Feedstock pretreatment feed device for alkylation reactions

Abstract

The application discloses a raw material pretreatment feeding device for an alkylation reaction, which comprises a heavy C4 storage tank, a light C4 storage tank, a heavy C4 conveying pump, a light C4 conveying pump, a first digital flow meter and a second digital flow meter. The discharge port of the heavy C4 storage tank is connected with a first pipe, and the first digital flow meter and the heavy C4 conveying pump are arranged on the connecting pipeline at intervals. The discharge port of the light C4 storage tank is connected with the feeding port pipeline of a hydrogenation reactor, and the light C4 conveying pump and the second digital flow meter are arranged on the connecting pipeline at intervals. The device can effectively ensure the stable product quality, reduce the load rate of a butane supplement assembly, avoid frequent load increase and decrease or start and stop of the butane supplement assembly, reduce the comprehensive energy consumption of the alkylation device, and avoid catalyst poisoning and deactivation in the hydrogenation reactor for alkylation raw material pretreatment.

Description

Technical Field

[0001] This application relates to the field of petrochemical technology, and in particular to a feedstock pretreatment device for alkylation reactions. Background Technology

[0002] Sulfuric acid alkylation is a reaction that uses butane and butene as raw materials and reacts under the catalysis of concentrated sulfuric acid to produce high-octane gasoline blending components. It is of great significance for improving fuel quality and promoting green energy technology.

[0003] Currently, the feedstock required for sulfuric acid alkylation units is pre-ether heavy C4 and post-ether light C4 produced by catalytic cracking units in oil refineries. Existing units mix the pre-ether heavy C4 and post-ether light C4 and then directly feed them into the alkylation feedstock pretreatment process before entering the alkylation reactor.

[0004] Problems exist:

[0005] 1. In the pretreatment process, it is difficult to mix the heavy C4 before etherification and the light C4 after etherification evenly. When the pretreated material is buffered in the storage tank, it is easy to cause stratification. This results in the olefin content of the feed material fed into the reactor fluctuating, which seriously affects the alkane-olefin ratio balance of the feed material and leads to unstable control of the alkylation unit and a decline in product quality.

[0006] 2. During the production process, the butane replenishment component is frequently subjected to load adjustments or start-ups and shutdowns, causing the isobutane in the system to be frequently withdrawn and then returned for use, increasing the steam energy consumption and electrical energy consumption of the unit.

[0007] 3. The high impurity content of the pre-ether C4 used in the existing process can easily lead to catalyst poisoning and deactivation in the hydrogenation reactor of the alkylation feedstock pretreatment process.

[0008] The information disclosed in the background section is intended only to enhance the understanding of the overall background of this utility model and should not be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art. Utility Model Content

[0009] This application addresses the aforementioned technical problems by providing a feedstock pretreatment device for alkylation reactions. This device can improve the matching of feedstocks before etherification (C4) and after etherification (C4) into the alkylation reaction unit, thereby improving product quality stability, reducing fluctuations, reducing the start-up and shutdown frequency of the butane replenishment component, and lowering energy consumption.

[0010] This application provides a feedstock pretreatment device for alkylation reaction, including: a hydrogenation reactor, a light component removal tower, a dehydrator, an alkylation reactor, and a butane replenishment assembly;

[0011] The dehydrator and butane replenishment unit are respectively connected to the alkylation reactor pipeline; the hydrogenation reactor and the light component removal tower pipeline are connected; the dehydrator and the light component removal tower are connected through the first feed pipe;

[0012] Includes: heavy C4 storage tank, light C4 storage tank, heavy C4 transfer pump, light C4 transfer pump, first digital flow meter, and second digital flow meter;

[0013] The discharge port of the heavy C4 storage tank is connected to the first material pipe, and the first digital display flow meter and heavy C4 conveying pump are installed at intervals on the connected pipe.

[0014] The outlet of the light C4 storage tank is connected to the inlet pipeline of the hydrogenation reactor, and a light C4 transfer pump and a second digital flow meter are installed at intervals on the connecting pipeline.

[0015] Preferably, it includes: a heavy C4 raw material feed pipe; one end of the heavy C4 raw material feed pipe is connected to the feed inlet pipe of the heavy C4 storage tank.

[0016] Preferably, it includes: a shutdown and maintenance pusher pipe; one end of the shutdown and maintenance pusher pipe is connected to the heavy C4 raw material feed pipe, and the other end is connected to the first material pipe; the outlet of the heavy C4 storage tank is connected to the shutdown and maintenance pusher pipe.

