Summary of the invention
The object of the present invention is to provide the selection method of hydrotreating of alkynes in a kind of carbon four hydrocarbon streams.
Concrete technical scheme is as follows:
The selection method of hydrotreating of alkynes in a kind of carbon four hydrocarbon streams, carbon four hydrocarbon streams that will comprise alkynes enter the hydrogenator that load type palladium catalyst is housed with hydrogen, 10~80 ℃ of temperature ins, making the selective acetylene hydrocarbon hydrogenation in carbon four hydrocarbon streams under hydrogen/alkynes mol ratio 1~10 and the reaction pressure 0.1~4Mpa is that the olefin/diene hydrocarbon is removed;
Described load type palladium catalyst comprises carrier, palladium and optional modified component, it is characterized in that described catalyzer in 40 ℃ of carbon monoxide absorption in-situ ft-ir figure that test down, 1930~1990cm
-1Place's bridge-type absorption peak and 1870~1930cm
-1The ratio of the area of place's bridge-type absorption peak is less than 0.2.
Preferably, described catalyzer adsorbs among the in-situ ft-ir figure at 40 ℃ of carbon monoxide of testing down, 1930~1990cm
-1Place's bridge-type absorption peak and 1870~1930cm
-1The ratio of the area of place's bridge-type absorption peak is less than 0.15.
More preferably described catalyzer is at 40 ℃ down behind the absorption carbon monoxide, uses 1870~1930cm among the in-situ ft-ir figure that nitrogen purging records in the time of 0 minute instead
-1The peak height of place's absorption peak with use 1800~1900cm among the in-situ ft-ir figure that nitrogen purging records in the time of 15 minutes instead
-1The ratio of the peak height of place's absorption peak is less than 5, preferably less than 2.
The carbon monoxide absorption infrared spectrogram of catalyzer adopts following method to record:
A) catalyst sample with powdered form places hydrogen gas stream to be warming up to 300 ℃; Temperature rise rate is 20 ℃/min, and hydrogen flowing quantity is 10ml/min;
B) in hydrogen gas stream, be incubated 2 hours down, be cooled to 40 ℃ then in 300 ℃; Rate of temperature fall is 20 ℃/min, and hydrogen flowing quantity is 10ml/min;
C) keeping temperature is 40 ℃, feeds stream of nitrogen gas and purges 30 minutes, and nitrogen flow is 5ml/min;
D) keeping temperature is 40 ℃, feeds carbon monoxide-argon gas gas mixture (molar content of carbon monoxide is 1%), adsorbs 30 minutes, and mixed gas flow is 5ml/min;
E) keeping temperature is 40 ℃, uses nitrogen purging instead, simultaneously the in-situ ft-ir of the carbon monoxide of working sample absorption at once figure;
F) keeping nitrogen flow is 5ml/min, writes down the in-situ ft-ir figure of sample when nitrogen purging 9min, 15min, 24min respectively.
Before testing, should be earlier granular catalyst sample be ground to Powdered, fill in the original position sample pool and keep surfacing.The purpose of step a~c is that the Pd in the catalyzer is reduced to the simple substance attitude, and removes the absorption impurity of catalyst surface.For going back the catalyzer of ortho states, palpus is through the treatment step of a~c, to guarantee test result accurately and reliably equally for Pd.
Finish at the carbon monoxide adsorption step (step d) and use nitrogen purging instead in, write down the infrared spectrogram (promptly purging 0 minute spectrogram) of sample at once, the carbon monoxide absorption in-situ ft-ir figure as this sample is used for 1870~1930cm
-1Place's bridge-type absorption peak and 1930~1990cm
-1The calculating of place's bridge-type absorption peak area.Using nitrogen purging to write down the infrared spectrum of sample after 15 minutes once more,, calculate 1800~1900cm with the spectrogram contrast that purges 0 minute
-1Place's absorption peak (purging 15 minutes spectrograms) and 1870~1930cm
-1The ratio of the peak height of place's absorption peak (purging 0 minute spectrogram).
In the CO of Pd absorption in-situ ft-ir, 1880~1990cm
-1The place has two tangible infrared absorption peaks usually, corresponding to the bridge-type absorption of CO on the different loci of Pd surface.For different Pd catalyzer, the relative intensity of two absorption peaks has bigger difference, and common two summits overlap, and one of them summit becomes the acromion at another peak in some cases.In order to calculate the area ratio of two absorption peaks, can use data processing software commonly used to 1750~2000cm
-1Interval absorption curve carries out the swarming match.For some sample, if specify two known peak positions can't obtain the matched curve that is consistent with absorption curve, then should be at 1880cm
-1Near match peak of increase, this match peak are not counted in and participate in correlated peak area corresponding to triple ADSORPTION STATE of CO.Those skilled in the art can judge the quantity and the position at match peak easily, and calculate the area at each match peak.
