Co-production method of various plasticizers

Abstract

The invention discloses a co-production method of multiple plasticizers, and belongs to the technical field of PVC modified materials. Comprising the following steps: by taking a crude aromatic hydrocarbon component material as a raw material, respectively producing a colorless aromatic hydrocarbon plasticizer, a light-color aromatic hydrocarbon plasticizer 1 #, a light-color aromatic hydrocarbon plasticizer 2 #, an aromatic hydrocarbon type plasticizer and a deep-color aromatic hydrocarbon plasticizer in a continuous rectifying tower group by controlling the temperature. Through the arrangement of the continuous rectifying tower group, the continuous production of various plasticizers is realized, the production efficiency is improved, and meanwhile, the stability and the consistency of the product quality are ensured.

Description

Technical Field

[0001] The invention discloses a method for co-producing multiple plasticizers, belonging to the technical field of PVC modified materials. Background Art

[0002] Plasticization is to soften rubber or PVC to have a certain degree of flexibility. The crystals of PVC are very regular and the forces between molecules are very strong. Therefore, PVC products are very hard and not easy to deform. In order to increase the toughness and softness of PVC, plasticizers are generally added to PVC products. Commonly used DOP (dioctyl phthalate) and DBP (dibutyl phthalate) are both aromatic plasticizers; their role in PVC is to allow long-chain molecules to extend between PVC molecular crystals, increase the lubricity between molecules, reduce the tightness of molecules, and allow molecules to "slide" slightly, making the product soft. One of the biggest features of aromatic plasticizers is that the dielectric constant is very large, which can increase the insulation effect of cables, so they are widely used in rubber sheathed cables and PVC cable industries.

[0003] There are several aromatic plasticizers that are nearly colorless and transparent, and can be used in some brightly colored rubber products or PVC products. Aromatic plasticizers can be specifically divided into:

[0004] 1) Dark aromatic plasticizers can be used as plasticizers for rubber products that require high temperature resistance, weather resistance and high performance, such as rubber sheath cable materials.

[0005] 2) Light-colored aromatic plasticizer 1# can be used as a plasticizer for rubber products used in the production of high-end colored tires, such as colored bicycle tires.

[0006] 3) Light-colored aromatic plasticizer 2# is used as a plasticizer for transparent rubber products, such as kayaks and windsurfing boards.

[0007] Light-colored aromatic plasticizer 1# and light-colored aromatic rubber plasticizer 2# can be used together with polyester plasticizer to improve the compatibility of polyester and PVC.

[0008] In the prior art, most plasticizers are extracted separately by intermittent distillation, which has low production efficiency and cannot guarantee the stability and consistency of product quality. Summary of the invention

[0009] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a method for co-producing multiple plasticizers with higher production efficiency.

[0010] The technical solution adopted by the present invention to solve its technical problem is: a method for co-producing multiple plasticizers, comprising the following steps: using crude aromatic component material as raw material, controlling the temperature in a continuous distillation tower group to respectively produce colorless aromatic plasticizer, light-colored aromatic plasticizer 1#, light-colored aromatic plasticizer 2#, aromatic plasticizer, and dark aromatic plasticizer.

[0011] Preferably, the continuous distillation tower group is a first distillation tower, a second distillation tower, a third distillation tower and a fourth distillation tower connected in series in sequence, each distillation tower extracts plasticizer from the top of the tower, and the bottom discharge port of the previous distillation tower is connected to the feed port in the middle of the next distillation tower; a heat exchanger is provided at the top gas phase outlet of each distillation tower as a raw material preheater, and the raw material is preheated by each raw material preheater before entering the first distillation tower.

[0012] Preferably, the colorless aromatic-based plasticizer is extracted from the top of the first distillation tower, the top temperature of the first distillation tower is 188°C to 193°C, the bottom temperature is 198°C to 203°C, and the system pressure is -0.009MPa to -0.012MPa.

