Utilization system of mixed gas containing ethylene and propylene

Abstract

The utility model relates to the field of refinery dry gas recycling, in particular to a utilization system of mixed gas containing ethylene and propylene, which comprises a gas source of the mixed gas containing ethylene and propylene, a first membrane separator, a first mixer, a primary reactor and a separation device which are sequentially connected according to the material flow direction, a second mixer and a second-stage reactor are sequentially connected along the material flowing direction of a gas material outlet of the separation device; the hydrogen peroxide source is respectively communicated with the feeding holes of the first mixer and the second mixer; a first switch valve and a second switch valve are further arranged at a gas material outlet of the separation device; the utilization system further comprises an online analyzer. By adopting the system disclosed by the utility model, mixed gas (such as refinery dry gas) containing ethylene and propylene can be directly utilized to obtain ethylene glycol and propylene glycol with high additional value.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of refinery dry gas recycling, in particular to a utilization system of mixed gas containing ethylene and propylene. BACKGROUND

[0002] Ethylene and propylene are important basic organic raw materials in petrochemical industry, and are the basis for producing various organic chemical products and three synthetic materials. However, ethylene and propylene are by-produced in the production process, which contains hydrogen, methane, ethane, ethylene, propylene and other carbon two and carbon three non-condensed gases, i.e. refinery dry gas. The conventional separation methods used in the factory are mainly cryogenic separation method and pressure swing adsorption method, etc. Due to the similar physical properties (such as similar boiling points) of the mixed gas, the conventional physical separation method is difficult to separate directly, such as Figure 1 as shown, Figure 1 The process flow chart for separating the mixed gas containing ethylene and propylene in the prior art by using direct separation method. After cryogenic separation, the distillation separation temperature is generally -20-80℃, and even as low as -100℃. The method has large equipment investment and high relative separation energy consumption, and is only suitable for large-scale refinery in a relatively concentrated area. The pressure swing adsorption method has large equipment and complex control system, and the obtained ethylene purity is low and the recovery rate is not high.

[0003] Ethylene glycol and propylene glycol, which are downstream products of ethylene and propylene, are also important chemical products. As mentioned earlier, in the recycling of refinery dry gas, the ethylene and propylene in the refinery dry gas need to be separated respectively, and then the ethylene and propylene are used to produce downstream products, such as using single ethylene to produce ethylene glycol and using single propylene to produce propylene glycol. Due to the complex types of raw materials in refinery dry gas, which contains hydrogen, methane, ethane, propylene and ethylene, etc., the conventional method cannot be directly used for downstream production. If the downstream production is directly carried out, the types of products obtained will be more complicated, which cannot be separated and utilized by economic and effective means. Therefore, the above becomes a difficult problem for the economic and effective recycling of refinery dry gas. SUMMARY

[0004] The utility model discloses a kind of utilization systems of mixed gas containing ethylene and propylene. The inventor of the utility model has unexpectedly found by research, using the system of the utility model can directly utilize mixed gas containing ethylene and propylene (such as refinery dry gas), obtain ethylene glycol and propylene glycol with high added value, overcome the problem of high energy consumption and large investment caused by the inherent mode of the separation process of traditional refinery dry gas gas components such as ethylene, propylene after separation and then utilization. Not only that, the operating conditions of the utilization system of the utility model are relatively mild, the separation energy consumption is less, and part of the product in the process can be reused to the process itself, the demand for external resources is less, which provides a new direction for the utilization of refinery dry gas, and has very high popularization and application value.

[0005] The utility model discloses a kind of utilization systems of mixed gas containing ethylene and propylene, according to material flow direction, including sequentially connected mixed gas containing ethylene and propylene's gas source, first membrane separator, first mixer, primary reactor and separation device;

[0006] The separation device is provided with liquid material discharge port and gas material discharge port, wherein, along the material flow direction of the gas material discharge port of the separation device, second mixer, two-stage reactor are sequentially connected;

[0007] Further including hydrogen peroxide source, the hydrogen peroxide source is connected with the feed port of first mixer, second mixer respectively and communicates;

[0008] Wherein, the gas material discharge port of the separation device is also selectively communicated with the feed port of the primary reactor by pipeline, and first switch valve is arranged on the pipeline;Second switch valve is arranged on the pipeline between the gas material discharge port of the separation device and the two-stage reactor;

[0009] The utilization system further includes online analyzer, which is arranged on the pipeline of the reaction material flowing out of the primary reactor, and the online analyzer is used to analyze the gas material composition flowing out of the primary reactor.

[0010] The gas material collected by the online analyzer in the utility model can be the gas material obtained after separation by the separation device, or the gas material flowing out of the outlet of the primary reactor. Preferably, the gas material collected by the online analyzer is the gas material flowing out of the outlet of the primary reactor. The online analyzer, such as gas chromatograph, can analyze the gas phase composition in the gas-liquid mixture, and directly output the gas material composition without gas-liquid separation, which is more direct for controlling the reaction degree of the material in the primary reactor.

[0011] Preferably, the mixed gas containing ethylene and propylene is refinery dry gas from upstream.

[0012] Preferably, the crude propylene glycol dehydration tower, the propylene glycol tower and the ethylene glycol tower are arranged in sequence along the material flow direction of the liquid material discharge port of the separation device.

[0013] Preferably, the secondary reactor is further connected in sequence with an ethylene glycol dehydration tower, a crude ethylene glycol separation tower, a diethylene glycol tower and a triethylene glycol tower.

[0014] Preferably, the first membrane separator is selected from a molecular sieve membrane separator.

[0015] Preferably, the crude propylene glycol dehydration tower, the propylene glycol tower and the ethylene glycol tower are arranged in sequence along the material flow direction of the liquid material discharge port of the separation device.

[0016] Preferably, the crude propylene glycol dehydration tower, the propylene glycol tower and the ethylene glycol tower are arranged in sequence along the material flow direction of the liquid material discharge port of the separation device.

[0017] Preferably, the crude propylene glycol dehydration tower, the propylene glycol tower and the ethylene glycol tower are arranged in sequence along the material flow direction of the liquid material discharge port of the separation device.

[0018] Preferably, the crude propylene glycol dehydration tower, the propylene glycol tower and the ethylene glycol tower are arranged in sequence along the material flow direction of the liquid material discharge port of the separation device.

[0019] Preferably, the propylene glycol tower is provided with an extractant feed port; more preferably, the extractant feed port is arranged in the upper half of the propylene glycol tower, and more preferably arranged at the 3rd-8th feed tray from the top of the propylene glycol tower. The extractant used is the extractant commonly used in the prior art for separating and extracting propylene glycol, and can also be at least one of the tower kettle liquid of the ethylene glycol tower in the system of the present application, the diethylene glycol product separated by the diethylene glycol tower, and the triethylene glycol product separated by the triethylene glycol tower.

[0020] Preferably, the crude propylene glycol dehydration tower, the propylene glycol tower and the ethylene glycol tower are arranged in sequence along the material flow direction of the liquid material discharge port of the separation device.

[0021] Preferably, the online analyzer is selected from an online gas chromatograph analyzer and / or an infrared spectrum analyzer.

[0022] Preferably, the separation device comprises a second membrane separator and a gas-liquid separation device connected in sequence, the second membrane separator is used to separate the solid particles (such as catalyst) contained in the feed liquid of the primary reactor, more preferably, the second membrane separator is a molecular sieve membrane separator; and / or, more preferably, the gas-liquid separation device is a gas-liquid separation tank.

[0023] The gas-liquid separation device is used to store the material from the primary reactor and separate the gas material and liquid material in the product of the primary reactor, the separated gas material mainly contains ethylene or contains a small amount of propylene, and the separated liquid material mainly contains propylene glycol, ethylene glycol and a small amount of heavy alcohol.

[0024] Preferably, the utilization system further comprises an OMS interlocking signal device, which can receive the composition information of the gas material output by the online analyzer, and can send the opening and closing instructions of the first and second switch valves according to the control target of the composition of the gas material, and then transmit the opening and closing instructions to the first and second switch valves through the OMS interlocking signal, to automatically determine the opening and closing states of the second and first switch valves.

[0025] As described above, the online analyzer is selected from an online gas chromatograph analyzer and / or an infrared spectrum analyzer, which is used to analyze the composition of the gas material flowing out of the primary reactor.

[0026] For example, when the online analyzer is an online gas chromatograph analyzer, the online gas chromatograph analyzer gives the opening or closing signal of the first and second switch valves by outputting the propylene content in the gas material: when the propylene content in the unreacted gas material in the primary reactor is within the target range, for example, <= 5wt%, the second switch valve is opened and the first switch valve is closed, otherwise, the second switch valve is closed and the first switch valve is opened.

[0027] When the online analyzer is an infrared spectrum analyzer, the infrared spectrum analyzer determines whether there is propylene in the unreacted gas material in the primary reactor by outputting the gas composition peak in the infrared spectrum of the unreacted gas material in the primary reactor, and gives the opening or closing signal of the first and second switch valves:

[0028] When there is no peak value of propylene in the infrared spectrum of the unreacted gas material in the primary reactor, it is determined that there is no propylene in the unreacted gas material in the primary reactor, and the second switch valve is opened and the first switch valve is closed;

[0029] When there is a peak value of propylene in the infrared spectrum of the unreacted gas material in the primary reactor, it is determined that there is propylene in the unreacted gas material in the primary reactor, and the second switch valve is closed and the first switch valve is opened.

[0030] By the process system as above, the mixed gas containing ethylene and propylene can be removed of related impurities by the first membrane separator, then the mixed gas containing ethylene and propylene is contacted with hydrogen peroxide to perform two-stage reaction, and the propylene in the mixed gas is directly converted into propylene glycol and reserved in the crude product liquid of the first-stage reaction by the on-line analyzer monitoring, and the unreacted gas material after removing most of the propylene in the gas phase raw material in the first-stage reaction is contacted with hydrogen peroxide to perform the second-stage reaction, and the ethylene is directly converted into ethylene glycol in the second-stage reaction, and the product of the first-stage reaction and the product of the second-stage reaction are separated respectively, so that the process flow is simple, the operation condition is relatively simple, and the separation energy consumption is low. In addition, the reaction process does not produce CO2 and toxic and harmful gas, so that the system meets the "double carbon" policy and the green chemical concept, and the alkanes obtained by the first membrane separator and the molecular sieve adsorption separation can be used as heat value recovery, the device reaction is an exothermic reaction, the reaction heat can be used again, and the two-stage reaction can generate corresponding polyols, and the products can be extracted from the separation columns in the rectification section, so that the diethylene glycol and triethylene glycol high value-added products can be separated, and the above products can be used as extractant to supplement to the system. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 A process flow diagram for separating the mixed gas containing ethylene and propylene by using the direct separation method in the prior art, Figure 1 a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r and s are respectively a cracking gas dryer, a first pre-cutting column, a second pre-cutting column, a demethanizer, new and old cold boxes, a methanation reactor, a deethanizer, a carbon two hydrogenation reactor, an ethylene dryer, an ethylene rectification column, a high-pressure depropanizer, a low-pressure depropanizer, a propylene dryer, a carbon three hydrogenation reactor, a methane steam-out column, a second propylene rectification column, a propylene rectification column, a debutanizer and a hydrogen gas dryer

[0032] Figure 2 A schematic diagram of the utilization system of the mixed gas containing ethylene and propylene in the utility model.

[0033] Figure 2 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13 and 14 are respectively a gas source of the mixed gas containing ethylene and propylene, a first membrane separator, a first mixer, a first-stage reactor, a separation device, a second mixer, a second-stage reactor, a crude propylene glycol dehydration column, a propylene glycol column, an ethylene glycol column, an ethylene glycol dehydration column, a crude ethylene glycol separation column, a diethylene glycol column and a triethylene glycol column.

[0034] Figure 3The utility model discloses a control process flow diagram through online analyzer analysis the composition of the gas material of primary reactor unreacted and the flow direction of the gas material. Figure 3 Middle: 4 primary reactor;5 separation device;15 online analyzer;16 first switch valve;17 second switch valve.

[0035] As Figure 3 The outlet gas material of primary reactor 4 is sampled and analyzed, and then the interlocking signal is transmitted through online analyzer 15, and then the interlocking control is carried out through switch valve.The default state of second switch valve 17 is closed, and the default state of first switch valve 16 is opened.When the sampling is carried out at the outlet of reactor through online analyzer 15, and the component analysis is carried out, when propylene is contained in the component and the propylene content is more, greater than the target content (for example greater than 5wt%), the OMS interlocking signal is transmitted, at this time, first switch valve 16 is opened, and second switch valve 17 is closed.When the component does not contain propylene or the propylene content is less, and is in the target content (for example, the content of propylene in the unreacted gas material in primary reactor <= 5wt%), the OMS interlocking signal is transmitted, at this time, second switch valve 17 is opened, and first switch valve 16 is closed. Specific embodiments

[0036] The utility model is specifically described below in combination with specific embodiments, and it is necessary to point out here that the following examples are only used for further description of the utility model, and cannot be understood as the limitation of the protection scope of the utility model, and some non-essential improvements and adjustments of the utility model by the person skilled in the art according to the content of the utility model still belong to the protection scope of the utility model.

[0037] The inventor finds in the research that when the mixed gas containing ethylene and propylene is contacted with hydrogen peroxide to carry out catalytic oxidation reaction, propylene in the mixed gas is first oxidized, and propylene is converted into propylene glycol and retained in the crude product liquid of primary reaction, and the utility model utilizes this point, and propylene in the mixed gas is directly converted into propylene glycol through the catalytic contact reaction of the mixed gas containing ethylene and propylene and hydrogen peroxide, i.e.primary reaction, in the reaction process, the propylene content in the gas phase raw material of primary reaction is monitored through online analyzer, and after most propylene in the gas phase raw material is removed, the catalytic contact with hydrogen peroxide is carried out again to carry out secondary reaction, and in the secondary reaction, ethylene is directly converted into ethylene glycol, so that the product of primary reaction and the product of secondary reaction are separated respectively.For example, through extraction distillation operation separation, propylene glycol product and ethylene glycol product are obtained.Compared with the conventional propylene and ethylene direct separation process, the separation difficulty is smaller, the operation condition is more moderate, the separation energy consumption is relatively less, and the shortcomings, such as high energy consumption and large investment of traditional ethylene and propylene separation, are overcome.

[0038] According to the utility model, the crude product liquid of the first-stage reaction is mainly propylene glycol, that is, the content of propylene glycol in the crude product liquid is the most.

[0039] According to the utility model, the unreacted gas material flowed out in the first-stage reaction is mainly ethylene, that is, the content of ethylene is the most.

[0040] According to the utility model, the crude product liquid of the second-stage reaction is mainly ethylene glycol, that is, the content of ethylene glycol in the crude product liquid is the most.

[0041] The gas source of the mixed gas containing ethylene and propylene is refinery dry gas, and further more preferably, the refinery dry gas contains hydrogen, methane, ethane, ethylene, propylene, preferably contains 5-35wt% of hydrogen, 5-20wt% of methane, 15-40wt% of ethane, 10-30wt% of ethylene, 5-10wt% of propylene, and 0.5-3.5wt% of other gases, with the total content of the refinery dry gas being 100%.

[0042] According to the utility model, preferably, before the first-stage reaction, the alkane and catalyst particles are removed through the first membrane separator 2, more preferably through a molecular sieve membrane.

[0043] According to the utility model, preferably, the crude product liquid of the first-stage reaction and the unreacted gas material in the first-stage reaction are separated through the separation device 5 including a second membrane separator and a gas-liquid separation device. In this process, the membrane separation is mainly used to remove some solids such as catalyst, and the gas-liquid separation device (such as a gas-liquid separation tank) is used to separate the gas-liquid product.

[0044] In general, the whole utilization system is divided into a reaction section, an ethylene glycol rectification section and a propylene glycol rectification section, and specifically:

[0045] (1) the reaction section:

[0046] The process and principle of the first-stage reaction are as follows:

[0047] The mixed gas containing ethylene and propylene first enters the first membrane separator 2 containing a molecular sieve membrane, removes the waste gas such as alkane which does not participate in the reaction through the physical adsorption method, and then enters the first-stage reactor 4 after being mixed with hydrogen peroxide to perform the first-stage reaction. Since the reaction of propylene is faster than that of ethylene, most of the propylene is converted into propylene glycol and a small amount of ethylene is converted into ethylene glycol in the first-stage reactor 4 through the action of the catalyst. The main reactions involved in the synthesis process are as follows:

[0048] C2H4+H2O2→C2H6O2

[0049] C3H6+H2O2→C3H8O2

[0050] 2H2O2→2H2O+O2

[0051] The crude product liquid from the primary reactor 4 and the unreacted gas material from the primary reactor are separated by a separation device 5. The separation device 5 preferably comprises a second membrane separator and a gas-liquid separation device, such as a gas-liquid separation tank, to separate solid particles by the second membrane separator and to separate gas and liquid by the gas-liquid separation device;

[0052] As mentioned above, in the above reaction process, propylene reacts faster than ethylene, the composition of the unreacted gas material from the primary reactor is analyzed and monitored by an on-line analyzer 15, when the propylene control target is reached, for example, when the content of propylene in the unreacted gas material from the primary reactor is <= 5wt%, the unreacted gas material from the primary reactor is subjected to a secondary reaction, otherwise, it is returned to the primary reactor 4 for further primary reaction, in this way, propylene is retained in the primary reactor crude product liquid in the form of the main product propylene glycol, accompanied by a small amount of ethylene glycol, most of the ethylene is reacted in the secondary reaction to generate the main product ethylene glycol, accompanied by diethylene glycol, triethylene glycol high value-added products, realizing the separate use of propylene and ethylene.

[0053] The process and principle of the secondary reaction are as follows: the unreacted gas material from the primary reactor is mixed with a certain proportion of hydrogen peroxide and enters the secondary reactor 7 for secondary reaction, in which the unreacted ethylene is converted into ethylene glycol, diethylene glycol and triethylene glycol and other polyols by the action of a catalyst, the main reactions involved in the synthesis process are as follows:

[0054] C2H4+H2O2→C2H6O2

[0055] 2C2H4+2H2O2→C4H 10 O3+H2O

[0056] 3C2H4+3H2O2→C6H 14 O4+H2O

[0057] 2H2O2→2H2O+O2

[0058] (2) Propylene glycol rectification section:

[0059] The primary reactor crude product liquid with propylene glycol as the main product separated from the separation device 5 is sent to the propylene glycol rectification section, first sent to the crude propylene glycol dehydration tower 8 to remove water in the crude product liquid, and the tower bottom liquid after dehydration is sent to the propylene glycol tower 9 for extractive rectification, preferably the extractant is added near the top of the tower, and propylene glycol is collected from the top of the tower, and then the tower bottom extractive liquid of the propylene glycol tower 9 is sent to the ethylene glycol tower 10, and ethylene glycol is collected from the top of the tower, and preferably the tower bottom extractive liquid is recycled back to the propylene glycol tower 9 after cooling.

[0060] (3) Ethylene glycol rectification section:

[0061] The crude product liquid mainly containing ethylene glycol from the secondary reactor 7 is sent to the ethylene glycol distillation section, first sent to the ethylene glycol dehydration tower 11 to remove water in the crude product liquid, the tower bottom take-off liquid after dehydration is sent to the crude ethylene glycol separation tower 12, preferably the crude ethylene glycol product is taken from the side line, the tower bottom take-off liquid is sent to the diethylene glycol tower 13, preferably the diethylene glycol product is taken from the side line, the tower bottom take-off liquid is sent to the triethylene glycol tower 14, preferably the triethylene glycol product is taken from the side line, and the tower bottom take-off heavy alcohol waste liquid is taken.

[0062] The separation section of the process has 7 towers, and the operating conditions of each tower are all prior art, specifically, the operating pressure of each tower is 0.005-0.3 MPa (A), and the operating temperature is 100-250°C, compared with the traditional ethylene and propylene direct low-temperature separation, the application conditions of the system of the utility model are more moderate.

[0063] In addition, the extractant adopted by the utility model takes polyhydric alcohol as the main component, and the diethylene glycol and triethylene glycol products taken from the ethylene glycol distillation section can be supplemented into the propylene glycol distillation section as the extractant.

