Recovery device for discharged materials of liquefied hydrocarbon tank field

Abstract

The utility model discloses a recovery device for discharged materials in a liquefied hydrocarbon tank field, which comprises a liquefied hydrocarbon discharge point and is characterized in that the liquefied hydrocarbon discharge point at least comprises a spherical tank, a loading arm, a delivery pump and a sampling box and is provided with a material recovery pipe according to the type of liquefied hydrocarbon or equipment; the discharge point of any liquefied hydrocarbon of the same kind of equipment is connected with the same material recovery pipe, or the discharge point of any kind of equipment of the same liquefied hydrocarbon is connected with the same material recovery pipe; the recovery device is provided with a material recovery header pipe, any material recovery pipe is connected with the material recovery header pipe, and the material recovery header pipe is connected to a product gas compressor. According to the device disclosed by the utility model, materials discharged by liquefied hydrocarbon tank field operation are recovered by the material recovery header pipe, sent to the product gas compressor, pressurized by the compressor and then returned to the device, so that hydrocarbon products are recovered.

Description

Technical Field

[0001] The utility model belongs to the technical field of methanol to olefins (MTO), and relates to a device for recovering materials discharged from a liquefied hydrocarbon tank area. Background Art

[0002] Methanol-to-olefins (MTO) plants produce ethylene and propylene using methanol as a feedstock. The liquefied hydrocarbons involved in the production process include, in addition to ethylene and propylene, ethane, propane, and C4 components. The storage and use of these materials, particularly liquefied hydrocarbon tanks for ethylene, propylene, and propane, often require operations such as sampling, loading, and emptying spherical tanks and pumping equipment.

[0003] The above operations will generate emission points for liquefied hydrocarbon materials. For example, during the production process in the liquefied hydrocarbon tank area, material sampling and analysis must be carried out regularly. During the sampling process, the outlet of the sampling box is connected to a flare. After sampling is completed, the remaining material in the sampling box is flared to release pressure. Products also need to be loaded and shipped for daily external sales. During the loading process, the crane pipe needs to be flared to release pressure. Before the product delivery pump in the tank area is inspected and repaired, the material in the pump needs to be emptied into the flare. Liquefied hydrocarbon spherical tanks require periodic pressure vessel inspections. When the spherical tanks are emptied and replaced, the liquefied hydrocarbons need to be flared to release pressure. The various operations in the liquefied hydrocarbon tank area are difficult to avoid the discharge of materials. Directly flaring causes material waste. When liquefied hydrocarbons are flared to release pressure at multiple locations on site at the same time, the flare will produce certain combustion emissions.

[0004] The shortcomings of the existing liquefied hydrocarbon tank farm discharge material treatment are mainly in the following two aspects:

[0005] 1. Operations such as liquefied hydrocarbon sampling, loading, and equipment emptying release pressure to the flare, resulting in material loss and increased energy consumption;

[0006] 2. When liquefied hydrocarbons are discharged into the flare, they cause flare combustion and emissions, increasing carbon emissions and bringing great environmental pressure to the company.

[0007] There is an urgent need to improve the device and operation to avoid material loss and reduce the environmental pressure of operation. The utility model is an effective way to solve these problems. Summary of the Invention

[0008] The purpose of the utility model is to provide a device for recovering materials discharged from a liquefied hydrocarbon tank area, so as to solve the problems of material loss and environmental pollution caused by directly emptying the discharged materials during the operation of the liquefied hydrocarbon tank area. The device recovers hydrocarbon products in the discharged materials during sampling, loading and equipment emptying in the liquefied hydrocarbon tank area, thereby reducing material loss and reducing the emission of flare hydrocarbons.

[0009] In order to achieve the above-mentioned purpose of the invention, the technical solution adopted by the present utility model is:

[0010] A device for recovering materials discharged from a liquefied hydrocarbon tank area includes a liquefied hydrocarbon discharge point, characterized in that the liquefied hydrocarbon discharge point includes at least a spherical tank, a loading crane pipe, a transfer pump and a sampling box, the liquefied hydrocarbon discharge point is provided with a material recovery pipe according to the type of liquefied hydrocarbon or equipment, and any liquefied hydrocarbon discharge point of the same type of equipment is connected to the same material recovery pipe, or the discharge point of any type of equipment of the same liquefied hydrocarbon is connected to the same material recovery pipe; the recovery device is provided with a material recovery main pipe, any material recovery pipe is connected to the material recovery main pipe, and the material recovery main pipe is connected to a product gas compressor.

[0011] Furthermore, the liquefied hydrocarbons include at least ethylene, propylene and propane, and may also include one or more of ethane and C4 components.

[0012] Furthermore, a recovery valve is provided on the material recovery pipe.

[0013] Furthermore, the liquefied hydrocarbon discharge point is connected to the flare pipe network through a discharge valve.

[0014] Beneficial Effects: The liquefied hydrocarbon tank farm discharge material recovery device of the present invention recovers the discharged material through the recovery main pipe during sampling, loading, and equipment emptying operations at the liquefied hydrocarbon tank farm. The recovered material is then sent to the low-pressure system, delivered to the product gas compressor, and then pressurized by the compressor and returned to the MTO unit to recover the hydrocarbon product. The device can switch the liquefied hydrocarbon discharge material from flaring to system recovery, avoiding the environmental impact caused by the short-term flaring of the discharge material from the liquefied hydrocarbon tank farm operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 A schematic structural diagram of a device for recovering materials discharged from a liquefied hydrocarbon tank farm according to the present invention;

[0016] Among them, 1-material recovery main pipe, 2-first material recovery pipe, 3-second material recovery pipe, 4-third material recovery pipe, 5-fourth material recovery pipe, 6-product gas compressor suction tank, 7-product gas compressor, 8-primary separation tower, 9-propylene distillation tower, 10-ethylene distillation tower, 11-flare pipe network. DETAILED DESCRIPTION

[0017] The specific implementation methods of the present invention are described in detail below. However, it should be noted that the protection scope of the present invention is not limited by these specific implementation methods, but is determined by the claims.

[0018] The liquefied hydrocarbons involved in methanol-to-olefins (MTO) plants include at least ethylene, ethane, propylene, propane, and C4 components. Ethylene, propylene, and propane are primarily produced in these liquefied hydrocarbon tank areas. These liquefied hydrocarbons are often sampled, loaded onto trucks, and emptied from spherical tanks and pumping equipment. Residual materials from equipment such as spherical tanks, loading cranes, transfer pumps, and sampling tanks during or after operation can create liquefied hydrocarbon discharge points.

[0019] like Figure 1 As shown, the recovery device for materials discharged from the liquefied hydrocarbon tank area of ​​the present invention includes spherical tanks, loading crane pipes, conveying pumps and sampling boxes for ethylene, propylene and propane. According to the position of each liquefied hydrocarbon discharge point, this embodiment sets the same material recovery pipe for the same type of equipment of ethylene, propylene and propane, such as the loading crane pipe is connected to the first material recovery pipe 2, the conveying pump is connected to the second material recovery pipe 3, the spherical tank is connected to the third material recovery pipe 4, and the sampling box is connected to the fourth material recovery pipe 5. Recovery valves are set on the material recovery pipes; the first, second, third and fourth material recovery pipes 2, 3, 4, 5 are connected to the material recovery main pipe 1, and the material recovery main pipe 1 is connected to the product gas compressor 7 to uniformly recover and process the system materials.

[0020] The emission processes for sampling, loading, emptying the pump, and depressurizing the spherical tank in the original device are: liquefied hydrocarbon product → sampling box → flare; liquefied hydrocarbon product → liquefied hydrocarbon loading pump → loading crane pipe → flare; liquefied hydrocarbon product → liquefied hydrocarbon pump → flare; liquefied hydrocarbon spherical tank → flare.

[0021] After adopting the device of the utility model, the discharged materials from the operations of sampling, loading, emptying the machine pump, and depressurizing the spherical tank in the liquefied hydrocarbon tank area can be recovered. The material recovery process is as follows: liquefied hydrocarbon product → sampling box → material recovery pipe - material recovery main pipe - product gas compressor; liquefied hydrocarbon product → liquefied hydrocarbon loading pump → loading crane pipe → material recovery pipe - material recovery main pipe - product gas compressor; liquefied hydrocarbon product → liquefied hydrocarbon pump → material recovery pipe - material recovery main pipe - product gas compressor; liquefied hydrocarbon spherical tank → material recovery pipe - material recovery main pipe - product gas compressor.

[0022] When liquefied hydrocarbon sampling, loading, pump emptying, spherical tank pressure relief and other operations are carried out, the original flare pipe network 11 ( Figure 1 The connection between the other liquefied hydrocarbon discharge points and the flare pipe network (except propylene) is not shown, and the discharge valve is closed and cut out, and the recovery valve to the material recovery pipe is opened to realize the recovery of the liquefied hydrocarbon material.

[0023] The specific instructions are as follows:

[0024] When loading liquefied hydrocarbon products, the flare pipe network 11 is disconnected, the connected first material recovery pipe 2 is opened, and the material is recovered through the material recovery main pipe 1 to the product gas compressor suction tank 6. For example, when loading propylene, the crane pipe material recovery process is activated to relieve the pressure to approximately 0.20 MPa. After the pressure relief is complete, the loading crane pipe is removed and replaced.

[0025] When the liquefied hydrocarbon product pump requires maintenance, the connection to the flare pipe network 11 is disconnected, the connected second material recovery pipe 3 is opened, and the material is recovered through the material recovery main pipe 1 to the product gas compressor suction tank 6. For example, using a propylene delivery pump, the pump body material recovery process is put into operation and the pressure is relieved to approximately 0.20 MPa. After replacement and pressure relief are completed, the remaining pressure is released to the flare for pump maintenance.

[0026] When a liquefied hydrocarbon product spherical tank requires maintenance, the connection to the flare pipe network 11 is disconnected, the connected third material recovery pipe 4 is opened, and the material is recovered through the material recovery main pipe 1 to the product gas compressor suction tank 6. Taking a propylene spherical tank as an example, the spherical tank material recovery process is put into use and the pressure is relieved to approximately 0.20 MPa. After replacement and pressure relief are completed, the remaining pressure is relieved to the flare for tank maintenance.

[0027] When sampling liquefied hydrocarbon products, the connection from the sampling box outlet to the flare pipe network 11 is closed, the connected fourth material recovery pipe 5 is opened, and the material is recovered through the material recovery main pipe 1 to the product gas compressor suction tank 6. Taking propylene sampling as an example, the pressure of the steel cylinder in the propylene sampling box is controlled at 1.60 MPa, and the pressure at the sampling box outlet to the fourth material recovery pipe 5 is controlled at approximately 0.20 MPa. After the sample replacement is completed, the steel cylinder sampling is carried out. After sampling is completed, the sampling box inlet and outlet valves are closed.

[0028] See attached Figure 1 Taking propylene recovery as an example, the recovered liquefied hydrocarbons are sent to the product gas compressor suction tank 6, compressed by the product gas compressor 7, and then enter the primary separation tower 8 for separation, and then pass through the propylene distillation tower 9 to separate the propylene product, and finally obtain the propylene product, completing the material recovery.

[0029] In addition, ethylene is similar to propylene. The recovered liquefied hydrocarbons are sent to the product gas compressor suction tank 6, compressed by the product gas compressor 7, and then enter the primary separation tower 8 for separation, and then pass through the ethylene distillation tower 10 to separate the ethylene product, and finally obtain the ethylene product, completing the material recovery.

[0030] Ethylene, propylene, and propane samples are collected at least once daily from the tank farm, resulting in approximately 22 tons of material being flared annually. If two truckloads of each product are loaded daily, approximately 219 tons of material will be flared annually. Pumps are overhauled every two years, resulting in approximately 4 tons of material being flared annually. Spherical tank pressure vessels are inspected, emptied, and replaced, resulting in approximately 80 tons of material being flared annually. By utilizing this utility model to recover discharged materials from the liquefied hydrocarbon tank farm, the estimated annual recovery of approximately 325 tons of olefin products is expected.

Claims

1. A device for recovering discharged materials from a liquefied hydrocarbon tank farm, comprising a liquefied hydrocarbon discharge point, characterized in that: The liquefied hydrocarbon discharge point includes at least a spherical tank, a loading crane pipe, a transfer pump and a sampling box. The liquefied hydrocarbon discharge point is provided with a material recovery pipe according to the type of liquefied hydrocarbon or equipment. The discharge point of any liquefied hydrocarbon of the same type of equipment is connected to the same material recovery pipe, or the discharge point of any type of equipment of the same liquefied hydrocarbon is connected to the same material recovery pipe; the recovery device is provided with a material recovery main pipe, and any material recovery pipe is connected to the material recovery main pipe, and the material recovery main pipe is connected to the product gas compressor.

2. The device for recovering discharged materials from a liquefied hydrocarbon tank farm according to claim 1, characterized in that: The liquefied hydrocarbons include at least ethylene, propylene and propane.

3. The device for recovering discharged materials from a liquefied hydrocarbon tank farm according to claim 2, characterized in that: The liquefied hydrocarbons also include one or more of ethane and C4 components.

4. The device for recovering discharged materials from a liquefied hydrocarbon tank farm according to claim 1, characterized in that: A recovery valve is provided on the material recovery pipe.

5. The device for recovering discharged materials from a liquefied hydrocarbon tank farm according to claim 1, characterized in that: The liquefied hydrocarbon discharge point is connected to the flare pipe network through a discharge valve.

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