[0013] Preferably, the colorless aromatic-based plasticizer extracted from the top of the first distillation tower is partially refluxed after condensation, and the extracted amount accounts for 29% to 34% of the total raw material amount.

[0014] The raw material crude aromatic component material first enters the raw material storage tank, is pressurized by the raw material delivery pump, and is measured by the raw material flow meter, and then enters the top raw material preheater in turn. The preheated crude aromatic component material enters the middle part of the first distillation tower of crude aromatic component material.

[0015] The raw material crude aromatic component is divided into two parts in the first distillation tower. The gas phase colorless aromatic-based plasticizer is distilled from the top of the tower. A part of it is cooled by the top raw material preheater, and then the gas-liquid phase is mixed into the top product cooler, and is completely cooled into liquid in the top product condenser. Then, it flows into the top product buffer tank by gravity, and a part of the material in the top product buffer tank flows into the top reflux pump by gravity. After being pressurized by the top reflux pump, it is measured and controlled by the top reflux flowmeter and then pumped back to the top of the tower as reflux to ensure the normal operation of the distillation tower. A part of the material in the top product buffer tank flows into the top extraction pump by gravity, and after being pressurized by the top extraction pump, the extraction amount of the top product is controlled by controlling the liquid level of the top buffer tank.

[0016] The bottom of the tower is used as the feed of the second aromatics fractionation tower. After being pressurized by the bottom extraction pump, the bottom extraction volume is controlled by controlling the bottom liquid level of the first crude aromatics component fractionation tower.

[0017] Preferably, the light-colored aromatic plasticizer 1# is extracted from the top of the second distillation tower, the top temperature of the second distillation tower is 194°C to 197°C, the bottom temperature is 218°C to 222°C, and the system pressure is -0.009 to -0.012 MPa.

[0018] Preferably, the light-colored aromatic-based plasticizer 1# extracted from the top of the second distillation tower is partially refluxed after condensation, and the extracted amount accounts for 27% to 31% of the total raw material amount.

[0019] Aromatics from the bottom pump of the first distillation tower enter the middle of the second distillation tower of crude aromatic component materials. In the second distillation tower, it is divided into two parts. The gas phase light-colored aromatic-based plasticizer 1# is distilled from the top of the tower; a part is cooled by the top raw material preheater, and then the gas-liquid phase is mixed and enters the top product cooler, and is completely cooled into liquid in the top product condenser. Then, it flows into the top product buffer tank by gravity, and a part of the material in the top product buffer tank flows into the top reflux pump by gravity. After being pressurized by the top reflux pump, it is measured and controlled by the top reflux meter and then pumped back to the top of the tower as reflux to ensure the normal operation of the distillation tower. A part of the material in the top product buffer tank flows into the top extraction pump by gravity, and after being pressurized by the top extraction pump, the extraction amount of the top product is controlled by controlling the liquid level of the top buffer tank.

[0020] The tower bottom is used as the feed of the third aromatics fractionation tower. After being pressurized by the tower bottom extraction pump, the tower bottom extraction volume is controlled by controlling the tower bottom liquid level of the second crude aromatics component fractionation tower.

[0021] Preferably, the light-colored aromatic plasticizer 2# is extracted from the top of the third distillation tower, the top temperature of the third distillation tower is 179°C to 182°C, the bottom temperature is 238°C to 242°C, and the system pressure is -0.048MPa to -0.052MPa.

[0022] Preferably, the light-colored aromatic-based plasticizer 2# extracted from the top of the third distillation tower is partially refluxed after condensation, and the extracted amount accounts for 18% to 22% of the total raw material amount.

