Propane dehydrogenation and CO2 capture-in-situ conversion coupling process
By introducing the CO2 capture-in-situ conversion process in the propane dehydrogenation process, the problems of high energy consumption and great environmental impact in propylene production are solved, and the production of propylene and the resource utilization of CO2 are achieved, which is green and environmentally friendly.
Patent Information
- Application Number
- CN202510102780.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-22
- Publication Date
- 2025-05-13
AI Technical Summary
The propane dehydrogenation process in propylene production has problems of high energy consumption and great environmental impact, which leads to large CO2 emissions, limiting its green and sustainable development.
The propane dehydrogenation and CO2 capture-in-situ conversion coupling process is adopted. By loading the propane dehydrogenation catalyst and CO2 capture agent in the reactor, the in-situ capture and conversion of CO2 is achieved, and the generated hydrogen is consumed to improve the propylene yield.
While increasing the production of propylene, CO2 capture and conversion is achieved, the energy consumption and environmental impact of the process are reduced, and the characteristics of green and environmental protection are green.
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Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of propylene production technology and CO2 capture and utilization, and specifically relates to a propane dehydrogenation and CO2 capture-in-situ conversion coupling process. Background Art
[0002] Propylene is an important basic chemical raw material, which can be used to produce a variety of high value-added downstream products, such as acrylonitrile, acetone, propylene oxide, etc., which can be used in many fields such as home appliances, textiles, building materials, plastics, automobiles, medical materials, etc. With the rapid growth of downstream markets, the global demand for propylene continues to increase.
[0003] There are three main traditional methods for producing propylene. The first is the process of producing propylene by cracking petroleum, which separates propylene from the by-products of the ethylene unit through a steam cracking process. However, the propylene yield of this process is greatly affected by the supply of petroleum resources and the composition of the cracking feedstock. The second is fluid catalytic cracking, which produces propylene as a by-product during the refining process, but its yield is relatively low and is subject to the overall fluctuations of the refining industry. With the rise of shale gas development, propane dehydrogenation (PDH) has gradually become one of the mainstream technologies for propylene production. This process directly dehydrogenates propane to produce propylene through a catalyst, with high selectivity and conversion rate. The current direct dehydrogenation processes are mainly UOP's Oleflex process based on the precious metal Pt and Lummus's Catofin process based on the metal oxide Cr2O3.
[0004] However, the chemical industry is an important source of global carbon emissions, accounting for more than 20% of industrial carbon emissions, of which carbon dioxide (CO2) emissions are about 900 million tons / year, accounting for 7% of the global total emissions. The main sources include fossil fuel combustion, process emissions (such as ethylene and ammonia production), and waste treatment. The PDH process is a strongly endothermic reaction (reaction enthalpy is about +120kJ / mol), and high temperatures (500-700℃) are required to achieve a considerable propylene yield. In industry, heat is usually provided by burning fossil fuels (such as natural gas), and the combustion process directly produces CO2 emissions. In the PDH process, in addition to the conversion of propane to propylene, cracking reactions may also occur (generating light hydrocarbons such as methane and ethylene), which will further produce CO2 if they are subsequently burned. In addition, such as the Catofin process, the catalyst needs to be regenerated regularly to remove carbon deposits. The regeneration process is usually completed by burning carbon deposits, resulting in CO2 emissions. If the equipment used in the PDH process (such as compressors, separation devices) relies on electricity to operate, and the electricity comes from fossil fuel power generation, the electricity consumption will indirectly lead to CO2 emissions. According to industrial data, the CO2 emissions of the PDH process are around 1.5-3.0t CO2 / t propylene.
[0005] In recent years, innovative technologies such as carbon dioxide conversion, methanol to propylene, and the use of biomass-based raw materials have gradually attracted attention. Although these methods have the potential for low carbon footprint and sustainable development in theory, their industrial application still faces challenges such as catalyst development, process stability and cost control. It is foreseeable that the PDH process will remain the main process for propylene production. However, the PDH process faces the problems of high energy consumption and great environmental impact, which are the main factors restricting its green and sustainable development. Summary of the invention
[0006] The present invention proposes a coupling process of propane dehydrogenation and CO2 capture-in-situ conversion. A CO2 capture agent is introduced into the propane dehydrogenation reaction process. By utilizing the in-situ capture and conversion of CO2, the capture-in-situ conversion and utilization of CO2 in the chemical industry can be realized while increasing the production of propylene.
