CN103804250A - Synthetic method of ethylene cracking coking inhibitor - Google Patents

Abstract

The invention relates to a synthetic method of an ethylene cracking coking inhibitor. The method is carried out in a closed circuit response system. The method is technically characterized in that the closed circuit response system comprises a raw material unit, a reaction unit, a two-phase separation unit and a reaction product separation unit, wherein the raw material unit comprises an olefin storage tank, a synthetic reaction kettle, a degassing kettle and an oil-water separation tank. The synthetic method of substituted methyl disulfide coking inhibitor belongs to the technical field of sulfides of acyclic unsaturated carbon frame. The synthetic method is characterized by comprising the following steps of: adding elemental sulfur and catalyst to a high-pressure kettle, raising the temperature to 150-250 DEG C, stirring for 0.5h, slowly adding butylenes to the kettle, raising the pressure to 2-6MPa after addition, reacting for 1-6h, then cooling to below 120 DEG C, pressing reaction mixture out of the high-pressure kettle by utilizing overbottom pressure, separating organic phase after standing for layering, and then carrying out reduced pressure distillation and filtering to obtain the product coking inhibitor.

Description

A kind of cracking of ethylene coking inhibitor synthetic method

A kind of cracking of ethylene coking inhibitor synthetic method, described method is carried out in closed circuit reactive system, its technical essential is: described closed circuit reactive system comprises material unit, reaction member, two separation units, reaction product separating unit, wherein material unit comprises alkene hold-up vessel, synthesis reaction vessel, degassed still and gun barrel.

A kind of cracking of ethylene coking inhibitor synthetic method, belong to the technical field of sulfide of acyclic unsaturated carbon skeleton, it is characterized in that comprising the following steps: elemental sulfur, catalyzer are added in autoclave, be warming up to 150-250 ℃, stir after 0.5h, in still, slowly add butylene, after adding, boost to 2-6MPa, reaction 1-6h, then be cooled to below 120 ℃, utilize overbottom pressure, reaction mixture is extruded to autoclave, after stratification, separate organic phase, then after underpressure distillation, filtration, obtain product vulcanizing agent; Catalyzer is inorganic weak bases material, or organic amine material.Technique of the present invention has that technique is simple, yield is high, production cost is low, advantage that reaction process is pollution-free, substitute existing oil refining Presulfiding Agent of Hydrogenation Catalyst and cracking of ethylene coking inhibitor and substitute Methyl disulfide cracking of ethylene kind coking inhibitor, the pollution problem in the production of solve at present-Methyl disulfide.There is good economic benefit and wide application prospect.

Technical field

The invention belongs to fine chemical technology field, specifically relate to the preparation method of cracking of ethylene coking inhibitor synthetic method, relate in particular to a kind of preparation method who vulcanizes butylene.

Background technology

Methyl disulfide is a kind of prevulcanized agent and cracking of ethylene coking inhibitor of refining oil hydrogenation catalyst, and oil soluble is good, and sulfur-bearing is high, but irritant, asphyxiating stench and toxicity.

Wherein, in production, raw materials used methyl-sulfate belongs to severe poisonous chemicals, and toxicity is larger.In addition, by product Sodium Sulphide and waste water, waste gas severe contamination environment.

The intense stimulus of Methyl disulfide and toxicity and danger, also very strict to the requirement of its transportation, isolated area is set conventionally, and operator must wear a gas mask or the Gas feeding helmet, self-contained breathing apparatus, chemical safety safety glasses, wear special impregnating material working suit, wear rubber gloves.Even if take above-mentioned measure can not guarantee operator's health completely, handling scene is necessary rational ventilation also, and avoids directly contacting stock liquid, avoids raw material to contact with combustiblesubstance.In summary, Methyl disulfide is as vulcanizing agent, and is difficult to guarantee on-the-spot safety, once occur that damage sequence cannot imagine.

In sum, Methyl disulfide production process environmental issue, the toxicity of Methyl disulfide and methyl-sulfate toxicity problem, all make Methyl disulfide produce to face and be forced to close and be difficult to maintain production, and domestic many enterprises are forced to stop production.The inventor through research and development for many years, realized the renewal of Methyl disulfide, the substitute products dialkyl polysulfide of exploitation environmental protection, has solved the prevulcanized agent of oil refining hydrogenation catalyst and the cracking of ethylene coking inhibitor environmental protection problem in producing.

Catalyzer of the present invention can recycle, and concrete method is: after reaction mixture sat layering, the aqueous solution that inorganic phase is catalyzer, analyzes its solubility, then adds to desired concn with new catalyzer.

Illustrate the preparation method who the present invention relates to by following example.The umber relating to below or per-cent are all by weight.

Example 1

Sulphur (526 parts, 16.4 moles) adds the autoclave of jacketed, and reactor is with agitator and internal cooling coil pipe.In sealed reactor, add elemental sulfur, be evacuated to-0.09Mpa, and add inorganic weak bases, 920 parts (16.4 moles) are passed into reactor with pump by 1-butylene.Utilize thermal oil, by chuck, reactor heating is exceeded to 3.5h, reach approximately 172 ℃.In the time that temperature of reactor reaches 168 ℃, there is peak pressure 2Mpa in reactor.Before temperature of reactor reaches maximum, the consumption of gaseous reactant makes reactor pressure start to decline and continual and steady reduction.At 170 ℃, after about 3.5h, reactor pressure is 2.8Mpa.When reactor pressure drops to after 2Mpa pressure, sulfur product is collected with liquid form.Degassed with sulfur product (mixture) being carried out at approximately 80 ℃ of pressure reducing modes, remove low-boiling point material (comprising unreacted 1-butylene, mercaptan and monosulphide).Material after degassed is needed sulfide, sulphur content 55.5%.

Example 2-

In example 2, preparation procedure is substantially identical with example 1, and has adopted different reactant ratios, temperature of reaction and reaction mixture composition.In example 2, the separation of low-boiling point material is to complete by the first nitrogen purging stripping that then reduces pressure.In example 2, the separation of low-boiling point material is by underpressure distillation (there is no nitrogen purging).If there is water to exist in these examples, crude product is first with aqueous phase separation and then carry out above-mentioned steps.

Claims (10)

1. the synthetic raw material of cracking of ethylene kind coking inhibitor synthetic method is the monoolefines such as butylene, iso-butylene, diisobutylene, triisobutene; Typical sulfide is under different condition, to react acquisition with sulphur by alkene (iso-butylene, diisobutylene, triisobutene), and the common feature of these products is to contain three-six sulphur or group.The olefin(e) compound that can be vulcanized by present method has a variety of, and they comprise at least one olefinic double bonds (the two keys of non-aromatic hydrocarbon).

2. as a rule, definition of olefins formula is R1R2C=CR3R4.Monoolefine and diolefin are more suitable for present method, especially monoolefine, be exactly R3 and R4 be hydrogen, R1 and R2 are alkyl or aromatic base (alkyl is better).Contain 3 to 10, preferably the olefin(e) compound of 3 to 6 (being in most cases less than 7) individual carbon atom is more applicable, iso-butylene, propylene and their dipolymer, trimer and tetramer, also having their mutual mixtures is all the olefin(e) compound that is applicable to present method.In the middle of these suitable olefin(e) compounds, best is iso-butylene and 1-butylene, diisobutylene.Although diisobutylene contains two kinds of isomrs, present method is used diisobutylene.

3. in the present invention, other two kinds of crucial reactants are sulphur.Present method does not have excessive demand to sulphur purity, and the existence of impurity does not have detrimentally affect to result, and the consumption of the sulphur that every mole of olefin(e) compound is corresponding is 0.3-2.0 mole, and inorganic weak bases is 0.1-1.5 mole.The consumption being more suitable for is the inorganic weak bases of 0.2-1.5 gram of molar sulphur and 0.2-1.25 mole, and best scope is the inorganic weak bases of 0.7-1.2 gram of molar sulphur and 0.2-0.8 mole.

4. under rhythmic reaction condition, reactant adds according to this ratio.Under semi-batch and successive reaction condition, reactant can mix in any proportion, but reactant is consumed according to aforementioned proportion on the basis of mass balance.For instance, if reactor is initially written into sulphur, olefin(e) compound and inorganic weak bases pass into reach aforementioned proportion gradually according to given pace so, normally 150-250 ℃ of the temperature range of reaction, proper is 160-200 ℃ degree Celsius, and best temperature range is at 155-180 ℃.Reaction is carried out under super-atmospheric pressure,, under autogenou pressure, can be still normally also external pressure.The autogenou pressure that reaction produces is relevant to design and the operating parameters of reactive system, temperature of reaction, and the vapour pressure of reactant and product all can affect pressure, and pressure is also different in the different steps of reaction.