[0023] Aromatic hydrocarbons from the bottom pump of the second distillation tower enter the middle of the third distillation tower, where they are divided into two parts. The gas phase light-colored aromatic-based plasticizer 2# is distilled out from the top of the tower; a part of it is cooled by the top raw material preheater, and then the gas-liquid phase is mixed and enters the top product cooler, where it is completely cooled into liquid in the top product condenser. Then, it flows into the top product buffer tank by gravity, and a part of the material in the top product buffer tank flows into the top reflux pump by gravity, and after being pressurized by the top reflux pump, it is metered and controlled by the top reflux meter and then pumped back to the top of the tower as reflux to ensure the normal operation of the distillation tower. A part of the material in the top product buffer tank flows into the top extraction pump by gravity, and after being pressurized by the top extraction pump, the extraction amount of the top product is controlled by controlling the liquid level of the top buffer tank.

[0024] The bottom of the tower is used as the feed of the fourth aromatics fractionation tower. After being pressurized by the bottom extraction pump, the bottom extraction volume is controlled by controlling the bottom liquid level of the third crude aromatics component fractionation tower.

[0025] Preferably, the top of the fourth distillation tower produces an aromatic plasticizer, and the bottom of the tower produces a dark aromatic plasticizer; the top temperature of the fourth distillation tower is 228°C to 232°C, the bottom temperature is 268°C to 272°C, and the system pressure is -0.089MPa to -0.092MPa.

[0026] Preferably, the amount of the aromatic plasticizer produced from the top of the fourth distillation tower accounts for 9% to 11% of the total amount of the raw materials, and the rest of the raw materials are produced from the bottom of the tower.

[0027] Aromatic hydrocarbons from the bottom pump of the third distillation tower enter the middle of the fourth distillation tower. In the fourth distillation tower, they are divided into two parts. The gas phase aromatic hydrocarbon plasticizer is distilled from the top of the tower; a part is cooled by the top raw material preheater, and then the gas and liquid phases are mixed and enter the top product cooler, and are completely cooled into liquid in the top product condenser. Then, it flows into the top product buffer tank by gravity, and a part of the material in the top product buffer tank flows into the top reflux pump by gravity. After being pressurized by the top reflux pump, it is measured and controlled by the top reflux meter and then pumped back to the top of the tower as reflux to ensure the normal operation of the distillation tower. A part of the material in the top product buffer tank flows into the top extraction pump by gravity, and after being pressurized by the top extraction pump, the extraction amount of the top product is controlled by controlling the liquid level of the top buffer tank.

[0028] The bottom of the tower is produced as a dark-colored aromatic-based plasticizer.

[0029] Compared with the prior art, the co-production method of a plurality of plasticizers of the present invention has the following beneficial effects: the present invention realizes the continuous production of a plurality of plasticizers through the setting of a continuous distillation tower group, improves the production efficiency, and ensures the stability and consistency of the product quality. Compared with the intermittent production process, the continuous production process has the advantages of low energy consumption and material consumption, thereby reducing the production cost. The present invention adopts a continuous distillation tower group, which has advanced process technology, high automation level, reduces manual operation, and reduces labor intensity. By accurately controlling the temperature and pressure of each distillation tower, the utilization efficiency of the raw materials is optimized, the waste of raw materials is reduced, and the conversion rate of the raw materials is improved. The method can co-produce a plurality of plasticizers, including colorless aromatic plasticizers, light-colored aromatic plasticizers 1#, light-colored aromatic plasticizers 2#, and dark aromatic plasticizers, to meet the needs of different application scenarios. The co-production method of a plurality of plasticizers of the present invention has significant advantages in improving production efficiency, reducing costs, enhancing product diversity, environmental protection, and economic benefits. DETAILED DESCRIPTION

[0030] The present invention is described in detail below by way of examples. Unless otherwise specified, all raw materials used are commercially available.

[0031] Example 1

[0032] Raw materials preparation:

[0033] The crude aromatic components are stored in the raw material storage tank. The raw materials are pressurized by the raw material delivery pump. After being measured by the raw material flow meter, the raw materials enter the raw material preheater at the top of the tower for preheating.

