Background technology
Along with the raising of China's refining capacity and the development of ethylene industry, refinery catalytic cracking and carbon that steam cracking device produces four C 4 fraction resource increases day by day, since 2010, China's C 4 fraction production capacity is more than ten million ton, wherein most C4 hydrocarbon directly uses as fuel using the form of liquefied gas, only have a small amount of as industrial chemicals, and the utilization rate of developed country C4 resource is higher than 70%.Along with China " the smooth enforcement of West-east Gas plan; liquefied gas as domestic fuel market at last replace by relatively cheap natural gas; a large amount of C4 hydrocarbon is badly in need of finding new chemical utilization approach; wherein; with the 2-butyl acetate product of the n-butene of rich content in C4 after ether for raw material production high added value; be namely realize C4 comprehensive utilization of resources, improves one of effective ways of Business Economic Benefit.
The production technology of current 2-butyl acetate mainly contains two kinds: (1) sec-butyl alcohol and acetic acid esterified reaction traditional handicraft; (2) n-butene and acetic acid addition reaction new technology.Esterification reaction tech is the method for producing 2-butyl acetate the earliest, but due to cost higher, replaced by the product of other similar nature gradually.Along with the development of petrochemical industry and catalysis technique, adopting n-butene and the direct addition of acetic acid in hybrid C 4 cut (after removing isobutene) to prepare 2-butyl acetate in recent years becomes the new way having both C4 resources effective utilization and 2-butyl acetate and synthesize.
Patent RU2176239 discloses the earliest by butylene and acetic acid direct esterification Synthesis of Butyl Acetate technology, have employed acid-exchange resin as catalyst.Cause catalysqt deactivation because resin catalyst there will be the problems such as sulfonic group runs off, resin particle is broken in course of reaction, and resin catalyst is difficult to regeneration, solid waste discharge after stain environment.Meanwhile, in the product of resin catalysis, sulfur content is higher, makes to there is peculiar smell in product, and impact uses.
Sec-butyl acetate synthetic method disclosed in patent CN101293824, employing heteropoly acid is catalyst, reaction temperature 70 ~ 180 DEG C,, pressure 0.5 ~ 6MPa, olefin(e) acid mol ratio 0.1 ~ 10 reaction condition under catalyze and synthesize sec-butyl acetate, the method can obtain good butene conversion and ester selective, and the problem of the Particle Breakage that use resin catalyst can be avoided to cause, catalysqt deactivation, but reaction is homogeneous system, be applicable to autoclave homogeneous reaction, not easily realize large-scale industrial production.Meanwhile, in homogeneous reaction system, heteropolyacid catalyst easily decomposes attachment and causes active component to be lost on the reactor wall, and reactivity declines gradually.
Patent CN101293210 discloses a kind of composite catalyst using method, add reaction system with heteropolyacid catalyst and porous decentralized medium simultaneously, along with reaction is carried out, after heteropoly acid is separated out from homogeneous system, to be adsorbed on decentralized medium and continue catalytic action, and react and transfer heterogeneous catalysis to by homogeneous catalysis.The method can solve the problem that active component runs off from reaction system to a certain extent, but due to the heterogeneous catalysis stage and homogeneous catalysis elementary reaction activity difference comparatively large, be difficult to ensure conversion ratio and selective.And this catalyst system and catalyzing is also only applicable to still reaction.
Summary of the invention
The object of this invention is to provide a kind of preparation method utilizing the acetic acid synthesized Zhong Ding ester catalyst of mixing carbon four C4, to solve the application of 2-butyl acetate synthetic reaction on fixed bed reactors, and the problem that the Particle Breakage that catalyst in use occurs (efflorescence), loss of active component and service life are short.
The present invention is a kind of preparation method utilizing the acetic acid synthesized Zhong Ding ester catalyst of mixing carbon four, it is characterized in that:
Adopt the heteropoly acid of structure with Keggin as active component, employing macro porous silica gel is carrier, with infusion process by loaded by heteropoly acid on macro porous silica gel carrier, obtain Kaolinite Preparation of Catalyst by super-dry, roasting;
Described heteropoly acid is the phosphotungstic acid of structure with Keggin, silico-tungstic acid, germanotungstic acid, phosphomolybdic acid, silicomolybdic acid or germanium molybdic acid, and heteropoly acid weight content is in the catalyst 5% ~ 30%;
Described macro porous silica gel specification is aperture ≮ 10nm, pore volume ≮ 1.0 ml/g, specific area ≮ 300 m
2/ g, profile is the spheric granules of particle diameter at 0.5 ~ 1mm, needs through peracid bubble, washing, dry and calcination process before using; Wherein, the acid that sour bubble process is used is sulfuric acid, hydrochloric acid or nitric acid, and acid concentration is 3% ~ 15%, and the sour bubble time is 1 ~ 8 hour; Water-washing process requires that being washed till filtrate pH value is 7; The baking temperature that described macro porous silica gel dry run uses is 100 ~ 130 DEG C, and drying time is 1 ~ 12 hour; The sintering temperature that macro porous silica gel roasting process uses is 500 ~ 700 DEG C, and roasting time is 1 ~ 7 hour;
Described active constituent loading method is equi-volume impregnating, with deionized water or ethanol for dissolution with solvents heteropoly acid preparation activity component impregnation liquid, and it is for subsequent use to be settled to the volume suitable with carrier water absorption, macro porous silica gel carrier after process is placed in maceration extract, under normal temperature, stirring, makes carrier uniform adsorption maceration extract and reach capacity;
Described Kaolinite Preparation of Catalyst dry run baking temperature is 100 ~ 130 DEG C, and drying time is 1 ~ 12 hour; Kaolinite Preparation of Catalyst roasting process sintering temperature is 180 ~ 300 DEG C, and roasting time is 1 ~ 5 hour.
