阅读说明：本技术 一种提高合成气制乙二醇工艺副产dmc回收率的装置和方法 (Device and method for improving recovery rate of byproduct DMC in process of preparing ethylene glycol from synthesis gas ) 是由 岳萌 布占杰 申彦红 袁青青 薛磊 于 2021-08-16 设计创作，主要内容包括：本发明属于合成气制乙二醇工艺中副产DMC提纯领域,针对将副产粗DMC精制后的重组作为副产品销售造成DMC浪费的问题,本发明公开了一种提高合成气制乙二醇工艺副产DMC回收率的装置和方法。装置包括：DMC精馏装置、DMC重组分输出泵、粗DMO储罐、DMO合成装置、粗DMO泵、DMO精馏装置、MF分离塔、DMC分离塔、粗DMC储罐；所述DMC精馏装置包括DMC脱轻塔,DMO精馏装置包括DMO脱轻塔。通过该装置将作为副产品销售的DMC重组分精馏为纯度高达99.5％的DMC产品,提高了DMC的回收率,取得了较好的经济效益。(The invention belongs to the field of by-product DMC purification in a process for preparing glycol from synthesis gas, and discloses a device and a method for improving the recovery rate of by-product DMC in the process for preparing glycol from synthesis gas, aiming at the problem that DMC is wasted due to the fact that recombination after by-product crude DMC is refined is sold as a by-product. The device comprises: the system comprises a DMC rectification device, a DMC heavy component output pump, a crude DMO storage tank, a DMO synthesis device, a crude DMO pump, a DMO rectification device, an MF separation tower, a DMC separation tower and a crude DMC storage tank; the DMC rectification device comprises a DMC lightness-removing column, and the DMO rectification device comprises a DMO lightness-removing column. The DMC heavy component sold as a byproduct is rectified into a DMC product with the purity of 99.5 percent by the device, the recovery rate of DMC is improved, and better economic benefit is obtained.)

1. The utility model provides an improve device of synthetic gas system ethylene glycol technology byproduct DMC recovery rate which characterized in that includes: the device comprises a DMC rectification device, a DMC heavy component output pump, a crude DMO storage tank, a DMO synthesis device, a crude DMO pump, a DMO light component removal tower, an MF separation tower, a DMC separation tower and a crude DMC storage tank; the method comprises the following steps of preparing a DMC rectifying device, wherein an outlet of a DMC lightness-removing tower in the DMC rectifying device is connected with an inlet 1 of a crude DMO storage tank, a DMC heavy component output pump is arranged between the DMC lightness-removing tower in the DMC rectifying device and the crude DMO storage tank, an inlet 2 of the crude DMO storage tank is connected with an outlet of a DMO synthesis device, an outlet of the crude DMO storage tank is connected with an inlet of the DMO lightness-removing tower of the DMO rectifying device, a crude DMO pump is arranged between the crude DMO storage tank and the DMO lightness-removing tower, an outlet 1 of the DMO lightness-removing tower is connected with an inlet of an MF separation tower, an outlet 2 of the DMO lightness-removing tower is connected with an inlet of the DMC separation tower, an outlet 1 of the DMC separation tower is connected with an ethylene glycol synthesis device, an outlet 2 of the DMC separation tower is connected with an inlet of the crude DMC storage tank, and an outlet of the crude DMC storage tank is connected with the DMC rectifying device.

2. A method for improving the recovery rate of byproduct DMC in a process of preparing ethylene glycol from synthesis gas is characterized by comprising the following steps: pressurizing the heavy DMC component from a DMC lightness-removing tower in a DMC rectification device to 0.35mpa by a heavy DMC component output pump, sending the heavy DMC component to a crude DMO storage tank, and mixing the heavy DMC component with crude DMO from a DMO synthesis device; after mixing, pressurizing to 0.45mpa by a crude DMO pump, and then sending to a DMO light component removal tower of a DMO rectification device for rectification; wherein, the impurity peak substance is rectified by a DMO lightness removing tower, and then is sent to an MF separating tower for separation as a light component, and is sent to an incinerator as a fuel after separation; sending the rest DMC heavy component and the coarse DMO to a DMC separation tower for separation, sending the separated DMC as a byproduct to a coarse DMC storage tank, and further sending the DMC to a DMC rectification device for rectification to obtain a DMC product with the purity of 99.5%; the DMC separation tower bottom is rectified DMO, and is sent to an ethylene glycol synthesis device for synthesizing ethylene glycol.

3. The method for improving the recovery rate of DMC (DMC) by-produced in the process of preparing ethylene glycol from synthesis gas according to claim 2, wherein the method comprises the following steps: the purity of DMC in the heavy DMC component from the DMC lightness-removing column in the DMC rectification plant is 75-90%.

4. The method for improving the recovery rate of DMC (DMC) by-produced in the process of preparing ethylene glycol from synthesis gas according to claim 2, wherein the method comprises the following steps: the yield of the heavy DMC components from the DMC lightness-removing column in the DMC rectification device is 150-200kg/h, and the yield of the crude DMO from the DMO synthesis device is 85-90 t/h.

Technical Field

The invention belongs to the field of purification of by-product DMC in a process for preparing glycol from synthesis gas, and particularly relates to a device and a method for improving the recovery rate of the by-product DMC in the process for preparing glycol from synthesis gas.

Background

Dimethyl carbonate (DMC), abbreviated as DMC, has excellent solubility, narrow melting point range, large surface tension, low viscosity, small dielectric constant and low toxicity, is widely used as a carbonylation and methylation reagent, a gasoline additive, a raw material for synthesizing Polycarbonate (PC) and the like, is an environment-friendly chemical raw material integrating cleanness and safety, and therefore, the DMC synthesis and purification technology is widely regarded by the chemical industry at home and abroad.

In the process of preparing the glycol by using the comprehensive tail gases such as coke oven gas, steel converter gas and the like, a byproduct DMC can be generated, the DMC which is not purified traditionally contains impurity components such as methanol and the like, and can only be used as solvent oil or dangerous waste fire oil for treatment, so that the economic value is low, and the purified DMC can be used as a raw material of a coating and a part of an adhesive, so that the economic value is greatly improved.

At present, the purification method is to send the by-product crude DMC to a DMC refining device, remove the light components in the crude DMC and send the light components to an incinerator for incineration, and send the heavy components to a heavy component storage tank for sale as a by-product. However, because the DMC concentration in the heavies is still above 75%, sale as a by-product can result in DMC waste and thus lower DMC recovery. Therefore, the effective components in the heavy components are recovered and sold as products, and the improvement of the recovery rate of DMC is of great significance.

Disclosure of Invention

The invention provides a device and a method for improving the recovery rate of a byproduct DMC in a process of preparing ethylene glycol from synthesis gas, aiming at the problem that DMC is wasted because the recombination after the byproduct crude DMC is refined is sold as a byproduct.

In order to achieve the purpose, the invention adopts the following technical scheme:

the invention provides a device for improving the recovery rate of a byproduct DMC in a process of preparing ethylene glycol from synthesis gas, which comprises the following steps: the device comprises a DMC rectification device, a DMC heavy component output pump, a crude DMO storage tank, a DMO synthesis device, a crude DMO pump, a DMO light component removal tower, an MF separation tower, a DMC separation tower and a crude DMC storage tank; the method comprises the following steps of preparing a DMC rectifying device, wherein an outlet of a DMC lightness-removing tower in the DMC rectifying device is connected with an inlet 1 of a crude DMO storage tank, a DMC heavy component output pump is arranged between the DMC lightness-removing tower in the DMC rectifying device and the crude DMO storage tank, an inlet 2 of the crude DMO storage tank is connected with an outlet of a DMO synthesis device, an outlet of the crude DMO storage tank is connected with an inlet of the DMO lightness-removing tower of the DMO rectifying device, a crude DMO pump is arranged between the crude DMO storage tank and the DMO lightness-removing tower, an outlet 1 of the DMO lightness-removing tower is connected with an inlet of an MF separation tower, an outlet 2 of the DMO lightness-removing tower is connected with an inlet of the DMC separation tower, an outlet 1 of the DMC separation tower is connected with an ethylene glycol synthesis device, an outlet 2 of the DMC separation tower is connected with an inlet of the crude DMC storage tank, and an outlet of the crude DMC storage tank is connected with the DMC rectifying device.

