CN104945223B

CN104945223B - A kind of method that load molecular sieve catalysis toluene synthesizes ortho-chlorotolu'ene

Info

Publication number: CN104945223B
Application number: CN201510343535.3A
Authority: CN
Inventors: 朱晓燕; 殷恒波
Original assignee: Jiangsu University
Current assignee: Jiangsu University
Priority date: 2015-06-19
Filing date: 2015-06-19
Publication date: 2017-09-05
Anticipated expiration: 2035-06-19
Also published as: CN104945223A

Abstract

The present invention relates to ortho-chlorotolu'ene technical field is prepared, a kind of AlCl is refered in particular to₃The method that the molecular sieve catalytic toluene of HZSM 5 synthesizes ortho-chlorotolu'ene is loaded, belongs to oriented chlorination of toluene technical field.This method uses AlCl₃It is catalyst, Cl to load the molecular sieves of HZSM 5₂For chlorinating agent, the selective chlorination of toluene is carried out using liquid phase chlorination method.The Toluene selective chlorination produces that ortho-chlorotolu'ene method synthesis technique is simple, reaction condition gentle, the AlCl used₃The load molecular sieve catalytic actives of HZSM 5 are good, easily separate with product, environmental pollution is small, equipment corrosion is small, and the invention has very high industrial application value.

Description

A kind of method that load molecular sieve catalysis toluene synthesizes ortho-chlorotolu'ene

Technical field

The present invention relates to ortho-chlorotolu'ene technical field is prepared, a kind of AlCl is refered in particular to₃Load HZSM-5 molecular sieve catalytic toluene The method for synthesizing ortho-chlorotolu'ene, belongs to oriented chlorination of toluene technical field.

Background technology

Ortho-chlorotolu'ene is a kind of important fine chemical material, is widely used in the side such as agricultural chemicals, medicine, dyestuff and paint Face, using ortho-chlorotolu'ene as raw material, can produce adjacent chlorobenzyl chloride, o-chlorobenzaldehyde, o-chlorobenzoyl chloride, 0-chloro-benzoic acid, cresols, Dichlorotoleune etc., they are mainly used to production bactericide, the raw material of agrochemical.

It is existing to prepare in ortho-chlorotolu'ene technology, common Lewis acid is mainly used for catalyst, including SbCl₃、 FeCl₃、AlCl₃Deng, though Lewis acid catalyst better catalytic activities, corrosivity is strong when being used alone, harsh to equipment requirement, And the three wastes are more, it is unfavorable for industrialization generation.

By AlCl₃It is carried on carrier, its catalytic activity changes little, and easily separated with catalyst with product, can weigh Multiple to utilize, environmental pollution is small, the features such as smaller to equipment corrosion, with good industrial prospect.

The content of the invention：

The present invention provides a kind of AlCl₃Load the method that HZSM-5 molecular sieve catalytics toluene synthesizes ortho-chlorotolu'ene, technique letter Single, reaction condition is gentle, selectivity of product is high, it is easy to industrialize.

AlCl₃The method that HZSM-5 molecular sieve catalytics toluene synthesizes ortho-chlorotolu'ene is loaded, it is characterized in that entering in the steps below Capable：

（1）HZSM-5 system with molecular sieve for preparing is standby

1. prepared by ZSM-5 molecular sieve：Preparation method bibliography：Chen Bingyi, Yang Xinli, Du Baoshi, wait inorganic amines to close Into ZSM-5 zeolite molecular sieve [J] Zhengzhou University journal, 2001,4（33）：70-72.

By 0.03 mol Al₂(SO₄)₃It is added to the mol/L H of 100 mL 1.5 of preparation₂S0₄In solution, stirring has been allowed to Fully dissolved；By 15 mL ammoniacal liquor（Mass fraction 25%）It is added in 100 mL distilled water, is uniformly mixed, the solution is slow It is added to above-mentioned Al₂(SO₄)₃/H₂S0₄In solution, stir, obtain solution A；By 150g waterglass（Modulus 3.2）It is added to In 225 mL distilled water, stir obtained solution B；Under agitation, solution A is slowly dropped to solution B with peristaltic pump In, react, mixture is put into water heating kettle after 2 h, the h of crystallization 120 at 170 DEG C at 30 DEG C, will be made with distilled water ZSM-5 molecular sieve wash to neutrality, 2 h are dried at 120 DEG C, it is standby.