Catalyzer have carrying out that is beneficial to vulcanization reaction, catalyzer can be acid, alkalescence or neutral.Useful neutrality and acidic catalyst agent material comprise acid-treated clay, p toluenesulphonic acids, dialkyl dithiophosphoric acid, phosphoric sulfide (such as thiophosphoric anhydride).The catalyzer that is more suitable for present method is alkaline, and catalyzer is inorganic oxide and salt, such as sodium hydroxide, and calcium oxide and sodium sulphite.Best basic catalyst is nitrogen base, comprises ammonia and amine.Amine comprises the primary, secondary and tertiary alkylamine, and alkyl is wherein alkyl, aryl, aralkyl, alkaryl or the similar alkyl containing 1-20 the carbon of having an appointment.Comprise aniline than better suited amine, benzylamine, dibenzylamine, lauryl amine, naphthylamines, tallow amine, N-ethyl dipropylamine, N-phenylbenzylamine, N, N-diethyl n-butylamine, meta-aminotoluene and 23 dimethyl aniline.Tetramethyleneimine, N-crassitude, piperidines, these heterocyclic amines of pyridine and quinoline are also suitable for.

6. the basic catalyst that is applicable to present method comprises ammonia and the primary, secondary and alkyl amine (alkyl contains 1-8 carbon atom).The representative of this class amine is methylamine, dimethylamine, Trimethylamine 99, triethylamine, diethylamine, triethylamine, Di-n-Butyl Amine, tri-n-butylamine, three Sec-Hexyl amine, tri-n-octyl amine.The mixture of these amine, and the mixture of they and ammonia also can use as suitable basic catalyst, the consumption of catalyzer is the 0.01-1.5 mole of olefin(e) compound weight normally.In the time using suitable ammonia and amine catalyst, every mole of alkene probably needs 0.2-0.5 mol catalyst (0.1-0.5 mole of the best).

7. in reactant, also may have water, water exists as the thinner of catalyzer or above-mentioned catalyzer.If there is water to exist, the amount of water is generally the 1-25% of alkene weight.The existence of water is not necessary, and on the contrary, in the time using certain type reaction equipment, anhydrous condition is more favourable to reaction, and after using above-mentioned catalyzer, the per-cent of the compound that contains three-six methylthio groups in product declines to a great extent.Such variation is favourable, because the existence of three methylthio groups can change product colour.Meanwhile, the product obtaining while using the alkaline matters such as ammonia or amine as catalyzer has better permanent stability.

8. in the present invention, conventionally do not relate to other solvent and the thinner outside dewatering.The use that the time of reaction needed is subject to reactant consumption, temperature of reaction, catalyzer whether, the impact of the condition such as reactant purity.Reaction process is normally observed tracking by the pressure that monitors reactor.When the pressure drop of reactor arrives certain constant value, think that reaction is through with substantially, reaction finishes to obtain after cured blend, next will remove the low boiling point component in mixture.In low boiling point component, except reactant is as olefin(e) compound, conventionally also contain mercaptan and single sulfide, be especially less than 6 carbon atoms when initial alkene contains.If these materials are gaseous states under envrionment temperature and pressure, they can be discharged and be reclaimed by reactor ventilation opening simply.If initial reactant is not volatile, may need so air distillation or underpressure distillation.Another kind of effective means is that rare gas element (as nitrogen) is passed through to mixture under suitable temperature and pressure.

9. in reaction mixture, remaining solid can be simply by separating with liquid.Filtration and centrifugation are all good selections, and the sulfur product obtaining is further processed to improve its smell, color.These treatment processs comprise utilizes acid clay process or filter by diatomite, gac, aluminum oxide clay etc.In the time using basic catalyst, the vulcanizate obtaining does not need to carry out these processing conventionally.

10. the precise chemical structure character of sulfur product still be can not determine, can only with their preparation method come classified description they.When sulfur product is when being less than 7 olefin(e) compound and being made by carbonatoms, they mainly contain disulphide, trisulphide and tetrasulfide.The sulphur content of sulfide is conventionally at 2-60% (weight percent), preferably 25-60%, that the most satisfied is about 40-56%, is that a kind of Methyl disulfide that substitutes is at oil refining ethene coking inhibitor and oil refining Presulfiding Agent of Hydrogenation Catalyst and cracking of ethylene coking inhibitor.。