1、“乙烯Bayer法”制备醋酸乙烯酯的工艺研究

展开更多 运用Aspen Plus软件完成醋酸乙烯酯的全流程工艺设计,通过优化得到纯度97.4%的产品,同时结合Aspen Energy Analyzer软件对过程进行了热集成分析,使能量最优化,充分合理利用能量,符合绿色环保理念。 方案运用低温SCOT工艺转化吸收技术、多次循环反应,实现原料的回收利用。 研究结果表明:设计的塔器、反应器校核合格,同时排放严格达标。 收起. 基金 池州学院科研项目 (CZ2019ZR01) 池州学院质量工程项目 (2018XMOOC03) 池州学院思政示范课程 (2019XKCSZ17) 安徽省质量工程项目 (2018jyxm0295)。

2、Theoretical study on the synthesis of vinyl acetate from acetylene and

In this study, we used density functional theory (DFT) to calculate the feasibility of preparing vinyl acetate (VAc) on four CN non-metallic materials (C 2 N, C 3 N, C 4 N and C 5 N) under the reaction conditions of 1 atm, 393.15–493.15 K at B3LYP/6-31G (d, p) level.

3、Vinyl Acetate Application and Preparation in China: Industry Uses

Discover expert insights on the application and preparation of vinyl acetate, including industrial uses, synthesis methods, safety guidelines, and market trends in China.

Vinyl acetate synthesis

Almost all vinyl acetate now is produced via the vapor-phase reaction of ethylene and acetic acid over a noble-metal catalyst, usually palladium. The reaction is typically carried out at 175–200 ºC and 5–9 bar pressure.

(PDF) Optimization of Vinyl Acetate Synthesis Process

Using the developed nano-catalyst, the kinetic laws of vinyl acetate synthesis were studied, the material balance of the process was calculated, and an improved technological scheme for the ...

Preparation Methods of Vinyl Acetate

1、methods of preparation of VINYL ACETATE In summary, the methods of preparation of vinyl acetate have evolved significantly over the years, with the ethylene route being the most efficient and commonly used in modern industry.

Vinyl acetate production methods and production process, what are the

In this article, we will introduce in detail the production methods and production process of vinyl acetate, what are the common raw materials, and understand the raw materials involved in the various manufacturing methods of vinyl acetate.

Preparation and Properties of Poly(vinyl acetate) Adhesive Modified

The modified structure of poly (vinyl acetate) was examined using infrared spectroscopy (IR), and the effect of the vinyl versatate content on the particle size, viscosity, mechanical properties, and T-peel strength of the modified poly (vinyl acetate) adhesive is discussed.

Preparation and properties of polyvinyl acetate using room temperature

In this paper, polyvinyl acetates (PVAcs) were prepared by free radical emulsion polymerisation at room temperature in the presence of persulphate and commercially available reducing agent monomer of 2- (dimethyl amino)ethyl methacrylate (DMAEMA).

Clean Production Technology for the Preparation of Vinyl Acetate by

In order to develop a clean production technology for the preparation of vinyl acetate by gas-phase oxidation of ethylene, a simulation process with an annual output 100 kt/a of vinyl...

In numerous fields of the chemical industry, organic synthesis reactions are key processes for achieving new materials, pharmaceuticals, and high-performance materials. Among these, the preparation of vinyl acetate is a fundamental and important chemical reaction. This article will elaborate on the preparation process of vinyl acetate, from the selection of raw materials to the control of reaction conditions, as well as the purification and analysis methods of the product, aiming to provide comprehensive guidance for researchers in related fields.

I. Introduction and Properties of Vinyl Acetate

Vinyl acetate is a colorless liquid with a distinctive aromatic odor. It is produced by the addition polymerization reaction of ethylene and acetic acid. As an important organic chemical raw material, vinyl acetate is widely used in industries such as plastics, rubber, coatings, and adhesives. Additionally, it can be used as a solvent, plasticizer, and for the manufacture of certain specialty chemicals.

II. Raw Materials for Preparing Vinyl Acetate

The preparation of vinyl acetate typically requires the following raw materials:

1. Ethylene (C₂H₄): Ethylene is the main raw material for preparing vinyl acetate, which can be obtained through petroleum cracking or the conversion of ethane in natural gas. Ethylene is the simplest unsaturated hydrocarbon, containing a double bond in its molecule, allowing it to undergo addition reactions with other compounds.

