System for reducing steam consumption in methanol rectification production

Abstract

The utility model discloses a system for reducing steam consumption in methanol rectification production. The system comprises a superior methanol rectification system, an MTO methanol rectification system, a first MTO-grade methanol parallel port pipeline and a second MTO-grade methanol parallel port pipeline, the superior methanol rectification system and the MTO methanol rectification system respectively comprise a superior methanol storage tower for storing superior methanol and an MTO-grade methanol storage tower for storing MTO-grade methanol; the superior methanol storage tower and the MTO-grade methanol storage tower are communicated with each other through a first MTO-grade methanol parallel port pipeline and a second MTO-grade methanol parallel port pipeline respectively. The system has the advantages that the superior methanol storage tower and the MTO-grade methanol storage tower are communicated by adding the parallel pipelines, superior methanol and MTO-grade methanol can be mutually mixed as required to form an optimized product which is lower in water content and qualified in other product quality, and customer requirements are met.

Description

Technical Field

[0001] The utility model relates to the technical field of methanol distillation, in particular to a system for reducing steam consumption in methanol distillation production. Background Art

[0002] Domestic methanol distillation processes mainly include double-tower distillation, three-tower distillation and four-tower distillation. Three-tower distillation and four-tower distillation require the use of high-quality steam as a heat source. With the continuous requirements of energy conservation and environmental protection, the number of distillation towers is increasing. Increasing the number of distillation towers can increase the concentration of distillation products and improve product quality. However, the increase in the number of distillation towers not only increases investment, but also increases energy consumption.

[0003] At present, methanol plants usually have two distillation systems, namely distillation system I and distillation system II. The methanol distillation system uses synthetically produced crude methanol as raw material and uses distillation to produce refined methanol or MTO grade methanol that meets the high purity grade of GB338-2011.

[0004] Under the condition of high-quality methanol, refined methanol is produced by removing gases such as dimethyl ether and other low-boiling impurities dissolved in crude methanol, as well as other heavy components such as water, ethanol, and alcohol-based liquid fuels, and sent to the refined methanol storage tank for sale. At the same time, the by-product alcohol-based liquid fuel and the pre-tower light fraction alkane oil are sent to the alcohol-based liquid fuel storage tank for sale, and the wastewater is sent to biochemical treatment. Under the condition of MTO-grade methanol, the alkali metal ions are removed from the crude methanol by using a multi-effect evaporation process to meet the MTO-grade methanol specification requirements.

[0005] Currently, most downstream customers in the methanol market are olefin users, and their requirements for methanol product quality are slightly different. If a factory runs two distillation systems at the same time to produce only MTO-grade methanol, the water content in the product will increase significantly, affecting the production load. If a factory runs two distillation systems at the same time to produce only high-quality methanol, it will increase energy consumption and cost expenditure, and fail to maximize benefits. Utility Model Content

[0006] The purpose of the utility model is to provide a system for reducing steam consumption in methanol distillation production, thereby solving the above-mentioned problems existing in the prior art.

[0007] In order to achieve the above purpose, the technical solution adopted by the utility model is as follows:

[0008] A system for reducing steam consumption in methanol distillation production, comprising a high-quality methanol distillation system, an MTO methanol distillation system, a first MTO-grade methanol parallel port pipeline and a second MTO-grade methanol parallel port pipeline; the high-quality methanol distillation system and the MTO methanol distillation system respectively comprise a high-quality methanol storage tower for storing high-quality methanol and an MTO-grade methanol storage tower for storing MTO-grade methanol; the high-quality methanol storage tower and the MTO-grade methanol storage tower are respectively connected to each other via the first MTO-grade methanol parallel port pipeline and the second MTO-grade methanol parallel port pipeline.

[0009] Preferably, a first control valve is provided on the first MTO-grade methanol parallel pipeline.

[0010] Preferably, a second control valve is provided on the second MTO-grade methanol parallel pipeline.

[0011] Preferably, the high-quality methanol distillation system further comprises a high-quality pre-distillation tower, a pressure distillation tower and an atmospheric distillation tower;

[0012] The methanol outlet of the superior product pre-distillation tower is connected to the methanol inlet of the pressurized distillation tower, the refined methanol outlet of the pressurized distillation tower is connected to the superior product methanol storage tower, the crude methanol outlet of the pressurized distillation tower is connected to the methanol inlet of the atmospheric distillation tower, and the refined methanol outlet of the atmospheric distillation tower is connected to the superior product methanol storage tower.

[0013] Preferably, the MTO-grade methanol distillation system also includes an MTO-grade pre-distillation tower and a plurality of multi-effect evaporators connected in series in sequence; the MTO-grade pre-distillation tower is connected to the methanol inlet of the multi-effect evaporator located at the head end, and the methanol outlet of the multi-effect evaporator located at the tail end is connected to the MTO-grade methanol storage tower.

[0014] The beneficial effects of the utility model are as follows: 1. By adding parallel pipelines to interconnect the superior methanol storage tower and the MTO-grade methanol storage tower, superior methanol and MTO-grade methanol can be mixed according to demand to form an optimized product with lower water content and other qualified product qualities to meet customer needs. 2. The superior methanol distillation system can adjust the water content in the product by reducing the steam consumption of the pressurized tower and reducing the reflux volume of the pressurized tower without affecting the water solubility experiment and chromaticity, so as to meet the customer's product water content requirements. 3. Without increasing investment and maintaining the original process flow of the distillation system, by adding parallel pipelines, methanol products can be mixed to produce high-quality products that meet customer requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a structural diagram of a system for reducing steam consumption in methanol distillation production in an embodiment of the utility model. DETAILED DESCRIPTION

[0016] In order to make the purpose, technical solution and advantages of the utility model more clear, the utility model is further described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation methods described here are only used to explain the utility model and are not used to limit the utility model.

[0017] like Figure 1 As shown, in this embodiment, a system for reducing steam consumption in methanol distillation production is provided, including a high-quality methanol distillation system, an MTO methanol distillation system, a first MTO-grade methanol parallel pipeline and a second MTO-grade methanol parallel pipeline; the high-quality methanol distillation system and the MTO methanol distillation system respectively include a high-quality methanol storage tower for storing high-quality methanol and an MTO-grade methanol storage tower for storing MTO-grade methanol; the high-quality methanol storage tower and the MTO-grade methanol storage tower are interconnected via the first MTO-grade methanol parallel pipeline and the second MTO-grade methanol parallel pipeline.

[0018] In this embodiment, a first control valve is provided on the first MTO-grade methanol parallel pipeline. A second control valve is provided on the second MTO-grade methanol parallel pipeline. The operator can adjust the control valve opening according to customer needs, thereby achieving the corresponding amount of methanol product intermixing. In order to ensure that the obtained products meet customer needs, corresponding sensors, such as purity sensors, can also be provided in the superior methanol storage tower and the MTO-grade methanol storage tower to detect the purity of the methanol in the storage tower in real time, and then produce products that meet customer needs after the superior methanol and the MTO-grade methanol are intermixed.

[0019] In this embodiment, the high-quality methanol distillation system also includes a high-quality pre-distillation tower, a pressurized distillation tower and an atmospheric distillation tower; the methanol outlet of the high-quality pre-distillation tower is connected to the methanol inlet of the pressurized distillation tower, the refined methanol outlet of the pressurized distillation tower is connected to the high-quality methanol storage tower, the crude methanol outlet of the pressurized distillation tower is connected to the methanol inlet of the atmospheric distillation tower, and the refined methanol outlet of the atmospheric distillation tower is connected to the high-quality methanol storage tower. The high-quality methanol distillation system can adjust the water content in the product by reducing the steam consumption of the pressurized tower and reducing the reflux volume of the pressurized tower without affecting the water solubility experiment and chromaticity, so as to meet the customer's product water content requirements.

[0020] In this embodiment, the MTO-grade methanol distillation system also includes an MTO-grade pre-distillation tower and a plurality of multi-effect evaporators connected in series in sequence; the MTO-grade pre-distillation tower is connected to the methanol inlet of the multi-effect evaporator located at the head end, and the methanol outlet of the multi-effect evaporator located at the tail end is connected to the MTO-grade methanol storage tower.

[0021] By adopting the above technical solution disclosed in the utility model, the following beneficial effects are obtained:

[0022] The utility model provides a system for reducing steam consumption in methanol distillation production. By adding parallel pipelines, the superior methanol storage tower and the MTO-grade methanol storage tower are interconnected. The superior methanol and the MTO-grade methanol can be mixed according to demand to form an optimized product with a lower water content and other qualified product qualities to meet customer needs. The superior methanol distillation system can adjust the water content in the product by reducing the steam consumption of the pressurized tower and reducing the reflux volume of the pressurized tower without affecting the water solubility experiment and chromaticity, thereby meeting the customer's product water content requirements. Without increasing investment and maintaining the original process flow of the distillation system, by adding parallel pipelines, methanol products can be mixed to produce high-quality products that meet customer requirements.

[0023] The above is only a preferred embodiment of the present invention. It should be pointed out that ordinary technicians in this technical field can make several improvements and modifications without departing from the principle of the present invention. These improvements and modifications should also be considered as the protection scope of the present invention.

Claims

1. A system for reducing steam consumption in methanol distillation production, characterized in that: It includes a high-quality methanol distillation system, an MTO methanol distillation system, a first MTO-grade methanol parallel pipeline and a second MTO-grade methanol parallel pipeline; the high-quality methanol distillation system and the MTO methanol distillation system respectively include a high-quality methanol storage tower for storing high-quality methanol and an MTO-grade methanol storage tower for storing MTO-grade methanol; the high-quality methanol storage tower and the MTO-grade methanol storage tower are connected to each other via the first MTO-grade methanol parallel pipeline and the second MTO-grade methanol parallel pipeline.

2. The system for reducing steam consumption in methanol distillation production according to claim 1, characterized in that: The first MTO-grade methanol parallel pipeline is provided with a first control valve.

3. The system for reducing steam consumption in methanol distillation production according to claim 1, characterized in that: A second control valve is provided on the second MTO-grade methanol parallel pipeline.

4. The system for reducing steam consumption in methanol distillation production according to claim 1, characterized in that: The high-quality methanol distillation system also includes a high-quality pre-distillation tower, a pressure distillation tower and an atmospheric distillation tower; The methanol outlet of the superior product pre-distillation tower is connected to the methanol inlet of the pressurized distillation tower, the refined methanol outlet of the pressurized distillation tower is connected to the superior product methanol storage tower, the crude methanol outlet of the pressurized distillation tower is connected to the methanol inlet of the atmospheric distillation tower, and the refined methanol outlet of the atmospheric distillation tower is connected to the superior product methanol storage tower.

5. The system for reducing steam consumption in methanol distillation production according to claim 1, characterized in that: The MTO-grade methanol distillation system also includes an MTO-grade pre-distillation tower and a plurality of multi-effect evaporators connected in series; the MTO-grade pre-distillation tower is connected to the methanol inlet of the multi-effect evaporator located at the head end, and the methanol outlet of the multi-effect evaporator located at the tail end is connected to the MTO-grade methanol storage tower.

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