[0017] Preferably, the butane replenishment assembly includes: a tray, a spray assembly, an isobutane removal tower, a cooler, a reflux tank, and a reflux pump;

[0018] The isobutane stripping tower contains multiple trays spaced apart; the spray assembly is located at the top of the isobutane stripping tower and is connected to the cooler pipeline; the cooler and reflux tank pipelines are connected; the reflux tank and reflux pump inlet pipelines are connected.

[0019] The outlet of the reflux pump is connected to the butane replenishment port of the alkylation reactor and the spray assembly pipeline, respectively.

[0020] Preferably, the butane replenishment assembly includes: a reflux valve;

[0021] The reflux valve is installed on the pipeline connecting the reflux pump outlet and the spray assembly.

[0022] Preferably, it includes: a valve; a valve is installed on the feed pipe of the heavy C4 raw material.

[0023] Preferably, it includes: a valve; a valve is installed on the feed pipe during shutdown and maintenance.

[0024] Preferably, it includes: a valve; the valve is installed on the pipeline connecting the heavy C4 storage tank and the first material pipe.

[0025] The beneficial effects that this application can produce include:

[0026] 1) The feed device for alkylation reaction pretreatment provided in this application can effectively ensure stable product quality, reduce the load rate of the butane replenishment component, avoid frequent load increases or decreases or start-ups and shutdowns of the butane replenishment component, reduce the overall energy consumption of the alkylation unit, and avoid catalyst poisoning and deactivation in the hydrogenation reactor of the alkylation feed pretreatment. Attached Figure Description

[0027] Figure 1 A schematic diagram of a feedstock pretreatment device for alkylation reaction in at least one embodiment provided in this application;

[0028] Figure 2 Line graph showing the results of online analysis of the feed alkane-olefin ratio for optimizing existing production facilities;

[0029] Figure 3 Line graph showing the online analysis results of the alkane-olefin ratio in the device feed of at least one embodiment provided in this application;

[0030] Legend:

[0031] Heavy C4 storage tank 1, Light C4 storage tank 11, Valve 12

[0032] Heavy C4 transfer pump 112, light C4 transfer pump 113, first feed pipe 223

[0033] Hydrogenation reactor 3, light component removal tower 31, dehydrator 32, alkylation reactor 33

[0034] The feed pipe 221, the first digital flow meter 21, and the second digital flow meter 22 were shut down for maintenance.

[0035] Tray 232, spray assembly 233, isobutane removal tower 231, cooler 234, reflux tank 235, reflux pump 121, reflux valve 125. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can typically be arranged and designed in various different configurations.

[0037] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0038] Technical means not detailed in this application and not used to solve the technical problems of this application are all set according to common general knowledge in the field, and multiple common general knowledge setting methods can be implemented.

[0039] See Figures 1-3 The feed pretreatment device for alkylation reaction provided in this application includes: a heavy C4 storage tank 1, a light C4 storage tank 11, a heavy C4 transfer pump 112, a light C4 transfer pump 113, a first digital flow meter 21, a second digital flow meter 22, a hydrogenation reactor 3, a light component removal tower 31, a dehydrator 32, an alkylation reactor 33, and a butane replenishment assembly.

[0040] The hydrogenation reactor 3, the light component removal tower 31, the dehydrator 32, and the alkylation reactor 33 used in this application are all commercially available products, and their specific structures are not described in detail here.

[0041] The outlet of the hydrogenation reactor 3 is connected to the inlet pipeline of the light component removal tower 31; the outlet of the light component removal tower 31 is connected to the inlet pipeline of the dehydrator 32; the outlet of the dehydrator 32 is connected to the inlet pipeline of the alkylation reactor 33; the outlet of the butane replenishment component is connected to the butane replenishment pipeline of the alkylation reactor 33.

[0042] The pipeline connecting the light component removal tower 31 and the dehydrator 32 is the first feed pipe 223; the outlet of the heavy C4 storage tank 1 is connected to the first feed pipe; a heavy C4 conveying pump 112 and a first digital display flow meter 21 are installed on the pipeline connecting the outlet of the heavy C4 storage tank 1 and the first feed pipe.

[0043] The outlet of the light C4 storage tank 11 is connected to the inlet of the hydrogenation reactor 3 via a pipeline; a light C4 transfer pump 113 and a second digital flow meter 22 are installed on the pipeline connecting the light C4 storage tank 11 and the hydrogenation reactor 3; the operator can control the feed flow of heavy C4 based on the obtained feed flow of light C4, thereby achieving matching of the feed flow of the two.

[0044] Simultaneously, this device can prevent sulfide-containing heavy C4 from entering the hydrogenation reactor 3, thereby avoiding catalyst poisoning in the hydrogenation reactor 3 due to heavy C4, effectively ensuring the catalytic effect of light C4, and guaranteeing the safety of the pretreated feedstock. Furthermore, since heavy C4 does not contain 1,3-butadiene, the absence of heavy C4 in the hydrogenation reactor 3 not only does not affect the normal progress of the alkylation reaction, but also saves steam energy consumption in the light hydrocarbon removal tower 31.

[0045] Meanwhile, the device ensures precise material proportioning and uniform mixing by introducing heavy C4 feedstock through pipelines at the first feed pipe, preventing unevenly mixed materials from entering the alkylation reaction unit. By changing the feed location using this device, the amount of butane replenishment can be reduced, improving production process stability and decreasing the frequency of butane replenishment unit start-ups and shutdowns.

[0046] In one specific embodiment, the butane replenishment assembly includes: tray 232, spray assembly 233, isobutane removal tower 231, cooler 234, reflux tank 235, reflux pump 121, and reflux valve 125; multiple trays 232 are spaced apart inside the isobutane removal tower 231; the spray assembly 233 is installed above the trays 232; after the material used to replenish butane enters the isobutane removal tower 231, butane is separated from other substances, and the butane is then transported through pipelines into the alkylation reactor to replenish butane for the alkylation reaction. The material used for replenishing butane is a commonly used raw material in the art and will not be described in detail here.

[0047] The top outlet of the deisobutane tower 231 is connected to the cooler 234 via a pipeline; the outlet of the cooler 234 is connected to the inlet of the reflux tank 235 via a pipeline; the reflux tank 235 is connected to the reflux pump 121 via a pipeline; the outlet of the reflux pump 121 is connected to the alkylation reactor 33 and the reflux port of the deisobutane tower 231 via pipelines respectively; a reflux valve 125 is installed on the pipeline connecting the outlet of the reflux pump 121 and the reflux port of the deisobutane tower 231.

[0048] In one specific embodiment, it includes: a shutdown and maintenance pusher pipe 221; one end of the shutdown and maintenance pusher pipe 221 is connected to the heavy C4 raw material inlet pipe, and the other end is connected to the first material pipe; the outlet of the heavy C4 storage tank 1 is connected to the shutdown and maintenance pusher pipe 221. By connecting to the shutdown and maintenance pusher pipe 221, the heavy C4 in the heavy C4 storage tank 1 is transported to the first material pipe, which can reduce pipeline modification, avoid pipeline leakage, and reduce modification costs. One end of the heavy C4 raw material pipe is connected to the inlet of the heavy C4 storage tank (1).

[0049] In one specific embodiment, it includes: a valve 12; a valve 12 is installed on the shutdown and maintenance pusher pipe 221. It is used to control material return.

[0050] In one specific embodiment, it includes: a valve 12; a valve 12 is installed on the feed pipe of the heavy C4 raw material. It is used to control the feeding.

[0051] In one specific embodiment, it includes: valve 12; valve 12 is installed on the pipeline connecting the heavy C4 storage tank 1 and the first material pipe 223.

[0052] In one specific embodiment, the system includes: a valve 12; the discharge pipe of the heavy C4 storage tank 1 includes: a first branch pipe and a second branch pipe; the first branch pipe is connected to the first feed pipe; the second branch pipe is connected to the light C4 discharge pipe; one end of the light C4 discharge pipe is connected to the light C4 storage tank 11; valve 12 is installed on the first branch pipe and the second branch pipe; this configuration can change the entry point of heavy C4 without altering the original mixing feed pipe of the heavy C4 storage tank 1 and the light C4 storage tank 11, thereby reducing changes to the original pipeline structure and improving the reliability of the modification.

[0053] Using the apparatus provided in this application for alkylation production, the resulting alkane-to-olefin ratio was measured online using a line graph, as shown below. Figure 3 As shown.

[0054] Comparative Example

[0055] The changes in the alkane-to-alkene ratio obtained from the alkylation reaction before using this device were measured online using a line graph, as shown below. Figure 2 As shown.

[0056] Alkylation production was carried out at Yuntian Petrochemical Company using the apparatus provided in this application and the equipment in the comparative example. The digital flow meters used in the following examples are mass flow meters; the alkylation reactor is... Alkylation reactor. The results are analyzed as follows:

[0057] 1. See Figures 2-3 It is evident that this device allows for the adjustment and control of the feed ratio of heavy C4 and light C4, enabling precise matching of olefins and alkanes in the feed. This avoids fluctuations in the olefin and alkane content.

[0058] 2. Operation status of the butane replenishment unit and the balance of the alkane-to-olefin ratio in the feed.

[0059] Table 1. Operating time of butane replenishment component and system alkane-to-olefin ratio balance.