The invention also provides a method for improving the recovery rate of the byproduct DMC in the process of preparing the ethylene glycol from the synthesis gas, which comprises the following steps: pressurizing the heavy DMC component from a DMC lightness-removing tower in a DMC rectification device to 0.35mpa by a heavy DMC component output pump, sending the heavy DMC component to a crude DMO storage tank, and mixing the heavy DMC component with crude DMO from a DMO synthesis device; after mixing, pressurizing to 0.45mpa by a crude DMO pump, and then sending to a DMO light component removal tower of a DMO rectification device for rectification; wherein, the impurity peak substance is rectified by a DMO lightness removing tower, and then is sent to an MF separating tower for separation as a light component, and is sent to an incinerator as a fuel after separation; sending the rest DMC heavy component and the coarse DMO to a DMC separation tower for separation, sending the separated DMC as a byproduct to a coarse DMC storage tank, and further sending the DMC to a DMC rectification device for rectification to obtain a DMC product with the purity of 99.5%; the DMC separation tower bottom is rectified DMO, and is sent to an ethylene glycol synthesis device for synthesizing ethylene glycol.

Further, the purity of the DMC in the DMC heavy component from the DMC lightness removal column is 75-90%.

Further, the yield of the heavy DMC components from the DMC lightness-removing column is 150-200kg/h, and the yield of the crude DMO from the DMO synthesis unit is 85-90 t/h.

Compared with the prior art, the invention has the following advantages:

1. according to the invention, the DMC heavy component sold as a byproduct is rectified into a DMC product with the purity as high as 99.5% by the device for improving the recovery rate of the byproduct DMC in the process of preparing the glycol from the synthesis gas, so that the recovery rate of the DMC is improved, and better economic benefit is obtained.

2. The device can recycle DMC in DMC heavy components as products for sale or distill DMO in crude DMO for synthesizing glycol on the premise of ensuring the normal operation of the original DMC rectification device, and the miscellaneous peak substances are sent to an incinerator for being used as fuel after being subjected to MF separation, so that heat can be recycled, and the generated steam can be used and cannot harm the environment.

Drawings

FIG. 1 is a schematic view of the apparatus of the present invention.

FIG. 2 is a flow chart of the method of the present invention.

Detailed Description

The technical solution in the embodiments of the present invention will be specifically and specifically described below with reference to the embodiments of the present invention and the accompanying drawings. It should be noted that variations and modifications can be made by those skilled in the art without departing from the principle of the present invention, and these should also be construed as falling within the scope of the present invention.

Example 1

As shown in fig. 1, an apparatus for increasing recovery rate of by-product DMC in a process of preparing ethylene glycol from syngas includes: the device comprises a DMC rectification device 1, a DMC heavy component output pump 2, a crude DMO storage tank 3, a crude DMO pump 4, a DMO lightness-removing column 5, a DMC separation column 6, a crude DMC storage tank 7, a DMO synthesis device 8 and an MF separation column 9, wherein an outlet of the DMC lightness-removing column in the DMC rectification device 1 is connected with a first inlet of the crude DMO storage tank 3, the DMC heavy component output pump 2 is arranged between the DMC lightness-removing column in the DMC rectification device 1 and the crude DMO storage tank 3, a second inlet of the crude DMO storage tank 3 is connected with an outlet of the DMO synthesis device 8, an outlet of the crude DMO storage tank 3 is connected with an inlet of the DMO lightness-removing column 5 of the DMO rectification device, the crude DMO storage tank 3 is arranged between the DMO lightness-removing column 5, the first outlet of the DMO lightness-removing column 5 is connected with an inlet of the MF separation column 9, the second outlet of the DMO lightness-removing column 5 is connected with an inlet of the DMC separation column 6, the first outlet of the DMC separation column 6 is connected with an inlet of the ethylene glycol synthesis device, and an outlet of the crude DMO separation column 7 are connected with an MF separation column 7, the outlet of the crude DMC tank 7 is connected to the DMC rectification apparatus 1.

Example 2

The DMC heavy component treatment is carried out by the device (as shown in FIG. 2), and the specific steps are as follows:

1. firstly, pressurizing and conveying DMC heavy components with purity up to 75% from a DMC lightness-removing tower to a crude DMO storage tank through a heavy component output pump, wherein the yield of the DMC heavy components is 150 kg/h;

2. the DMC heavy components sent to the crude DMO storage tank were separated from the crude DMO from the DMO synthesis unit at 85t/h in a volume of 5000m³Mixing the crude DMO storage tanks;

3. sending the components mixed in the step 2 to a DMO lightness-removing tower through a crude DMO pump for rectification treatment, sending the light components obtained after the rectification of the miscellaneous peak substances in the mixture to an MF separation tower for separation after the rectification of the miscellaneous peak substances in the mixture through the DMO lightness-removing tower, sending the light components to an incinerator for incineration after the separation, recovering heat, and generating steam; sending mixed components except the impurity peak substances to a DMC separation tower for separation;

4. DMC separated by the DMC separation tower is sent to a crude DMC storage tank as a byproduct, and is further sent to a DMC rectification device, and the DMC is rectified into a DMC product with the purity of 99.5 percent; the rectified DMO is sent to an ethylene glycol synthesis device to be used for synthesizing ethylene glycol.

Example 3

The DMC heavy component treatment is carried out by the device (as shown in FIG. 2), and the specific steps are as follows:

1. firstly, pressurizing and conveying DMC heavy components with the purity up to 90% from a DMC lightness-removing tower to a crude DMO storage tank through a heavy component output pump, wherein the yield of the DMC heavy components is 200 kg/h;

2. the DMC heavy components sent to the crude DMO storage tank were separated from the crude DMO from the DMO synthesis unit at 90t/h in a volume of 5000m³Mixing the crude DMO storage tanks;

3. sending the components mixed in the step 2 to a DMO lightness-removing tower through a crude DMO pump for rectification treatment, sending the light components obtained after the rectification of the miscellaneous peak substances in the mixture to an MF separation tower for separation after the rectification of the miscellaneous peak substances in the mixture through the DMO lightness-removing tower, sending the light components to an incinerator for incineration after the separation, recovering heat, and generating steam; sending mixed components except the impurity peak substances to a DMC separation tower for separation;

4. DMC separated by the DMC separation tower is sent to a crude DMC storage tank as a byproduct, and is further sent to a DMC rectification device, and the DMC is rectified into a DMC product with the purity of 99.5 percent; the rectified DMO is sent to an ethylene glycol synthesis device to be used for synthesizing ethylene glycol.

Example 4

The DMC heavy component treatment is carried out by the device (as shown in FIG. 2), and the specific steps are as follows:

1. firstly, pressurizing and conveying heavy DMC components with the purity up to 88% from a heavy DMC lightness-removing tower to a crude DMO storage tank through a heavy component output pump, wherein the yield of the heavy DMC components is 180 kg/h;

2. the DMC heavy components sent to the crude DMO storage tank were separated from the crude DMO from the DMO synthesis unit at 88t/h in a volume of 5000m³Mixing the crude DMO storage tanks;

3. sending the components mixed in the step 2 to a DMO lightness-removing tower through a crude DMO pump for rectification treatment, sending the light components obtained after the rectification of the miscellaneous peak substances in the mixture to an MF separation tower for separation after the rectification of the miscellaneous peak substances in the mixture through the DMO lightness-removing tower, sending the light components to an incinerator for incineration after the separation, recovering heat, and generating steam; sending mixed components except the impurity peak substances to a DMC separation tower for separation;

4. DMC separated by the DMC separation tower is sent to a crude DMC storage tank as a byproduct, and is further sent to a DMC rectification device, and the DMC is rectified into a DMC product with the purity of 99.5 percent; the rectified DMO is sent to an ethylene glycol synthesis device to be used for synthesizing ethylene glycol.