Method for obtaining fine methanol products by using methanol to olefins (MTO) methanol products

Abstract

The invention discloses a method for obtaining fine methanol products by using methanol to olefins (MTO) methanol products. The key is as follows: a fine methanol rectifying tower is added in a three-tower distillation process of producing MTO-grade methanol products, so as to obtain the fine methanol products and meet the requirements of downstream products on the fine methanol. The method comprises the following concrete steps: separating out a part of MTO-grade methanol products from the top of an MTO methanol pressure tower; and feeding to the fine methanol rectifying tower, thereby obtaining the fine methanol products from the top of the fine methanol rectifying tower in a rectifying manner and returning the tower bottom liquid of the fine methanol rectifying tower back to an MTO methanol atmospheric tower. The fine methanol products are obtained under the condition that a few of equipment are added by the steps, and production of the original MOT-grade methanol products is not affected, so that the target of saving investments is achieved.

Description

technical field

[0001] The invention belongs to the field of chemical industry, and in particular relates to the technical field of methanol preparation and purification. Background technique

[0002] With the development of the methanol-to-olefins (MTO) process, the number of domestic MTO methanol plants has increased. Due to the low concentration of MTO methanol (its volume concentration is generally lower than 95%), when refined methanol is required, the MTO methanol plant cannot meet the requirements, and MTO methanol needs to be purified, and if a new set of refined methanol plant is built, it will occupy an area And equipment investment, also need to increase supporting public works. Moreover, to obtain refined methanol by rectification on the basis of finished MTO methanol, it is necessary to pressurize and pump the MTO methanol and reheat it from normal temperature, which consumes a lot of energy and costs too much. Contents of the invention

[0003] The purpose...

Examples

Embodiment 1

[0033] Such as figure 2 Shown: A kind of equipment that utilizes MTO methanol products to obtain refined methanol products, and a set of refined methanol rectification system is added on the basis of the existing MTO methanol three-tower rectification equipment. The equipment specifically includes: a pre-rectification tower 1, a pressurized rectification tower 2, a refined methanol rectification tower 3, and an atmospheric rectification tower 4. The raw material inlet in the middle of the pre-rectification tower 1 is supplied with crude methanol through a pipeline. The system is connected, the tower top outlet of the pre-rectification tower 1 is connected with the exhaust gas treatment system or the fuel pipe network through the pipeline, and the tower still outlet is connected with the raw material inlet in the middle part of the pressurized rectification tower 2 through the pipeline and the booster pump 6 The outlet at the top of the pressurized rectification tower 2 is con...

Embodiment 2

[0037] This embodiment is a flow process with an annual output of 300,000 tons of MTO grade methanol and a by-product of 24,000 tons of refined methanol (see figure 1 ), using equipment such as figure 2 shown.

[0038]Crude methanol flow rate ~ 45900kg / h enters the three-tower rectification system of MTO grade methanol, discharges non-condensable gas from the top of the pre-rectification tower, and produces MTO grade methanol from the top of the pressurized rectification tower and the top of the atmospheric rectification tower. Among them, 18,887 kg / h of MTO grade methanol is extracted from the top of the pressurized rectification tower, and 19,953 kg / h of MTO grade methanol is mined from the top of the atmospheric distillation tower, and the bottom liquid of the atmospheric distillation tower is pumped to the sewage treatment system. The device produced a total of 38.840t / h of MTO grade methanol.

[0039] The content of MTO grade methanol is 95%, which cannot meet the sta...

technical field

[0001] The invention belongs to the field of chemical industry, and in particular relates to the technical field of methanol preparation and purification. Background technique

[0002] With the development of the methanol-to-olefins (MTO) process, the number of domestic MTO methanol plants has increased. Due to the low concentration of MTO methanol (its volume concentration is generally lower than 95%), when refined methanol is required, the MTO methanol plant cannot meet the requirements, and MTO methanol needs to be purified, and if a new set of refined methanol plant is built, it will occupy an area And equipment investment, also need to increase supporting public works. Moreover, to obtain refined methanol by rectification on the basis of finished MTO methanol, it is necessary to pressurize and pump the MTO methanol and reheat it from normal temperature, which consumes a lot of energy and costs too much. Contents of the invention

[0003] The purpose...

Examples

Embodiment 1

[0033] Such as figure 2 Shown: A kind of equipment that utilizes MTO methanol products to obtain refined methanol products, and a set of refined methanol rectification system is added on the basis of the existing MTO methanol three-tower rectification equipment. The equipment specifically includes: a pre-rectification tower 1, a pressurized rectification tower 2, a refined methanol rectification tower 3, and an atmospheric rectification tower 4. The raw material inlet in the middle of the pre-rectification tower 1 is supplied with crude methanol through a pipeline. The system is connected, the tower top outlet of the pre-rectification tower 1 is connected with the exhaust gas treatment system or the fuel pipe network through the pipeline, and the tower still outlet is connected with the raw material inlet in the middle part of the pressurized rectification tower 2 through the pipeline and the booster pump 6 The outlet at the top of the pressurized rectification tower 2 is con...

Embodiment 2

[0037] This embodiment is a flow process with an annual output of 300,000 tons of MTO grade methanol and a by-product of 24,000 tons of refined methanol (see figure 1 ), using equipment such as figure 2 shown.

[0038]Crude methanol flow rate ~ 45900kg / h enters the three-tower rectification system of MTO grade methanol, discharges non-condensable gas from the top of the pre-rectification tower, and produces MTO grade methanol from the top of the pressurized rectification tower and the top of the atmospheric rectification tower. Among them, 18,887 kg / h of MTO grade methanol is extracted from the top of the pressurized rectification tower, and 19,953 kg / h of MTO grade methanol is mined from the top of the atmospheric distillation tower, and the bottom liquid of the atmospheric distillation tower is pumped to the sewage treatment system. The device produced a total of 38.840t / h of MTO grade methanol.

[0039] The content of MTO grade methanol is 95%, which cannot meet the sta...

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