The original vacuum pump system of extraction unit is steam jet pump. This kind of vacuum pump has many advantages but many disadvantages. It is a high energy consumption equipment only from the point of view of steam consumption (400kg / h); the steam condensate becomes oily sewage, and the sewage treatment increases the cost; because the water cooling effect of the original system water cooler is not ideal, the direct recovery of hydrocarbon materials in the non condensable liquid has become a problem. In view of the above problems, the company gives instructions to carry out transformation. Aromatics workshop actively prepares the transformation plan and selects oil-free vacuum pump in the construction transformation. The practical application of oil-free vacuum pump in aromatics extraction system fundamentally solves the problems of the original vacuum system, greatly reduces the production cost and increases the company’s benefit.
In this way, chemical production has been improved in continuous transformation and summary. This paper relates to the technical field of aromatics extraction, in particular to an aromatics extraction device.
Aromatics extraction, also known as aromatics extraction, is a liquid-liquid extraction process in which aromatics are separated from hydrocarbon mixtures by an extractant. It is mainly used to recover light aromatics (benzene, toluene, various xylenes) from catalytic reforming and hydrocarbon cracking steam. Sometimes it is also used to recover naphthalene from catalytic cracking diesel oil. The non aromatics remaining after aromatics extraction is called raffinate oil. Aromatic hydrocarbon is called “arene” for short, usually refers to the hydrocarbon with benzene ring structure in the molecule.
In terms of energy saving, compared with oil-free vacuum pump, oil-free vacuum pump saves a lot of costs in the year of steam and power consumption. In terms of environmental protection and emission reduction, the amount of sewage discharge before and after the transformation has been greatly reduced, and the sewage delivery system has been reduced from one delivery every two days to one delivery every week. In the aspect of material recovery, the raw material can only be returned to the raw material system through the cooling of the vent system for the use of raw materials. After the transformation, the raw material can be directly returned through the liquid separation tank and separated into qualified products through the benzene tower, thus reducing the production load of the former system.
There are two other benefits:
1. Stable tower pressure, stable operation and improved product quality rate. Tower pressure is greatly affected by environmental temperature, wind and other external factors. In the previous operation, it was realized by adjusting the opening of louver of air cooler on the top of the tower. Manual operation by personnel not only takes time and effort, but also has slow regulation lag of regulation speed, and the effect is not obvious, which affects the quality and production operation to a certain extent The work is smooth. After the oil-free vacuum pump is put into use, it not only reduces human and material resources, but also improves the flexibility of benzene tower operation, makes the operation more stable, and greatly improves the rate of superior products.
2. Improve the environment, recycle and discharge aromatic hydrocarbon oil, improve the environmental quality and economic benefits
The original design of benzene tower, toluene tower reflux tank and backwash tank directly empties the atmosphere. Aromatic hydrocarbon steam causes great harm to human body, seriously affects the physical and mental health of employees, pollutes the environment and affects the environmental indicators. After the oil-free vacuum pump is put into use, it not only protects the physical and mental health of employees, but also improves economic benefits.
The practical application of oil-free vacuum pump in aromatics extraction system makes only the uncooled oil and gas can be vented and drained, improves the recovery rate of oil products, reduces the pollution degree to the environment, and is convenient for disassembly and assembly, so it is convenient for cleaning and replacement, simple in structure and convenient in use.