According to the preparation method of catalyst of the present invention, it is characterized in that use, described catalyst is used for the reaction of fixed-bed catalytic carbon four C4 butylene and acetic synthesis 2-butyl acetate, and reaction condition is pressure 0.5 ~ 3MPa, reaction temperature 80 ~ 120 DEG C, acetic acid Feed space velocities 0.5 ~ 2h
-1, carbon four C4 and acetic acid feed rate are than being 1:2 ~ 2.5:1, and reaction is carried out being not less than 200 hours continuously.
Detailed description of the invention
Below will set forth feature of the present invention further by specific embodiment, the percentage below related to all is weight percentage.
Embodiment 1
Get the macro porous silica gel 20g that profile is 0.5 ~ 1mm spheric granules, at 110 DEG C, drying 4 hours, for subsequent use as catalyst carrier.Get 5g phosphotungstic acid and be dissolved in 20mL deionized water, until completely dissolved, be settled to 40mL.Dried carrier is placed in above-mentioned heteropoly acid solution, floods 3 hours under normal temperature, dry 4 hours through 110 DEG C after taking-up, 250 DEG C of roastings obtain required catalyst in 3 hours, are numbered C-1.
Embodiment 2
Get the macro porous silica gel 20g that profile is 0.5 ~ 1mm spheric granules, configuration concentration is the salpeter solution 30mL of 5%, macro porous silica gel is placed in salpeter solution to soak 3 hours, after taking-up with washed with de-ionized water to filtrate pH value for 7, dry 4 hours through 110 DEG C, 500 DEG C of roastings obtain required catalyst carrier in 3 hours again.
Get 2.2g phosphotungstic acid and be dissolved in 20mL deionized water, until completely dissolved, be settled to 30mL.Roasting carrier is placed in above-mentioned heteropoly acid solution, floods 3 hours under normal temperature, dry 4 hours through 110 DEG C after taking-up, 250 DEG C of roastings obtain required catalyst in 3 hours, are numbered C-2.
Embodiment 3
Get the macro porous silica gel 20g that profile is 0.5 ~ 1mm spheric granules, configuration concentration is the salpeter solution 30mL of 10%, macro porous silica gel is placed in salpeter solution to soak 5 hours, after taking-up with washed with de-ionized water to filtrate pH value for 7, dry 4 hours through 110 DEG C, 500 DEG C of roastings obtain required catalyst carrier in 3 hours again.
Get 3.5g phosphotungstic acid and be dissolved in 20mL deionized water, until completely dissolved, be settled to 30mL.Roasting carrier is placed in above-mentioned heteropoly acid solution, floods 3 hours under normal temperature, dry 4 hours through 110 DEG C after taking-up, 250 DEG C of roastings obtain required catalyst in 3 hours, are numbered C-3.
Embodiment 4
Get the macro porous silica gel 20g that profile is 0.5 ~ 1mm spheric granules, configuration concentration is the hydrochloric acid solution 30mL of 5%, macro porous silica gel is placed in salpeter solution to soak 7 hours, after taking-up with washed with de-ionized water to filtrate pH value for 7, dry 4 hours through 110 DEG C, 500 DEG C of roastings obtain required catalyst carrier in 4 hours again.
Get 6.6g phosphotungstic acid and be dissolved in 20mL absolute ethyl alcohol, until completely dissolved, be settled to 30mL with absolute ethyl alcohol.Roasting carrier is placed in above-mentioned heteropoly acid solution, floods 3 hours under normal temperature, dry 4 hours through 110 DEG C after taking-up, 250 DEG C of roastings obtain required catalyst in 3 hours, are numbered C-4.
Embodiment 5
Get the macro porous silica gel 20g that profile is 0.5 ~ 1mm spheric granules, configuration concentration is the hydrochloric acid solution 30mL of 10%, macro porous silica gel is placed in salpeter solution to soak 7 hours, after taking-up with washed with de-ionized water to filtrate pH value for 7, dry 4 hours through 110 DEG C, 500 DEG C of roastings obtain required catalyst carrier in 4 hours again.
