Alpha olefin separation method adopting heat integration

Abstract

The invention discloses a method for separating alpha olefin by adopting heat integration. The method comprises the following steps: step 1, putting a product: putting the product into a solvent tower to separate out C6 olefin; the product flowing out of the solvent tower is sequentially conveyed to a C8 tower, a C10 tower and a C12 tower through a pump body, the third step of product separation, the fourth step of cooling mechanism installation, the fifth step of product backflow and the sixth step of product recovery. According to the invention, the gas phase at the top of the separation tower for separating 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene and 1-octadecene products is respectively used as a cooling medium, and the heated solvent returns to the solvent refining tower in the cooling process to provide heat for the solvent refining tower to refine the solvent, so that the steam consumption of the solvent tower is greatly reduced; meanwhile, the consumption of cooling water at the top of the separation tower for 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene and 1-octadecene products is reduced, and the energy-saving effect is particularly obvious.

Description

Technical Field

[0001] The invention relates to the technical field of petrochemical engineering, and in particular to a separation method of alpha olefins using heat integration. Background Art

[0002] Linear α-olefins (LAO) are important fine chemical raw materials. Molecular chains of different lengths have different uses: C4-C8 is used in high-density and low-density polyethylene, C 10 -C 12 Used for polymerization to prepare advanced lubricating oil, C 12 -C 16 It is used in the preparation of detergents. Other uses include the preparation of alcohols, epoxides, amines, thiols and synthetic fatty acids.

[0003] The main methods for producing α-olefins include wax cracking, ethylene polymerization, extraction separation, fatty alcohol dehydrogenation, internal olefin isomerization, Alfene and Fischer-Tropsch synthesis.

[0004] Ethylene oligomerization and Fischer-Tropsch synthesis are currently the main methods for producing α-olefins. The product of ethylene oligomerization is a mixture of solvent and α-olefins.

[0005] Fischer-Tropsch synthesis is one of the most effective ways to utilize coal cleanly and efficiently. Fischer-Tropsch synthetic oil has the advantages of high α-olefin content, no sulfur, no nitrogen, and less aromatics. The traditional way to utilize Fischer-Tropsch synthetic oil is to produce finished oil through hydrogenation process, which fails to effectively utilize high-value-added α-olefin resources and needs to seek new high-value utilization methods. Aiming at the high-value utilization of Fischer-Tropsch synthetic oil, the complete set of technology consists of Fischer-Tropsch synthetic oil deoxygenation, alkane-olefin separation and α-olefin carbonyl synthesis process, which can realize the high-value utilization of Fischer-Tropsch synthetic oil and further improve the economic benefits of enterprises.

[0006] Regardless of the production method, the reaction products of alpha olefin production generally include solvents, 1-butene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene and a series of alpha olefins. It is a complex and energy-intensive process to separate each high-purity 1-butene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene and a series of alpha olefin products from the mixed alpha olefins of the reaction products. The process usually adopts a distillation tower sequential separation process, the tower bottom is heated by steam, and the tower top is cooled by circulating water. Such separation requires a large amount of steam and circulating water, consumes a lot of energy, and cannot meet people's separation needs. How to overcome the shortcomings of traditional alpha olefin separation, find a more effective and economical method for separating alpha olefins, reduce production costs, improve production efficiency, and make production more economical, is a problem before us. Summary of the invention

[0007] The object of the present invention is to provide a separation method of alpha olefins using heat integration to solve the problems raised in the above background technology.

[0008] To achieve the above object, the present invention provides the following technical solution: a method for separating alpha olefins using heat integration, comprising the following steps:

[0009] Step 1: Product placement: Place the product in a solvent tower to separate C6 olefins;

[0010] Step 2, product transportation: the product flowing out of the solvent tower is transported to the C8 tower, C10 tower, C12 tower, C14 tower, C16 tower and C18 tower in sequence through a pump body;

[0011] Step 3: Product separation: The products are sequentially passed through the separation tower to separate the products;

[0012] Step 4, installing cooling mechanism: installing condensers on the top of the carbon 8 tower, carbon 10 tower, carbon 12 tower, carbon 14 tower, carbon 16 tower and carbon 18 tower respectively;

[0013] Step 5, product reflux: The gas phase at the top of the separation tower is used as a cooling medium. At the same time, the heated solvent during the cooling process returns to the solvent refining tower to provide heat to the solvent refining tower to refine the solvent.