[0007] The above-mentioned object of the present invention is achieved through the following technical solutions:
[0008] The present invention provides a coupling process of propane dehydrogenation and CO2 capture-in-situ conversion, by which a propane dehydrogenation catalyst and a CO2 capture agent are loaded in the same reactor, thereby realizing the integration of a propane dehydrogenation process for producing propylene and a CO2 capture-in-situ conversion process;
[0009] Firstly, the CO2 capture agent captures CO2 in a CO2-containing atmosphere; secondly, the propane dehydrogenation catalyst and the CO2 capture agent respectively carry out propane dehydrogenation reaction and CO2 in-situ conversion reaction in a propane-containing atmosphere; wherein, the propane dehydrogenation reaction produces propylene and hydrogen, the hydrogen is consumed in-situ by the reverse water gas reaction, and at the same time, the captured CO2 is converted into CO in-situ.
[0010] Furthermore, the propane dehydrogenation catalyst and the CO2 capture agent are loaded in the reactor in one of the following ways: upper and lower bed loading, particle mixed loading, and powder mixed and then molded loading; wherein, upper and lower bed loading means that the upper bed is loaded with the propane dehydrogenation catalyst and the lower bed is loaded with the CO2 capture agent.
[0011] Furthermore, the CO2 captured gas is at least one of flue gas, pure CO2 gas, and diluted CO2 gas.
[0012] Furthermore, the CO2 capture agent is at least one of Mg-based, Ca-based, Li-based, Na-based, and Sr-based.
[0013] Furthermore, the propane dehydrogenation catalyst is a type that does not require reduction or a type that requires reduction.
[0014] Wherein, the propane dehydrogenation catalyst that does not require reduction is VO x / Al2O3,VO xOne of / ZrO2,Cr2O3 / Al2O3,Ga2O3 / Al2O3. VO x / Al2O3 and VO x / ZrO2 are both vanadium oxide-based propane dehydrogenation catalysts.
[0015] Among them, the propane dehydrogenation catalyst that needs to be reduced is one of PtSn / Al2O3, PtSn / SiO2, PtCu / SiO2, and PtCu / SBA-15.
[0016] Furthermore, the propane dehydrogenation catalyst is a type that does not require reduction; the process comprises the following steps:
[0017] S1: Loading a propane dehydrogenation catalyst that does not require reduction and a CO2 capture agent into a reactor;
[0018] S2: heating the reactor to 600-800°C and performing inert atmosphere degassing treatment;
[0019] S3: air-cooling the reactor to 500-600°C;
[0020] S4: maintaining the reactor temperature at 500-600°C, switching to a CO2-containing atmosphere, and performing CO2 capture;
[0021] S5: maintaining the reactor temperature at 500-600° C., switching to an inert atmosphere, and performing a reactor bed purge treatment;
[0022] S6: Maintain the reactor temperature at 500-600°C, switch to a propane-containing atmosphere, and carry out propane dehydrogenation and CO2 in-situ conversion reactions.
[0023] The preferred process is:
[0024] In the CO2 capture process of S4: CO2 is the reaction gas, other inert gases are the balance gas, the reaction pressure is normal pressure, and the volume fraction based on CO2 is 1-100%.
[0025] The most preferred volume fraction based on CO2 is 35-45%.
[0026] During the propane dehydrogenation and CO2 in-situ conversion reaction of S6: C3H8 is the reaction gas, other inert gases are the balance gas, the reaction pressure is normal pressure, and the volume fraction based on propane is 8-30%.
[0027] The most preferred reaction temperature is 550°C.
[0028] Furthermore, the propane dehydrogenation catalyst is a type that requires reduction; the process comprises the following steps:
[0029] S1: Loading CO2 capture agent into the reactor;
[0030] S2: heating the reactor to 600-800°C and performing inert atmosphere degassing treatment;
[0031] S3: air-cooling the reactor to 500-600°C;
[0032] S4: maintaining the reactor temperature at 500-600°C, switching to a CO2-containing atmosphere, and performing CO2 capture;
[0033] S5: Cool the reactor to room temperature and take out the CO2 capture agent for standby use;
[0034] S6: loading the propane dehydrogenation catalyst in the reduced form into the reactor;
[0035] S7: heating the reactor to 600-800° C. and performing inert atmosphere degassing treatment;
[0036] S8: air-cooling the reactor to 500-800°C, switching to an atmosphere containing H2, and performing a propane dehydrogenation catalyst reduction treatment;
[0037] S9: air-cooling the reactor to room temperature, taking out the reduced propane dehydrogenation catalyst for standby use;
[0038] S10: loading the propane dehydrogenation catalyst obtained in S9 and the CO2 capture agent obtained in S5 into a reactor, and heating the reactor to 500-600° C.;
[0039] S11: The reactor temperature is maintained at 500-600°C, and the atmosphere is switched to propane-containing atmosphere to carry out propane dehydrogenation and CO2 in-situ conversion reaction.
[0040] The preferred process is:
[0041] In the CO2 capture process of S4: CO2 is the reaction gas, other inert gases are the balance gas, the reaction pressure is normal pressure, and the volume fraction based on CO2 is 1-100%.
[0042] The most preferred volume fraction based on CO2 is 35-45%.
[0043] In the propane dehydrogenation catalyst reduction treatment process of S8: H2 is the reaction gas, other inert gases are the balance gas, the reaction pressure is normal pressure, and the volume fraction based on H2 is 10-100%.
[0044] The most preferred reaction temperature is 600°C.
[0045] The most preferred H2-based volume fraction is 20-40%.
[0046] In the propane dehydrogenation and CO2 in-situ conversion reaction process of S11: C3H8 is the reaction gas, other inert gases are the balance gas, the reaction pressure is normal pressure, and the volume fraction based on propane is 8-30%.
[0047] The most preferred reaction temperature is 550°C.
[0048] The most preferred volume fraction based on propane is 24-25%.
[0049] The beneficial effects of the present invention are:
[0050] The two processes of propane dehydrogenation and CO2 capture-in-situ conversion are coupled into one process. By consuming the hydrogen generated by propane dehydrogenation in situ, the captured CO2 is not only converted into CO with higher added value, but also the purpose of producing more propylene is achieved. The process of the present invention has the characteristics of simple modification of existing processes, simple operation, and green environmental protection. On the basis of the existing propane dehydrogenation process, the process can be modified by coupling the CO2 capture agent to realize the process of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS
[0051] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope of the present invention.
[0052] Figure 1 A schematic diagram of a fixed bed reaction system constructed for the present invention;
[0053] Figure 2 This is a reaction flow chart of the propane dehydrogenation catalyst without reducing type in the present invention;
[0054] Figure 3 This is a reaction flow chart of a reduced propane dehydrogenation catalyst required in the present invention;
[0055] Figure 4 The XRD spectrum of the CaMnZr CO2 capture agent before and after capturing CO2 in Example 1 of the present invention;
[0056] Figure 5 The reaction performance diagram of different bed filling methods in Examples 1-5 of the present invention;
[0057] Figure 6 This is a performance comparison chart of a single propane dehydrogenation process and a propane dehydrogenation coupled CO2 capture-in-situ conversion process in Examples 6-11 of the present invention. DETAILED DESCRIPTION
[0058] like Figure 1As shown, the present invention independently designs and constructs a fixed bed reaction system, which consists of a gas cylinder, a pressure reducing valve, a steel pipeline, a gas mass flow meter, a premixing tank, a reactor, a quartz reaction tube, a gas chromatograph, a propane dehydrogenation catalyst, a CO2 capture agent, etc.
