CN102527424A - After-treatment technology of Beckmann gas-phase rearrangement S-1 full-silica molecular sieve based catalyst - Google Patents
After-treatment technology of Beckmann gas-phase rearrangement S-1 full-silica molecular sieve based catalyst Download PDFInfo
- Publication number
- CN102527424A CN102527424A CN2011104600434A CN201110460043A CN102527424A CN 102527424 A CN102527424 A CN 102527424A CN 2011104600434 A CN2011104600434 A CN 2011104600434A CN 201110460043 A CN201110460043 A CN 201110460043A CN 102527424 A CN102527424 A CN 102527424A
- Authority
- CN
- China
- Prior art keywords
- molecular sieve
- total silicon
- silicon molecular
- acid
- hydrofluoric acid
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Landscapes
- Catalysts (AREA)
Abstract
The invention discloses an after-treatment technology of a Beckmann gas-phase rearrangement S-1 full-silica molecular sieve based catalyst, which comprises the following steps of: preparing a mixed solution of strong acid with a certain concentration and hydrofluoric acid in proportion, weighing a certain mass of S-1 full-silica molecular sieve based catalyst and putting into a reactor, measuring out the prepared mixed solution of strong acid and hydrofluoric acid based on the mass of the catalyst and pouring into the reactor, starting stirring, maintaining a certain rotation speed, stopping stirring after reacting for a period of time at room temperature, and washing by using de-ionized water to be neutral. According to the invention, By changing the formula of an S-1 full-silica molecular sieve after-treatment solution and using the mixed solution of strong acid and hydrofluoric acid as an after-treatment solution, the after treatment is carried out at room temperature dropping from about 100 DEG C in conventional processes, the problem that the material of a heat exchanger must be made of an expensive Monel metal due to strong corrosivity of the hydrofluoric acid in the conventional after-treatment process is solved, and equipment cost is substantially saved.
Description
Technical field
The invention belongs to the Preparation of Catalyst field, relate to S-1 total silicon molecular sieve post-treatment new process in a kind of Beckman vapour phase rearrangement synthesis of caprolactam, in particular, relate to a kind of low-cost processes S-1 total silicon molecular sieve technology.
Background technology
Caprolactam is a kind of important chemical material, is the monomer of synthetic nylon 6 and engineering plastics.The process route of synthesis of caprolactam mainly contains two kinds of liquid and gas Beckmann rearrangements at present.On commercial production, mainly be at present with sulfuric acid catalysis liquid phase rearrangement technology.This technology be cyclohexanone oxime under the concentrated sulfuric acid or oleum effect in uniform temperature generation Beckmann rearrangement, utilize the acid caprolactam that generates of ammonia neutralization reaction system then.This technology comparatively maturation, reaction condition mitigation, feed stock conversion and selectivity of product is all higher, but also has a lot of shortcomings.At first the concentrated sulfuric acid is understood etching apparatus, understands discharge harmful in the production process, does not meet the idea of development of environmental protection; Simultaneously also can by-product a large amount of cheap ammonium sulfate (data show 1 ton of caprolactam of every production can by-product about 2 tons ammonium sulfate), economic benefit is relatively poor.Therefore, to increase economic efficiency and environmental benefit is the important directions that the novel caprolactam synthesis technique of purpose becomes recent research.Though since the last century the eighties, people have reduced the use of sulfuric acid and the generation of ammonium sulfate through changing reactor types with process conditions, owing to the problem of sulfuric acid use generation is solved always at all.