Among the CO absorption in-situ ft-ir figure of described catalyzer, 1870~1930cm
-1Place's bridge-type absorption peak and 1930~1990cm
-1The ratio of place's bridge-type absorption peak area limits, thereby the assurance catalyst surface has a particular types Pd site, and then has guaranteed that catalyzer has specific reaction preference.
After using nitrogen to purge, the intensity of CO infrared absorption peak weakens gradually.1870~1930cm
-1The CO bridge-type absorption absorption peak at place is with red shift to 1800 gradually~1870cm
-1Triple absorption absorption peaks and final the disappearance are changed in the place.Purge 15 minutes spectrogram 1800~1900cm
-10 minute spectrogram 1870~1930cm of place's absorption peak and purging
-1The ratio of the peak height of place's absorption peak can be used for showing the adsorption strength of CO on the Pd surface, limits this ratio and can guarantee that catalyzer has suitable adsorptive power for specific reactants, and then guarantee that catalyzer has specific reaction preference and activity.
Described catalyzer is catalytic active component with Pd, and its content is 0.01~50wt% of carrier gross weight, is preferably 0.01~10wt%, more preferably 0.03~5wt%.Pd is a kind of in simple substance attitude, oxide compound and other Pd compounds or two or more mixed state in them in the form that exists of catalyst surface.
The carrier of described catalyzer can be selected from a kind of in gac, carbon black, carbon nanotube, aluminum oxide, wilkinite, clay, diatomite, zeolite, molecular sieve, titanium oxide, magnesium oxide, silicon oxide and the polymer materials or two or more mixture in them.Special-shaped strips such as that the shape of carrier includes but not limited to is Powdered, granular, spherical, sheet, tooth are spherical, strip or trifolium.Optional 1~the 500m of the specific surface area of carrier
2/ g is preferably 50~300m
2/ g, more preferably 100~250m
2/ g.
Described catalyzer can be loading type list Pd catalyzer, also can comprise loading type Pd catalyzer modified component commonly used.Modified component is selected from Bi, Sb, Pb, In and is different from least a in group VIII element, IB group element, rare earth element, alkali metal, alkali earth metal and the haloid element of palladium, and its content is 0~20wt% of carrier gross weight.Modified component can be used as and helps active ingredient to be distributed in the specific position of carrier, and the properties-correcting agent that also can be used as carrier is uniformly distributed among the carrier.
Another object of the present invention is to provide a kind of method for preparing above-mentioned loading type Pd catalyzer.This method is characterised in that and comprises following steps: the solution that (1) uses spraying method will comprise the palladium precursor is carried on the carrier; (2) use the load of ionizing rays irradiation that the system of carrier, water and the free-radical scavengers of palladium precursor is arranged.
In preparation method of the present invention, preferably before the palladium precursor solution is loaded to carrier, use basic solution to regulate pH to 2~13 of palladium solution; Perhaps use basic solution to handle carrier before or after the supported palladium precursor, described treatment process is spraying.Wherein said basic solution includes but not limited to the aqueous solution and ammoniacal liquor such as sodium hydroxide, potassium hydroxide, sodium bicarbonate, yellow soda ash for the basic cpd aqueous solution commonly used.
In preparation method of the present invention, described ionizing rays can be selected from gamma-rays, X ray or electron beam; Gamma ray source is optional
60Co (γ source),
137Cs (γ source), x-ray source or rumbatron (electron beam), preferred
60Co, x-ray source or rumbatron, more preferably
60Co.The absorbed dose rate of the ionizing rays that described ionizing rays irradiation is used is 1~1 * 10
7Gy/min, preferred 10~10000Gy/min, more preferably 20~100Gy/min; The absorption dose of ionizing rays is 0.01~1 * 10
5KGy, preferred 5~100kGy.Described ionizing rays irradiation process can be carried out in air, inert atmosphere or vacuum, preferably carries out in inert atmosphere and vacuum; Described ionizing rays irradiation process can be carried out at various temperatures, preferably at room temperature carries out.
In preparation method of the present invention, described Pd precursor be selected from Palladous chloride, Palladous nitrate, palladium, palladous sulfate, palladous oxide and and the organometallics of palladium in a kind of.The Pd precursor is formulated as solution in advance, uses spraying method to be carried on the carrier.
When catalyzer comprises modified component, as helping active ingredient, can separately or load on the carrier simultaneously with Pd as modified component; As the properties-correcting agent of modified component, can in the preparing carriers process, add as carrier.
In preparation method of the present invention, described free-radical scavengers is selected from least a in alcohols and the formic acid, preferably at least a in methyl alcohol, ethanol, ethylene glycol, Virahol, more preferably Virahol and ethylene glycol.In by the irradiation system, the volume ratio optional 1%~99%, preferred 5%~50% of whole liquid in the volume of free-radical scavengers and the system.
In preparation method of the present invention, not needing usually has the carrier roasting at high temperature of Pd precursor to decompose load.With the oven dry after appropriate amount of deionized water is washed 1-5 time of the carrier behind the ionizing rays irradiation, also can promptly obtain catalyzer of the present invention after the oven dry without directly oven dry of washing.Oven dry can be carried out under air atmosphere or vacuum, preferably carries out under air atmosphere.Optional 50~200 ℃ of bake out temperature, preferred 50~120 ℃.Optional 5~48 hours of drying time, preferred 5~24 hours.
Load type palladium catalyst that method of the present invention is used and preparation method thereof has the following advantages:
(1) load type palladium catalyst of the present invention is a feature with CO absorption In-situ Infrared spectrogram, guarantees that catalyst surface has the Pd site of particular types; And further with purge specific absorption peak-to-peak in 15 minutes spectrograms high be changed to feature, guarantee that catalyzer has suitable adsorptive power to specific reactants.The infrared analysis feature of catalyzer is easy to quantitatively, thereby has guaranteed that catalyzer has specific reaction preference and activity.
(2) method for preparing catalyst of the present invention need not use specific Pd precursor or crystal control agent, does not need high-temperature roasting step in the traditional method can obtain having the loaded catalyst in specific Pd site yet, and is simple, saves energy consumption.The Pd that makes catalyst surface can exist with the simple substance attitude, need not reduce before use, and have higher reactivity worth under normal conditions.
Method of the present invention can be applicable to the selective removal of (comprising vinylacetylene (VA), ethylacetylene (MA) and methylacetylene (MA)) of alkynes in the cracking mixed c 4 crude butadiene cut.Because the activity of such catalysts component that the present invention adopts has specific crystal plane structure and reactivity worth, method of the present invention has high reactivity, highly selective and satisfactory stability, can long-term operation.
Embodiment
Following examples are more detailed the describing for example to catalyzer of the present invention, but the present invention is not limited to these embodiment.
Embodiment 1
Get 13.5ml 10mg/ml PdCl
2Solution after dropping 1mol/L NaOH solution transfers pH to be 5.6, is sprayed into 100.0g Al
2O
3Ball type carrier surface, the isopropanol water solution that uses 20ml 50%v/v with carrier wetting after, under vacuum state, use
60In the Co gamma emitter under room temperature irradiation 15h, absorbed dose rate is 35Gy/min.Sample places baking oven behind the irradiation, dries 12h down at 80 ℃ and 120 ℃ successively, obtains described catalyst A, and its outward appearance is a grey black, and Pd content is 0.135wt%.
Embodiment 2
Get 30ml 10mg/ml PdCl
2Solution is sprayed into the Al of 100.0g through La and K modification
2O
3Tooth ball type carrier surface sprays 5ml 1mol/L NaOH solution again, the isopropanol water solution that uses 20ml 50%v/v with carrier wetting after, under vacuum state, use
60In the Co gamma emitter under room temperature irradiation 15h, absorbed dose rate is 70Gy/min.Sample places baking oven behind the irradiation, dries 12h down at 80 ℃ and 120 ℃ successively, obtains described catalyst B, and its outward appearance is a grey, and Pd content is 0.300wt%.
Comparative Examples 1
Get 13.5ml 10mg/ml PdCl
2Solution after dropping 1mol/L NaOH solution transfers pH to be 5.6, is sprayed into 100.0g Al
2O
3The ball type carrier surface is immersed carrier in an amount of aqueous isopropanol afterwards, is placed to reduction under the room temperature fully after (the carrier color is black by xanthochromia), place baking oven to dry 12h down at 80 ℃ and 120 ℃ successively, obtain catalyzer C, its outward appearance is a grey black, and Pd content is 0.135wt%.
Comparative Examples 2
Get 13.5ml 10mg/ml PdCl
2Solution after dropping 1mol/L NaOH solution transfers pH to be 5.6, is sprayed into 100.0g Al
2O
3The ball type carrier surface places baking oven with carrier afterwards, behind oven dry 12h under 80 ℃, in 450 ℃ of roasting 8h, obtains catalyzer D under air atmosphere, and its outward appearance is a khaki color, and Pd content is 0.135wt%.
Comparative Examples 3
Get 20.0ml 10mg/ml PdCl
2Solution uses deionized water to be diluted to 100ml, uses 1mol/L NaOH solution to regulate its pH to 3.0.Get Al
2O
3Ball type carrier 100g adds PdCl
2Solution leaves standstill dipping 20min.Add Virahol 10ml afterwards in steeping fluid, the homodisperse hypsokinesis goes out excess solution, and carrier is used under vacuum
60The Co gamma emitter is irradiation 15h under room temperature, and absorbed dose rate is 35Gy/min.Sample places baking oven behind the irradiation, dries 12h down at 80 ℃ and 120 ℃ successively, obtains described catalyzer E, and its outward appearance is a grey black, and Pd content is 0.140wt%.
Use In-situ Infrared instrument (Bruker Vertex 70), according to method mentioned above embodiment and Comparative Examples are carried out the CO adsorption experiment, measure each sample at the infrared absorption spectra of nitrogen purging in the time of 0 minute, 9 minutes, 15 minutes, 24 minutes, spectrogram is shown in Fig. 1.The absorption peak that purges 0 minute spectrogram 1750~2000cm-1 place is carried out match, calculate 1930~1990cm
-1Place's bridge-type absorption peak and 1870~1930cm
-1The ratio (A2/A1) of the area of place's bridge-type absorption peak; 1870~1930cm among the in-situ ft-ir figure that the measurement nitrogen purging recorded in the time of 0 minute
-1The peak height of place's absorption peak with use 1800~1900cm among the in-situ ft-ir figure that nitrogen purging records in the time of 15 minutes instead
-1The peak height of place's absorption peak calculates its ratio (H1/H3).Calculation result is listed in the table 1.
The infrared spectra calculation result of table 1. embodiment of the invention and Comparative Examples
Calculation result shows, the A2/A1 value of embodiment of the invention A, B is less than 0.15, and the A1/A2 value of Comparative Examples C, D, E is greater than 0.20, and this explanation embodiment A, B have crystal plane structure and the ratio that is different from Comparative Examples C, D, E.The value of the H1/H3 of embodiment of the invention A, B is less than 2, and the H1/H3 value of Comparative Examples C is 93.31, and this explanation embodiment A, B have stronger adsorptive power to carbon monoxide, and Comparative Examples C is relatively poor to the adsorptive power of carbon monoxide.Infrared test is the result show, the embodiment of the invention has the crystal face that is different from Comparative Examples to be formed and stronger reactant adsorptive power, therefore will have the reactivity worth that is different from Comparative Examples.
Use ethylene unit cracking mixed c 4 cut liquid phase selective hydrogenation side line device that the catalytic performance of embodiment and comparative example is estimated.Adopt fixed-bed reactor, loaded catalyst is 200ml, reaction pressure 1MPa.Contain ethylacetylene (EA) and vinylacetylene (VA) 1.12mol% in the reactor inlet raw material, 1,3-butadiene (BD) 50.2mol%, all the other components are butane and butylene; The experiment air speed is 16h
-1Evaluation result is listed in the table 2.
The catalytic performance test result of table 2. embodiment of the invention and Comparative Examples
Sample |
T
in *(℃)
|
H
2/(EA+VA) (mol/mol)
|
BD?selectivity(%) |
?(EA+VA)conversion?(%) |
A |
40.2 |
1.34 |
33.73 |
74.11 |
B |
38.5 |
1.13 |
46.75 |
68.75 |
C |
39.8 |
1.33 |
20.63 |
56.25 |
D |
39.6 |
1.41 |
10.45 |
59.82 |
E |
40.6 |
1.45 |
11.28 |
52.66 |
*Reactor inlet temperature.
Evaluation result shows that embodiment of the invention A, B remove alkyne reaction for carbon four liquid phase selective hydrogenations and have good selectivity, and its performance obviously is better than Comparative Examples C, D, E.This explanation embodiment A, specific crystal face composition and the reactant adsorptive power of B can obviously be improved its catalytic performance.