[0064] Since the utility model is divided into two reaction sections, considering that the ethylene and propylene compositions in the actual mixed gas feed are different, the propylene reaction degree in the primary reaction is different, and other factors, the crude ethylene glycol product taken from the ethylene glycol distillation section may contain different degrees of propylene glycol, therefore, the utility model adds a detection point to the crude ethylene glycol separation tower 12 side line product discharge, that is, a second online analyzer is arranged, when the ethylene glycol purity in the taken crude ethylene glycol is low, for example, the content is <95wt%, the crude ethylene glycol product is sent to the ethylene glycol tower 10 in the propylene glycol distillation section, and separation is achieved through extractive distillation.

[0065] In particular, the step of separating the crude product liquid of the primary reaction includes:

[0066] The crude product liquid of the primary reaction is subjected to extractive distillation in the propylene glycol tower 9 after dehydration to obtain a propylene glycol product, the tower bottom liquid of the propylene glycol tower 9 is subjected to separation in the ethylene glycol tower 10 to obtain an ethylene glycol product, and the tower bottom liquid of the ethylene glycol tower 10 is optionally returned to the propylene glycol tower 9 as an extractive solvent;

[0067] Preferably, the extractive solvent is added in the upper half of the propylene glycol tower 9, and the feed tray plate position is preferably the 3rd-8th from the top.

[0068] In particular, the step of separating the crude product liquid of the primary reaction includes:

[0069] The crude product liquid of the secondary reaction is sent into a crude ethylene glycol separation tower 12 after dehydration to obtain a crude ethylene glycol product, which is optionally sent into an ethylene glycol tower 10; the tower bottom liquid of the crude ethylene glycol separation tower 12 is sent into a diethylene glycol tower 13 for separation to obtain a diethylene glycol product, and the tower bottom liquid of the diethylene glycol tower 13 is sent into a triethylene glycol tower 14 for separation to obtain a triethylene glycol product and a tower bottom liquid containing heavy alcohols;

[0070] Preferably, the diethylene glycol product and the triethylene glycol product are each optionally returned to the propylene glycol tower 9 as an extraction solvent.

[0071] Through the above process flow, the utility model can remove the relevant alkanes from the mixed gas mainly containing ethylene and propylene, and then perform two-stage reactions with hydrogen peroxide. When the mixed gas containing ethylene and propylene is in contact with hydrogen peroxide for catalytic oxidation reaction, propylene in the mixed gas is first oxidized. Through online analyzer monitoring, propylene in the mixed gas is directly converted into propylene glycol and retained in the crude product liquid of the first-stage reaction. After the first-stage reaction removes most of the propylene in the gas phase raw material, the second-stage reaction is performed with catalytic contact with hydrogen peroxide. Ethylene is directly converted into ethylene glycol. The product of the first-stage reaction and the product of the second-stage reaction are separated respectively. The process flow is simple, the operating conditions are relatively mild, the separation energy consumption is low. In addition, since hydrogen peroxide reacts with ethylene and propylene, no CO2 and toxic and harmful gases are generated during the reaction process. Therefore, the device meets the "double carbon" policy and the green chemical concept. Secondly, the alkanes obtained by molecular sieve adsorption separation in the device can be used as heat value recovery. The device reaction is an exothermic reaction, and the reaction heat can also be used twice. Furthermore, by changing the two-stage reaction, corresponding polyols are generated, and the products are extracted in the rectification section. This process flow can also separate diethylene glycol and triethylene glycol high-value-added products, and the above products can be used as extractants to supplement the device.

[0072] More preferably, the utility model uses an online analyzer 15 to analyze the composition of the unreacted gas material in the first-stage reactor, and controls the flow direction of the unreacted gas material in the first-stage reactor in real time. More preferably, the flow direction of the unreacted gas material in the first-stage reactor is automatically controlled through an OMS interlocking signal. The control of the degree of the first-stage reaction is more accurate, which can further reduce the generation of by-products and is beneficial to the separation of subsequent products.

[0073] The conditions of the primary reaction, the conditions of the secondary reaction, and the conditions of the separation of the subsequent product from each separation column can all be referenced from the prior art. For example, the conditions of the primary reaction can be referenced from CN 103012064A; the conditions of the secondary reaction can be referenced from CN 102951998 A. The crude products of the primary reaction and the secondary reaction are common crude products in the chemical industry, and the specific separation conditions can be referenced from the column separation conditions in the prior art. Specifically, for example:

[0074] In particular, the step of separating the crude product liquid of the primary reaction includes:

[0075] The crude product liquid of the primary reaction is subjected to dehydration and then subjected to extractive distillation in a propylene glycol column 9 to obtain a propylene glycol product, the column still liquid of the propylene glycol column 9 is separated in an ethylene glycol column 10, an ethylene glycol product is obtained in the ethylene glycol column 10, and the column still liquid of the ethylene glycol column 10 is optionally returned to the propylene glycol column 9 as an extraction solvent;

[0076] The conditions for separating the crude product liquid of the primary reaction include:

[0077] The dehydration in the separation of the crude product liquid of the primary reaction is carried out in a dehydration column, preferably, the dehydration column has a top pressure <= 0.035 MPa, preferably 0.015-0.035 MPa, a reflux ratio of 0.5-3, and a number of trays of 10-30; and / or,

