Crude oil volatile gas dehumidification material grading method and crude oil volatile gas dehumidification method

Abstract

The invention relates to the technical field of crude oil volatile gas dehumidification, and discloses a crude oil volatile gas dehumidification material grading method and a crude oil volatile gas dehumidification method.The grading method comprises the steps that when the relative humidity of crude oil volatile gas is smaller than or equal to 30% RH, a reactor is sequentially filled with a molecular sieve dehumidification material and an MOFs dehumidification material in the material flow direction; the relative humidity of crude oil volatile gas is gt; when the RH is 30%, the reactor is sequentially filled with a silica gel dehumidification material, a molecular sieve dehumidification material and an MOFs dehumidification material in the material flow direction; and the filling amount of the MOFs dehumidification material is not less than 10% by volume based on the total volume of the dehumidification materials filled in the reactor. The silica gel, the molecular sieve and the MOFs are effectively graded, so that the crude oil volatile gas with different humidities can be deeply dehumidified, and the relative humidity of the dehumidified crude oil volatile gas is 1% RH or below, so that the efficient recovery of the crude oil volatile gas is realized; in addition, the method is low in dehumidification cost of the crude oil volatile gas.

Description

Technical Field

[0001] The present invention relates to the technical field of crude oil volatile gas dehumidification, and specifically relates to a method for grading a crude oil volatile gas dehumidification material and a method for dehumidifying a crude oil volatile gas. Background Art

[0002] During the exploitation, storage, and transportation of oilfield crude oil, the emission of VOCs will inevitably occur. In order to reduce environmental pollution and improve the efficiency of oilfields, it is urgent to effectively recover and utilize crude oil volatile gas. A large amount of water is accompanied during the crude oil exploitation process, so the moisture content in the crude oil volatile gas is relatively high. In the process of recovering and treating VOCs from crude oil volatile gas by using the "condensation + adsorption" process, before the oil and gas enter the condensation system, it is necessary to remove water vapor. Otherwise, the presence of water vapor will affect the recovery ability of the oil and gas and reduce the heat exchange efficiency of the equipment, and even cause "frost blockage" of the heat exchanger, posing a safety hazard. Using the adsorption method for deep dehumidification of water-containing crude oil volatile gas is a relatively simple and low-cost method. The core of the adsorption dehumidification technology is a porous solid dehumidification material. Currently, commonly used dehumidification materials include zeolite / molecular sieve, silica gel, alumina, activated carbon, etc.

[0003] Zeolite is a natural aluminosilicate existing in nature, which has the functions of molecular sieving and adsorption. The artificially synthesized zeolite is called molecular sieve, and the molecular sieve also has the function of screening molecules and has a strong adsorption effect on water molecules, and is applied in many occasions where humidity needs to be controlled. The main component of silica gel is amorphous silica. Its production process is mature, the price is cheap and it is easy to obtain, and it has been widely used as a desiccant in various industries. Activated alumina is a porous and highly dispersed solid material with uniform particle size, large mechanical strength, and strong hygroscopicity. It is an efficient desiccant for deep drying of trace water. Activated carbon has the advantages of large specific surface area, developed pore structure, strong adsorption ability, etc., and can have a certain ability to adsorb water vapor at a relatively high relative humidity. By modifying traditional porous solid materials, composite porous materials can be obtained. The composite dehumidification material is to dope salts with high hygroscopic performance but unstable physical and chemical properties (such as halogen salts, etc.) into porous materials with stable physical and chemical properties but limited hygroscopic performance (such as activated carbon, molecular sieve, silica gel, etc.) to balance the advantages and disadvantages of the two, and obtain a stable and efficient dehumidification material between the two. In addition, some new materials can also be used for solid adsorption dehumidification, such as metal-organic framework materials (MOFs). The high specific surface area of MOFs gives it good hygroscopic performance.

[0004] Regarding the water removal of crude oil volatile gas, the water removal effects of the above-mentioned traditional materials such as silica gel and molecular sieve are not good, and the water removal is not thorough enough, which affects the recovery efficiency of crude oil volatile gas; while for composite dehumidification materials such as calcium chloride modified porous materials, although the water absorption performance has been greatly improved after modification, the presence of halogen ions such as chloride ions will cause corrosion of devices and pipelines such as adsorption beds, resulting in high maintenance costs; new materials such as MOFs materials have a high water absorption capacity, but due to certain limitations in the large-scale preparation of materials, the cost is high. Therefore, there is an urgent need to provide a method with low cost and good dehumidification effect for crude oil volatile gas. Summary of the Invention

[0005] The purpose of the present invention is to overcome the problems that the existing dehumidification materials have poor water removal effects for crude oil volatile gas with different humidities or high treatment costs, and to provide a method for grading crude oil volatile gas dehumidification materials and a method for dehumidifying crude oil volatile gas.

[0006] To achieve the above purpose, on the one hand, the present invention provides a method for grading crude oil volatile gas dehumidification materials, and the grading method includes:

[0007] When the relative humidity of the crude oil volatile gas ≤ 30% RH, the molecular sieve dehumidification material and the MOFs dehumidification material are filled in the reactor in sequence along the material flow direction;

[0008] When the relative humidity of the crude oil volatile gas > 30% RH, the silica gel dehumidification material, the molecular sieve dehumidification material and the MOFs dehumidification material are filled in the reactor in sequence along the material flow direction;

[0009] Among them, based on the total volume of each dehumidification material filled in the reactor, the filling amount of the MOFs dehumidification material is not less than 10% by volume.

[0010] Preferably, the specific surface area of the silica gel dehumidification material is 500 - 700m 2 / g.

[0011] Preferably, the pore diameter of the silica gel dehumidification material is 0.5 - 10nm.

[0012] Preferably, the specific surface area of the molecular sieve dehumidification material is less than 600m 2 / g, and the pore diameter is 0.3 - 2nm.

[0013] Preferably, the molecular sieve dehumidification material is selected from one or more of 3A molecular sieve, 4A molecular sieve, 5A molecular sieve and 13X molecular sieve.

[0014] Preferably, the specific surface area of the MOFs dehumidification material is 900 - 3500m 2 / g, and the pore diameter is 0.5 - 3.5nm.

[0015] Preferably, the MOFs dehumidifying material is selected from one or more of HKUST-1, MOF-5, MOF-74, MOF-303, MOF-801, MOF-808, MIL-101, MIL-100, MIL-53, UIO-66, UIO-67, ZIF-8, ZIF-67, ZIF-90, and modified MOFs prepared from organic ligands modified with amino or hydroxyl functional groups.

[0016] Preferably, the MOFs dehumidifying material is one or more of MOF-303, MOF-801, and MIL-101.

[0017] Preferably, when the relative humidity of the crude oil volatile gas ≤ 30% RH, based on the total volume of each dehumidifying material filled in the reactor, the filling amount of the molecular sieve dehumidifying material is 40 - 90% by volume, and the filling amount of the MOFs dehumidifying material is 10 - 60% by volume.

[0018] Preferably, when the relative humidity of the crude oil volatile gas > 30% RH, based on the total volume of each dehumidifying material filled in the reactor, the filling amount of the silica gel dehumidifying material is 30 - 70% by volume, the filling amount of the molecular sieve dehumidifying material is 20 - 40% by volume, and the filling amount of the MOFs dehumidifying material is 10 - 30% by volume.

[0019] In the second aspect of the present invention, a method for dehumidifying crude oil volatile gas is provided, and the method includes: subjecting the crude oil volatile gas to dehumidification treatment by passing it through a reactor filled by the grading method as described above.

[0020] Preferably, the relative humidity of the crude oil volatile gas is 10 - 100% RH.

[0021] Preferably, the crude oil volatile gas contains C1 - C5 alkanes.

[0022] In the technical solution provided by the present invention, through the effective grading of three types of dehumidifying materials, namely silica gel, molecular sieve, and MOFs, the crude oil volatile gas with different humidities can be deeply dehumidified, and the relative humidity of the dehumidified crude oil volatile gas is below 1% RH, thereby effectively avoiding the "frost blockage" problem of the heat exchanger caused by the presence of water vapor during the process of recovering crude oil volatile gas by the "condensation + adsorption" process, and further realizing the efficient recovery of crude oil volatile gas; in addition, in the grading method provided by the present invention, by using low-cost silica gel and molecular sieve dehumidifying materials, the use of MOFs dehumidifying materials is reduced, making the dehumidification cost of this method for crude oil volatile gas low. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a schematic structural diagram of an adsorption bed filled with an embodiment of the grading method provided by the present invention. Detailed Embodiments

[0024] The following will describe in detail the specific embodiments of the present invention with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only for the purpose of illustrating and explaining the present invention, and are not intended to limit the present invention.

[0025] In the ranges disclosed herein, the endpoints and any values are not limited to the exact ranges or values, and these ranges or values should be understood to include values close to these ranges or values. For numerical ranges, the endpoint values of each range, between the endpoint values of each range and individual point values, and between individual point values can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed herein.

[0026] The present invention provides a method for grading a dehumidification material for crude oil volatile gas, and the grading method includes:

[0027] When the relative humidity of the crude oil volatile gas ≤ 30% RH, the reactor is filled with a molecular sieve dehumidification material and a MOFs dehumidification material in sequence along the logistics direction;

[0028] When the relative humidity of the crude oil volatile gas > 30% RH, the reactor is filled with a silica gel dehumidification material, a molecular sieve dehumidification material and a MOFs dehumidification material in sequence along the logistics direction;

[0029] Wherein, based on the total volume of each dehumidification material filled in the reactor, the filling amount of the MOFs dehumidification material is not less than 10% by volume.

[0030] In the present invention, regardless of whether the relative humidity of the crude oil volatile gas is ≤ 30% RH or > 30% RH, in order to ensure the dehumidification effect, in the reactor, the filling amount of the MOFs dehumidification material is not less than 10% by volume.

[0031] When the relative humidity of the crude oil volatile gas ≤ 30% RH, the silica gel dehumidification material has poor adsorption performance for water vapor in the crude oil volatile gas. Considering both cost savings and ensuring deep dehumidification, only the molecular sieve dehumidification material and the MOFs dehumidification material are filled in the reactor along the logistics direction.

[0032] By effectively grading the three types of dehumidification materials, namely silica gel, molecular sieve, and MOFs, in combination with the adsorption characteristics of these three types of dehumidification materials for water vapor, the present invention can be applied to the deep dehumidification of crude oil volatile gas with different humidities (10 - 100% RH), making the relative humidity of the dehumidified crude oil volatile gas below 1% RH, and solving the problem that the dehumidification effect of a single dehumidification material on crude oil volatile gas is not ideal.

[0033] The grading method provided by the present invention reduces the use of relatively expensive MOFs dehumidification materials by using inexpensive silica gel and molecular sieve dehumidification materials. Further, for crude oil volatile gases with different humidities, by adjusting the filling ratios of the above three types of dehumidification materials, the adsorption performance of all dehumidification materials for water vapor can be maximized, thereby further reducing the amount of dehumidification materials while ensuring deep dehumidification of crude oil volatile gases; in addition, this grading method is simple to operate. Therefore, when the grading method provided by the present invention is used to treat crude oil volatile gases, the treatment cost is low.

[0034] It can be understood that when the relative humidity of the crude oil volatile gas is ≤30%RH or >30%RH, the specific selection of the molecular sieve dehumidification material in the reactor can be the same or different, as long as it is a molecular sieve dehumidification material. Similarly, when the relative humidity of the crude oil volatile gas is ≤30%RH or >30%RH, the specific selection of the MOFs material is also independent of each other.

[0035] In a preferred embodiment, the specific surface area of the silica gel dehumidification material is 500 - 700m 2 / g.

[0036] In a preferred embodiment, the pore diameter of the silica gel dehumidification material is 0.5 - 10nm, so that the effect of deep dehumidification is better.

[0037] Further preferably, the pore diameter of the silica gel dehumidification material is 0.5 - 2nm.

[0038] The present invention does not limit the specific structure of the molecular sieve dehumidification material. In a preferred embodiment, the specific surface area of the molecular sieve dehumidification material is less than 600m 2 / g, and the pore diameter is 0.3 - 2nm. Further preferably, the specific surface area of the molecular sieve dehumidification material is 20 - 600m 2 / g.

[0039] The present invention also does not limit the specific type of the molecular sieve dehumidification material. In a preferred embodiment, the molecular sieve dehumidification material is selected from one or more of 3A molecular sieve, 4A molecular sieve, 5A molecular sieve, and 13X molecular sieve.

[0040] In a preferred embodiment, the specific surface area of the MOFs dehumidification material is 900 - 3500m 2 / g, and the pore diameter is 0.5 - 3.5nm.

[0041] More preferably, the pore diameter of the MOFs dehumidification material is 0.5 - 2nm.

[0042] In a preferred embodiment, the MOFs dehumidification material is selected from one or more of HKUST-1, MOF-5, MOF-74, MOF-303, MOF-801, MOF-808, MIL-101, MIL-100, MIL-53, UIO-66, UIO-67, ZIF-8, ZIF-67, ZIF-90, and modified MOFs prepared by modifying organic ligands with amino or hydroxyl functional groups. The present invention does not limit the specific source of the above MOFs dehumidification material, which can be a commercially available product or can be prepared by oneself according to the conventional preparation methods in the art.

[0043] Further preferably, the MOFs dehumidification material is one or more of MOF-303, MOF-801, and MIL-101. By selecting the above MOFs materials, their adsorption performance for water vapor is better, so that the deep dehumidification of crude oil volatile gas is more thorough.

[0044] In a preferred embodiment, when the relative humidity of the crude oil volatile gas ≤ 30% RH, based on the total volume of each dehumidification material filled in the reactor, the filling amount of the molecular sieve dehumidification material is 40 - 90% by volume, and the filling amount of the MOFs dehumidification material is 10 - 60% by volume.

[0045] Further preferably, when the relative humidity of the crude oil volatile gas ≤ 30% RH, based on the total volume of each dehumidification material filled in the reactor, the filling amount of the molecular sieve dehumidification material is 40 - 70% by volume, and the filling amount of the MOFs dehumidification material is 30 - 60% by volume.

[0046] In a preferred embodiment, when the relative humidity of the crude oil volatile gas > 30% RH, based on the total volume of each dehumidification material filled in the reactor, the filling amount of the silica gel dehumidification material is 30 - 70% by volume, the filling amount of the molecular sieve dehumidification material is 20 - 40% by volume, and the filling amount of the MOFs dehumidification material is 10 - 30% by volume.

[0047] The present invention does not limit the reactor, which can be any reactor that enables the raw material volatile gas to come into contact with the dehumidification material for adsorption. In a specific embodiment, the reactor is an adsorption bed.

[0048] Please refer to Figure 1, in a specific embodiment, when the relative humidity of the crude oil volatile gas > 30% RH, the grading method includes: the adsorption bed is filled with silica gel dehumidification material, molecular sieve dehumidification material and MOFs dehumidification material in sequence along the logistics direction. Among them, the part filled with silica gel dehumidification material forms a silica gel layer, the part filled with molecular sieve dehumidification material forms a molecular sieve layer, and the part filled with MOFs material forms a MOFs layer. Specifically, the adsorption bed filled by the grading method has three adsorption bed layers, which are the silica gel layer, the molecular sieve layer and the MOFs layer from bottom to top. When the adsorption bed is used for dehumidifying the crude oil volatile gas, the crude oil volatile gas is introduced from the lower end, and it passes through the silica gel layer, the molecular sieve layer and the MOFs layer in sequence.

[0049] The present invention also provides a method for dehumidifying crude oil volatile gas, which includes: dehumidifying the crude oil volatile gas by passing it through an adsorption bed filled by the grading method as described above.

[0050] In specific implementation, when the relative humidity of the crude oil volatile gas ≤ 30% RH, the adsorption bed is filled with molecular sieve dehumidification material and MOFs dehumidification material in sequence along the logistics direction, so that the adsorption bed has a molecular sieve layer and a MOFs layer. The crude oil volatile gas with a relative humidity ≤ 30% RH is introduced into the adsorption bed, and it passes through the molecular sieve layer and the MOFs layer in sequence for adsorption and water removal.

[0051] In specific implementation, when the relative humidity of the crude oil volatile gas > 30% RH, the adsorption bed is filled with silica gel dehumidification material, molecular sieve dehumidification material and MOFs dehumidification material in sequence along the logistics direction, so that the adsorption bed has a silica gel layer, a molecular sieve layer and a MOFs layer. The crude oil volatile gas with a relative humidity > 30% RH is introduced into the adsorption bed, and it passes through the silica gel layer, the molecular sieve layer and the MOFs layer in sequence for adsorption and water removal.

[0052] In the dehumidification method of the present invention, there is no limit to the specific humidity of the crude oil volatile gas. In a preferred embodiment, the relative humidity of the crude oil volatile gas is 10 - 100% RH.

[0053] In the dehumidification method of the present invention, there is also no limit to the specific types of VOCs in the crude oil volatile gas. In a specific embodiment, the crude oil volatile gas contains C1 - C5 alkanes. Specifically, for example, it can be methane, ethane, propane, butane and pentane.

[0054] The present invention will be described in detail below through embodiments, but the protection scope of the present invention is not limited thereto. In the following examples, the main components of the crude oil volatile gas are C1-C5 alkanes. Sampling data of VOCs during a single loading of crude oil in a certain oilfield is selected for simulated gas mixing. The volume fraction of VOCs in the simulated crude oil volatile gas is 10 VOL%, and the concentration ratio of methane, ethane, propane, butane, and pentane in VOCs is 25%:15%:25%:20%:15%.

[0055] In the following examples, the volume of the adsorption bed is fixed, that is, the total volume of each dehumidifying material is the same.

[0056] In the following examples, microporous silica gel was purchased from Qingdao Ocean Chemical Co., Ltd., Shandong;

[0057] 3A / 4A / 5A / 13X molecular sieves were purchased from Jiangsu Xianfeng Nano Materials Technology Co., Ltd.;

[0058] The MOF-801 material was synthesized according to the method in the literature J. Am. Chem. Soc. 2014, 136, 4369-4381, MIL-101 was synthesized according to the method in the literature ACS Catal. 2014, 4, 4254-4260, and MOF-303 was synthesized according to the method in the literature Sci. Adv. 2018, 4(6), 3198.

[0059] Among them, the measurement results of the specific surface area and pore diameter of the above dehumidifying materials are as described in Table 1 below.

[0060] Table 1

[0061] Type <![CDATA[Specific surface area, m 2 / g]]> Pore diameter, nm Microporous silica gel 596 1.15 3A molecular sieve 23 0.3 4A molecular sieve 34 0.4 5A molecular sieve 465 0.56 13X molecular sieve 555 1.75 MOF-801 950 0.56-0.74 MIL-101 3220 2.8-3.4 MOF-303 1375 0.6

[0062] Example 1

[0063] Gas mixing was carried out according to the following components, concentrations, and ratios: the volume fraction of VOCs in the crude oil volatile gas was 10 VOL%, and the concentration ratio of methane, ethane, propane, butane, and pentane in VOCs was 25%:15%:25%:20%:15%; the relative humidity of the crude oil volatile gas was adjusted to 30% RH.

[0064] In the adsorption bed, two dehumidifying materials, 3A molecular sieve and MOF-801, were loaded from bottom to top in sequence, and their loading volume ratio was 50:50. The crude oil volatile gas passed through the adsorption bed layer from bottom to top and contacted the 3A molecular sieve and MOF-801 loaded in the adsorption column respectively.

[0065] After the crude oil volatile gas was treated by adsorption, the concentrations of each component were: methane 25120 ppm, ethane 15030 ppm, propane 24500 ppm, butane 19740 ppm, pentane 14520 ppm, and the relative humidity was 0.5% RH.

[0066] Example 2

[0067] The gas is prepared according to the following components, concentrations and ratios: the volume fraction of VOCs in the crude oil volatile gas is 10 VOL%, and the concentration ratio of methane, ethane, propane, butane and pentane in VOCs is 25%: 15%: 25%: 20%: 15%; the relative humidity of the crude oil volatile gas is adjusted to 50% RH.

[0068] In the adsorption bed, three dehumidification materials, namely microporous silica gel, 3A molecular sieve and MOF-801, are loaded from bottom to top in sequence, and their loading volume ratio is 30:40:30. The crude oil volatile gas passes through the adsorption bed layer from bottom to top and contacts the microporous silica gel, 3A molecular sieve and MOF-801 loaded in the adsorption column respectively.

[0069] After the adsorption treatment of the crude oil volatile gas, the concentrations of each component are: methane 25040 ppm, ethane 15110 ppm, propane 24680 ppm, butane 19490 ppm, pentane 14710 ppm, and the relative humidity is 0.6% RH.

[0070] Example 3

[0071] The gas is prepared according to the following components, concentrations and ratios: the volume fraction of VOCs in the crude oil volatile gas is 10 VOL%, and the concentration ratio of methane, ethane, propane, butane and pentane in VOCs is 25%: 15%: 25%: 20%: 15%; the relative humidity of the crude oil volatile gas is adjusted to 70% RH.

[0072] In the adsorption bed, three dehumidification materials, namely microporous silica gel, 3A molecular sieve and MOF-801, are loaded from bottom to top in sequence, and their loading volume ratio is 50:30:20. The crude oil volatile gas passes through the adsorption bed layer from bottom to top and contacts the microporous silica gel, 3A molecular sieve and MOF-801 loaded in the adsorption column respectively.

[0073] After the adsorption treatment of the crude oil volatile gas, the concentrations of each component are: methane 25340 ppm, ethane 15130 ppm, propane 24230 ppm, butane 19380 ppm, pentane 14360 ppm, and the relative humidity is 0.8% RH.

[0074] Example 4

[0075] The gas is prepared according to the following components, concentrations and ratios: the volume fraction of VOCs in the crude oil volatile gas is 10 VOL%, and the concentration ratio of methane, ethane, propane, butane and pentane in VOCs is 25%: 15%: 25%: 20%: 15%; the relative humidity of the crude oil volatile gas is adjusted to 90% RH.

[0076] In the adsorption bed, three dehumidification materials, namely microporous silica gel, 3A molecular sieve, and MOF-801, are filled from bottom to top in sequence, and their filling volume ratios are 70:20:10. The volatile gas of crude oil passes through the adsorption bed layer from bottom to top and contacts the microporous silica gel, 3A molecular sieve, and MOF-801 filled in the adsorption column respectively.

[0077] After the volatile gas of crude oil is treated by adsorption, the concentrations of each component are as follows: methane 25120 ppm, ethane 15030 ppm, propane 24500 ppm, butane 19740 ppm, pentane 14520 ppm, and the relative humidity is 0.9% RH.

[0078] Example 5

[0079] The gas is prepared according to the following components, concentrations, and ratios: the volume fraction of VOCs in the volatile gas of crude oil is 10 VOL%, and the concentration ratio of methane, ethane, propane, butane, and pentane in VOCs is 25%:15%:25%:20%:15%; the relative humidity of the volatile gas of crude oil is adjusted to 70% RH.

[0080] In the adsorption bed, three dehumidification materials, namely microporous silica gel, 3A molecular sieve, and MIL-101, are filled from bottom to top in sequence, and their filling volume ratios are 50:30:20. The volatile gas of crude oil passes through the adsorption bed layer from bottom to top and contacts the microporous silica gel, 3A molecular sieve, and MIL-101 filled in the adsorption column respectively.

[0081] After the volatile gas of crude oil is treated by adsorption, the concentrations of each component are as follows: methane 25450 ppm, ethane 15010 ppm, propane 24020 ppm, butane 19130 ppm, pentane 14210 ppm, and the relative humidity is 0.7% RH.

[0082] Example 6

[0083] The gas is prepared according to the following components, concentrations, and ratios: the volume fraction of VOCs in the volatile gas of crude oil is 10 VOL%, and the concentration ratio of methane, ethane, propane, butane, and pentane in VOCs is 25%:15%:25%:20%:15%; the relative humidity of the volatile gas of crude oil is adjusted to 70% RH.

[0084] In the adsorption bed, three dehumidification materials, namely microporous silica gel, 3A molecular sieve, and MOF-303, are filled from bottom to top in sequence, and their filling volume ratios are 50:30:20. The volatile gas of crude oil passes through the adsorption bed layer from bottom to top and contacts the microporous silica gel, 3A molecular sieve, and MOF-303 filled in the adsorption column respectively.

[0085] After the adsorption treatment of the crude oil volatile gas, the concentrations of each component are as follows: methane 25130 ppm, ethane 15060 ppm, propane 24720 ppm, butane 19530 ppm, pentane 14650 ppm, and the relative humidity is 0.6% RH.

[0086] Example 7

[0087] The gas is prepared according to the following components, concentrations and ratios: the volume fraction of VOCs in the crude oil volatile gas is 10 VOL%, and the concentration ratio of methane, ethane, propane, butane and pentane in VOCs is 25%:15%:25%:20%:15%; the relative humidity of the crude oil volatile gas is adjusted to 70% RH.

[0088] In the adsorption bed, three dehumidification materials, namely microporous silica gel, 4A molecular sieve and MOF-801, are loaded from bottom to top in sequence, and their loading volume ratio is 50:30:20. The crude oil volatile gas passes through the adsorption bed layer from bottom to top and contacts the microporous silica gel, 4A molecular sieve and MOF-801 filled in the adsorption column respectively.

[0089] After the adsorption treatment of the crude oil volatile gas, the concentrations of each component are as follows: methane 25330 ppm, ethane 15200 ppm, propane 24190 ppm, butane 19400 ppm, pentane 14310 ppm, and the relative humidity is 0.8% RH.

[0090] Example 8

[0091] The gas is prepared according to the following components, concentrations and ratios: the volume fraction of VOCs in the crude oil volatile gas is 10 VOL%, and the concentration ratio of methane, ethane, propane, butane and pentane in VOCs is 25%:15%:25%:20%:15%; the relative humidity of the crude oil volatile gas is adjusted to 70% RH.

[0092] In the adsorption bed, three dehumidification materials, namely microporous silica gel, 5A molecular sieve and MOF-801, are loaded from bottom to top in sequence, and their loading volume ratio is 50:30:20. The crude oil volatile gas passes through the adsorption bed layer from bottom to top and contacts the microporous silica gel, 5A molecular sieve and MOF-801 filled in the adsorption column respectively.

[0093] After the adsorption treatment of the crude oil volatile gas, the concentrations of each component are as follows: methane 25230 ppm, ethane 15090 ppm, propane 24460 ppm, butane 19250 ppm, pentane 14290 ppm, and the relative humidity is 0.8% RH.

[0094] Example 9

[0095] The gas is prepared according to the following components, concentrations and ratios: the volume fraction of VOCs in the volatile gas of crude oil is 10 VOL%, and the concentration ratio of methane, ethane, propane, butane and pentane in VOCs is 25%:15%:25%:20%:15%; the relative humidity of the volatile gas of crude oil is adjusted to 70% RH.

[0096] In the adsorption bed, three dehumidification materials, namely microporous silica gel, 13X molecular sieve and MOF-801, are filled from bottom to top in sequence, and their filling volume ratio is 50:30:20. The volatile gas of crude oil passes through the adsorption bed layer from bottom to top and contacts the microporous silica gel, 13X molecular sieve and MOF-801 filled in the adsorption column respectively.

[0097] After the volatile gas of crude oil is treated by adsorption, the concentrations of each component are: methane 25420 ppm, ethane 15180 ppm, propane 24300 ppm, butane 19520 ppm, pentane 14570 ppm, and the relative humidity is 0.9% RH.

[0098] Example 10

[0099] The gas is prepared according to the following components, concentrations and ratios: the volume fraction of VOCs in the volatile gas of crude oil is 10 VOL%, and the concentration ratio of methane, ethane, propane, butane and pentane in VOCs is 25%:15%:25%:20%:15%; the relative humidity of the volatile gas of crude oil is adjusted to 90% RH.

[0100] In the adsorption bed, three dehumidification materials, namely microporous silica gel, 3A molecular sieve and MOF-303, are filled from bottom to top in sequence, and their filling volume ratio is 70:20:10. The volatile gas of crude oil passes through the adsorption bed layer from bottom to top and contacts the microporous silica gel, 3A molecular sieve and MOF-303 filled in the adsorption column respectively.

[0101] After the volatile gas of crude oil is treated by adsorption, the concentrations of each component are: methane 24820 ppm, ethane 14930 ppm, propane 25200 ppm, butane 20150 ppm, pentane 14930 ppm, and the relative humidity is 0.7% RH.

[0102] Comparative Example 1

[0103] The method described in Example 3 is implemented, except that the adsorption bed is not filled with microporous silica gel.

[0104] Specifically, the gas is prepared according to the following components, concentrations and ratios: the volume fraction of VOCs in the volatile gas of crude oil is 10 VOL%, and the concentration ratio of methane, ethane, propane, butane and pentane in VOCs is 25%:15%:25%:20%:15%; the relative humidity of the volatile gas of crude oil is adjusted to 50% RH.

[0105] In the adsorption bed, two dehumidification materials, 3A molecular sieve and MOF-801, are filled from bottom to top in sequence, and their filling volume ratio is 80:20. The crude oil volatile gas passes through the adsorption bed layer from bottom to top and contacts the 3A molecular sieve and MOF-801 filled in the adsorption column respectively.

[0106] After the adsorption treatment of the crude oil volatile gas, the concentrations of each component are as follows: methane 25510 ppm, ethane 14143 ppm, propane 24124 ppm, butane 19521 ppm, pentane 14625 ppm, and the relative humidity is 18% RH.

[0107] Comparative Example 2

[0108] The method described in Example 3 was implemented, except that the 3A molecular sieve was not filled in the adsorption bed.

[0109] Specifically, the gas was prepared according to the following components, concentrations and ratios: the volume fraction of VOCs in the crude oil volatile gas was 10 VOL%, and the concentration ratio of methane, ethane, propane, butane and pentane in VOCs was 25%:15%:25%:20%:15%; the relative humidity of the crude oil volatile gas was adjusted to 50% RH.

[0110] In the adsorption bed, three dehumidification materials, microporous silica gel and MOF-801, are filled from bottom to top in sequence, and their filling volume ratio is 80:20. The crude oil volatile gas passes through the adsorption bed layer from bottom to top and contacts the microporous silica gel and MOF-801 filled in the adsorption column respectively.

[0111] After the adsorption treatment of the crude oil volatile gas, the concentrations of each component are as follows: methane 25140 ppm, ethane 15142 ppm, propane 24313 ppm, butane 19358 ppm, pentane 14568 ppm, and the relative humidity is 12% RH.

[0112] Comparative Example 3

[0113] The method described in Example 3 was implemented, except that the MOF-801 was not filled in the adsorption bed.

[0114] Specifically, the gas was prepared according to the following components, concentrations and ratios: the volume fraction of VOCs in the crude oil volatile gas was 10 VOL%, and the concentration ratio of methane, ethane, propane, butane and pentane in VOCs was 25%:15%:25%:20%:15%; the relative humidity of the crude oil volatile gas was adjusted to 50% RH.

[0115] In the adsorption bed, two dehumidification materials, microporous silica gel and 3A molecular sieve, are filled from bottom to top in sequence, and their filling volume ratio is 50:50. The crude oil volatile gas passes through the adsorption bed layer from bottom to top and contacts the microporous silica gel and 3A molecular sieve filled in the adsorption column respectively.

[0116] After the adsorption treatment of the crude oil volatile gas, the concentrations of each component are as follows: methane 25681 ppm, ethane 15683 ppm, propane 24310 ppm, butane 19521 ppm, pentane 14523 ppm, and the relative humidity is 25% RH.

[0117] Comparative Example 4

[0118] The method described in Example 3 was implemented, except that based on the total volume of each dehumidification material filled in the adsorption bed, the filling amount of the MOFs dehumidification material was 5% by volume.

[0119] The gas was prepared according to the following components, concentrations and ratios: the volume fraction of VOCs in the crude oil volatile gas was 10 VOL%, and the concentration ratio of methane, ethane, propane, butane and pentane in VOCs was 25%:15%:25%:20%:15%; the relative humidity of the crude oil volatile gas was adjusted to 50% RH.

[0120] In the adsorption bed, three dehumidification materials, namely microporous silica gel, 3A molecular sieve and MOF-801, were filled from bottom to top in sequence, and their filling volume ratio was 60:35:5. The crude oil volatile gas passed through the adsorption bed layer from bottom to top and contacted the microporous silica gel, 3A molecular sieve and MOF-801 filled in the adsorption column respectively.

[0121] After the adsorption treatment of the crude oil volatile gas, the concentrations of each component are as follows: methane 25341 ppm, ethane 15242 ppm, propane 24331 ppm, butane 19384 ppm, pentane 14362 ppm, and the relative humidity is 6% RH.

[0122] Comparative Example 5

[0123] The method described in Example 3 was implemented, except that in the adsorption bed, MOF-801, 3A molecular sieve and microporous silica gel were filled from bottom to top in sequence.

[0124] Specifically, the gas was prepared according to the following components, concentrations and ratios: the volume fraction of VOCs in the crude oil volatile gas was 10 VOL%, and the concentration ratio of methane, ethane, propane, butane and pentane in VOCs was 25%:15%:25%:20%:15%; the relative humidity of the crude oil volatile gas was adjusted to 50% RH.

[0125] In the adsorption bed, three dehumidification materials, namely MOF-801, 3A molecular sieve and microporous silica gel, were filled from bottom to top in sequence, and their filling volume ratio was 20:30:50. The crude oil volatile gas passed through the adsorption bed layer from bottom to top and contacted the MOF-801, microporous silica gel and 3A molecular sieve filled in the adsorption column respectively.

[0126] After the adsorption treatment of the crude oil volatile gas, the concentrations of each component are as follows: methane 25342 ppm, ethane 15133 ppm, propane 21228 ppm, butane 19385 ppm, pentane 14362 ppm, and the relative humidity is 35% RH.

[0127] The conditions and some performance data in the above Examples 1-10 and Comparative Examples 1-5 are shown in Table 2 below, where the filling order refers to the order along the logistics direction (i.e., the order of contacting the crude oil volatile gas in sequence).

[0128] Table 2

[0129]

[0130]

[0131] It can be seen from Table 2 that the relative humidity of the crude oil volatile gas after being treated in Examples 1-10 is below 1% RH, indicating that the grading method provided by the present invention can deeply dehumidify the crude oil volatile gas with different humidities.

[0132] In Examples 3, 5-6, the types of MOFs materials are different. Combining Table 2 and the data of C1-C5 alkanes in the previous text, it can be seen that the dehumidification effects of the three MOFs materials are quite the same. However, when MIL-101 is used as the adsorbent, some ethane, propane, butane, and pentane will be adsorbed by MIL-101, which may be due to the mesopores contained in this MOFs material. While MOF-303 and MOF-801 are microporous MOFs, and the loss of C2-C5 alkanes is relatively small.

[0133] It can be seen from the data of Comparative Examples 1-5 that no matter any one of silica gel, molecular sieve, and MOFs is removed, the humidity of the crude oil volatile gas cannot be reduced to below 1% RH. Reducing the volume ratio of the MOFs material to less than 10% (such as 5%) also cannot control the humidity below 1% RH. By changing the filling order of the materials, that is, replacing silica gel, molecular sieve, and MOFs with MOFs, molecular sieve, and silica gel, the dehumidification effect is not ideal.

[0134] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited thereto. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solutions of the present invention, including any other suitable combination of each technical feature. These simple modifications and combinations should also be regarded as the content disclosed by the present invention and fall within the protection scope of the present invention.

Claims

1. A method for grading a dehumidification material for crude oil volatile gas, characterized in that, This grading method includes: When the relative humidity of the crude oil volatile gas ≤ 30% RH, the reactor is filled with a molecular sieve dehumidification material and a MOFs dehumidification material in sequence along the logistics direction; When the relative humidity of the crude oil volatile gas > 30% RH, the reactor is filled with a silica gel dehumidification material, a molecular sieve dehumidification material and a MOFs dehumidification material in sequence along the logistics direction; Among them, based on the total volume of each dehumidification material filled in the reactor, the filling amount of the MOFs dehumidification material is not less than 10% by volume.

2. The grading method according to claim 1, characterized in that, The specific surface area of the silica gel dehumidification material is 500 to 700 m 2 / g.

3. The grading method according to claim 1 or 2, characterized in that, The pore size of the silica gel dehumidification material is 0.5 - 10 nm.

4. The grading method according to claim 1, characterized in that The specific surface area of the molecular sieve dehumidification material is less than 600 m 2 / g, and the pore diameter is 0.3 to 2 nm.

5. The grading method according to claim 1 or 4, characterized in that, The molecular sieve dehumidification material is selected from one or more of 3A molecular sieve, 4A molecular sieve, 5A molecular sieve and 13X molecular sieve.

6. The grading method according to claim 1, characterized in that, The specific surface area of the MOF dehumidification material is 900 - 3500 m 2 / g, and the pore size is 0.5 - 3.5 nm.

7. The grading method according to claim 1, wherein The MOFs dehumidification material is selected from one or more of HKUST-1, MOF-5, MOF-74, MOF-303, MOF-801, MOF-808, MIL-101, MIL-100, MIL-53, UIO-66, UIO-67, ZIF-8, ZIF-67, ZIF-90 and modified MOFs prepared from organic ligands modified with amino or hydroxyl functional groups.

8. The grading method according to claim 1, characterized in that, One or more of the MOFs dehumidification materials MOF-303, MOF-801 and MIL-101.

9. The grading method according to any one of claims 1-8, characterized in that, When the relative humidity of the crude oil volatile gas ≤ 30% RH, based on the total volume of each dehumidification material filled in the reactor, the filling amount of the molecular sieve dehumidification material is 40 - 90% by volume, and the filling amount of the MOFs dehumidification material is 10 - 60% by volume.

10. The grading method according to any one of claims 1-8, characterized in that, When the relative humidity of the crude oil volatile gas > 30% RH, based on the total volume of each dehumidification material filled in the reactor, the filling amount of the silica gel dehumidification material is 30 - 70% by volume, the filling amount of the molecular sieve dehumidification material is 20 - 40% by volume, and the filling amount of the MOFs dehumidification material is 10 - 30% by volume.

11. A method for dehumidifying crude oil volatile gas, characterized in that, This method includes: passing the crude oil volatile gas through a reactor filled by the grading method described in any one of claims 1 - 10 for dehumidification treatment.

12. The method according to claim 11, wherein The relative humidity of the crude oil volatile gas is 10 - 100% RH.

13. The method according to claim 11 or 12, characterized in that, The crude oil volatile gas contains C1 - C5 alkanes.

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