[0034] First distillation tower operation:

[0035] The preheated crude aromatic component enters the middle of the first distillation tower. The tower top temperature is controlled at 190°C, the tower bottom temperature is controlled at 200°C, and the system pressure is controlled at -0.01MPa. Colorless aromatic-based plasticizer is distilled out from the tower top.

[0036] Condensation and reflux of colorless aromatic plasticizers:

[0037] The colorless aromatic plasticizer is cooled into liquid in the product cooler at the top of the tower. Part of the material flows back to the top of the tower to ensure the normal operation of the distillation tower. The remaining material flows into the extraction pump at the top of the tower to control the extraction volume, which accounts for 31% of the total raw material.

[0038] Second distillation tower operation:

[0039] The aromatic hydrocarbons at the bottom of the first distillation tower are used as feed for the second distillation tower. The tower top temperature is controlled at 195°C, the tower bottom temperature is controlled at 220°C, and the system pressure is controlled at -0.01MPa. A light-colored aromatic-based plasticizer 1# is distilled from the tower top.

[0040] Condensation and reflux of light-colored aromatic plasticizer 1#:

[0041] Light-colored aromatic plasticizer 1# is cooled into liquid in the product cooler at the top of the tower. Part of the material flows back to the top of the tower to ensure the normal operation of the distillation tower. The remaining material flows into the extraction pump at the top of the tower to control the extraction volume, which accounts for 29% of the total raw material.

[0042] The third distillation tower operation:

[0043] The aromatic hydrocarbons at the bottom of the second distillation tower are used as feed for the third distillation tower. The tower top temperature is controlled at 180°C, the tower bottom temperature is controlled at 240°C, and the system pressure is controlled at -0.05MPa. A light-colored aromatic-based plasticizer 2# is distilled from the tower top.

[0044] Condensation and reflux of light-colored aromatic plasticizer 2#:

[0045] Light-colored aromatic plasticizer 2# is cooled into liquid in the product cooler at the top of the tower. Part of the material flows back to the top of the tower to ensure the normal operation of the distillation tower. The remaining material flows into the extraction pump at the top of the tower to control the extraction volume, which accounts for 20% of the total raw material.

[0046] Fourth distillation tower operation:

[0047] The aromatic hydrocarbons at the bottom of the third distillation tower are used as feed for the fourth distillation tower. The tower top temperature is controlled at 230℃, the tower bottom temperature is controlled at 270℃, and the system pressure is controlled at -0.09MPa. Aromatic hydrocarbon plasticizers are distilled from the tower top; dark aromatic hydrocarbon-based plasticizers are distilled from the tower bottom.

[0048] Condensation and reflux of aromatic plasticizers:

[0049] Aromatic plasticizers are cooled into liquid in the product cooler at the top of the tower. Part of the material flows back to the top of the tower to ensure the normal operation of the distillation tower. The remaining material flows into the top of the tower extraction pump to control the extraction volume, which accounts for 10% of the total raw material volume.

[0050] Example 2

[0051] Raw materials preparation:

[0052] The crude aromatic components are stored in the raw material storage tank. The raw materials are pressurized by the raw material delivery pump. After being measured by the raw material flow meter, the raw materials enter the raw material preheater at the top of the tower for preheating.

[0053] First distillation tower operation:

[0054] The preheated crude aromatic component material enters the middle of the first distillation tower. The tower top temperature is controlled at 189°C, the tower bottom temperature is controlled at 199°C, and the system pressure is controlled at -0.01MPa. A colorless aromatic-based plasticizer is distilled out from the tower top.

[0055] Condensation and reflux of colorless aromatic plasticizers:

[0056] The colorless aromatic plasticizer is cooled into liquid in the product cooler at the top of the tower. Part of the material flows back to the top of the tower to ensure the normal operation of the distillation tower. The remaining material flows into the extraction pump at the top of the tower to control the extraction volume, which accounts for 32% of the total raw material.