[0078] The conditions of the extractive distillation include: the extraction solvent used for the extractive distillation is a polyol; and / or, the extraction solvent is added in the upper half of the propylene glycol column 9, preferably the feed tray position is the 3rd-8th from the top; and / or, preferably, the extraction solvent contains a polyethylene glycol ether ester, preferably the amount of the polyethylene glycol ether ester is 1-2 times the amount of the main material feed at the initial loading, and the amount of the subsequent supplemental extraction agent is not higher than 0.01wt% of the amount of the main material feed in terms of mass content; and / or,

[0079] The polyethylene glycol ether ester is selected from at least one of diethylene glycol, triethylene glycol, ethylene glycol monomethyl ether, ethylene glycol dimethyl ether, ethylene glycol monomethyl ester, and ethylene glycol dimethyl ester;

[0080] And / or, the pressure of the propylene glycol column 9 is 0.01-0.2 MPa, the reflux ratio is 0.5-5, and the number of trays is 10-60; and / or,

[0081] The top pressure of the ethylene glycol column 10 is 0.01-0.1 MPa, the reflux ratio is 0.5-4, and the number of trays is 10-30.

[0082] In particular, the step of separating the crude product liquid of the secondary reaction includes:

[0083] The crude product liquid of the secondary reaction is sent into a crude ethylene glycol separation tower 12 after dehydration to obtain a crude ethylene glycol product, which is optionally sent into an ethylene glycol tower 10; the tower bottom liquid of the crude ethylene glycol separation tower 12 is sent into a diethylene glycol tower 13 for separation to obtain a diethylene glycol product, and the tower bottom liquid of the diethylene glycol tower 13 is sent into a triethylene glycol tower 14 for separation to obtain a triethylene glycol product and a tower bottom liquid containing heavy alcohols;

[0084] Preferably, the diethylene glycol product and the triethylene glycol product are each optionally returned to the propylene glycol tower 9 as an extraction solvent.

[0085] The conditions for separating the crude product liquid of the secondary reaction include:

[0086] The dehydration is carried out in a dehydration tower, preferably, the dehydration tower has a top pressure <= 0.035 MPa, preferably 0.015-0.035 MPa, a mole reflux ratio of 0.5-3, and 10-30 plates; and / or,

[0087] The crude ethylene glycol separation tower 12 has a top pressure <= 0.030 MPa, preferably 0.01-0.030 MPa, a mole reflux ratio of 1-10, and 10-50 plates; and / or,

[0088] The diethylene glycol tower 13 has a top pressure <= 0.020 MPa, preferably 0.001-0.020 MPa, a mole reflux ratio of 1-10, and 10-50 plates, and the diethylene glycol product is preferably taken out from the side line of the diethylene glycol tower 13; and / or,

[0089] The triethylene glycol tower 14 has a top pressure of 0.01-0.2 MPa, preferably 0.001-0.020 MPa, a mole reflux ratio of 1-10, and 10-50 plates, and the triethylene glycol product is preferably taken out from the side line of the triethylene glycol tower 4.

[0090] Example 1

[0091] As shown in Figure 2 , Figure 3 The utility model provides a kind of utilization system of mixed gas containing ethylene and propylene, according to material flow direction, including connection in proper order: the gas source 1 of mixed gas containing ethylene and propylene, first membrane separator 2, first mixer 3, primary reactor 4 and separation device 5;

[0092] The separation device 5 includes being provided with liquid material discharge port and gas material discharge port, wherein, along the material flow direction of gas material discharge port of separation device 5, second mixer 6, secondary reactor 7 are sequentially arranged;

[0093] The system also comprises a hydrogen peroxide source, which is connected with the feed inlet of the first mixer 3 and the second mixer 6 respectively; wherein a second switch valve 17 is arranged on the pipeline between the gas material outlet of the separation device 5 and the secondary reactor 7, and the gas material outlet of the separation device 5 is selectively connected with the feed inlet of the primary reactor 4 through a pipeline and a first switch valve 16 arranged on the pipeline;

[0094] The utilization system also comprises an online analyzer 15 for analyzing the composition of the gas material flowing out of the primary reactor 4. In use, the gas source 1 containing the mixed gas of ethylene and propylene enters the first mixer 3 after being separated to remove alkanes and other gases by the first membrane separator 2, and the hydrogen peroxide from the hydrogen peroxide source enters the first mixer 3 and is mixed with the mixed gas containing ethylene and propylene, and then enters the primary reactor 4 to undergo a primary reaction, and the crude product liquid obtained by the primary reaction and the unreacted gas material are obtained in the primary reactor 4. The above-mentioned mixed material flows out of the primary reactor 4 and is separated by the separation device 5 to obtain the crude product liquid obtained by the primary reaction and the unreacted gas material, respectively. The online analyzer 15 (gas chromatograph) analyzes the composition of the gas material flowing out of the primary reactor 4 in real time at the outlet of the primary reactor 4. By default, the first switch valve 16 is opened, and the second switch valve 17 is closed. When the propylene content in the gas material flowing out of the primary reactor 4 does not reach the target content, the gas material flowing out of the primary reactor 4 is returned to the primary reactor 4 to continue the primary reaction, and the process is repeated. When the propylene content in the gas material flowing out of the primary reactor 4 reaches the target content, the second switch valve 17 is opened, and the first switch valve 16 is closed. The gas material flowing out of the primary reactor 4 is transported to the second mixer 6. The gas material flowing out of the primary reactor 4 is mixed with the hydrogen peroxide from the hydrogen peroxide source in the second mixer 6 and then enters the secondary reactor 7. After the secondary reaction, the crude product liquid of the secondary reaction is obtained.

[0095] Example 2

[0096] As Figure 2 shown, in the mixed gas utilization system of the utility model described in example 1, along the material flow direction of the liquid material outlet of the separation device 5, a crude propylene glycol dehydration tower 8, a propylene glycol tower 9 and an ethylene glycol tower 10 are sequentially arranged to perform the separation process of the primary reactor crude product liquid. The secondary reactor 7 is further sequentially connected with an ethylene glycol dehydration tower 11, a crude ethylene glycol separation tower 12, a diethylene glycol tower 13 and a triethylene glycol tower 14 to perform the subsequent separation of the crude product liquid of the secondary reaction.

[0097] The separation process for the crude product liquid obtained from the first-stage reaction includes: along the material flow direction of the liquid outlet of the separation device 5, a crude propylene glycol dehydration tower 8 is sequentially installed to remove water from the crude product liquid obtained from the first-stage reaction; the bottom liquid of the crude propylene glycol dehydration tower is passed through a propylene glycol tower 9 to obtain propylene glycol product; the bottom liquid of the propylene glycol tower 9 is passed through an ethylene glycol tower 10 to obtain ethylene glycol product; the bottom liquid of the ethylene glycol tower is heavy alcohol. The separation process for the crude product liquid obtained from the second-stage reaction includes: the crude product liquid flowing out of the second-stage reactor 7 is passed through an ethylene glycol dehydration tower 11 to remove water; the bottom liquid of the ethylene glycol dehydration tower 11 is passed through a crude ethylene glycol separation tower 12 to obtain crude ethylene glycol product; the bottom liquid of the crude ethylene glycol separation tower 12 is passed through a diethylene glycol tower 13 to obtain diethylene glycol product; and the bottom liquid of the diethylene glycol tower 13 is passed through a triethylene glycol tower 14 to obtain triethylene glycol product.

[0098] Comparative Example 1

[0099] like Figure 1 As shown, the existing technology separates refinery dry gas containing a mixture of ethylene and propylene. This system employs cryogenic separation, with distillation temperatures typically ranging from -20 to -80°C, and sometimes even as low as -100°C. Furthermore, this method involves large equipment investments, relatively high energy consumption, and is only suitable for areas with a high concentration of large refineries. Additionally, the equipment is bulky, the control system is complex, and the resulting ethylene has low purity and low recovery rate.

[0100] Literature review revealed that, for example, the energy consumption of the cryogenic separation ethylene unit in Comparative Example 1 is generally 500-800 kg standard oil / t, with the separation section accounting for at least 2 / 3 of the total energy consumption. Furthermore, the operating temperature is between -100 and -20 °C, requiring very low operating temperatures that are difficult to control and present significant challenges. In contrast, the process system in this invention directly utilizes the mixed gas of ethylene and propylene without separation, achieving the separation of ethylene glycol and propylene glycol. According to the separation operating conditions described in existing technologies, the required energy consumption is 150-400 kg standard oil / t, with an operating temperature between 80 and 250 °C (referencing the distillation temperatures of the products mentioned above). This energy consumption is lower than that of ethylene-propylene separation, and the operating conditions are more moderate.

[0101] Through the description of the prior art, and the material flow and composition in the utility model, it can be undoubtedly concluded that the utility model realizes direct conversion of ethylene and propylene, and can be separated through a simple manner. According to the preferred operation condition described in the utility model, the separation energy consumption is 150-400 kg of standard oil / t, and the operation temperature is 80-250 DEG C, compared with the general energy consumption of 500-800 kg of standard oil / t by using cryogenic separation (the specific process separation energy consumption can also be obtained through actual experiment and heat balance calculation), and the cryogenic separation operation temperature is (-100) to (-20) DEG C, the utility model also has the characteristics of low energy consumption and relatively mild operation condition, and unexpected technical effects are achieved.

[0102] It should be noted that the above-described embodiments are only used to explain the utility model, and do not constitute any limitation on the utility model. The utility model has been described by referring to typical embodiments, but it should be understood that the words used therein are descriptive and explanatory words, rather than limiting words. The utility model can be modified within the scope of the claims of the utility model, and the utility model can be revised within the scope and spirit of the utility model. Although the utility model described therein relates to specific methods, materials and embodiments, it does not mean that the utility model is limited to the specific examples disclosed therein, on the contrary, the utility model can be extended to all other methods and applications with the same function.

[0103] All publications, patent applications, patents and other references mentioned in this specification are hereby incorporated by reference. Unless otherwise defined, all technical and scientific terms used in this specification have the meaning commonly understood by one of ordinary skill in the art. In case of conflict, the present specification will control.

[0104] When the specification derives material, substance, method, step, device or component, etc. with the word head "known to those skilled in the art", "prior art" or similar words, the object derived by the word head covers those commonly used in the art at the time of the application, but also includes those not commonly used at present, but will be recognized as suitable for similar purposes in the art.

[0105] The endpoints of the ranges and any values described in this application document are not limited to the precise values stated. The ranges and values should be interpreted as being approximate. For numeric values, the endpoints of the various ranges, the endpoints of the various ranges and individual point values, and individual point values can be combined with each other to obtain one or more new numeric ranges, which should be considered as specifically disclosed herein. In the following, the various technical solutions can be combined with each other in principle to obtain new technical solutions, which should also be considered as specifically disclosed herein.

[0106] In the context of the present specification, unless explicitly stated otherwise, any reference to any item or matter not mentioned is taken to mean that which is known in the art without any need for any change.

[0107] Furthermore, any embodiment described herein can be freely combined with one or more other embodiments described herein, whereby the technical solution or technical idea formed thereby is deemed to be part of the original disclosure or original teaching of the present application and should not be deemed to be new content not disclosed or anticipated herein, unless the combination is deemed to be obviously unreasonable by a person skilled in the art.

Claims

1. A utilization system of a mixed gas containing ethylene and propylene, comprising, in sequence, a gas source of the mixed gas containing ethylene and propylene, a first membrane separator, a first mixer, a primary reactor and a separation device, according to a material flow direction. The separation device is provided with a liquid material discharge port and a gas material discharge port, wherein A second mixer and a secondary reactor are connected in sequence along a material flow direction of a gas material outlet of the separation device. The utilization system further comprises a hydrogen peroxide source, which is connected to feed inlets of the first mixer and the second mixer, respectively. The gas material outlet of the separation device is selectively connected to a feed inlet of the primary reactor through a pipeline, and a first switch valve is arranged on the pipeline. A second switch valve is arranged on a pipeline between the gas material outlet of the separation device and the secondary reactor. The utilization system further comprises an online analyzer arranged on a pipeline through which a reaction material of the primary reactor flows out, and the online analyzer is used to analyze a composition of the gas material flowing out of the primary reactor. 2.The utilization system of the mixed gas containing ethylene and propylene according to claim 1, wherein the gas source of the mixed gas containing ethylene and propylene is refinery dry gas from an upstream; and / or a crude propylene glycol dehydration tower, a propylene glycol tower and an ethylene glycol tower are arranged in sequence along a material flow direction of a liquid material outlet of the separation device; and / or an ethylene glycol dehydration tower, a crude ethylene glycol separation tower, a diethylene glycol tower and a triethylene glycol tower are further connected in sequence after the secondary reactor. 3.The utilization system of the mixed gas containing ethylene and propylene according to claim 1, wherein the first membrane separator is selected from a molecular sieve membrane separator. 4.The utilization system of the mixed gas containing ethylene and propylene according to claim 2, wherein a tower kettle liquid outlet of the crude propylene glycol dehydration tower is connected to a feed inlet of the propylene glycol tower, and a tower kettle liquid outlet of the propylene glycol tower is connected to a feed inlet of the ethylene glycol tower; and / or product outlets are arranged above the propylene glycol tower and the ethylene glycol tower, respectively. 5.The utilization system of the mixed gas containing ethylene and propylene according to claim 2, wherein a tower kettle liquid outlet of the ethylene glycol dehydration tower is connected to a feed inlet of the crude ethylene glycol separation tower; tower kettle liquid outlets of the crude ethylene glycol separation tower, the diethylene glycol tower and the triethylene glycol tower are connected to feed inlets of downstream tower devices, respectively; and / or product outlets are arranged on side lines of the crude ethylene glycol separation tower, the diethylene glycol tower and the triethylene glycol tower, respectively. 6.The utilization system of the mixed gas containing ethylene and propylene according to claim 2, wherein the propylene glycol tower is provided with an extractant feed inlet. 7.The utilization system of the mixed gas containing ethylene and propylene according to claim 6, wherein the extractant feed inlet is arranged in an upper half of the propylene glycol tower. 8.The utilization system of the mixed gas containing ethylene and propylene according to claim 7, wherein the extractant feed inlet is arranged at 3rd-8th feed trays from an upper part of the propylene glycol tower. 9.The utilization system of the mixed gas containing ethylene and propylene according to claim 6, wherein ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ The bottom liquid outlet of the ethylene glycol column, the product outlet of the diethylene glycol column, and the product outlet of the triethylene glycol column are each optionally in communication with the extractant feed inlet of the propylene glycol column.

10. The system for utilizing the mixed gas containing ethylene and propylene according to claim 1, wherein: The on-line analyzer is selected from an on-line gas chromatograph and / or an infrared spectrometer.

11. The system for utilizing the mixed gas containing ethylene and propylene according to claim 1, wherein: The separation device comprises a second membrane separator and a gas-liquid separation device in sequence, and the second membrane separator is used for separating solid particles contained in the feed liquid from the primary reactor.

12. The system for utilizing the mixed gas containing ethylene and propylene according to claim 11, wherein: The second membrane separator is a molecular sieve membrane separator; and / or the gas-liquid separation device is a gas-liquid separation tank.

13. The system for utilizing the mixed gas containing ethylene and propylene according to any one of claims 1-12, wherein: The utilization system further comprises an OMS interlocking signal device, which can receive the composition information of the gas material output by the on-line analyzer, and can issue an opening and closing instruction of the first and second switch valves according to the control target of the gas material composition, and then transmit the opening and closing instruction to the first and second switch valves through the OMS interlocking signal, so as to automatically determine the opening and closing state of the second switch valve and the first switch valve.

Images