In order to address the above problem, it is the gas phase beckmann rearrangement production technology of catalyst that people begin one's study with the solid acid.This technology can be avoided the use of sulfuric acid fully, and the developing direction while production cost that therefore meets very much low-carbon environment-friendly also is expected to be reduced.Solid acid catalyst commonly used mainly contains two types in oxide and molecular sieve.Wherein USP5914398, USP3586668, USP5942613, USP4717769, USP4709024, Appl.Catal., 1999,188:361, J.Catal.; 1994,148 (1): 138, Catal.Lett., 1998; 49 (3-4): relevant reports such as 229 show that the oxide catalyst life-span is shorter; Cyclohexanone oxime conversion ratio and caprolactam selectivity are not high, and regeneration effect is bad, still do not have industrial value.For example, among the USP5914398 with amorphous little mesopore SiO
2-Al
2O
3Be catalyst, at cyclohexanone oxime weight space velocity (WHSV)=2.2h
-1Down, react after 23 hours, the cyclohexanone oxime conversion ratio reduces to 97.9%, and the caprolactam selectivity is merely 81.4%.People are the reaction effect of catalyst in research with the molecular sieve also in addition.For example, J.Catal., 1992,137:252 is a catalyst with S-1 total silicon molecular sieve, and the life-span, the cyclohexanone oxime conversion ratio was 90% less than 30h, and the caprolactam selectivity is 81%.The easy inactivation of catalyst in the above-mentioned research, and the caprolactam selectivity is not high.
Research shows, S-1 total silicon molecular sieve catalyst is carried out appropriate postprocessing can significantly improve its reactivity worth.For example, Chinese J.Chem., 2005,26 (5): 417 have reported NH
3-HNO
3Mixed solution can obviously prolong the deactivation rate of S-1 molecular sieve; And Chinese J.Chem., 2006,27 (3): the selectivity of discovering S-1 total silicon molecular sieve caprolactam after 0.04% hydrofluoric acid treatment in 245 significantly improves; USP5403801 has then reported the S-1 total silicon molecular sieve of handling through inorganic alkali solution, at WHSV=8h
-1, reaction 6.25h cyclohexanone oxime conversion ratio is 99.5%, the caprolactam selectivity is 96.5%; Feeding the saturated air that contains methyl alcohol then regenerated 23 hours; After 30 times, the cyclohexanone oxime conversion ratio is 95.3% under the same reaction conditions repeatedly, and the caprolactam selectivity is 95.3%;
But the condition of in the above-mentioned research S-1 total silicon molecular sieve being carried out the hydrofluoric acid post processing is generally about 100 ℃, need heat hydrofluoric acid solution and will reach this temperature.As everyone knows, hydrofluoric acid has very strong corrosivity, and therefore alternative heat exchanger material is very limited, and monel metal becomes first-selection with its good anti-corrosion usually.But monel metal is very expensive, and its price is up to 1 kilogram in hundreds of unit, is that the heat exchanger cost of material is high with this alloy therefore, how can address this problem the direction that becomes our research.
Summary of the invention
For the problems of the prior art; The invention provides a kind of Beckman vapour phase rearrangement S-1 total silicon molecular sieve catalyst aftertreatment technology; The hydrofluoric acid high temperature corrosion is strong in the solution prior art, and heat exchanger material range of choice is little, uses the high problem of expensive monel metal heat exchanger cost.
The present invention realizes through following technical scheme:
A kind of Beckman vapour phase rearrangement S-1 total silicon molecular sieve catalyst aftertreatment technology comprises the steps:
1) preparation of S-1 total silicon molecular sieve aftertreatment fluid
A kind of strong acid is added deionized water be diluted to H
+Concentration is 0.01-0.1mol/l, and hydrofluoric acid is added deionized water, and to be diluted to mass fraction be 0.01-0.2%, and it is subsequent use then these two kinds of solution to be mixed the back with volume ratio 1: 1-3;
Said strong acid is a kind of in hydrochloric acid, sulfuric acid, the nitric acid.
Said strong acid dilution back H
+Concentration is 0.02-0.06mol/l.
Said hydrofluoric acid mass fraction is 0.02-0.16%.
2) S-1 total silicon molecular sieve aftertreatment technology
Take by weighing 40-100g S-1 total silicon molecular sieve catalyst and put into the reactor of polytetrafluoroethylene (PTFE) or polypropylene material; Measuring the strong acid for preparing and the mixed solution 200-1000ml of hydrofluoric acid pours in the reactor; Open and stir; Rotating speed is 50-100r/min, stops to stir behind the reaction 2-6h down in room temperature condition, is washed till neutrality with deionized water; This process is carried out 3 times repeatedly, after reaction is accomplished, with the oven dry of S-1 total silicon molecular sieve, with 500-650 ℃ of following roasting 3-6h, get final product S-1 total silicon molecular sieve catalyst product.
Described room temperature condition is 25 ℃.
How to prepare S-1 total silicon molecular sieve and do not belong to claim scope of the present invention.Content involved in the present invention is to be directed against S-1 total silicon molecular sieve post processing category treatment technology different from the past to reach the purpose of at ambient temperature S-1 total silicon molecular sieve being carried out post processing.More particularly, the temperature conditions that utilizes hydrofluoric acid containing solution to carry out post processing to S-1 total silicon molecular sieve in the past is about 100 ℃, and this has just caused chooses difficulty to the heat exchanger material in the hydrofluoric acid solution heating process.The present invention has improved the prescription of S-1 total silicon molecular sieve post-treatment solution through research, and last handling process can be carried out at ambient temperature, need not it is heated, and therefore obviously provides cost savings.
The post-processing approach advantage of S-1 total silicon molecular sieve of the present invention is:
1) the present invention is through improving the prescription of S-1 total silicon molecular sieve post-treatment solution, and the mixed solution that uses strong acid and hydrofluoric acid is as aftertreatment fluid, feasible its post-processing temperature is reduced under the room temperature condition and can carries out by about 100 ℃ in the technology in the past.The present invention has fundamentally solved in the past in the aftertreatment technology because the severe corrosive of hydrofluoric acid, and the heat exchanger material must be selected the problem of expensive monel metal for use, saved equipment cost significantly.
2) since among the present invention post-processing temperature be room temperature condition, therefore significantly reduced in the aftertreatment technology the consumption of energy, meet the developing direction of national energy-saving and emission-reduction.
The specific embodiment
Below in conjunction with specific embodiment the present invention is further described.In following embodiment and comparative example, evaluating catalyst adopts following method:
Get and put into reactor formation beds, inflated with nitrogen after 0.5g S-1 total silicon molecular sieve and 5g quartz sand mix; Being warming up to 550 ℃ of reaction 4h, being cooled to 340 ℃, with measuring pump the cyclohexanone oxime methanol solution of mass fraction 40% is injected said beds, is 4h at the cyclohexanone oxime mass space velocity
-1Under carry out vapor phase beckmann rearrangement reaction and promptly get caprolactam, keep reaction 40h, every 10h is to product sample analysis 1 time.
Following example has comprised the comparative example of embodiment and embodiment.Wherein embodiment is the evaluation result of the S-1 total silicon molecular sieve catalyst of preparation under the catalyst post-treatment condition in claim scope of the present invention that carries out in order to prove validity of the present invention; Comparative example is the S-1 total silicon molecular sieve catalyst that adopts existing aftertreatment technology preparation.
Embodiment 1:
Hydrochloric acid is added deionized water, and to be diluted to H+ concentration be 0.02mol/l, and hydrofluoric acid is added deionized water, and to be diluted to mass fraction be 0.02%, and it is subsequent use then these two kinds of solution to be mixed the back with volume ratio at 1: 3.
Take by weighing 40g S-1 total silicon molecular sieve catalyst and put into the reactor of polytetrafluoroethylene (PTFE) or polypropylene material; Measuring the strong acid for preparing and the mixed solution 200ml of hydrofluoric acid pours in the reactor; Open and stir; Rotating speed is 50r/min, stops to stir behind the reaction 2h down in room temperature condition, is washed till neutrality with deionized water.This process is carried out 3 times repeatedly.After reaction is accomplished, with the oven dry of S-1 total silicon molecular sieve, in 500 ℃ of following roasting 3h, get final product S-1 total silicon molecular sieve catalyst product.
The evaluating catalyst result of S-1 total silicon molecular sieve gas phase beckmann rearrangement synthesis of caprolactam sees table 1.
Embodiment 2:
Sulfuric acid is added deionized water be diluted to H
+Concentration is 0.03mol/l, and hydrofluoric acid is added deionized water, and to be diluted to mass fraction be 0.06%, and it is subsequent use then these two kinds of solution to be mixed the back with volume ratio at 1: 2.