[0057] Second distillation tower operation:

[0058] The aromatic hydrocarbons at the bottom of the first distillation tower are used as feed for the second distillation tower. The tower top temperature is controlled at 196°C, the tower bottom temperature is controlled at 219°C, and the system pressure is controlled at -0.01MPa. A light-colored aromatic-based plasticizer 1# is distilled from the tower top.

[0059] Condensation and reflux of light-colored aromatic plasticizer 1#:

[0060] Light-colored aromatic plasticizer 1# is cooled into liquid in the product cooler at the top of the tower. Part of the material flows back to the top of the tower to ensure the normal operation of the distillation tower. The remaining material flows into the extraction pump at the top of the tower to control the extraction volume, which accounts for 28% of the total raw material.

[0061] The third distillation tower operation:

[0062] The aromatic hydrocarbons at the bottom of the second distillation tower are used as feed for the third distillation tower. The tower top temperature is controlled at 180°C, the tower bottom temperature is controlled at 239°C, and the system pressure is controlled at -0.049MPa. A light-colored aromatic-based plasticizer 2# is distilled from the tower top.

[0063] Condensation and reflux of light-colored aromatic plasticizer 2#:

[0064] Light-colored aromatic plasticizer 2# is cooled into liquid in the tower top product cooler. Part of the material flows back to the tower top to ensure the normal operation of the distillation tower. The remaining material flows into the tower top extraction pump to control the extraction volume, which accounts for 19% of the total raw material.

[0065] Fourth distillation tower operation:

[0066] The aromatic hydrocarbons at the bottom of the third distillation tower are used as feed for the fourth distillation tower. The tower top temperature is controlled at 229°C, the tower bottom temperature is controlled at 269°C, and the system pressure is controlled at -0.09MPa. Aromatic plasticizers are distilled from the tower top; dark aromatic plasticizers are distilled from the tower bottom.

[0067] Condensation and reflux of aromatic plasticizers:

[0068] Aromatic plasticizers are cooled into liquid in the product cooler at the top of the tower. Part of the material flows back to the top of the tower to ensure the normal operation of the distillation tower. The remaining material flows into the top of the tower extraction pump to control the extraction volume, which accounts for 10% of the total raw material volume.

[0069] Example 3

[0070] Raw materials preparation:

[0071] The crude aromatic components are stored in the raw material storage tank. The raw materials are pressurized by the raw material delivery pump. After being measured by the raw material flow meter, the raw materials enter the raw material preheater at the top of the tower for preheating.

[0072] First distillation tower operation:

[0073] The preheated crude aromatic component material enters the middle of the first distillation tower. The tower top temperature is controlled at 191°C, the tower bottom temperature is controlled at 201°C, and the system pressure is controlled at -0.011MPa. A colorless aromatic-based plasticizer is distilled out from the tower top.

[0074] Condensation and reflux of colorless aromatic plasticizers:

[0075] The colorless aromatic plasticizer is cooled into liquid in the product cooler at the top of the tower. Part of the material flows back to the top of the tower to ensure the normal operation of the distillation tower. The remaining material flows into the extraction pump at the top of the tower to control the extraction volume, which accounts for 30% of the total raw material.

[0076] Second distillation tower operation:

[0077] The aromatic hydrocarbons at the bottom of the first distillation tower are used as feed for the second distillation tower. The tower top temperature is controlled at 196°C, the tower bottom temperature is controlled at 221°C, and the system pressure is controlled at -0.011MPa. A light-colored aromatic-based plasticizer 1# is distilled from the tower top.

[0078] Condensation and reflux of light-colored aromatic plasticizer 1#:

[0079] Light-colored aromatic plasticizer 1# is cooled into liquid in the product cooler at the top of the tower. Part of the material flows back to the top of the tower to ensure the normal operation of the distillation tower. The remaining material flows into the extraction pump at the top of the tower to control the extraction volume, which accounts for 28% of the total raw material.