[0060]

[0061] The butane replenishment unit primarily serves to replenish butane to maintain the alkane-to-alkene ratio balance in the alkylation reaction system. Under normal circumstances, the smaller the deviation in the alkane-to-alkene ratio of the alkylation reaction system feed, the lower the load on the butane replenishment unit can be controlled. Simultaneously, a shorter operating time for the butane replenishment unit indicates a more precise and stable matching of olefins and alkanes in the alkylation reaction system feed, and less ineffective operating time for the butane replenishment unit.

[0062] 3. The operating conditions of the alkylation feedstock pretreatment hydrogenation reactor before and after using the apparatus provided in this application are shown in Tables 2 and 3 below:

[0063] Table 2 Comparison of Running Time

[0064]

[0065] The feedstock pretreatment hydrogenation reactor of the alkylation unit was put into production in September 2017. In October 2018, the catalyst was poisoned and deactivated. After the above-mentioned unit was put into operation in June 2019, the catalyst regeneration of the feedstock pretreatment hydrogenation reactor was completed and it has been running continuously since then.

[0066] Table 3. Catalyst Reaction Status Observation Table

[0067]

[0068]

[0069] 4. The economic benefits resulting from the optimization of the alkylation feedstock method are shown in the table below:

[0070] Table 4

[0071]

[0072] Using the apparatus provided in this application for pretreatment of feedstock for alkylation reaction increases economic benefits by RMB 7.1181 million annually.

[0073] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A feedstock pretreatment device for alkylation reaction, comprising: Hydrogenation reactor (3), light component removal tower (31), dehydrator (32), alkylation reactor (33), butane replenishment assembly; The dehydrator (32) and butane replenishment assembly are respectively connected to the alkylation reactor (33) by pipeline; the hydrogenation reactor (3) and the light component removal tower (31) are connected by pipeline; the dehydrator (32) and the light component removal tower (31) are connected by the first feed pipe (223); Its features include: Heavy C4 storage tank (1), light C4 storage tank (11), heavy C4 transfer pump (112), light C4 transfer pump (113), first digital flow meter (21), second digital flow meter (22); The discharge port of the heavy C4 storage tank (1) is connected to the first material pipe (223), and the first digital flow meter (21) and the heavy C4 transfer pump (112) are installed at intervals on the connected pipe. The outlet of the light C4 storage tank (11) is connected to the inlet pipeline of the hydrogenation reactor (3), and a light C4 transfer pump (113) and a second digital flow meter (22) are installed at intervals on the connecting pipeline.

2. The feed pretreatment device for alkylation reaction according to claim 1, characterized in that, include: Heavy C4 raw material feed pipe; one end of the heavy C4 raw material feed pipe is connected to the feed port pipeline of the heavy C4 storage tank (1).

3. The feed pretreatment device for alkylation reaction according to claim 2, characterized in that, include: Shut down for maintenance of the pusher pipe (221); One end of the shutdown and maintenance pusher pipe (221) is connected to the heavy C4 raw material feed pipe, and the other end is connected to the first material pipe (223); the outlet of the heavy C4 storage tank (1) is connected to the shutdown and maintenance pusher pipe (221).

4. The feed pretreatment device for alkylation reaction according to claim 1, characterized in that, The butane replenishment components include: trays (232), spray assembly (233), isobutane removal tower (231), cooler (234), reflux tank (235), and reflux pump (121); The isobutane stripping tower (231) contains multiple trays (232) spaced apart; the spray assembly (233) is located on the upper part of the isobutane stripping tower (231) and connected to the cooler (234) via pipeline; the cooler (234) and the reflux tank (235) are connected via pipeline; the reflux tank (235) and the feed inlet of the reflux pump (121) are connected via pipeline; The outlet of the reflux pump (121) is connected to the butane supply port of the alkylation reactor (33) and the pipeline of the spray assembly (233).

5. The feed pretreatment apparatus for alkylation reaction according to claim 1, characterized in that, The butane replenishment assembly includes: a reflux valve (125); The reflux valve (125) is located on the pipeline connecting the outlet of the reflux pump (121) and the spray assembly (233).

6. The feed pretreatment device for alkylation reaction according to claim 2, characterized in that, include: Valve (12); Valve (12) is installed on the feed pipe of heavy C4 raw material.

7. The feed pretreatment device for alkylation reaction according to claim 3, characterized in that, include: Valve (12); Valve (12) is installed on the material pusher pipe (221) during shutdown and maintenance.

8. The feed pretreatment apparatus for alkylation reaction according to claim 1, characterized in that, include: Valve (12); A valve (12) is installed on the pipeline connecting the heavy C4 storage tank (1) and the first material pipe (223).

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