Oxide recovery device for methanol-to-olefin device
By introducing components such as a top reflux tank and a reflux pump into the oxide stripping tower, the recovery process of oxygen-containing compounds was optimized, solving the equipment blockage and separation problems caused by the accumulation of oxygen-containing compounds in the MTO unit, and achieving stable operation of the unit and improved economic benefits.
Patent Information
- Application Number
- CN202422841701.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-21
- Publication Date
- 2025-10-28
- Estimated Expiration
- 2034-11-21
AI Technical Summary
In the existing MTO process, oxygen-containing compounds such as methanol, dimethyl ether, aldehydes, and ketones accumulate during the recycling process, leading to equipment blockage and separation problems, affecting the stable operation and economic benefits of the device.
Introducing components such as the top reflux tank, reflux pump, remote pressure gauge and flow control valve into the oxide stripping tower optimizes the recovery process of oxygen-containing compounds. The unnecessary oxygen-containing compounds are sent to the tank area for sale through the top reflux tank and reflux pump to avoid recycling to the reactor.
It effectively solves the equipment blockage and separation problems caused by the accumulation of oxygen-containing compound concentration, ensures the long-term stable operation of the device, and improves economic benefits.
Smart Images
Figure CN223474439U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of methanol-to-olefins (MTO) technology, specifically relating to an oxide recovery device for a methanol-to-olefins plant, which uses an oxide stripping tower to remove unwanted or undesirable oxygen-containing compounds from the recycle. Background Technology
[0002] MTO (Methanol-to-Olefins) is one of the main methods for producing olefins from methanol worldwide. During the methanol-to-olefins reaction, various oxygen-containing byproducts are generated. To increase the yield of low-carbon olefins, the process water from the MTO washing tower and separation tower, as well as the condensate from the first stage of the product gas compressor, which contains small amounts of oxides (such as methanol, dimethyl ether, aldehydes, and ketones), is sent to an oxide stripping tower for stripping to recover these organic compounds. The recovered organic compounds are then sent back to the MTO reactor to participate in the reaction again. In other words, the purpose of stripping this oxide-containing wastewater is to recover the small amounts of oxygen-containing compounds entrained in the MTO unit's water system, thereby increasing the yield of the target product and producing purified water that meets design specifications, thus reducing the pressure on public utility wastewater treatment.
[0003] In actual production, although dimethyl ether and methanol are recycled through stripping to maintain a high utilization rate of hydrocarbon products in the MTO feed, some unwanted or undesirable oxygen-containing compounds (mainly aldehydes and ketones) that can cause problems in production are also recycled back to the MTO reactor. The oxide stripping tower has limited processing capacity, leading to the accumulation of these oxygen-containing compounds in the recycle, clogging downstream equipment, and even causing separation problems (such as emulsion formation, foaming, and oil entrainment). This has become a common problem in the MTO industry. Therefore, production practice needs to explore an effective and efficient method to remove unwanted or undesirable oxygen-containing compounds from the recycle stream entering the MTO reactor. Summary of the Invention
[0004] The purpose of this invention is to provide an oxide recovery device for methanol-to-olefins (MTO) plants. This device utilizes an oxide stripping tower to remove unwanted or undesirable oxides from the oxide recirculation process, thereby optimizing oxide recovery in MTO plants. The device effectively solves the problems of oxygen compound accumulation in the product gas of MTO plants, clogging of downstream equipment, and separation issues in the water system (such as emulsion, foaming, and oil entrainment), ensuring long-term stable operation of the plant. Simultaneously, the oxygen compounds stripped from the recirculation stream (undesirable or undesirable oxygen compounds) can be sent to the tank farm for loading and sale, improving overall economic efficiency.
[0005] To achieve the above-mentioned objectives, the present invention adopts the following technical solution:
[0006] An apparatus for oxide recovery in a methanol-to-olefins plant, comprising an oxide stripping tower, characterized in that the apparatus further comprises:
[0007] A top reflux tank is provided, wherein the top gas phase outlet of the oxide stripping tower is connected to a cooler, and after passing through the cooler, it is connected to the top reflux tank, and the top gas phase outlet of the top reflux tank is connected to a reactor;
[0008] A cooler;
[0009] A reflux pump is provided, with the liquid phase outlet at the bottom of the top reflux tank connected to the reflux pump, which is connected to the tank area and the oxide stripping tower.
[0010] Furthermore, a remote pressure gauge is installed at the top of the oxide stripping tower, and a pressure control valve is installed at the top gas phase outlet of the top reflux tank. The pressure of the oxide stripping tower is accurately controlled through the pressure control valve.
[0011] Furthermore, the top reflux tank is equipped with a remote level gauge to control the liquid level in the top reflux tank; the material in the top reflux tank is transferred to the tank area or returned to the oxide stripping tower by a reflux pump.
[0012] Furthermore, a flow control valve is installed on the pipeline from the outlet of the reflux pump to the oxide stripping tower to control the reflux flow rate.