[0080] The third distillation tower operation:

[0081] The aromatic hydrocarbons at the bottom of the second distillation tower are used as feed for the third distillation tower. The tower top temperature is controlled at 181°C, the tower bottom temperature is controlled at 241°C, and the system pressure is controlled at -0.051MPa. A light-colored aromatic-based plasticizer 2# is distilled from the tower top.

[0082] Condensation and reflux of light-colored aromatic plasticizer 2#:

[0083] Light-colored aromatic plasticizer 2# is cooled into liquid in the product cooler at the top of the tower. Part of the material flows back to the top of the tower to ensure the normal operation of the distillation tower. The remaining material flows into the extraction pump at the top of the tower to control the extraction volume, which accounts for 21% of the total raw material.

[0084] Fourth distillation tower operation:

[0085] The aromatic hydrocarbons at the bottom of the third distillation tower are used as feed for the fourth distillation tower. The tower top temperature is controlled at 231°C, the tower bottom temperature is controlled at 271°C, and the system pressure is controlled at -0.091MPa. Aromatic hydrocarbon plasticizers are distilled from the tower top; dark aromatic hydrocarbon-based plasticizers are distilled from the tower bottom.

[0086] Condensation and reflux of aromatic plasticizers:

[0087] Aromatic plasticizers are cooled into liquid in the product cooler at the top of the tower. Part of the material flows back to the top of the tower to ensure the normal operation of the distillation tower. The remaining material flows into the top of the tower extraction pump to control the extraction volume, which accounts for 10% of the total raw material volume.

[0088] Example 4

[0089] Raw materials preparation:

[0090] The crude aromatic components are stored in the raw material storage tank. The raw materials are pressurized by the raw material delivery pump. After being measured by the raw material flow meter, the raw materials enter the raw material preheater at the top of the tower for preheating.

[0091] First distillation tower operation:

[0092] The preheated crude aromatic component material enters the middle of the first distillation tower. The tower top temperature is controlled at 188°C, the tower bottom temperature is controlled at 198°C, and the system pressure is controlled at -0.009MPa. A colorless aromatic-based plasticizer is distilled out from the tower top.

[0093] Condensation and reflux of colorless aromatic plasticizers:

[0094] The colorless aromatic plasticizer is cooled into liquid in the product cooler at the top of the tower. Part of the material flows back to the top of the tower to ensure the normal operation of the distillation tower. The remaining material flows into the extraction pump at the top of the tower to control the extraction volume, which accounts for 29% of the total raw material.

[0095] Second distillation tower operation:

[0096] The aromatic hydrocarbons at the bottom of the first distillation tower are used as feed for the second distillation tower. The tower top temperature is controlled at 194°C, the tower bottom temperature is controlled at 218°C, and the system pressure is controlled at -0.009MPa. A light-colored aromatic-based plasticizer 1# is distilled from the tower top.

[0097] Condensation and reflux of light-colored aromatic plasticizer 1#:

[0098] Light-colored aromatic plasticizer 1# is cooled into liquid in the product cooler at the top of the tower. Part of the material flows back to the top of the tower to ensure the normal operation of the distillation tower. The remaining material flows into the extraction pump at the top of the tower to control the extraction volume, which accounts for 27% of the total raw material.

[0099] The third distillation tower operation:

[0100] The aromatic hydrocarbons at the bottom of the second distillation tower are used as feed for the third distillation tower. The tower top temperature is controlled at 179°C, the tower bottom temperature is controlled at 238°C, and the system pressure is controlled at -0.048MPa. A light-colored aromatic-based plasticizer 2# is distilled from the tower top.

[0101] Condensation and reflux of light-colored aromatic plasticizer 2#:

[0102] Light-colored aromatic plasticizer 2# is cooled into liquid in the product cooler at the top of the tower. Part of the material flows back to the top of the tower to ensure the normal operation of the distillation tower. The remaining material flows into the extraction pump at the top of the tower to control the extraction volume, which accounts for 18% of the total raw material.

[0103] Fourth distillation tower operation:

[0104] The aromatic hydrocarbons at the bottom of the third distillation tower are used as feed for the fourth distillation tower. The tower top temperature is controlled at 228°C, the tower bottom temperature is controlled at 268°C, and the system pressure is controlled at -0.089MPa. Aromatic plasticizers are distilled from the tower top; dark aromatic plasticizers are distilled from the tower bottom.

[0105] Condensation and reflux of aromatic plasticizers:

[0106] Aromatic plasticizers are cooled into liquid in the product cooler at the top of the tower. Part of the material flows back to the top of the tower to ensure the normal operation of the distillation tower. The remaining material flows into the top of the tower extraction pump to control the extraction volume, which accounts for 9% of the total raw material volume.

[0107] Example 5

[0108] Raw materials preparation:

[0109] The crude aromatic components are stored in the raw material storage tank. The raw materials are pressurized by the raw material delivery pump. After being measured by the raw material flow meter, the raw materials enter the raw material preheater at the top of the tower for preheating.

[0110] First distillation tower operation:

[0111] The preheated crude aromatic component material enters the middle of the first distillation tower. The tower top temperature is controlled at 193°C, the tower bottom temperature is controlled at 203°C, and the system pressure is controlled at -0.012MPa. A colorless aromatic-based plasticizer is distilled out from the tower top.

[0112] Condensation and reflux of colorless aromatic plasticizers:

[0113] The colorless aromatic plasticizer is cooled into liquid in the product cooler at the top of the tower. Part of the material flows back to the top of the tower to ensure the normal operation of the distillation tower. The remaining material flows into the extraction pump at the top of the tower to control the extraction volume, which accounts for 34% of the total raw material.

[0114] Second distillation tower operation:

[0115] The aromatic hydrocarbons at the bottom of the first distillation tower are used as feed for the second distillation tower. The tower top temperature is controlled at 197°C, the tower bottom temperature is controlled at 222°C, and the system pressure is controlled at -0.012MPa. A light-colored aromatic-based plasticizer 1# is distilled from the tower top.

[0116] Condensation and reflux of light-colored aromatic plasticizer 1#:

[0117] Light-colored aromatic plasticizer 1# is cooled into liquid in the product cooler at the top of the tower. Part of the material flows back to the top of the tower to ensure the normal operation of the distillation tower. The remaining material flows into the extraction pump at the top of the tower to control the extraction volume, which accounts for 31% of the total raw material.

[0118] The third distillation tower operation:

[0119] The aromatic hydrocarbons at the bottom of the second distillation tower are used as feed for the third distillation tower. The tower top temperature is controlled at 182°C, the tower bottom temperature is controlled at 242°C, and the system pressure is controlled at -0.052MPa. A light-colored aromatic-based plasticizer 2# is distilled from the tower top.

[0120] Condensation and reflux of light-colored aromatic plasticizer 2#:

[0121] Light-colored aromatic plasticizer 2# is cooled into liquid in the product cooler at the top of the tower. Part of the material flows back to the top of the tower to ensure the normal operation of the distillation tower. The remaining material flows into the extraction pump at the top of the tower to control the extraction volume, which accounts for 22% of the total raw material.

[0122] Fourth distillation tower operation:

[0123] The aromatic hydrocarbons at the bottom of the third distillation tower are used as feed for the fourth distillation tower. The tower top temperature is controlled at 232°C, the tower bottom temperature is controlled at 272°C, and the system pressure is controlled at -0.092MPa. Aromatic hydrocarbon plasticizers are distilled from the tower top; dark aromatic hydrocarbon-based plasticizers are distilled from the tower bottom.

[0124] Condensation and reflux of aromatic plasticizers:

[0125] Aromatic plasticizers are cooled into liquid in the product cooler at the top of the tower. Part of the material flows back to the top of the tower to ensure the normal operation of the distillation tower. The remaining material flows into the top of the tower extraction pump to control the extraction volume, which accounts for 11% of the total raw material volume.

[0126] The above is only a preferred embodiment of the present invention, and does not limit the present invention in other forms. Any technician familiar with the profession may use the above disclosed technical content to change or modify it into an equivalent embodiment with equivalent changes. However, any simple modification, equivalent change and modification made to the above embodiment according to the technical essence of the present invention without departing from the technical solution of the present invention still belongs to the protection scope of the technical solution of the present invention.

Claims

1. A method for co-producing multiple plasticizers, characterized in that: The following steps are involved: Using crude aromatic component material as raw material, the temperature is controlled in a continuous distillation tower group to produce colorless aromatic plasticizer, light-colored aromatic plasticizer 1#, light-colored aromatic plasticizer 2#, aromatic plasticizer, and dark aromatic plasticizer.

2. The method for co-producing multiple plasticizers according to claim 1, characterized in that: The continuous distillation tower group is a first distillation tower, a second distillation tower, a third distillation tower and a fourth distillation tower connected in series in sequence. Each distillation tower extracts plasticizer from the top of the tower, and the bottom discharge port of the previous distillation tower is connected to the feed port in the middle of the next distillation tower. A heat exchanger is provided at the gas phase outlet at the top of each distillation tower as a raw material preheater. Before the raw material enters the first distillation tower, it is preheated by each raw material preheater.

3. A method for co-producing multiple plasticizers according to claim 2, characterized in that: The colorless aromatic plasticizer is extracted from the top of the first distillation tower. The top temperature of the first distillation tower is 188°C to 193°C, the bottom temperature is 198°C to 203°C, and the system pressure is -0.009MPa to -0.012MPa.

4. The method for co-producing multiple plasticizers according to claim 3, characterized in that: The colorless aromatic-based plasticizer extracted from the top of the first distillation tower is partially refluxed after condensation, and the extracted amount accounts for 29% to 34% of the total raw material amount.

5. The method for co-producing multiple plasticizers according to claim 2, characterized in that: The light-colored aromatic plasticizer 1# is extracted from the top of the second distillation tower. The top temperature of the second distillation tower is 194°C to 197°C, the bottom temperature is 218°C to 222°C, and the system pressure is -0.009 to -0.012MPa.

6. A method for co-producing multiple plasticizers according to claim 5, characterized in that: The light-colored aromatic-based plasticizer 1# extracted from the top of the second distillation tower is partially refluxed after condensation, and the amount extracted accounts for 27% to 31% of the total raw material amount.

7. The method for co-producing multiple plasticizers according to claim 2, characterized in that: The light-colored aromatic plasticizer 2# is extracted from the top of the third distillation tower. The top temperature of the third distillation tower is 179°C to 182°C, the bottom temperature is 238°C to 242°C, and the system pressure is -0.048MPa to -0.052MPa.

8. A method for co-producing multiple plasticizers according to claim 7, characterized in that: The light-colored aromatic-based plasticizer 2# extracted from the top of the third distillation tower is partially refluxed after condensation, and the amount extracted accounts for 18% to 22% of the total raw material amount.

9. The method for co-producing multiple plasticizers according to claim 2, characterized in that: The top of the fourth distillation tower produces an aromatic plasticizer, and the bottom of the tower produces a dark aromatic plasticizer; the top temperature of the fourth distillation tower is 228°C to 232°C, the bottom temperature is 268°C to 272°C, and the system pressure is -0.089MPa to -0.092MPa.

10. A method for co-producing multiple plasticizers according to claim 9, characterized in that: The amount of aromatic plasticizer produced from the top of the fourth distillation tower accounts for 9% to 11% of the total raw material, and the remaining part of the raw material is produced from the bottom of the tower.