Method for separating paraxylene by using suspension melt crystallization

A suspension melt crystallization and p-xylene technology, applied in crystallization purification/separation, organic chemical methods, organic chemistry, etc., can solve problems such as high production energy consumption, unstable operation of aging kettles, small crystal particle size, etc., and achieve product performance Reduced consumption, stable product purity and output, and improved crystal particle size

Inactive 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

[0009] The technical problem to be solved by the present invention is the problem of unstable operation of the aging kettle, small crystal particle size and high production energy consumption existing in the production of p-xylene, and a novel method for separating p-xylene by suspension melting crystallization is provided

Method used

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  • Method for separating paraxylene by using suspension melt crystallization

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Embodiment 1

[0025] The crystallization method for producing p-xylene by suspension melt crystallization of the present invention.

[0026] like figure 1Said, the raw material 1 containing p-xylene concentration of about 82% enters the raw material buffer tank A, the flow rate is 1075kg / h, and a part of the raw material 2 enters the aging kettle B, the flow rate is 645kg / h, and the temperature is 15°C. Toluene crystals 13 are mixed, beating, washing and heating aging are carried out. The operating temperature of the aging tank is 5.4°C. Part of the raw material 3 is cooled by the pre-cooler C and enters the crystallizer D for crystallization. The flow rate is 430kg / h. The final temperature is 10°C, and the operating temperature of the crystallizer is -8°C; the crystal slurry 4 in the aging kettle B is separated by the solid-liquid separator E to obtain p-xylene crystals 5 and aging mother liquor 6, and the aging mother liquor 6 is divided into two strands , the aging mother liquor 7 that ...

Embodiment 2

[0028] The method for producing p-xylene by suspension melting crystallization described in the present invention.

[0029] According to the operating condition of embodiment 1, wherein, the flow rate that raw material 2 enters in aging kettle B is 538kg / h, the flow rate that raw material 3 enters crystallizer D after being cooled by precooler C is 537kg / h, the temperature after precooling 4°C, and the results are listed in Table 1.

Embodiment 3

[0031] The method for producing p-xylene by suspension melting crystallization described in the present invention.

[0032] According to the operating condition of embodiment 1, wherein, the flow rate that raw material 2 enters in aging kettle B is 430kg / h, the flow rate that raw material 3 enters crystallizer D after being cooled by precooler C is 645kg / h, the temperature after precooling is 3.8°C, and the results are listed in Table 1.

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Abstract

The present invention relates to a method for separating paraxylene by using suspension melt crystallization. The method comprises the steps: branching raw materials, adjusting the quantity and the temperature of the raw materials entering an aging kettle to ensure that the operation in the aging kettle is stable so as to further ensure product purity and yield stabilization; and feeding part of the raw materials into a pre-cooling device for cooling, and generating part of crystals as seed crystals of a crystallizer, so that the crystal granularity in the crystallizer is increased, and further the follow-up solid-liquid separation efficiency is improved; and a technical scheme adopted in the present invention can well solve problems that the operation in the aging kettle is unstable, the crystal granularity is low, 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 present invention relates to a method for separating paraxylene by suspension melting crystallization. [0002] technical background [0003] Paraxylene (PX) is an important organic chemical raw material. It is mainly used as a raw material for the production of purified terephthalic acid (PTA) and dimethyl terephthalate (DMT). PTA is used to produce polyparaphenylene. Polyester products such as ethylene dicarboxylate (PET) and polybutylene terephthalate (PBT). In recent years, my country's polyester industry has continued to develop rapidly. Although China has become the world's largest PX producer, the domestic PX production capacity is far from meeting the market demand, and a large number of imports are required every year. In the next few years, my country's PX consumption will continue to maintain a good growth momentum, and the shortage of PX supply will continue to exist. Therefore, the current task of increasing PX production and saving en...

Claims

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Application Information

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IPC IPC(8): C07C15/08C07C7/14
CPCC07C7/14C07B2200/13C07C15/08
Inventor 宗弘元陈亮张鸿翔郭艳姿
Owner CHINA PETROLEUM & CHEM CORP
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