Take by weighing 60g S-1 total silicon molecular sieve catalyst and put into the reactor of polytetrafluoroethylene (PTFE) or polypropylene material; Measuring the strong acid for preparing and the mixed solution 400ml of hydrofluoric acid pours in the reactor; Open and stir; Rotating speed is 80r/min, stops to stir behind the reaction 3h down in room temperature condition, is washed till neutrality with deionized water.Then under the same conditions, this reaction is carried out 3 times repeatedly.After reaction is accomplished, with the oven dry of S-1 total silicon molecular sieve, in 550 ℃ of following roasting 4h, get final product S-1 total silicon molecular sieve catalyst product.
The evaluating catalyst result of S-1 total silicon molecular sieve gas phase beckmann rearrangement synthesis of caprolactam sees table 1.
Embodiment 3:
Hydrochloric acid is added deionized water be diluted to H
+Concentration is 0.05mol/l, and hydrofluoric acid is added deionized water, and to be diluted to mass fraction be 0.1%, and it is subsequent use then these two kinds of solution to be mixed the back with volume ratio at 1: 1.
Take by weighing 80g S-1 total silicon molecular sieve catalyst and put into the reactor of polytetrafluoroethylene (PTFE) or polypropylene material; Measuring the strong acid for preparing and the mixed solution 800ml of hydrofluoric acid pours in the reactor; Open and stir; Rotating speed is 100r/min, stops to stir behind the reaction 4h down in room temperature condition, is washed till neutrality with deionized water.This process is carried out 3 times repeatedly.After reaction is accomplished, with the oven dry of S-1 total silicon molecular sieve, in 600 ℃ of following roasting 5h, get final product S-1 total silicon molecular sieve catalyst product.
The evaluating catalyst result of S-1 total silicon molecular sieve gas phase beckmann rearrangement synthesis of caprolactam sees table 1.
Embodiment 4:
Nitric acid is added deionized water, and to be diluted to H+ concentration be 0.06mol/l, and hydrofluoric acid is added deionized water, and to be diluted to mass fraction be 0.16%, and it is subsequent use then these two kinds of solution to be mixed the back with volume ratio at 1: 1.
Take by weighing 100g S-1 total silicon molecular sieve catalyst and put into the reactor of polytetrafluoroethylene (PTFE) or polypropylene material; Measuring the strong acid for preparing and the mixed solution 1000ml of hydrofluoric acid pours in the reactor; Open and stir; Rotating speed is 100r/min, stops to stir behind the reaction 6h down in room temperature condition, is washed till neutrality with deionized water.This process is carried out 3 times repeatedly.After reaction is accomplished, with the oven dry of S-1 total silicon molecular sieve, in 650 ℃ of following roasting 6h, get final product S-1 total silicon molecular sieve catalyst product.
The evaluating catalyst result of S-1 total silicon molecular sieve gas phase beckmann rearrangement synthesis of caprolactam sees table 1.
Embodiment 5:
Nitric acid is added deionized water be diluted to H
+Concentration is 0.02mol/l, and hydrofluoric acid is added deionized water, and to be diluted to mass fraction be 0.04%, and it is subsequent use then these two kinds of solution to be mixed the back with volume ratio at 1: 2.
Take by weighing 70g S-1 total silicon molecular sieve catalyst and put into the reactor of polytetrafluoroethylene (PTFE) or polypropylene material; Measuring the strong acid for preparing and the mixed solution 900ml of hydrofluoric acid pours in the reactor; Open and stir; Rotating speed is 90r/min, stops to stir behind the reaction 4h down in room temperature condition, is washed till neutrality with deionized water.This process is carried out 3 times repeatedly.After reaction is accomplished, with the oven dry of S-1 total silicon molecular sieve, in 550 ℃ of following roasting 5h, get final product S-1 total silicon molecular sieve catalyst product.
The evaluating catalyst result of S-1 total silicon molecular sieve gas phase beckmann rearrangement synthesis of caprolactam sees table 1.
Comparative example:
Take by weighing 40g S-1 total silicon molecular sieve catalyst and put into reactor, add the hydrofluoric acid solution of 600ml mass fraction 0.06%, open and stir; Rotating speed is 50r/min; Speed with 6 ℃/min is warming up to 100 ℃, keeps to stop behind the 2h stirring, and is washed till neutrality with deionized water.This process is carried out 3 times repeatedly.After reaction is accomplished, with the oven dry of S-1 total silicon molecular sieve, in 500 ℃ of following roasting 3h, get final product S-1 total silicon molecular sieve catalyst product.
The evaluating catalyst result of S-1 total silicon molecular sieve gas phase beckmann rearrangement synthesis of caprolactam sees table 1.
The present invention can realize post processing under the room temperature condition of S-1 total silicon molecular sieve, thoroughly solves in the post-treatment solution owing to contain the etching problem that hydrofluoric acid brings.The embodiment that the invention is not restricted in the literary composition to be mentioned; The foregoing description only is used to prove applicability, not deviating from the essence that the present invention is disclosed and describe, does not exceed under the situation of claim scope; Can select corresponding post-treatment condition according to the disclosed content of specification.
Claims (5)
1. a Beckman vapour phase rearrangement S-1 total silicon molecular sieve catalyst aftertreatment technology is characterized in that comprising the steps:
1) preparation of S-1 total silicon molecular sieve aftertreatment fluid
A kind of strong acid is added deionized water, and to be diluted to H+ concentration be 0.01-0.1mol/l, and hydrofluoric acid is added deionized water, and to be diluted to mass fraction be 0.01-0.2%, and it is subsequent use then these two kinds of solution to be mixed the back with volume ratio 1: 1-3;
2) S-1 total silicon molecular sieve aftertreatment technology
Take by weighing 40-100g S-1 total silicon molecular sieve catalyst and put into the reactor of polytetrafluoroethylene (PTFE) or polypropylene material; Measuring the strong acid for preparing and the mixed solution 200-1000ml of hydrofluoric acid pours in the reactor; Open and stir; Rotating speed is 50-100r/min, stops to stir behind the reaction 2-6h down in room temperature condition, is washed till neutrality with deionized water; This process is carried out 3 times repeatedly, after reaction is accomplished, with the oven dry of S-1 total silicon molecular sieve, with 500-650 ℃ of following roasting 3-6h, get final product S-1 total silicon molecular sieve catalyst product.
2. S-1 total silicon molecular sieve catalyst aftertreatment technology according to claim 1 is characterized in that said strong acid is a kind of in hydrochloric acid, sulfuric acid, the nitric acid.
3. S-1 total silicon molecular sieve catalyst aftertreatment technology according to claim 1 is characterized in that said strong acid dilution back H+ concentration is 0.02-0.06mol/l.
4. S-1 total silicon molecular sieve catalyst aftertreatment technology according to claim 1 is characterized in that said hydrofluoric acid mass fraction is 0.02-0.16%.
5. S-1 total silicon molecular sieve catalyst aftertreatment technology according to claim 1 is characterized in that described room temperature condition is 25 ℃.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201110460043 CN102527424B (en) | 2011-12-31 | 2011-12-31 | After-treatment technology of Beckmann gas-phase rearrangement S-1 full-silica molecular sieve based catalyst |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201110460043 CN102527424B (en) | 2011-12-31 | 2011-12-31 | After-treatment technology of Beckmann gas-phase rearrangement S-1 full-silica molecular sieve based catalyst |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN102527424A true CN102527424A (en) | 2012-07-04 |
| CN102527424B CN102527424B (en) | 2013-08-14 |
Family
ID=46336171
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 201110460043 Active CN102527424B (en) | 2011-12-31 | 2011-12-31 | After-treatment technology of Beckmann gas-phase rearrangement S-1 full-silica molecular sieve based catalyst |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN102527424B (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104310413A (en) * | 2014-10-21 | 2015-01-28 | 太原理工大学 | Preparation method and application of thin-layer nano flaky total-silicon molecular sieve for preparing caprolactam |
| CN108080027A (en) * | 2017-12-23 | 2018-05-29 | 中国天辰工程有限公司 | A kind of resin catalyst treatment process of liquid phase Beckmann rearrangement caprolactam |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4359587A (en) * | 1980-09-22 | 1982-11-16 | Mirkhasil Abdurakhmanov | Method for preparing carbonyl compounds |
| CN102120589A (en) * | 2010-12-30 | 2011-07-13 | 中国天辰工程有限公司 | S-1 full-silicon molecular sieve and preparation method thereof as well as application of S-1 full-silicon molecular sieve in caprolactam preparation |
-
2011
- 2011-12-31 CN CN 201110460043 patent/CN102527424B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4359587A (en) * | 1980-09-22 | 1982-11-16 | Mirkhasil Abdurakhmanov | Method for preparing carbonyl compounds |
| CN102120589A (en) * | 2010-12-30 | 2011-07-13 | 中国天辰工程有限公司 | S-1 full-silicon molecular sieve and preparation method thereof as well as application of S-1 full-silicon molecular sieve in caprolactam preparation |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104310413A (en) * | 2014-10-21 | 2015-01-28 | 太原理工大学 | Preparation method and application of thin-layer nano flaky total-silicon molecular sieve for preparing caprolactam |
| CN104310413B (en) * | 2014-10-21 | 2016-04-06 | 太原理工大学 | A kind of preparation method and application preparing the thin layer nano-sheet silica zeolite of hexanolactam |
| CN108080027A (en) * | 2017-12-23 | 2018-05-29 | 中国天辰工程有限公司 | A kind of resin catalyst treatment process of liquid phase Beckmann rearrangement caprolactam |
| CN108080027B (en) * | 2017-12-23 | 2021-05-28 | 中国天辰工程有限公司 | Resin catalyst treatment process for preparing caprolactam through liquid phase Beckmann rearrangement |
Also Published As
| Publication number | Publication date |
|---|---|
| CN102527424B (en) | 2013-08-14 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN103159191B (en) | A kind of preparation method of hydroxylammonium salt | |
| CN102120589B (en) | S-1 full-silicon molecular sieve and preparation method thereof as well as application of S-1 full-silicon molecular sieve in caprolactam preparation | |
| CN102260174B (en) | Application of solid acid catalyst in preparation of 2,5-dichloronitrobenzene | |
| CN111704145A (en) | Method for in-situ synthesis of nano hydrogen type Cu-SSZ-13 molecular sieve | |
| CN102070530A (en) | N-alkylamino-2-perfluoroalkylimidazoline quaternary ammonium salt and preparation method thereof | |
| CN112495362B (en) | Catalyst suitable for preparing nitrile by intramolecular dehydration of primary amide compound and preparation method and application thereof | |
| CN101891681A (en) | Novel Beckmann rearrangement method for preparing caprolactam from cyclohexanone oxime | |
| CN102527424B (en) | After-treatment technology of Beckmann gas-phase rearrangement S-1 full-silica molecular sieve based catalyst | |
| CN111875504B (en) | Cyclohexyl diamine ionic liquid and application thereof in sulfur dioxide absorption | |
| CN103787963A (en) | Efficient preparation of 4-dimethylaminopyridine | |
| CN107262140B (en) | 2, 6-dimethylnaphthalene catalyst prepared from 2-methylnaphthalene, preparation and application thereof | |
| CN103396286B (en) | With the method that sodium-chlor and low-concentration ethanol are raw material production monochloroethane | |
| CN102887530B (en) | Production technique of potassium fluoride | |
| CN104529822B (en) | A kind of citronellal prepares the production technology of 3,7-Dimethyl-6-octenenitrile | |
| CN105879904A (en) | Preparation method of SCR catalyst | |
| CN102558060A (en) | Process for preparing imidazolidine | |
| CN108080027B (en) | Resin catalyst treatment process for preparing caprolactam through liquid phase Beckmann rearrangement | |
| CN101671303B (en) | Process for directly synthesizing caprolactam by using cyclohexanone | |
| CN102228833B (en) | Cobalt-containing porous material and application thereof in preparation of phenol through benzene hydroxylation | |
| CN113603602A (en) | Method for preparing beta-aminopropionic acid with high selectivity | |
| CN101891581B (en) | Method for recovering styrene and other aromatic hydrocarbon raw materials by catalyzing and cracking waste polystyrene | |
| CN103408434B (en) | Method for synthesizing aniline by directly oxidizing and aminating benzene by one step | |
| CN103285905A (en) | Overall structure catalyst, preparation method of overall structure catalyst, and method for preparing caprolactam | |
| CN102399173B (en) | Method for preparing biurea | |
| CN106242947A (en) | A kind of method utilizing cerium modified zirconium-silicon molecular sieve catalyst to prepare dichlorohydrin |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant |