Method for producing paraxylene by using suspension melt crystallization

A suspension melt crystallization, para-xylene technology, applied in crystallization purification/separation, organic chemistry, etc., can solve the problems of wide particle size distribution, small average particle size, complex process, etc., and achieve wide particle size distribution and small particle size. , The effect of simplifying the process

Active Publication Date: 2017-06-13
CHINA PETROLEUM & CHEM CORP +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0007] The technical problem to be solved by the present invention is the problems of small average particle size, wide particle size distribution, complicated process and high energy consumption in the existing p-xylene crystallization production, and a novel method for producing p-xylene by suspension melting crystallization is provided method

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  • Method for producing paraxylene by using suspension melt crystallization
  • Method for producing paraxylene by using suspension melt crystallization
  • Method for producing paraxylene by using suspension melt crystallization

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Embodiment 1

[0023] The method for producing p-xylene by suspension melting crystallization described in the present invention.

[0024] Such as figure 1As mentioned above, the raw material 1 containing p-xylene concentration of 82% has a flow rate of 1075kg / h. It is precooled from 50°C to 15°C and divided into two strands. One strand of raw material 2 enters the aging kettle A with a flow rate of 645kg / h. , another stream of raw material 3 enters in the crystallizer B, and the flow rate is 430kg / h; The residence time in B is 30 minutes, and the magma 4 separates p-xylene crystal 5 and crystallization mother liquor 6 through solid-liquid separator C, and p-xylene crystal 5 enters in aging kettle A, and its average particle diameter is 350 μ m, crystal The particle size distribution range is 50 μm to 800 μm, the crystallization mother liquor 6 is divided into two streams, the first crystallization mother liquor 7 accounting for 55% by weight returns to the crystallizer, and the second crys...

Embodiment 2

[0028] The method for producing p-xylene by suspension melting crystallization described in the present invention. According to the operating conditions of Example 1, wherein, the flow rate of raw material 2 into the aging kettle A is 215kg / h, the operating temperature of the aging kettle is 5.5°C, the crystal content in the magma is 35%, and the operating temperature of the crystallizer is -8 ℃, the crystal content in the magma is 35%, and the results are listed in Table 1.

Embodiment 3

[0032] The method for producing p-xylene by suspension melting crystallization described in the present invention. The method for producing p-xylene by suspension melting crystallization described in the present invention. According to the operating conditions of Example 1, wherein, the flow rate of raw material 2 into the aging kettle A is 0kg / h, the operating temperature of the aging kettle is 4°C, the crystal content in the magma is 35%, and the operating temperature of the crystallizer is -8°C. ℃, the crystal content in the magma is 35%, and the results are listed in Table 1.

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Abstract

The present invention relates to a method for producing paraxylene by using suspension melt crystallization. In the method, a crystal aging and cooling crystallization method is adopted to separate and purify paraxylene from a raw material with the concentration of paraxylene of 70-97%; technological parameters, such as operation temperature, dwell time, and content of crystals, in an aging kettle and a crystallizer are optimized, mean grain sizes of crystals are increased, a grain size distribution interval is shortened, and further the solid-liquid separation efficiency and product purity are improved, a fine crystal recovering step is omitted, a technological process is simplified, and the energy consumption in separation is reduced. A technical scheme adopted in the present invention can well solve problems that the mean grain sizes of the crystals are small, the grain size distribution is wide, the technological process is complex, and the energy consumption in production is high in the prior art, so that the method can be used for production of paraxylene.

Description

technical field [0001] The invention relates to a method for producing p-xylene by suspension melting crystallization. [0002] technical background [0003] Paraxylene (PX) is an important organic chemical raw material, mainly used to produce purified terephthalic acid, and then produce polyethylene terephthalate (PET), and finally made into Polyester fiber (polyester), beverage bottles and various insulating packaging materials. At present, more than 30 million tons of PX are produced in the world, and most of them become the raw materials of polyester fibers. A large amount of polyester fiber is processed into clothing, which not only meets the dressing problems of more than 6 billion people in the world, but also meets people's requirements for clothing color, luster, folds, thickness, transparency, etc. my country is a major producer of polyester. Although the production capacity of PX has reached 10 million tons per year, it still cannot meet the market demand. In 201...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C7/14C07C15/08
Inventor 陈亮宗弘元张鸿翔郭艳姿王清立
Owner CHINA PETROLEUM & CHEM CORP
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