2. Acetic Acid (CH₃COOH): Acetic acid is an organic acid that can be extracted from vinegar or acetate salts or synthesized. It has high solubility in water and strong acidity, making it suitable as a reaction medium.

3. Catalyst: The role of the catalyst is crucial in the preparation of vinyl acetate. Common catalysts include sulfuric acid, hydrogen peroxide, and peroxyacetic acid. These catalysts can accelerate the reaction rate between ethylene and acetic acid, improving yield.

III. Chemical Reactions for Preparing Vinyl Acetate

The preparation of vinyl acetate is primarily achieved through the addition polymerization reaction of ethylene and acetic acid. This reaction is a typical free radical polymerization, with the following steps:

1. Initiation Stage: Ethylene gas is first introduced into a solution containing a certain amount of acetic acid. An initiator, such as sulfuric acid, hydrogen peroxide, or peroxyacetic acid, is added to initiate the reaction between ethylene and acetic acid. These initiators provide sufficient energy to start the free radical chain reaction.

2. Propagation Stage: After initiation, ethylene radicals collide and combine with acetic acid radicals, generating new radicals. These new radicals continue to react with more ethylene and acetic acid molecules, forming long-chain polymers. As the reaction proceeds, the polymer gradually grows until it reaches a certain molecular weight.

3. Termination Stage: To control the molecular weight and quality of the polymer, a terminating agent is often added. Common terminating agents include alcohols such as methanol or ethanol. These agents combine with radicals, interrupting the chain reaction and stopping the reaction under specific conditions.

IV. Condition Control for Preparing Vinyl Acetate

Precise control of reaction conditions is critical for preparing vinyl acetate. Key conditions include:

1. Temperature: Temperature significantly affects reaction rate and polymer quality. Generally, the reaction temperature should be controlled within an appropriate range. Excessive temperatures may lead to side reactions, reducing yield; low temperatures may slow the reaction rate, prolonging the process.

2. Pressure: Pressure also impacts the reaction rate between ethylene and acetic acid. Higher pressure increases contact between reactants, improving reaction rates; excessive pressure may cause side reactions, affecting product quality.

3. Catalyst Dosage: Catallyst dosage greatly influences the reaction. Excessive catalyst may promote side reactions, reducing yield; insufficient catalyst may fail to effectively initiate the reaction, leading to low yields. Selecting the appropriate catalyst dosage is a critical step in preparing vinyl acetate.

4. Reaction Time: Controlling reaction time is essential for ensuring product quality and yield. Short reaction times may result in low molecular weight polymers, affecting performance; prolonged reaction times may induce side reactions, reducing yield. reaction time should be optimized to ensure complete reaction while avoiding overprocessing.

V. Purification and Analysis of Vinyl Acetate

Prepared vinyl acetate must be purified to improve purity and quality. Common purification methods include distillation, crystallization, and extraction:

1. Distillation: Distillation is a widely used method for separating and purifying organic compounds. By heating the mixture to its boiling point and exploiting differences in boiling points, impurities such as unreacted monomers, low-molecular-weight polymers, and contaminants can be removed.

2. Crystallization: Under certain conditions, vinyl acetate can crystallize from solution. This method is suitable for producing high-purity vinyl acetate.

3. Extraction: Extraction, based on the principle of "like dissolves like," transfers vinyl acetate from the aqueous phase to an organic phase. Common extractants include hexane or benzene.

Advanced analytical techniques such as chromatography and mass spectrometry can also be used for quantitative and qualitative analysis of vinyl acetate. These methods provide comprehensive information to help researchers better understand the properties and structure of the product.

The preparation of vinyl acetate involves multiple steps, from raw material selection and reaction condition control to product purification and analysis. Each step significantly impacts the final product quality. Through precise control of reaction conditions and effective purification methods, the yield and purity of vinyl acetate can be improved to meet diverse application requirements. In the future, advancements in technology and the development of new catalysts will make the preparation process of vinyl acetate more efficient, environmentally friendly, and economical.