separation requirement is higher, can adopt double tower.Butane tower has 60 ~ 120 pieces of theoretical stages, and column plate pattern can be bubble plate, floating valve tray, sieve plate, also can adopt structured packing or random packing.Lightness-removing column tower top pressure is 0.5 ~ 0.8 MPa, and tower top temperature is 40 ~ 60 DEG C, and full tower pressure drop is 80 ~ 120kPa, and column bottom temperature is 60 ~ 75 DEG C, and trim the top of column is than >=7, preferential 9-12.In this example, the positive structure unit of Trimethylmethane stream f1 feedback feeding of butane tower top uses as charging.The heating medium of butane tower tower bottom reboiler can be low-pressure steam, hot water, thermal oil or dispatch by factory scenario.

embodiment two

The present embodiment, on the basis of embodiment one, is prepared feed stream a with the raw material comprising butane and prepares normal butane two parts by feed stream a, wherein preparing normal butane part run by feed stream a identical with embodiment one.

The present embodiment is prepared feed stream a with the raw material comprising butane and is comprised the steps:

A21) raw material containing butane is provided;

A22) utilize step e) in lightness-removing column remove iso-butylene, 1-butylene, 2-butylene and other unsaturated hydrocarbons in above-mentioned material, obtain the stream containing normal butane and Trimethylmethane;

A23) utilize step F) in butane tower be separated normal butane thus formed Trimethylmethane stream namely formed comprise 80%(mass percent) the feed stream a of Trimethylmethane.

At A21) in step, there is provided the raw material containing butane can use refining alkane stream from refinery, this raw material packet is containing butane, the butylene of <1%, the light constituent (propane, ethane) of 1-10mol%, the heavy constituent (pentane) of 0.1-10mol% of 90-99mol%.

The whole technological process of the present embodiment is: as shown in Figure 2,

By the raw material containing butane after lightness-removing column 104, butane tower 106 remove weight component, obtain the Trimethylmethane air-flow of higher degree, and be supplied to positive structure reactor 101 after mixing with hydrogen stream as feed stream a.

Trimethylmethane is converted into normal butane in positive structure reactor, and temperature of reaction is 500 DEG C, reaction pressure 3.0MPa, per pass conversion >=40% of Trimethylmethane, representative value about 50%, selectivity >=85% of normal butane, representative value about 90%.In positive structure catalyzer, carrier is silicon-dioxide, magnesian two kinds of mixing, and lifting capacity is mass percent 90%; Active constituent is palladium lifting capacity is mass percent 3%; Acidic components are muriate, and its lifting capacity is mass percent 3%; Described auxiliary agent is manganese oxide, and its lifting capacity is mass percent 4%.The described hydrogen stream provided is pure hydrogen, and in its hydrogen total amount and feed stream a, the mol ratio of Trimethylmethane content is 2.2:1.

Air-flow b from positive structure reactor enters hydrotreated lube base oil reactor 102.The alkene that positive structureization reaction produces is converted into alkane, temperature of reaction 150 DEG C, reaction pressure 100 kPa in hydrotreated lube base oil reactor, and hydrogen total amount and Trimethylmethane content in feed stream a are than being 2.2mol:1mol, olefin conversion >=99%.

Air-flow c from hydrotreated lube base oil reactor enters condensing equipment 103, and condensing temperature is 15 DEG C, obtains vapor phase stream d1 and liquid phase stream d2.Remove in vapor phase stream d1 and obtain high-purity hydrogen after C4 component, high-purity hydrogen can be used as a part in hydrogen stream after pressurization and pure hydrogen is mixed into positive structure reactor.

Liquid phase stream d2 from condensing equipment 103 enters lightness-removing column 104.At the product stream e1 of lightness-removing column top extraction containing methane, ethane, propane and Trimethylmethane, product stream e1 enters segregation fractionating column 105.Product stream e1 is separated in segregation fractionating column 105, and the main stream g3 containing Trimethylmethane from discharging at the bottom of the tower of segregation fractionating column, and returns and enters lightness-removing column top; The main tower top liquid phase extraction of stream g2 from segregation fractionating column containing propane; The main stream g1 containing methane, ethane is from the top gaseous phase extraction of segregation fractionating column.

Extraction is removed after light constituent bottom lightness-removing column containing Trimethylmethane and normal butane product stream e2 through lightness-removing column 104, product stream e2 enters butane tower 106, in butane tower 106, Trimethylmethane is separated with normal butane, the Trimethylmethane stream f1 circulation of higher degree enters positive structure reactor, and normal butane stream f2 is from extraction at the bottom of the tower of butane tower, obtains normal butane product.

The present embodiment technique is simple, controlled, the raw material produced using butane as normal butane, improves the economic value added of butane; Do not have the Trimethylmethane of by-product, factory is without the need to arranging Trimethylmethane products pot and huge head tank group, and handling and traffic unit also greatly can reduce scale simultaneously; And can the normal butane of production purity >=98.5.

Claims (10)

1. prepared a method for normal butane by Trimethylmethane, it comprises the following steps:

The feed stream a at least comprising mass percent 80% Trimethylmethane is provided;

Feed stream a is fed at least one positive structure region, and under catalyst action, make Trimethylmethane that the reaction of positive structureization occurs, thus obtain the product gas flow b comprising Trimethylmethane, normal butane, methane, ethane, propane, propylene, iso-butylene, 1-butylene, 2-butylene, hydrogen;

Product gas flow b is fed at least one hydrotreated lube base oil region and carry out hydrogenation catalyst reaction, make iso-butylene, 1-butylene, 2-butylene, propene thus obtain comprising the air-flow c of Trimethylmethane, normal butane, methane, ethane, propane and hydrogen;

Condensation separation air-flow c at 0-40 DEG C, obtains comprising the vapor phase stream d1 of the lower boiling secondary components such as hydrogen, methane, ethane, propane and comprising the liquid phase stream d2 of methane, ethane, propane, normal butane, Trimethylmethane;

Liquid phase stream d2 is fed the first distillation zone to be separated the lower boiling secondary component such as methane, ethane, propane in liquid phase stream d2 further and to be formed and comprise the product stream e1 of methane, ethane, propane and Trimethylmethane and comprise the product stream e2 of Trimethylmethane and normal butane;

Stream e2 is fed after-fractionating region, and separation Trimethylmethane and normal butane are formed and comprise Trimethylmethane stream f1 and normal butane stream f2, Trimethylmethane stream f1 circulation are fed back to positive structure region simultaneously.

2. method according to claim 1, it is characterized in that: step B) described in the reaction of positive structureization temperature 200 DEG C-700 DEG C, working pressure is carry out under the hydro condition of 2-5MPa, described in the hydrogen total content that provides and feed stream a the mol ratio of Trimethylmethane content be 1-3:1; Used catalyst comprises carrier and live body component, and wherein carrier is the mixing of one or more refractory oxides, and active constituent is the VIII transition element composition of one or more periodic table of elements.

3. method according to claim 2, is characterized in that: described carrier is one or more mixing in zirconium white, zinc oxide, aluminum oxide, silicon-dioxide, titanium dioxide, magnesium oxide, lanthanum trioxide, cerium oxide; Described active constituent is platinum and/or palladium, and its lifting capacity is mass percent 0.01 ~ 5%.

4. method according to claim 2, is characterized in that: also comprise acidic components and auxiliary agent in used catalyst, and described acidic components are muriate, and its lifting capacity is mass percent 0.01 ~ 5%; Described auxiliary agent is the one in cerium oxide, stannic oxide, zinc oxide, vanadium oxide, lanthanum trioxide, chromic oxide, ferric oxide, zirconium white, manganese oxide, and its lifting capacity is mass percent 0.01 ~ 5%.

5. method according to claim 1, it is characterized in that: step C) described in hydrogenation catalyst reaction temperature 50-250 DEG C, carry out under reaction pressure 50-200 kPa condition, described in the hydrogen total content that provides with Trimethylmethane content in feed stream a than being 1-3mol:1mol.

6. the method according to claim 2 or 4, is characterized in that: step B) and step C) in involved hydrogen provide form to be flow of pure hydrogen or/and be less than the mixing hydrogen stream of 20 % containing light paraffins molar percentage.

7. method according to claim 1, it is characterized in that: be provided with step G): by step e) in the stream e1 that obtains be separated further, obtain the streams g3 containing mass percent 20-40% Trimethylmethane, and streams g3 is recycled to the first distillation zone.

8. method according to claim 1, is characterized in that: step e) described in operate in lightness-removing column and carry out.

9. the method according to claim 1 or 8, is characterized in that: step F) described in operate in butane tower and carry out.

10. method according to claim 9, is characterized in that: described incoming flow a is formed by the Raw material processing containing butane, and concrete steps are:

A21) raw material containing butane is provided;

A22) utilize step e) in lightness-removing column remove iso-butylene, 1-butylene, 2-butylene and other unsaturated hydrocarbons in above-mentioned material, obtain the stream containing normal butane and Trimethylmethane;

A23) utilize step F) in butane tower be separated normal butane thus formed Trimethylmethane stream namely formed comprise 80%(mass percent) the feed stream a of Trimethylmethane.