2. the preparation of HZSM-5 molecular sieves is by ZSM-5 molecular sieve made from 10 g and 100 mL NH₄NO₃（30wt%）Solution It is added in 250 mL three-necked flasks, is stirred at 90 DEG C after 3 h, filtration washing, obtained sample is done in 120 DEG C of baking ovens Dry 2 h, is calcined 2 h, you can obtain HZSM-5 molecular sieves in Muffle furnace in 500 DEG C.

（2）AlCl₃Load HZSM-5 molecular sieves

N₂Under protection, by AlCl₃It is added to HZSM-5 molecular sieves in absolute ethyl alcohol, is warming up to 80 DEG C, return stirring 3 H, after reaction terminates, sample filtering is dried, grind, calcined, and AlCl is can obtain after cooling₃Load HZSM-5 molecular sieves.

Further, the AlCl₃Mass ratio with HZSM-5 molecular sieves is：0.01-0.1 :1, i.e. load capacity are 1%- 10%。

Further, the quality volume of HZSM-5 molecular sieves and absolute ethyl alcohol is：1g : 10mL.

Further, the calcining calcines 2 h to be warming up to 300 DEG C.

（3）Toluene chlorination step adds a certain amount of catalyst in toluene, and stirring makes it be uniformly dispersed, Ran Houxiang The chlorine dried by the concentrated sulfuric acid is passed through in system, under certain chlorination reaction temperature, reaction certain time obtains ortho-chlorotolu'ene, Tail gas absorbs through NaOH solution removes unreacted Cl₂。

Wherein, step（3）The addition of described catalyst is the 0.1% ~ 2% of toluene quality.

Wherein, step（3）Chlorination reaction temperature is 50 ~ 80 DEG C.

Wherein, step（3）The described chlorination reaction time is 2 ~ 8 h.

Wherein, step（3）The chlorine flowrate that the described process concentrated sulfuric acid is dried is 30 mL/min.

The advantage of the invention is that：

1. the present invention uses AlCl₃HZSM-5 molecular sieve catalytic toluene chlorinations are loaded, traditional Lewis acid is solved Etching apparatus during for catalyst, causes the shortcomings of three wastes are more, is conducive to ortho-chlorotolu'ene industrialized production.

2. AlCl prepared by the present invention₃Load HZSM-5 molecular sieves have catalytic activity height, good product selectivity, are easy to The advantages of product separation, repeatable recycling, beneficial to lasting industrialized production.

Embodiment

It is below presently preferred embodiments of the present invention, better understood when the present invention, but embodiments of the invention are not limited to This, while its shown data does not represent the limitation to feature of present invention scope.

Embodiment 1

（1）HZSM-5 system with molecular sieve for preparing is standby

1. prepared by ZSM-5 molecular sieve：By 0.03 mol Al₂(SO₄)₃It is added to the mol/L of 100 mL 1.5 of preparation H₂S0₄In solution, stirring is allowed to be completely dissolved, by 15 mL ammoniacal liquor（Mass fraction 25%）It is added in 100 mL distilled water, stirs It is well mixed, the solution is slowly added into above-mentioned Al₂(SO₄)₃/H₂S0₄In solution, stir, obtain solution A；By 150g Waterglass（Modulus 3.2）It is added in 225 mL distilled water, stir obtained solution B；Under agitation, will with peristaltic pump Solution A is slowly dropped in solution B, is reacted at 30 DEG C, mixture is put into water heating kettle after 2 h, the crystallization at 170 DEG C 120 h, are washed obtained ZSM-5 molecular sieve to neutrality with distilled water, and 2 h are dried at 120 DEG C, standby.

2. the preparation of HZSM-5 molecular sieves：By ZSM-5 molecular sieve made from 10 g and 100 mL NH₄NO₃（30wt%）It is molten Liquid is added in 250 mL three-necked flasks, is stirred at 90 DEG C after 3 h, filtration washing, by obtained sample in 120 DEG C of baking ovens Dry 2 h.2 h are calcined in 500 DEG C, you can obtain HZSM-5 molecular sieves in Muffle furnace.

（2）AlCl₃Load the preparation of HZSM-5 molecular sieves：N₂Under protection, by 0.5 g AlCl₃Divide with 10.0 g HZSM-5 Son sieve is added in the 250 mL three-necked flasks equipped with 100 mL absolute ethyl alcohols, is warming up to 80 DEG C, the h of return stirring 3, reaction knot Shu Hou, sample filtering is dried, grinding, and 300 DEG C of 2 h of calcining are warming up in Muffle furnace, AlCl is can obtain after cooling₃It is negative Carrying capacity is 5% catalyst.

（3）Toluene chlorination step：50 g toluene are added in 100 mL four-hole boiling flask, 0.25 g AlCl are added₃ Load capacity is 5% molecular sieve, and stirring makes it be uniformly dispersed, and is then passed through what 30 mL/min were dried by the concentrated sulfuric acid into system Chlorine, at 65 DEG C, 8 h of reaction obtain ortho-chlorotolu'ene, and tail gas absorbs through NaOH solution removes unreacted Cl₂。

Change AlCl₃Amount, prepare AlCl₃Load capacity is 1%, 2%, 10% catalyst, you can obtain different AlCl₃Load Measure the influence to chlorination toluene process, such as table 1：

The difference of table 1 AlCl₃Influence of the load capacity to toluene chlorination

Table 1 reflects AlCl₃Influence of the load capacity to toluene chlorination.As it can be seen from table 1 with AlCl₃Load capacity Increase to 10% from 1%, the conversion ratio of toluene increases to 100.0% from 68.3%；The ratio of ortho-chlorotolu'ene and parachlorotoluene in product First increase and reduce afterwards, work as AlCl₃When load capacity is 5%, the ratio of ortho-chlorotolu'ene and parachlorotoluene reaches maximum, is 2.82.As a result Show, AlCl₃Load capacity has large effect to toluene chlorination；AlCl₃The increase of load capacity, active component increases, and has Beneficial to quickening reaction rate.Meanwhile, AlCl₃The ratio of the increase of load capacity, ortho-chlorotolu'ene and parachlorotoluene declines, and this is mainly Because the further chlorination generation dichlorotoleune of monochlorotoluene.

Embodiment 2

AlCl is produced using the same method of embodiment 1₃HZSM-5 molecular sieves are loaded, toluene chlorination step is with implementation Example 1, changes AlCl₃It is 0.05 g, 0.5 g, 1.0 g to load HZSM-5 molecular sieves consumption, can obtain catalyst amount to toluene The influence of chlorination reaction process, such as table 2：

The catalyst amount of table 2 influences on toluene chlorination

Table 2 shows influence of the catalyst amount to toluene chlorination.As catalyst amount increases to from 0.1% 2.0%, the conversion ratio of toluene increases to 100.0% from 62.5%；The ratio of ortho-chlorotolu'ene and parachlorotoluene is increased to from 2.59 2.82, after be down to 2.60；From table 2 it can be seen that the consumption of increase catalyst is conducive to improving toluene chlorination speed, but together When also result in the ratio of ortho-chlorotolu'ene and parachlorotoluene and decline, this is primarily due to the further chlorination generation dichloro of monochlorotoluene Toluene.

Embodiment 3

AlCl is produced using the same method of embodiment 1₃HZSM-5 molecular sieves are loaded, toluene chlorination step is with implementation Example 1, it is 50 DEG C, 80 DEG C to change reaction temperature, can obtain influence of the differential responses temperature to chlorination toluene process, such as table 3：

The differential responses temperature of table 3 influences on toluene chlorination

Reaction temperature/DEG C	Toluene conversion/%	Ortho-chlorotolu'ene/parachlorotoluene
			50	86.4	2.59
65	98.2	2.82
			80	100.0	2.50

Table 3 reflects influence of the reaction temperature to toluene chlorination；From table 3 it can be seen that the conversion ratio of toluene with The rise of reaction temperature and increase.When reaction temperature is 65 DEG C, the ratio highest of ortho-chlorotolu'ene and parachlorotoluene in product, For 2.82.

As a result show, high temperature is conducive to the raising of ortho-chlorotolu'ene selectivity.

Embodiment 4

AlCl is produced using the same method of embodiment 1₃HZSM-5 molecular sieves are loaded, toluene chlorination step is with implementation Example 1, the change reaction time is 2 h, 4 h, 6 h, can obtain influence of the differential responses time to chlorination toluene process, such as table 4：

Influence of the differential responses time of table 4 to toluene chlorination

Table 4 reflects influence of the reaction time to toluene chlorination.As can be seen from the table, as the reaction time is from 2 H extends to 8 h, and the conversion ratio of toluene increases to 98.2% from 20.9%；The ratio of ortho-chlorotolu'ene and parachlorotoluene declines from 2.90 To 2.82；Test result indicates that, the extension reaction time is conducive to the raising of toluene conversion, but also results in ortho-chlorotolu'ene simultaneously Reduced with the ratio of parachlorotoluene.

Embodiment 5

AlCl is produced using the same method of embodiment 1₃HZSM-5 molecular sieves are loaded, toluene chlorination step is with implementation Example 1, by AlCl₃Load HZSM-5 molecular sieves are separated with chlorizate, and using the 2nd time, the 3rd time, the 4th, the 5th must can be urged Influence of the agent access times to chlorination toluene process, such as table 5：：

Influence of the catalyst access times of table 5 to toluene chlorination

Table 5 reflects influence of the catalyst access times to toluene chlorination, as can be seen from Table 5, with catalyst The increase of access times, the conversion ratio of toluene slowly declines with the value of ortho-chlorotolu'ene/parachlorotoluene, makes for the 5th time when catalyst Used time, the conversion ratio of toluene remains at 94.1%, and the value of ortho-chlorotolu'ene/parachlorotoluene maintains 2.71%.This shows, AlCl₃ Load HZSM-5 molecular sieve catalysts stability strong, cycle performance is good.

Claims

1. a kind of method that load molecular sieve catalysis toluene synthesizes ortho-chlorotolu'ene, it is characterised in that：With AlCl₃Load HZSM-5 points Son sieve is catalyst, and catalysis Toluene selective chlorination produces ortho-chlorotolu'ene；AlCl is added in toluene₃Load HZSM-5 molecular sieves As catalyst, stirring makes it be uniformly dispersed, the chlorine dried by the concentrated sulfuric acid is then passed through into system, anti-in certain chlorination At a temperature of answering, reaction certain time obtains ortho-chlorotolu'ene, and tail gas absorbs through NaOH solution removes unreacted Cl₂；

The addition of the catalyst is the 0.5% of toluene quality；The chlorination reaction temperature is 65 DEG C；Described chlorination reaction Time is 8h；The AlCl₃The preparation method for loading HZSM-5 molecular sieves is as follows：N₂Under protection, by AlCl₃With HZSM-5 molecules Sieve is added in absolute ethyl alcohol, is warming up to 80 DEG C, return stirring 3h after reaction terminates, sample filtering is dried, grind, calcined, AlCl is can obtain after cooling₃Load HZSM-5 molecular sieves；AlCl₃Mass ratio with HZSM-5 molecular sieves is：0.05:1, that is, bear Carrying capacity is 5%.

2. the method that a kind of load molecular sieve catalysis toluene as claimed in claim 1 synthesizes ortho-chlorotolu'ene, it is characterised in that：Institute The chlorine flowrate that the process concentrated sulfuric acid stated is dried is 30mL/min.

3. the method that a kind of load molecular sieve catalysis toluene as claimed in claim 1 synthesizes ortho-chlorotolu'ene, it is characterised in that： The quality volume of HZSM-5 molecular sieves and absolute ethyl alcohol is：1g:10mL；The calcining calcines 2h to be warming up to 300 DEG C.