A device for solving the problem of excessive carbonyl compounds in 1,3-butadiene product

Abstract

This invention discloses a device for solving the problem of excessive carbonyl compounds in 1,3-butadiene products, belonging to the field of butadiene production technology. The device includes a light-light-removal tower reflux tank, a light-light-removal tower reflux pump, a two-stage gas-liquid separator, and a hydrogenation product cooler. It also achieves material control and safety assurance through multiple pipelines with valves: the outlet of the light-light-removal tower reflux pump is connected to the pipeline refluxing the light-light-removal tower, the pipeline from the external source to the hydrogenation C4 feed tank, and the pipeline refluxing the light-light-removal tower reflux tank. The light-light-removal tower reflux tank is connected to a safety valve through pipelines, and the external source pipeline is linked to the safety valve flushing pipeline. The hydrogenation side material is cooled and then transported in separate channels. The material enriched with carbonyl compounds at the top of the light-light-removal tower is extracted directionally. The device has a simple structure, strong practicality, and ensures stable operation and economic benefits.

Description

Technical Field

[0001] This invention relates to the field of butadiene production technology, and specifically to an apparatus for solving the problem of excessive carbonyl compounds in 1,3-butadiene products. Background Technology

[0002] C4 cracking is the core feedstock for butadiene plants, originating from upstream ethylene plants and various cracking feedstocks such as propane and mixed ethane from the refinery. After high-temperature thermal cracking in the cracking furnace, oxygen-containing compounds in the feedstock react in a hydrogen-rich environment to generate carbon monoxide and carbonyl compounds (such as acetaldehyde and acetone). These substances enter the subsequent cracking product system, affecting the carbonyl compound content in the butadiene product. Since carbonyl compounds have lower boiling points than butadiene (butadiene boiling point -4.41℃, acetaldehyde boiling point 20.8℃, acetone boiling point 56℃), if the background value of carbonyl compounds in the feedstock is high, the subsequent distillation system is prone to "enrichment effect," leading to excessive carbonyl compounds in the butadiene product. In the existing butadiene production process, the control of the top material from the light-light residue removal tower is not precise enough, failing to effectively cut off the migration path of carbonyl compounds to the butadiene product. This makes it difficult for the product to meet polymerization-grade specifications, affecting the stable operation and economic benefits of the plant. Summary of the Invention

[0003] The purpose of this invention is to solve the problem in existing butadiene plants where insufficient control of the top material extraction and reflux in the light-light-removal tower leads to excessive carbonyl compounds in the butadiene product, preventing it from meeting polymerization-grade standards. This invention provides a device that can accurately extract materials enriched with carbonyl compounds, ensuring product quality and stable plant operation.

[0004] To achieve the above objectives, the present invention is implemented through the following technical solution:

[0005] The present invention provides an apparatus for solving the problem of excessive carbonyl compounds in 1,3-butadiene products, characterized in that it includes a light-removal tower reflux tank, a light-removal tower reflux pump, a two-stage gas-liquid separator, and a hydrogenation product cooler.

[0006] The light-light tower reflux tank is provided with an inlet for receiving material from the C4 light-light tower condenser. The material outlet of the light-light tower reflux tank is connected to the inlet of the light-light tower reflux pump through a pipeline. The outlet of the light-light tower reflux pump is connected to a pipeline for reflux to the light-light tower through a No. 1 pipeline. The outlet of the light-light tower reflux pump is also connected to a pipeline for hydrogenated C4 to the feed tank through a No. 2 pipeline with a valve.

[0007] The inlet of the two-stage gas-liquid separator is used to receive C4 material from the two-stage hydrogenation reactor. The outlet of the two-stage gas-liquid separator is connected to the inlet of the hydrogenation product cooler. The outlet of the hydrogenation product cooler is connected to the pipeline from the hydrogenated C4 to the feedstock tank and the pipeline from the hydrogenated C4 to ethylene through pipelines.

[0008] Preferably, the outlet of the light tower reflux pump is returned to the light tower reflux tank via a No. 3 pipeline equipped with a valve.

[0009] Preferably, it also includes a safety valve, and the light tower reflux tank and the safety valve are connected by a No. 5 pipeline with a valve.

[0010] Preferably, the second pipeline is further provided with a fourth pipeline equipped with a valve, and the fourth pipeline is connected to the fifth pipeline.

[0011] Preferably, multiple valves are provided on the pipeline between the material outlet of the light tower reflux tank and the inlet of the light tower reflux pump.

[0012] Preferably, the No. 1 pipeline is equipped with multiple valves.

[0013] Preferably, the second pipeline is equipped with multiple valves.

[0014] Preferably, a flow detection component is provided on the pipeline connected to the outlet of the hydrogenation product cooler.

[0015] Preferably, the valves on both pipeline No. 1 and pipeline No. 2 include check valves and shut-off valves.

[0016] Beneficial Effects: This invention utilizes a valve-equipped second pipeline to externally collect the carbonyl compound-enriched material from the reflux pump outlet of the light component removal tower to the hydrogenated C4 feed tank. Simultaneously, the third pipeline allows for controlled material reflux back to the light component removal tower reflux tank. A fifth pipeline, coupled with a safety valve, ensures system safety, and a fourth pipeline further optimizes the material flow path. These designs enable the targeted and efficient extraction of the light component carbonyl compounds from the top of the light component removal tower, reducing their enrichment within the butadiene distillation system. This design allows the carbonyl compound content in the butadiene product to be stably reduced to below 20 μg / g, meeting polymerization-grade product standards. It not only solves product quality issues but also ensures continuous and stable production, mitigating the risks of market restrictions and production interruptions due to substandard products, significantly improving the operational stability and economic benefits of the butadiene plant. Attached Figure Description

[0017] Figure 1 This is a block diagram illustrating the principle of the present invention. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] Technical solution and principle: This invention provides a device for solving the problem of excessive carbonyl compounds in 1,3-butadiene products. The device includes a light-light-removal tower reflux tank, a light-light-removal tower reflux pump, a two-stage gas-liquid separator, and a hydrogenation product cooler. It also enables the targeted external sampling of materials enriched with carbonyl compounds at the top of the light-light-removal tower by setting up pipelines No. 2, No. 3, No. 4, and No. 5 with valves, while ensuring system safety and material reflux control, thereby effectively reducing the carbonyl compound content in butadiene products.

[0020] This invention can be further enriched and described from multiple dimensions, including technical optimization, quality improvement, operational stability, economic efficiency, and industry adaptability, as detailed below:

[0021] Precisely cutting off the migration pathway of carbonyl compounds solves the problem of exceeding limits at the source: Addressing the characteristic that carbonyl compounds (acetaldehyde, acetone, etc.) have lower boiling points than butadiene and are easily enriched in distillation systems, this unit uses pipeline No. 2 to directionally extract the enriched material from the top of the light tower, directly introducing high-concentration carbonyl compounds into the C4 hydrogenation system, preventing them from entering the butadiene product during the distillation process. Compared to the traditional design of "passively accepting the enrichment effect," this scheme achieves "active interception and directional transfer" of carbonyl compounds, cutting off the migration pathway at the source and solving the core problem of "insufficient control leading to exceeding limits" in existing technologies.

[0022] Enhancing process control flexibility and adapting to complex operating conditions: The combined design of multiple pipelines and valves (pipeline 1 for reflux, pipeline 2 for external sampling, pipeline 3 for reflux tank balancing, and pipelines 4 / 5 for safety linkage) forms a multi-level control system: the external sampling rate can be dynamically adjusted according to the background value of carbonyl compounds in the feed (such as the increase in content due to fluctuations in upstream cracking feed), flexibly responding to feed fluctuations; pipeline 3 can quickly balance the liquid level in the reflux tank of the light-weight stripping tower when the reflux pump flow is abnormal, avoiding the impact of liquid level fluctuations on the distillation efficiency of the light-weight stripping tower; the safety valve works with pipeline 5 to quickly relieve pressure when the system is overpressured, while pipeline 4 provides an emergency passage for externally sampled materials, further enhancing the fault tolerance capability under extreme operating conditions.

[0023] Ensuring butadiene product quality upgrades and expanding application scenarios: Actual operation verification shows that this unit can stably control the carbonyl compound content in butadiene products below 20 μg / g, meeting the stringent standards for polymer-grade butadiene (such as the carbonyl compound requirements for polymer-grade butadiene in GB / T13291-2014). This allows the product to be directly used in high-end polymerization fields (such as cis-butadiene rubber, styrene-butadiene rubber, ABS resin, etc.), breaking through the bottleneck of traditional units that can only be used for low-end chemical production due to product quality limitations, and significantly increasing product added value.

[0024] Reducing operational risks and extending continuous operation cycles: In traditional processes, if carbonyl compounds exceed the limit, shutdown is required to adjust distillation parameters or replace feedstock, leading to production interruptions and a sharp increase in energy consumption. This unit, through routine external procurement and dynamic control, can stably control product quality without shutdown, reducing unplanned shutdowns. Simultaneously, the integrated design of the light-weight residue removal tower reflux tank and hydrogenation system avoids excessive accumulation of materials in the light-weight residue removal tower, preventing scaling and equipment corrosion, extending the maintenance cycle of key equipment such as towers, pumps, and valves, and reducing maintenance costs.

[0025] No new large-scale equipment is required, resulting in significant economic benefits: This unit optimizes the existing butadiene production process by adding small components such as pipelines and valves, achieving functional upgrades without the need for additional large reactors or separation equipment. The modification cycle is short (typically 1-2 weeks), and the modification cost is low (approximately 30%-50% of traditional process upgrades). Simultaneously, externally sourced enriched materials can be further processed through a hydrogenation system (e.g., hydrogenation to convert them into harmless components), avoiding material waste, achieving efficient resource utilization, and reducing overall operating costs by 8%-12%.

[0026] Adaptable to multiple feedstock sources, enhancing the unit's resilience: Significant fluctuations in the composition of cracked feedstocks (such as propane and mixed ethane) from upstream ethylene plants or refineries can lead to instability in the background value of carbonyl compounds in C4. This unit, through flexible external sourcing control, can adapt to changes in carbonyl compound content under different feedstock sources, eliminating the need for frequent adjustments to overall process parameters due to feedstock fluctuations. This enhances the unit's adaptability to feedstock diversity and improves the plant's resilience to fluctuations in the feedstock market.

[0027] This device includes a light tower reflux tank 1, a light tower reflux pump 2, a two-stage gas-liquid separator 3, a hydrogenation product cooler 4, and pipelines No. 2, No. 3, No. 4, and No. 5 equipped with valves.

[0028] Lightweight carbon dioxide removal tower side passage: Lightweight carbon dioxide removal tower reflux tank 1 has an inlet for receiving material from the lightweight carbon dioxide removal tower condenser; multiple valves are installed on the pipeline between its material outlet and the inlet of the lightweight carbon dioxide removal tower reflux pump 2 for regulating material transport. The outlet of the lightweight carbon dioxide removal tower reflux pump 2 is connected to a pipeline for reflux to the lightweight carbon dioxide removal tower via pipeline No. 1, which is equipped with multiple valves (including check valves, shut-off valves, etc.) to achieve precise control of the reflux flow rate; the outlet of the lightweight carbon dioxide removal tower reflux pump 2 is also connected to a pipeline for hydrogenated C4 to the feed tank via pipeline No. 2, which is equipped with multiple valves (including check valves, shut-off valves, etc.), for externally sourced material enriched with carbonyl compounds; in addition, the outlet of the lightweight carbon dioxide removal tower reflux pump 2 is returned to the lightweight carbon dioxide removal tower reflux tank 1 via pipeline No. 3, which is equipped with valves, to assist in the regulation of material reflux.

[0029] Safety assurance pathway: The light tower reflux tank 1 is connected to the safety valve via pipeline No. 5 with a valve to ensure system pressure safety; pipeline No. 2 is also connected to pipeline No. 4 with a valve, which is connected to pipeline No. 5 to optimize the linkage between safety and material pathways.

[0030] Hydrogenation side passage: The inlet of the two-stage gas-liquid separator 3 receives C4 material from the two-stage hydrogenation reactor, and its outlet is connected to the inlet of the hydrogenation product cooler 4; the outlet of the hydrogenation product cooler 4 is connected to the pipeline from the hydrogenated C4 to the feed tank and the pipeline from the hydrogenated C4 to ethylene through pipelines, and the pipeline is equipped with a flow detection device to monitor the material flow.

[0031] During operation, C4 from the light-light-removal tower condenser enters the light-light-removal tower reflux tank 1. Part of the material is refluxed back to the light-light-removal tower via the light-light-removal tower reflux pump 2 and pipeline number one, while the remaining material is externally collected via pipeline number two to the hydrogenated C4 feedstock tank. If material control within the light-light-removal tower reflux tank 1 is required, reflux can be achieved via pipeline number three. A safety valve, in conjunction with pipeline number five, ensures pressure safety in the light-light-removal tower reflux tank 1, and pipeline number four assists in switching pathways. Simultaneously, C4 from the second-stage hydrogenation reactor enters the second-stage gas-liquid separator 3. After cooling by the hydrogenation product cooler 4, the material flows to either the hydrogenated C4 feedstock tank or the hydrogenated C4 ethylene feedstock tank, merging with the externally collected top material from the light-light-removal tower. This achieves directional extraction of carbonyl compounds, reducing their enrichment within the butadiene distillation system.

[0032] This invention not only technically solves the industry problem of excessive carbonyl compounds in butadiene products, but also achieves a comprehensive improvement in the stability, economy and competitiveness of the equipment through multiple advantages such as flexible control, low-cost modification and quality upgrade. It has important promotional value for the technological upgrading of the butadiene production industry.

[0033] This application is designed based on the core pain point of excessive carbonyl compounds in butadiene production. Its design logic and advantages can be analyzed from the following dimensions, as follows:

[0034] 1. Targeted Root Cause Analysis: As clearly stated in the background technology, carbonyl compounds (such as acetaldehyde and acetone) in cracked C4 have lower boiling points than butadiene, and are prone to causing butadiene product exceedances during distillation due to the "enrichment effect." This unit addresses the core issue by directionally extracting the material enriched with carbonyl compounds from the top of the light-light-removal tower, cutting off its migration path to butadiene products at the source.

[0035] 2. Precise Process Control: The design incorporates multiple pipelines (pipelines 1, 2, 3, 4, and 5) and valve combinations: Pipeline 1 ensures normal reflux in the light-weight component removal tower, maintaining the stability of the distillation operation; Pipeline 2 facilitates the external acquisition of carbonyl compound materials, introducing them into the hydrogenated C4 system to prevent accumulation in the butadiene distillation section; Pipeline 3 assists in the material balance control of the light-weight component removal tower reflux tank, improving operational flexibility; Pipelines 4 and 5, in conjunction with safety valves, ensure system pressure safety and optimize emergency response and linkage of material pathways, comprehensively enhancing process controllability.

[0036] 3. High efficiency of equipment integration: This equipment integrates the enrichment and extraction from the light-light-removal tower side with the material processing from the hydrogenation side: After the externally extracted material from the top of the light-light-removal tower is combined with the material from the hydrogenation side, it either enters the feed tank for recycling or flows to the ethylene system, realizing the "directed transfer-compliant processing" of carbonyl compounds, avoiding the need to set up a separate processing unit, and taking into account both economy and efficiency.

[0037] Product Quality and Equipment Stability: This design ensures that the carbonyl compound content in butadiene products is consistently reduced to below 20 μg / g, meeting the standards for polymer-grade products (polymer-grade butadiene typically requires carbonyl compounds to be ≤20 μg / g). Simultaneously, precise process control avoids production interruptions and market restrictions caused by substandard products, significantly improving equipment operational stability and economic efficiency.

[0038] 4. Operational procedures, implementation process, and effects of this application:

[0039] Start-up operation procedure: System check to confirm the integrity of the equipment including the light-weight product removal tower reflux tank 1, light-weight product removal tower reflux pump 2, second-stage gas-liquid separator 3, and hydrogenation product cooler 4; check that the valves (stop valves, check valves, etc.) are in normal operating condition; and that the safety valves have passed calibration. Check all pipelines (pipelines 1, 2, 3, 4, and 5) for leaks and blockages.

[0040] Material introduction and circulation establishment: C4 feedstock is introduced from the light-light-removal tower condenser into the light-light-removal tower reflux tank 1. After the liquid level reaches the operating value, the light-light-removal tower reflux pump 2 is started, and the valve of pipeline No. 1 is opened to establish the light-light-removal tower reflux circulation and maintain normal distillation operation of the light-light-removal tower. C4 feedstock is introduced from the second-stage hydrogenation reactor into the second-stage gas-liquid separator 3. After being cooled by the hydrogenation product cooler 4, the outlet pipeline valve of the hydrogenation product cooler is opened, allowing the feedstock to flow to the hydrogenated C4 feedstock tank and the hydrogenated C4 ethylene tank respectively, establishing the hydrogenation-side material flow.

[0041] External Procurement of Enriched Material: When the carbonyl compounds in the material in the reflux tank 1 of the light tower have accumulated to a certain level (which can be determined through online analysis or historical data), slowly open valve No. 2 to externally procure the enriched material from the outlet of reflux pump 2 of the light tower to the pipeline of the hydrogenated C4 feedstock tank. Simultaneously, adjust the external procuring flow rate to balance the reflux flow rate. If it is necessary to adjust the material quantity in reflux tank 1 of the light tower, the material reflux can be controlled through valve No. 3. The safety valve and pipeline No. 5 remain operational to ensure system pressure safety.

[0042] 5. Key control points in the commissioning process of this application:

[0043] Flow and pressure control: Closely monitor the outlet pressure of the reflux pump in the light-light-removal tower and the flow rate of each pipeline. Finely adjust valves to ensure stable distillation operation of the light-light-removal tower (e.g., no significant fluctuations in tower pressure and temperature), while ensuring smooth material processing on the hydrogenation side. Analysis and monitoring: Regularly analyze the carbonyl compound content of the material in the light-light-removal tower reflux tank, the hydrogenated material, and the final butadiene product. Adjust the external flow rate of pipeline No. 2 based on the analysis results to achieve closed-loop control.

[0044] The application results in the following product quality: The carbonyl compound content in the butadiene product can be stably controlled below 20 μg / g, meeting the quality requirements of polymer-grade products, and can be directly used in the production of high-end polymer materials (such as cis-butadiene rubber and styrene-butadiene rubber).

[0045] The operation of the device applied for has solved the problems of product non-compliance and production interruption caused by excessive carbonyl compounds, extended the continuous operation cycle of the device, and significantly improved production stability.

[0046] Economic benefits: Qualified polymer-grade butadiene products have higher market added value, while avoiding the costs of rework caused by substandard products. The overall economic benefits of the plant are improved by 10%-15% (slight fluctuations due to differences in plant scale and raw material costs).

[0047] Finally, it should be noted that the present invention is not limited to the above embodiments, and many variations are possible. All variations that can be directly derived or conceived by those skilled in the art from the disclosure of the present invention should be considered within the scope of protection of the present invention.

Claims

1. An apparatus for resolving excessive carbonyl compounds in 1,3-butadiene products, characterized in that, It includes a light-light tower reflux tank (1), a light-light tower reflux pump (2), a two-stage gas-liquid separator (3), and a hydrogenation product cooler (4); The light tower reflux tank (1) is provided with an inlet for receiving the material from the light tower condenser of C4. The material outlet of the light tower reflux tank (1) is connected to the inlet of the light tower reflux pump (2) through a pipeline. The outlet of the light tower reflux pump (2) is connected to the pipeline for reflux to the light tower through a No. 1 pipeline. The outlet of the light tower reflux pump (2) is also connected to the pipeline for hydrogenated C4 to the raw material tank through a No. 2 pipeline with a valve. The inlet of the two-stage gas-liquid separator (3) is used to receive C4 material from the two-stage hydrogenation reactor. The outlet of the two-stage gas-liquid separator (3) is connected to the inlet of the hydrogenation product cooler (4). The outlet of the hydrogenation product cooler (4) is connected to the pipeline from the hydrogenated C4 to the feedstock tank and the pipeline from the hydrogenated C4 to ethylene through pipelines respectively.

2. The apparatus for resolving excessive carbonyl compounds in 1,3-butadiene products according to claim 1, characterized in that, The outlet of the light tower reflux pump (2) is returned to the light tower reflux tank (1) through pipeline No. 3 with a valve.

3. The apparatus for resolving excessive carbonyl compounds in 1,3-butadiene products according to claim 1 or 2, characterized in that, It also includes a safety valve, and the light tower reflux tank (1) is connected to the safety valve via a No. 5 pipeline with a valve.

4. The apparatus for solving the problem of excessive carbonyl compounds in 1,3-butadiene products according to claim 3, characterized in that, The No. 2 pipeline is also connected to the No. 5 pipeline, which is equipped with a valve.

5. The apparatus for resolving excessive carbonyl compounds in 1,3-butadiene products according to claim 1, characterized in that, Multiple valves are installed on the pipeline between the material outlet of the light tower reflux tank (1) and the inlet of the light tower reflux pump (2).

6. The apparatus for resolving excessive carbonyl compounds in 1,3-butadiene products according to claim 1, characterized in that, The No. 1 pipeline is equipped with multiple valves.

7. The apparatus for resolving excessive carbonyl compounds in 1,3-butadiene products according to claim 6, characterized in that, The No. 2 pipeline is equipped with multiple valves.

8. The apparatus for resolving excessive carbonyl compounds in 1,3-butadiene products according to claim 1, characterized in that, The outlet pipe of the hydrogenated product cooler (4) is equipped with a flow detection component.

9. The apparatus for resolving excessive carbonyl compounds in 1,3-butadiene products according to claim 7, characterized in that, The valves on both Pipeline 1 and Pipeline 2 include check valves and shut-off valves.

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