Large-scale methanol multi-effect energy-saving rectifying device and process

Abstract

The invention relates to large-scale methanol multi-effect energy-saving rectifying device and process. Main equipment used in the process sequentially comprises a pre-rectifying tower, a second rectifying tower, a pressurizing tower, an atmospheric tower and a recovering tower, wherein the tops of the second rectifying tower, the pressurizing tower and the atmospheric tower are respectively usedfor discharging refined methanol, the top of the recovering tower is used for discharging fusel oil, and the bottom is used for discharging purified wastewater. Because one rectifying tower is additionally arranged, and the process parameter of each tower is adjusted, two methanol multi-effect energy-saving rectifying processes by five towers are obtained, the effective energy loss is reduced, thereby energy consumption is reduced. In addition, the diameter of each tower is reduced, the amplification effect of relevant equipment, caused by the oversize diameter of each tower, is greatly reduced. The process has the advantages of reasonable design, the energy is fully and reasonably utilized in the process, the energy consumption of the whole device used in the process is reduced by 20%-30% higher than that of the device used in the traditional double-effect process, and the purity of a product reaches the American AA-level standard.

Description

technical field [0001] The invention relates to the technical field of rectification, in particular to multi-effect rectification energy-saving equipment and a scale optimization process in the process of enlarging a methanol plant. Background technique [0002] Methanol is the basic organic chemical raw material and high-quality fuel. It has a wide range of uses and is mainly used in the fields of fine chemicals, plastics, pesticides and medicine. Methanol can also be used as a new type of clean fuel after deep processing. [0003] In order to obtain high-purity and high-quality methanol products, methanol rectification has become an important post-treatment process for methanol production enterprises, and its energy consumption accounts for about 20% of the total energy consumption of methanol. The energy consumption of this process has an important impact on the cost of methanol products. influences. How to improve the quality of methanol and reduce energy consumption ...

AI Technical Summary

Problems solved by technology

However, it can be seen from the analysis that there are still many links to be improved in the double-effect distillation

Taking the three-plus-one-tower distillation process as an example, the bottom discharge of the atmospheric pressure tower is usually used as the feed of the recovery tower. This process has certain limitations: (1) The heat source used for the reboiler of the pre-rectification tower is steam, Increased the energy consumption per unit of methanol; (2) Since the concentration of methanol discharged from the bottom of the atmospheric tower is much lower than that of the crude methanol in the feed, the recovery tower must increase the reflux ratio and increase the recovery rate in order to achieve the desired separation effect. Tower load; (3) For methanol in a large-scale methanol plant, the diameter of each tower is too large, which brings about the operation amplification effect of related equipment and the problems of installation and transportation

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