Get 8.6g phosphotungstic acid and be dissolved in 20mL absolute ethyl alcohol, until completely dissolved, be settled to 30mL with absolute ethyl alcohol.Roasting carrier is placed in above-mentioned heteropoly acid solution, floods 2 hours under normal temperature, dry 4 hours through 110 DEG C after taking-up, 250 DEG C of roastings obtain required catalyst in 3 hours, are numbered C-5.
Embodiment 6
Get the macro porous silica gel 20g that profile is 0.5 ~ 1mm spheric granules, configuration concentration is the hydrochloric acid solution 30mL of 10%, macro porous silica gel is placed in salpeter solution to soak 7 hours, after taking-up with washed with de-ionized water to filtrate pH value for 7, dry 4 hours through 110 DEG C, 500 DEG C of roastings obtain required catalyst carrier in 4 hours again.
Get 6.6g silico-tungstic acid and be dissolved in 20mL deionized water, until completely dissolved, be settled to 30mL.Roasting carrier is placed in above-mentioned heteropoly acid solution, floods 2 hours under normal temperature, dry 4 hours through 110 DEG C after taking-up, 250 DEG C of roastings obtain required catalyst in 3 hours, are numbered C-6.
Embodiment 7
Get the macro porous silica gel 20g that profile is 0.5 ~ 1mm spheric granules, configuration concentration is the hydrochloric acid solution 30mL of 10%, macro porous silica gel is placed in salpeter solution to soak 7 hours, after taking-up with washed with de-ionized water to filtrate pH value for 7, dry 4 hours through 110 DEG C, 500 DEG C of roastings obtain required catalyst carrier in 4 hours again.
Get 6.6g phosphomolybdic acid and be dissolved in 20mL deionized water, until completely dissolved, be settled to 30mL.Roasting carrier is placed in above-mentioned heteropoly acid solution, floods 2 hours under normal temperature, dry 4 hours through 110 DEG C after taking-up, 250 DEG C of roastings obtain required catalyst in 3 hours, are numbered C-7.
Embodiment 8-14
This example illustrates the reactivity worth of catalyst refinery hybrid C 4 provided by the invention and the direct acetic acid synthesized secondary butyl ester of acetic acid.
The hybrid C 4 raw material adopted is C4 after the ether of removal isobutene, and reaction unit is 20mL fixed-bed micro-reactor, and loaded catalyst is 10mL, and beds is all filled with inert ceramic balls up and down.Reaction system is by nitrogen pressurising, and C4 and acetic acid merge a road and enters reactor, and enter high score after beds reacts and carry out gas-liquid separation, gas circuit is emptying after crossing condensation.
The reaction condition adopted is: operating pressure 1.0 MPa, reaction temperature 100 DEG C, acetic acid Feed space velocities 1h
-1, C4 and acetic acid feed rate are than being 2:1.Different catalysts reaction result is in table 1,2.
Comparative example 1
This comparative example illustrates that carried heteropoly acid catalyst provided by the invention contrasts with the reactivity worth purchasing available macropore sulfuric acid resin catalyst, and contrast through long time running rear catalyst physical behavior, azochlorosulfonate acid resin catalyst is numbered R-1, and the reaction condition of employing is identical with embodiment 8-14.
Table 1
Catalyst |
Vehicle element |
Loaded by heteropoly acid amount/% |
Acetic acid conversion ratio/% |
Ester is selective/% |
C-1 |
Untreated |
20 |
50.8 |
58.6 |
C-2 |
Process |
10 |
68.9 |
76.2 |
C-3 |
Process |
15 |
80.2 |
82.8 |
C-4 |
Process |
25 |
88.6 |
89.2 |
C-5 |
Process |
30 |
87.5 |
88.4 |
Table 2
Catalyst |
Heteropoly acid kind |
Loaded by heteropoly acid amount/% |
Acetic acid conversion ratio/% |
Ester is selective/% |
C-4 |
Phosphotungstic acid |
25 |
88.6 |
89.2 |
C-6 |
Silico-tungstic acid |
25 |
76.5 |
68.1 |
C-7 |
Phosphomolybdic acid |
25 |
71.7 |
62.4 |
R-1 |
- |
- |
84.7 |
90.4 |
Under the reaction condition that catalyst C-4 and R-1 embodiment 4 and comparative example 1 provided provides at embodiment 8-14 continuous run 800 hours after, catalyst is drawn off from reactor, find that resin catalyst R-1 has obvious Particle Breakage, powder phenomenon-tion, but do not occur the phenomenon of Particle Breakage with the heteropolyacid catalyst C-4 of silica-gel carrier load; Carry out XRF analysis to the C-4 catalyst drawn off to show, there is not the loss of active component in catalyst after long period reaction yet; The statistics each stage acetic acid conversion ratio of reaction and the known catalyst activity of ester selective data also can keep stable, show that carried heteropoly acid catalyst provided by the invention can be used for long period successive reaction catalytic mixing C4 and acetic synthesis 2-butyl acetate.