Preparation of magnesium metal modified low-silicon SSZ-13 molecular sieve and MTO reaction performance thereof

A molecular sieve, metal magnesium technology, applied in the direction of molecular sieve catalyst, molecular sieve and alkali exchange compounds, non-metallic elements, etc., can solve the problems of acid enhancement, molecular sieve product specific surface area decrease, crystallinity decrease, etc., to achieve low acid strength, superior MTO The effect of reactivity

Inactive Publication Date: 2017-04-05
TIANJIN POLYTECHNIC UNIV
View PDF4 Cites 1 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, with the increase of the silicon-aluminum ratio of the SSZ-13 molecular sieve, the specific surfa

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Preparation of magnesium metal modified low-silicon SSZ-13 molecular sieve and MTO reaction performance thereof
  • Preparation of magnesium metal modified low-silicon SSZ-13 molecular sieve and MTO reaction performance thereof
  • Preparation of magnesium metal modified low-silicon SSZ-13 molecular sieve and MTO reaction performance thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0044] Example 1: Preparation of Mg-SSZ-13 by Magnesium Nitrate Exchange

[0045] Preparation of lye: add 0.83g of sodium hydroxide to 18g of water, stir until the sodium hydroxide is dissolved, add 3.43g of N,N,N-trimethyladamantane ammonium hydroxide (template agent), and stir until a homogeneous solution.

[0046] Preparation of gel: Add 13.05g of silica sol to the reaction kettle, stir in a water bath at room temperature, then add lye, stir evenly, add 3.25g of aluminum sulfate, stir evenly, add 0.16g of molecular sieve of chabazite (CHA) crystal phase as crystal species, and stirred at room temperature for 4 hours to obtain a homogeneous gel.

[0047] Crystallization: Put the initial gel into a PTFE autoclave and crystallize at 165°C for 2-4 days. After the crystallization is complete, wash the product with deionized water until the filtrate is neutral, and dry at 100°C 12h.

[0048] Calcination: The dried samples were heated up to 600°C under an air atmosphere for 4 hour...

Embodiment 2

[0051] Example 2: Preparation of Mg-SSZ-13 by Magnesium Acetate Exchange

[0052] Preparation of lye: add 0.83g of sodium hydroxide to 18g of water, stir until the sodium hydroxide is dissolved, add 3.43g of N,N,N-trimethyladamantane ammonium hydroxide (template agent), and stir until a homogeneous solution.

[0053] Preparation of gel: Add 13.05g of silica sol into a beaker, stir in a water bath at room temperature, add lye, stir evenly, add 3.25g of aluminum sulfate, stir evenly, add 0.16g of chabazite (CHA) crystal phase molecular sieve as a seed crystal, and After stirring for 4 hours, a homogeneous gel was obtained.

[0054] Crystallization: Put the initial gel into a PTFE high-pressure reactor and crystallize at 165°C for 2-4 days. After the crystallization is complete, wash the product with deionized water until the filtrate is neutral, and dry at 100°C 12h.

[0055] Calcination: The dried samples were heated to 600°C for 4 hours in the air atmosphere, kept for 4 hour...

Embodiment example 3

[0057] Example 3: One-step synthesis of Mg-SSZ-13 using magnesium nitrate

[0058] Preparation of lye: add 0.83g of sodium hydroxide to 18g of water, stir until the sodium hydroxide is dissolved, add 3.43g of N,N,N-trimethyladamantane ammonium hydroxide (template agent), and stir until a homogeneous solution.

[0059] Preparation of gel: Add 13.05g of silica sol into a beaker, stir in a water bath at room temperature, then add lye, stir evenly, add 3.25g of aluminum sulfate, stir evenly, add 1.47g of magnesium nitrate, add 0.16g of chabazite (CHA) crystal Phase molecular sieves were used as seed crystals, and stirred at room temperature for 4 hours to obtain a uniform gel.

[0060] Crystallization: Put the initial gel into a PTFE high-pressure reactor and crystallize at 165°C for 2-4 days. After the crystallization is complete, wash the product with deionized water until the filtrate is neutral, and dry at 100°C 12h.

[0061] Calcination: The dried samples were heated to 600...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

No PUM Login to view more

Abstract

The invention provides a preparation method of a magnesium metal modified low-silicon molecular sieve material. The magnesium metal modified low-silicon molecular sieve material comprises 0.1-6% of magnesium (calculated by magnesium oxide), 5.36-20% of aluminum (calculated by aluminum oxide), 69-94.5% of silicon (calculated by silicon oxide) and 0.01-5% of alkali metal (calculated by oxide), and has a CHA type topological structure, and the specific surface (through the BET method) of the magnesium metal modified low-silicon molecular sieve material is no smaller than 565 m2/g after the magnesium metal modified low-silicon molecular sieve material is calcinated at 630 DEG C for 4 h. The preparation method of the magnesium metal modified low-silicon molecular sieve material comprises the steps that a template agent and a sodium hydroxide aqueous solution are added into an alkaline silica sol to be uniformly stirred, aluminum sulfate is added to be uniformly stirred, and chabasite crystalline phase seed crystal is added to be stirred at room temperature for 4 h to obtain uniform gel; and a product is obtained through crystallization, calcination and magnesium ion exchange, wherein magnesium ions can also be led in the molecular sieve synthesization process by one step. The molecular sieve material prepared through the preparation method has the advantages that the molecular sieve material is low in silicon-aluminum ratio, adjustable in acid center concentration, low in acid strength and high in MTO diolefin selectivity, and a large amount of ammonium chloride waste liquid does not exist in the preparation process.

Description

technical field [0001] The invention relates to a preparation method of metal magnesium-modified low-silicon SSZ-13 molecular sieve and its application as a methanol-to-olefin (MTO) catalyst. Background technique [0002] Methanol-to-olefins (MTO) is a new process that can replace the traditional petroleum route to produce low-carbon olefins. In recent years, with the shortage of petroleum resources, this process has attracted widespread attention from all over the world. The core of the MTO process is the catalyst problem. At present, the active component of MTO catalyst commonly used in the market is SAPO-34 molecular sieve. At the same time, the MTO properties of silico-alumina zeolite molecular sieves with the same CHA structure as SAPO-34 molecular sieves have also been intensively studied. [0003] SSZ-13 molecular sieve was invented by American Chevron (Chevron) Petroleum Company and disclosed in patent US4544538. Since the SSZ-13 molecular sieve synthesized in thi...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
IPC IPC(8): C01B39/00B01J29/85C07C11/06C07C11/04C07C1/20
CPCY02P20/52Y02P30/20Y02P30/40
Inventor 李渊王文婷赵飞
Owner TIANJIN POLYTECHNIC UNIV
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap