Energy-saving and consumption-reducing atmospheric and vacuum light hydrocarbon recovery integrated device
By adding a primary top reflux tank, a reflux cooler and a drainage pump to the atmospheric and vacuum light hydrocarbon recovery unit, the naphtha at the top of the primary distillation tower is roughly separated, which solves the problem of increased energy consumption caused by high naphtha yield and achieves the effect of energy saving and consumption reduction.
Patent Information
- Application Number
- CN202422595472.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-25
- Publication Date
- 2025-09-26
- Estimated Expiration
- 2034-10-25
AI Technical Summary
Since the raw materials processed by the atmospheric and vacuum units become lighter and the naphtha yield is high, the recovery of light hydrocarbons requires more atmospheric and medium heat sources, which increases the operating costs and gas usage of the unit. The problem of large changes in the energy consumption of the unit needs to be solved.
A primary top first-stage reflux tank (three-phase separation tank), a primary top reflux cooler and a primary top first-stage drainage pump are added between the crude oil/primary top gas heat exchanger and the primary top air cooler to achieve rough separation of the naphtha at the top of the primary distillation tower and send it directly to the reforming pre-hydrogenation unit to avoid repeated heating and separation.
The gas usage was reduced by about 260Nm3/h, the energy consumption of the device was reduced, and the operating cost was reduced without affecting the light oil blending amount.
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Figure CN223386094U_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of petrochemical industry, and in particular relates to an energy-saving and consumption-reducing atmospheric and vacuum light hydrocarbon recovery combined device. Background Art
[0002] The information disclosed in this background technology section is only intended to enhance understanding of the overall background of the invention and should not necessarily be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to those skilled in the art.
[0003] The naphtha distilled from the atmospheric and vacuum primary distillation tower contains about 6% C3C4 hydrocarbons. The naphtha is sent to the light hydrocarbon stabilization tower in the light hydrocarbon recovery unit, and is heated in the reboiler at the bottom of the stabilization tower (heat source in the atmospheric and vacuum secondary distillation tower) to separate C3C4 and distill from the top of the tower. The relatively pure stable naphtha is obtained at the bottom of the tower and sent to the reforming pre-hydrogenation unit as the raw material for the reforming pre-hydrogenation unit.
[0004] In the existing technical solutions, such as Figure 1 The crude oil / primary overhead gas from the top of the atmospheric and vacuum primary distillation tower is piped through the crude oil / primary overhead gas heat exchanger and the primary overhead air cooler before being delivered to the primary overhead product and reflux tank. The primary overhead non-condensable gas from the top of the primary overhead product and reflux tank is split into two routes: one route is delivered to the gas buffer tank, and the other route is delivered to the inlet of the rich gas compressor of the catalytic unit. The primary overhead oil from the bottom of the primary overhead product and reflux tank is pressurized by a pump and delivered to the light hydrocarbon recovery unit.
[0005] The inventors discovered that: because the raw materials processed by the atmospheric and vacuum device become lighter, the naphtha yield is high, and the amount of naphtha going to the light hydrocarbon stabilizer increases by about one-fold, more constant-secondary heat sources are needed to achieve stable operation of light hydrocarbon recovery. This change has led to a surge in the use of atmospheric and vacuum gas, posing a great challenge to the control of device operating costs. Obviously, when the properties of the raw materials change greatly and the naphtha yield at the top of the primary distillation tower increases from the original 52t / h to 90t / h, it will lead to an increase in the load of the light hydrocarbon stabilizer reboiler and stabilizer, a large change in the energy consumption of the device, and an increase in operating costs. In order to reduce the energy consumption and operating costs of the device, maximize the benefits, and improve the competitive advantage, it is urgent to solve the problem of device energy consumption. Utility Model Content
[0006] In order to address the deficiencies of the prior art, the purpose of the present invention is to provide an energy-saving and consumption-reducing atmospheric and vacuum light hydrocarbon recovery combined unit, to transform and optimize the naphtha system at the top of the primary distillation tower, to solve the problem of increased operating costs of the unit due to the increase in naphtha, and to achieve the purpose of energy saving and consumption reduction.
[0007] In order to achieve the above object, the technical solution of the present invention is:
[0008] The present invention provides an energy-saving and consumption-reducing atmospheric and vacuum light hydrocarbon recovery combined device, comprising an atmospheric and vacuum primary distillation tower, an initial top first-level reflux tank, an initial top product and a reflux tank, a light hydrocarbon recovery device and a reforming pre-hydrogenation device. The top of the atmospheric and vacuum primary distillation tower is connected to the initial top first-level reflux tank through a first pipeline, the top of the initial top first-level reflux tank is connected to the initial top product and the top of the reflux tank through a second pipeline, the initial top product and the reflux tank are connected to the light hydrocarbon recovery device through a third pipeline, the bottom of one side of the initial top first-level reflux tank is connected to a fourth pipeline, the fourth pipeline is respectively connected to a fifth pipeline and a sixth pipeline, the sixth pipeline is connected to the second pipeline, the fifth pipeline is respectively connected to a seventh pipeline and an eighth pipeline, the seventh pipeline is connected to the reforming pre-hydrogenation device, and the eighth pipeline is connected to the top of one side of the atmospheric and vacuum primary distillation tower; the bottom of the initial top first-level reflux tank is connected to a ninth pipeline, and the ninth pipeline is connected to the second pipeline.
[0009] Furthermore, the primary top level reflux tank is a three-phase separation tank.
[0010] Furthermore, a crude oil / primary top gas heat exchanger is installed on the first pipeline. The number of heat exchangers is adjusted according to actual conditions. If multiple heat exchangers are used, they are connected in parallel. For example, two heat exchangers are connected in parallel in this embodiment.
[0011] Furthermore, a primary top air cooler is installed on the second pipeline, so that the uncondensed oil and gas from the top of the primary top first-level reflux tank is cooled by the primary top air cooler and then enters the primary top product and reflux tank. At this time, the oil and gas condensed by the primary top air cooler is light naphtha (this naphtha is called secondary oil).
[0012] Furthermore, a primary top and secondary oil pumps are installed on the third pipeline, so that the products from the primary top and the products in the reflux tank are sent to the light hydrocarbon recovery device through the primary top and secondary oil pumps.
[0013] Furthermore, a primary top oil pump is installed on the fourth pipeline, so that the heavy naphtha (the naphtha is called primary oil) separated from the primary top first reflux tank is pumped out and pressurized by the primary top first oil pump and then divided into two routes, the fifth pipeline and the sixth pipeline.
[0014] Furthermore, the fifth pipeline is equipped with a top reflux air cooler. After cooling in the top reflux air cooler, the cooled heavy naphtha is further divided into two routes: the seventh and eighth pipelines. The seventh pipeline is connected to the reforming pre-hydrogenation unit, so that the heavy naphtha separated from the top first-stage reflux tank is transported to the reforming pre-hydrogenation unit. The eighth pipeline is connected to the top of one side of the atmospheric and vacuum primary distillation column.
[0015] Furthermore, the sixth pipeline is connected to the pipeline in front of the primary top air cooler installed in the second pipeline, so that the heavy naphtha separated from the primary top first-level reflux tank is transported to the second pipeline through the sixth pipeline, merged with the oil and gas from the top of the primary top first-level reflux tank, and then cooled by the primary top air cooler and transported to the primary top product and reflux tank.
[0016] Furthermore, a primary top first-stage drainage pump is installed on the ninth pipeline, and the ninth pipeline is connected to the pipeline behind the primary top air cooler installed on the second pipeline, so that the water phase separated from the primary top first-stage reflux tank is transported to the second pipeline through the ninth pipeline and merged with the light naphtha cooled by the primary top air cooler.
[0017] Furthermore, the initial top product and the lower part of the reflux tank are connected to the tenth pipeline, and an initial top secondary drainage pump is installed on the tenth pipeline. After being pressurized by the initial top secondary drainage pump, it is divided into two paths. One path is connected to the water injection point of the first pipeline to inject water into the oil and gas coming out of the top of the primary distillation tower; the other path is sulfur-containing wastewater, which is connected to the acidic water stripping device.
[0018] Furthermore, the initial top product and the top of the reflux tank are connected to the eleventh pipeline, and the initial top non-condensable gas is transported to the gas buffer tank through the eleventh pipeline.
[0019] The beneficial effects of the utility model are:
[0020] (1) The present invention is based on the original process. In the process between the crude oil / primary top gas heat exchanger and the primary top air cooler, a primary top first-stage reflux tank (three-phase separation tank), a primary top reflux cooler and a primary top first-stage drainage pump (acid water pump) are newly added. The oil and gas coming out of the primary distillation tower are roughly separated, and the heavier naphtha fraction at the top of the tower is transported to the reforming pre-hydrogenation unit as the raw material composition of the reforming pre-hydrogenation, thereby avoiding repeated entry of light hydrocarbons for heating and separation, which increases the energy consumption of the device.
[0021] (2) The design of the device of the utility model is consistent with the operation of the original reflux tank. The system operation does not increase the difficulty. It can separate about 40% of the heavy naphtha first and send it directly to the reforming pre-hydrogenation. After calibration, this design can reduce about 260Nm 3 / h of gas usage, which solves the problem of a significant increase in energy consumption of the device without affecting the light oil blending amount. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] The drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation on the present invention.
[0023] Figure 1 This is a diagram of a conventional atmospheric and vacuum light hydrocarbon recovery combined unit;
[0024] Figure 2 This is a diagram of a combined atmospheric and vacuum light hydrocarbon recovery device for energy saving and consumption reduction in Example 1 of the present utility model;
[0025] Among them: 1-atmospheric and vacuum primary distillation tower, 2-primary top first-level reflux tank, 3-primary top product and reflux tank, 4-light hydrocarbon recovery unit, 5-reforming pre-hydrogenation unit, 6-first pipeline, 7-second pipeline, 8-third pipeline, 9-fourth pipeline, 10-fifth pipeline, 11-sixth pipeline, 12-seventh pipeline, 13-eighth pipeline, 14-ninth pipeline, 15-tenth pipeline, 16-eleventh pipeline, 17-crude oil / primary top gas heat exchanger, 18-primary top air cooler, 19-primary top second-level oil pump, 20-primary top first-level oil pump, 21-primary top reflux air cooler, 22-primary top first-level drainage pump, 23-primary top second-level drainage pump. DETAILED DESCRIPTION
[0026] In order to enable those skilled in the art to more clearly understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below with reference to specific embodiments.
[0027] Example 1
[0028] according to Figure 2 The present invention discloses an energy-saving and consumption-reducing atmospheric and vacuum light hydrocarbon recovery combined device, comprising an atmospheric and vacuum primary distillation tower 1, an initial top first-stage reflux tank 2, an initial top product and reflux tank 3, a light hydrocarbon recovery device 4, and a reforming pre-hydrogenation device 5. The top of the atmospheric and vacuum primary distillation tower 1 is connected to the initial top first-stage reflux tank 2 through a first pipeline 6, the top of the initial top first-stage reflux tank 2 is connected to the top of the initial top product and reflux tank 3 through a second pipeline 7, and the bottom of the initial top product and reflux tank 3 is connected to the light hydrocarbon recovery tank through a third pipeline 8. Device 4 is connected, the bottom of one side of the initial top first-level reflux tank 2 is connected to the fourth pipeline 9, the fourth pipeline 9 is respectively connected to the fifth pipeline 10 and the sixth pipeline 11, the sixth pipeline 11 is connected to the second pipeline 7, the fifth pipeline 10 is respectively connected to the seventh pipeline 12 and the eighth pipeline 13, the seventh pipeline 12 is connected to the reforming pre-hydrogenation device 5, and the eighth pipeline 13 is connected to the top of one side of the atmospheric and vacuum primary distillation tower 1; the bottom of the initial top first-level reflux tank 2 is connected to the ninth pipeline 14, and the ninth pipeline 14 is connected to the second pipeline 7.
[0029] The primary top first-stage reflux tank is a three-phase separation tank, set as one. The existing design is that the oil and gas at the top of the primary distillation tower are cooled by the crude oil / primary top gas heat exchanger and the primary top air cooler to 40°C, and then enter the primary top product and reflux tank (primary top oil and gas separation tank).
[0030] The transformation of the utility model is to add a three-phase separation tank (primary top first-level reflux tank), a primary top reflux cooler and an acid water pump (primary top first-level drainage pump) to the process between the crude oil / primary top gas heat exchanger and the primary top air cooler. The top oil and gas from the primary distillation tower are cooled to approximately 75°C via a crude oil / top gas heat exchanger and then enter a top primary reflux tank for separation. Approximately 40% of the heavy naphtha (referred to as first-grade oil) is condensed, meeting the reforming pre-hydrogenation feedstock specification (initial boiling point > 40°C). This naphtha is then directly delivered to the reforming pre-hydrogenation unit via a top primary oil pump and a top reflux cooler. The gas phase exiting the top of the top primary reflux tank is cooled in a top air cooler and condensed into light naphtha (referred to as second-grade oil). This enters the top product and reflux tank, where it is then pressurized by a top secondary oil pump and delivered to the light hydrocarbon stabilization tower in the light hydrocarbon recovery unit for separation. A water phase is also separated from the bottom of the top primary reflux tank and delivered to a second pipeline cooled by the top primary drainage pump. The water phase is then combined and delivered to the top product and reflux tank.
[0031] This device design enables a simple, rough separation of the heavier naphtha fraction at the top of the tower, resulting in a feedstock composition suitable for reforming pre-hydrogenation. This avoids repeated heating and separation of light hydrocarbons, which would increase the device's energy consumption. A crude oil / primary overhead gas heat exchanger 17 is installed on the first pipeline 6. The number of heat exchangers can be adjusted based on actual conditions. If multiple heat exchangers are used, they can be connected in parallel. In this embodiment, two heat exchangers are connected in parallel.
[0032] The first pipeline 6 is also provided with a water injection point and a neutralizer injection point, which merges with the initial top oil and gas coming out of the atmospheric and vacuum primary distillation tower and then enters the crude oil / initial top gas heat exchanger 17.
[0033] A primary top air cooler 18 is installed on the second pipeline 7, so that the uncondensed oil and gas from the top of the primary top first-level reflux tank 2 is cooled by the primary top air cooler 18 and then enters the primary top product and reflux tank 3. At this time, the oil and gas condensed by the primary top air cooler is light naphtha (this naphtha is called secondary oil).
[0034] The primary top and secondary oil pumps 19 are installed on the third pipeline 8 so that the primary top product and the product in the reflux tank are sent to the light hydrocarbon recovery device 4 through the primary top and secondary oil pumps 19 .
[0035] A primary oil pump 20 is installed on the fourth pipeline 9. This pump pumps the heavy naphtha (called primary oil) from the primary reflux tank 2, pumping it out and boosting its pressure before diverting it into two routes: the fifth pipeline 10 and the sixth pipeline 11. Compared to the prior art, the modified primary oil pump can be replaced with a higher-flow capacity one, and two primary oil pumps can be installed.
[0036] The fifth pipeline is cooled and then divided into two routes after cooling. One route is to control the temperature of the top of the tower, and the other route controls the liquid level of the primary top first-stage reflux tank to transport the separated heavy naphtha to the reforming pre-hydrogenation device. The sixth pipeline adjusts the flow rate according to the load of the back-end compressor on a daily basis. Specifically, a primary top reflux air cooler 21 is installed on the fifth pipeline 10. After cooling by the primary top reflux air cooler 21, the cooled heavy naphtha is divided into two routes, the seventh pipeline 12 and the eighth pipeline 13. The seventh pipeline 12 is connected to the reforming pre-hydrogenation device 5, so that the heavy naphtha separated from the primary top first-stage reflux tank 2 is transported to the reforming pre-hydrogenation device 5. The eighth pipeline 13 is connected to the top of one side of the atmospheric and vacuum primary distillation tower 1. The sixth pipeline 11 is connected to the pipeline in front of the primary top air cooler 18 installed on the second pipeline 7, so that the heavy naphtha separated from the primary top first-level reflux tank 2 is transported to the second pipeline 7 through the sixth pipeline 11, merged with the oil and gas from the top of the primary top first-level reflux tank 2, and then cooled by the primary top air cooler 18 and transported to the primary top product and reflux tank 3.
[0037] A primary top-stage drainage pump 22 is installed on the ninth pipeline 14. The ninth pipeline 14 is connected to the pipeline after the primary top-stage air cooler 18 of the second pipeline 7. The aqueous phase separated from the primary top-stage reflux tank 2 is transported to the second pipeline 7 via the ninth pipeline 14, where it merges with the light naphtha cooled by the primary top-stage air cooler 18. Two additional primary top-stage drainage pumps can be installed.
[0038] The lower part of the primary top product and reflux tank 3 is connected to the tenth pipeline 15. The primary top secondary drainage pump 23 is installed on the tenth pipeline. After being pressurized by the primary top secondary drainage pump 23, it is divided into two paths. One path is connected to the water injection point of the first pipeline 6 to inject water into the oil and gas coming out of the top of the atmospheric and vacuum primary distillation tower 1 (this connection relationship is not shown in the figure); the other path is sulfur-containing wastewater, which is connected to the acid water stripping device.
[0039] The initial top product and the reflux tank top 3 are connected to the eleventh pipeline 16, and the initial top non-condensable gas is transported to the gas buffer tank through the eleventh pipeline 16.
[0040] The flow path of the energy-saving and consumption-reducing atmospheric and vacuum light hydrocarbon recovery combined unit is:
[0041] The top oil and gas coming out of the top of the primary distillation tower are heated to 75°C in the crude oil / top gas heat exchanger on the first pipeline and then enter the newly added top first-level reflux tank for separation. The uncondensed oil and gas coming out of the top of the top first-level reflux tank enter the inlet of the top air cooler installed on the second pipeline under self-pressure. The oil separated from the top first-level reflux tank is pumped out and pressurized by the top first-level oil pump and then divided into two routes (the fifth pipeline and the sixth pipeline). Among them, the fifth pipeline is cooled to 40°C in the newly added top reflux cooler and then divided into two routes (the seventh pipeline and the eighth pipeline). The eighth pipeline is sent to the top of the primary distillation tower, and the seventh pipeline is sent to the reforming pre-hydrogenation unit as the top first-level oil product (heavy naphtha); the sixth pipeline is combined with the uncondensed oil and gas on the second pipeline and enters the inlet of the top air cooler installed on the second pipeline. The oil gas and first-level oil are cooled to 40℃ by the primary top air cooler and then enter the primary top product and reflux tank. The primary top non-condensable gas is sent to the gas buffer tank, and then pressurized by the liquid ring compressor and sent to the light hydrocarbon raw gas buffer tank in the light hydrocarbon recovery unit. The primary top secondary oil is extracted and pressurized by the primary top secondary oil pump and also sent to the light hydrocarbon recovery unit stabilization tower.
[0042] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that the present invention is susceptible to various modifications and variations. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.
Claims
1. An energy-saving and consumption-reducing atmospheric and vacuum light hydrocarbon recovery combined device, characterized in that: It includes a normal vacuum primary distillation tower, a primary top first-level reflux tank, a primary top product and a reflux tank, a light hydrocarbon recovery device and a reforming pre-hydrogenation device. The top of the normal vacuum primary distillation tower is connected to the primary top first-level reflux tank through a first pipeline, the top of the primary top first-level reflux tank is connected to the top of the primary top product and the reflux tank through a second pipeline, the primary top product and the reflux tank are connected to the light hydrocarbon recovery device through a third pipeline, the bottom of one side of the primary top first-level reflux tank is connected to the fourth pipeline, the fourth pipeline is respectively connected to the fifth pipeline and the sixth pipeline, the sixth pipeline is connected to the second pipeline, the fifth pipeline is respectively connected to the seventh pipeline and the eighth pipeline, the seventh pipeline is connected to the reforming pre-hydrogenation device, and the eighth pipeline is connected to the top of one side of the normal vacuum primary distillation tower; the bottom of the primary top first-level reflux tank is connected to the ninth pipeline, and the ninth pipeline is connected to the second pipeline.
2. The energy-saving and consumption-reducing atmospheric and vacuum light hydrocarbon recovery combined device according to claim 1 is characterized in that: The primary top level reflux tank is a three-phase separation tank.
3. The energy-saving and consumption-reducing atmospheric and vacuum light hydrocarbon recovery combined device according to claim 1 is characterized in that: A crude oil / primary top gas heat exchanger is installed on the first pipeline.
4. The energy-saving and consumption-reducing atmospheric and vacuum light hydrocarbon recovery combined device according to claim 1 is characterized in that: A primary top air cooler is installed on the second pipeline.
5. The energy-saving and consumption-reducing atmospheric and vacuum light hydrocarbon recovery combined device according to claim 1 is characterized in that: Install the primary and secondary oil pumps on the third pipeline.
6. The energy-saving and consumption-reducing atmospheric and vacuum light hydrocarbon recovery combined device according to claim 1 is characterized in that: The fourth pipeline is equipped with a primary top first-stage oil pump, so that the heavy naphtha separated from the primary top first-stage reflux tank is pumped out and pressurized by the primary top first-stage oil pump and then divided into two routes, the fifth pipeline and the sixth pipeline.
7. The energy-saving and consumption-reducing atmospheric and vacuum light hydrocarbon recovery combined device according to claim 1 or 6, characterized in that: The fifth pipeline is equipped with a primary top return air cooler. After being cooled by the primary top return air cooler, the cooled heavy naphtha is divided into two routes, the seventh pipeline and the eighth pipeline. The sixth pipeline is connected to the pipeline in front of the second pipeline where the primary top air cooler is installed.
8. The energy-saving and consumption-reducing atmospheric and vacuum light hydrocarbon recovery combined device according to claim 1 is characterized in that: The ninth pipeline is equipped with a primary top first-stage drainage pump, and the ninth pipeline is connected to the pipeline behind the second pipeline where the primary top air cooler is installed.
9. The energy-saving and consumption-reducing atmospheric and vacuum light hydrocarbon recovery combined device according to claim 1 is characterized in that: The initial top product and the lower part of the reflux tank are connected to the tenth pipeline. An initial top secondary drainage pump is installed on the tenth pipeline. After being pressurized by the initial top secondary drainage pump, it is divided into two paths, one of which is connected to the water injection point of the first pipeline; the other is sulfur-containing wastewater, which is connected to the acid water stripping device.
10. The energy-saving and consumption-reducing atmospheric and vacuum light hydrocarbon recovery combined device according to claim 1 is characterized in that: The top of the initial top product and the reflux tank are connected to the eleventh pipeline, and the initial top non-condensable gas is transported to the gas buffer tank through the eleventh pipeline.