[0014] As a preferred technical solution of the present invention, in step 1, the solvent tower bottom is controlled by the total heat load of the solvent tower, and the energy consumption required for solvent tower distillation is saved by calculating and providing the solvent tower reboiler with the required amount of supplementary steam for the solvent tower.

[0015] As a preferred technical solution of the present invention, the control process of the condenser in step 4 is specifically as follows: the flow rate of the hot solvent required for the condenser is controlled by the liquid level of the top condenser and the temperature of the condensate, the condensation load required for the top condenser is controlled, and the hot solvent replaces the circulating cooling water or the air cooler, thereby reducing the consumption of circulating cooling water or electricity consumption and achieving energy saving.

[0016] As a preferred technical solution of the present invention, the product transportation in the step 2 is specifically to use a pump at the bottom of the solvent tower to send the solvent of the solvent tower to the top gas phase of the separation tower for separating 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, and 1-octadecene products as a cooling medium.

[0017] As a preferred technical solution of the present invention, the product reflux in step 5 is specifically that the heated solvent in the cooling process returns to the solvent refining tower to provide heat to the solvent refining tower to purify the solvent.

[0018] As a preferred technical solution of the present invention, the separation tower in the step 2 is specifically a carbon 8 tower, a carbon 10 tower, a carbon 12 tower, a carbon 14 tower, a carbon 16 tower and a carbon 18 tower.

[0019] As a preferred technical solution of the present invention, the separated products in step 2 are specifically 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene and 1-octadecene.

[0020] Compared with the prior art, the invention has the following beneficial effects: the solvent of the solvent tower is used to provide the gas phase at the top of the separation tower for separating 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene and 1-octadecene products as cooling medium, and the heated solvent is returned to the solvent refining tower during the cooling process to provide heat to the solvent refining tower for refining the solvent, thereby greatly reducing the steam consumption of the solvent tower and saving the consumption of cooling water at the top of the separation tower for separating the 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene and 1-octadecene products, and the energy-saving effect is particularly obvious. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a flow chart of the present invention;

[0022] Figure 2 It is the overall flow chart of the separation method of the present invention;

[0023] Figure 3 This is the energy-saving separation control flow chart of the present invention;

[0024] Figure 4 This is a condenser control flow chart of the present invention. DETAILED DESCRIPTION

[0025] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0026] See also Figure 1-4 The present invention provides a method for separating alpha olefins using heat integration, comprising the following steps:

[0027] Step 1: Product placement: Place the product in a solvent tower to separate C6 olefins;

[0028] Step 2, product transportation: the product flowing out of the solvent tower is transported to the C8 tower, C10 tower, C12 tower, C14 tower, C16 tower and C18 tower in sequence through a pump body;

[0029] Step 3: Product separation: The products are sequentially passed through the separation tower to separate the products;

[0030] Step 4, installing cooling mechanism: installing condensers on the top of the carbon 8 tower, carbon 10 tower, carbon 12 tower, carbon 14 tower, carbon 16 tower and carbon 18 tower respectively;

[0031] Step 5, product reflux: The gas phase at the top of the separation tower is used as a cooling medium. At the same time, the heated solvent during the cooling process returns to the solvent refining tower to provide heat to the solvent refining tower to refine the solvent.

[0032] In step 1, the solvent tower bottom is controlled by the total heat load of the solvent tower, and the energy consumption required for solvent tower distillation is saved by providing the solvent tower reboiler with the required amount of supplementary steam for the solvent tower through calculation.

[0033] The control process of the condenser in step 4 is specifically as follows: the flow rate of the hot solvent required by the condenser is controlled by the liquid level of the top condenser and the temperature of the condensate, the condensation load required by the top condenser is controlled, and the hot solvent replaces the circulating cooling water or air cooler, which reduces the consumption of circulating cooling water or electricity consumption and achieves energy saving.

[0034] In step 2, the product transportation is specifically to use a pump at the bottom of the solvent tower to send the solvent of the solvent tower to the top gas phase of the separation tower for separating 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, and 1-octadecene products as a cooling medium.

[0035] The product reflux in step 5 specifically refers to the heated solvent in the cooling process returning to the solvent refining tower to provide heat to the solvent refining tower to purify the solvent.

[0036] The separation towers in step 2 are specifically a carbon 8 tower, a carbon 10 tower, a carbon 12 tower, a carbon 14 tower, a carbon 16 tower and a carbon 18 tower.

[0037] The separated products in step 2 are specifically 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene and 1-octadecene.

[0038] In the present invention, the product is put into a solvent tower to separate C6 olefins; the product flowing out of the solvent tower is sequentially transported to a carbon eight tower, a carbon ten tower, a carbon twelve tower, a carbon fourteen tower, a carbon sixteen tower and a carbon eighteen tower through a pump body; the product passes through the separation tower in sequence to separate products, and the separated products are specifically 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene and 1-octadecene; condensers are respectively installed on the top of the carbon eight tower, the carbon ten tower, the carbon twelve tower, the carbon fourteen tower, the carbon sixteen tower and the carbon eighteen tower, and the solvent of the solvent tower is respectively sent to the top gas phase of the separation tower for separating 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene and 1-octadecene products by a pump at the bottom of the solvent tower as a cooling medium; the top gas phase of the separation tower is used as a cooling medium, and the heated solvent in the cooling process is returned to the solvent refining tower to provide heat to the solvent refining tower to purify the solvent, and the solvent is purified by the solvent refining tower. Figure 3 , the solvent tower bottom control process is disclosed, the total heat load control of the solvent tower is adopted, and the amount of supplementary steam required by the solvent tower is provided to the solvent tower reboiler by calculation, thus saving the energy consumption required for solvent tower distillation. Figure 4 , disclose the control process of each top condenser, control the flow of hot solvent required by the condenser through the liquid level of the top condenser and the temperature of the condensate, that is, control the condensation load required by the top condenser, and the hot solvent replaces the circulating cooling water or air cooler, reducing the consumption of circulating cooling water or electricity consumption, so as to achieve the purpose of energy saving. The solvent of the solvent tower is respectively sent to the top gas phase of the separation tower for separating 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene and 1-octadecene products by pump at the bottom of the solvent tower as cooling medium. At the same time, the heated solvent in the cooling process returns to the solvent refining tower to provide heat to the solvent refining tower to refine the solvent.

[0039] Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for separating alpha olefins using heat integration, characterized in that: The following steps are involved: Step 1: Product placement: Place the product in a solvent tower to separate C6 olefins; Step 2, product transportation: the product flowing out of the solvent tower is transported to the C8 tower, C10 tower, C12 tower, C14 tower, C16 tower and C18 tower in sequence through a pump body; Step 3: Product separation: The products are sequentially passed through the separation tower to separate the products; Step 4, installing cooling mechanism: installing condensers on the top of the carbon 8 tower, carbon 10 tower, carbon 12 tower, carbon 14 tower, carbon 16 tower and carbon 18 tower respectively; Step 5, product reflux: The gas phase at the top of the separation tower is used as a cooling medium. At the same time, the heated solvent during the cooling process returns to the solvent refining tower to provide heat to the solvent refining tower to refine the solvent.

2. The method for separating alpha olefins using heat integration according to claim 1, characterized in that: In the step 1, the solvent tower bottom is controlled by the total heat load of the solvent tower, and the amount of supplementary steam required by the solvent tower is provided to the solvent tower reboiler through calculation.

3. The method for separating alpha olefins using heat integration according to claim 1, characterized in that: The control process of the condenser in step 4 is specifically as follows: the flow rate of the hot solvent required by the condenser is controlled by the liquid level of the top condenser and the temperature of the condensate, the condensation load required by the top condenser is controlled, and the hot solvent replaces the circulating cooling water or the air cooler.

4. The method for separating alpha olefins using heat integration according to claim 1, characterized in that: The product transportation in step 2 is specifically to use a pump at the bottom of the solvent tower to send the solvent of the solvent tower to the top gas phase of the separation tower for separating 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, and 1-octadecene products as a cooling medium.

5. The method for separating alpha olefins using heat integration according to claim 1, characterized in that: The product reflux in step 5 specifically refers to the heated solvent in the cooling process returning to the solvent refining tower to provide heat to the solvent refining tower to refine the solvent.

6. The method for separating alpha olefins using heat integration according to claim 1, characterized in that: The separation towers in the step 2 are specifically a carbon 8 tower, a carbon 10 tower, a carbon 12 tower, a carbon 14 tower, a carbon 16 tower and a carbon 18 tower.

7. The method for separating alpha olefins using heat integration according to claim 1, characterized in that: The separated products in step 2 are specifically 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene and 1-octadecene.

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