[0013] Furthermore, the conveying pipe is made of an acid and alkali resistant material.
[0014] Beneficial Effects: This invention relates to an oxide recovery device for methanol-to-olefins (MTO) units. It utilizes an oxide stripping tower to remove unwanted or undesirable oxides from the recirculation process, thereby optimizing oxide recovery in MTO units. This device effectively solves the problems of oxygen compound accumulation in the product gas of MTO units, clogging downstream equipment, and causing separation issues in the water system (such as emulsion formation, foaming, and oil entrainment). This ensures long-term stable operation of the unit. Simultaneously, the oxygen compounds stripped from the recirculation stream (unwanted or undesirable oxygen compounds) can be sent to the tank farm for loading and sale, improving overall economic efficiency. Attached Figure Description
[0015] Figure 1 This is a schematic diagram of the structure of an oxide recovery device in a methanol-to-olefins plant according to the present invention.
[0016] In the diagram: 1-Oxide stripping tower; 2-Top reflux tank; 3-Reflux pump; 4-Remote pressure gauge; 5-Remote level gauge; 6-Pressure control valve; 7-First gate valve; 8-Second gate valve; 9-Flow control valve; 10-Cooler. Detailed Implementation
[0017] The specific embodiments of the present invention will be described in detail below. However, it should be noted that the scope of protection of the present invention is not limited by these specific embodiments, but is determined by the claims.
[0018] like Figure 1 As shown, this utility model discloses an oxide recovery device for a methanol-to-olefins (MTO) plant. It can be modified from the existing oxide stripping tower 1 by adding a top reflux tank 2, a reflux pump 3, a remote pressure gauge 4, a remote level gauge 5, a cooler 10, and several valves. A branch line is installed at the top gas phase outlet of the oxide stripping tower 1 to the reactor. This branch line passes through the cooler 10 and enters the top reflux tank 2. The top gas phase of the top reflux tank 2 returns to the reactor. A remote pressure gauge 4 is installed at the top of the oxide stripping tower 1, and a pressure control valve 6 is installed at the top gas phase outlet of the top reflux tank 2. A first gate valve 7 and a second gate valve 8 are respectively installed on the pipelines from the oxide stripping tower 1 to the reactor and to the top reflux tank 2. The bottom material of the top reflux tank 2 is sent to the tank area or returned to the oxide stripping tower 1 via the reflux pump 3. A flow control valve 9 is installed on the pipeline from the outlet of the reflux pump 3 to the oxide stripping tower 1 to control the reflux flow rate.
[0019] The oxide recovery device of this invention for a methanol-to-olefins (MTO) unit changes the original process of directly sending the top gaseous material from the oxide stripping tower 1 to the reactor. Instead, the material passes through a cooler 10 and enters the top reflux tank 2 (with the second gate valve 8 open and the first gate valve 7 closed). The gaseous material then returns to the reactor via a pressure control valve 6. The liquid phase in the top reflux tank 2 is sent back to the oxide stripping tower 1 via a reflux pump 5. The reflux flow rate is controlled by a flow control valve 9 on the pipeline, maintaining a small amount delivered to the tank area to keep the liquid level in the top reflux tank 2 stable. After heat exchange in the cooler 10, the stripped gas from the top of the oxide stripping tower 1 enters the top reflux tank 2. Part of the condensate in the top reflux tank 2 is returned to the top tray as reflux liquid from the oxide stripping tower 1, and the other part is sent to the tank area as concentrate (unwanted or undesirable oxygen-containing compounds). The non-condensable gas generated in the top reflux tank 2 is recovered to the MTO reactor.
Claims
1. A device for oxide recovery in a methanol-to-olefins plant, comprising an oxide stripping tower (1), characterized in that, The device further includes: A top reflux tank (2) is provided, the top gas phase outlet of the oxide stripping tower (1) is connected to a cooler (10), and after passing through the cooler (10), it is connected to the top reflux tank (2), the top gas phase outlet of the top reflux tank (2) is connected to a reactor; A cooler (10); A reflux pump (3) is connected to the bottom liquid phase outlet of the top reflux tank (2), and the reflux pump (3) is connected to the tank area and the oxide stripping tower (1).
2. The apparatus for oxide recovery in a methanol-to-olefins unit according to claim 1, characterized in that, The oxide stripping tower (1) is equipped with a remote pressure gauge (4) at the top.
3. The apparatus for oxide recovery in a methanol-to-olefins unit according to claim 1, characterized in that, The top gas phase outlet of the reflux tank (2) is equipped with a pressure control valve (6).
4. The apparatus for oxide recovery in a methanol-to-olefins unit according to claim 1, characterized in that, The top reflux tank (2) is equipped with a remote level gauge (5).
5. The apparatus for oxide recovery in a methanol-to-olefins unit according to claim 1, characterized in that, A flow control valve (9) is installed on the pipeline from the outlet of the reflux pump (3) to the oxide stripping tower (1).