[0059] There are five gases in total, namely argon (Ar), propane (C3H8), hydrogen (H2), nitrogen (N2), carbon dioxide (CO2), and air (Air). Among them, Ar is used as a carrier gas for chromatographic use.
[0060] In any process, the gas first enters the premixing tank, the premixed mixed gas enters the preheating furnace, and then enters the reaction heating furnace after preheating in the preheating furnace. The catalyst required for the reaction is loaded in the quartz reaction tube of the reaction heating furnace, and the gas product after the reaction enters the gas chromatography detection.
[0061] like Figure 2 As shown, for a propane dehydrogenation catalyst that does not require reduction, the reaction is carried out according to the following steps:
[0062] Step 1, a propane dehydrogenation catalyst that does not require reduction and a CO2 capture agent are pressed into tablets, sieved, and then loaded into a reactor;
[0063] In step 1, the tableting pressure is preferably 10 MPa, and the mesh size of the propane dehydrogenation catalyst and CO2 capture agent particles after sieving is preferably 20-40 mesh. The filling method can be upper and lower bed filling, particle mixed filling or powder tableting mixed filling; wherein, upper and lower bed filling means that the upper bed is filled with propane dehydrogenation catalyst and the lower bed is filled with CO2 capture agent.
[0064] Step 2, starting from room temperature 20-30°C, introducing an inert atmosphere, heating the reactor to 600-800°C at a programmed heating rate of 2-10°C / min, and keeping the temperature for 30-60min to perform degassing treatment;
[0065] In step 2, the inert atmosphere is preferably N2 atmosphere; the heating rate is preferably 10°C / min, and the reactor temperature is preferably 600°C.
[0066] Step 3: After the degassing treatment in step 2 is completed, the inert atmosphere is maintained unchanged, the heating furnace is air-cooled to 500-600°C, and purged for 10 minutes;
[0067] Step 4, after the purge in step 3 is completed, the atmosphere is switched to an atmosphere containing CO2 at a temperature of 500-600°C and kept warm for 30-60 minutes to capture CO2;
[0068] In step 4, CO2 is preferably used as the reaction gas, N2 is used as the balance gas, the reaction pressure is normal pressure, the volume fraction based on CO2 is 8-30%, the preferred temperature is 600°C, and the preferred insulation time is 60 minutes.
[0069] Step 5, after step 4 is completed, the reactor temperature is maintained at 500-600° C., the atmosphere is switched to an inert atmosphere, and the reactor bed is purged;
[0070] Step 6, after the purging in step 5 is completed, the reactor temperature is maintained at 500-600°C, the inert atmosphere is switched to an atmosphere containing propane, and propane dehydrogenation and CO2 in-situ conversion reaction are carried out;
[0071] In step 6, C3H8 is preferably used as the reaction gas, N2 is used as the balance gas, the reaction pressure is normal pressure, and the volume fraction based on propane is 8-30%; the preferred temperature is 550°C.
[0072] Step 7, click on the gas chromatograph to start collecting reaction exhaust gas for analysis.
[0073] like Figure 3 As shown, for the reduced propane dehydrogenation catalyst required, the reaction is carried out according to the following steps:
[0074] Step 1, compressing the CO2 capture agent into tablets, sieving it and then filling it into the reactor;
[0075] In step 1, the tableting pressure is preferably 10 MPa, and the CO2 capture agent particles are preferably sieved to have a mesh size of 20-40 meshes.
[0076] Step 2, starting from room temperature 20-30°C, heating the heating furnace to 600-800°C at a programmed heating rate of 2-10°C / min, and keeping the temperature for 30-60min to perform inert atmosphere degassing treatment;
[0077] In step 2, the inert atmosphere is preferably N2 atmosphere; the heating rate is preferably 10°C / min, and the reactor temperature is preferably 600°C.
[0078] Step 3: After the degassing treatment in step 2 is completed, the inert atmosphere is maintained unchanged, the heating furnace is air-cooled to 500-600°C, and purged for 10 minutes;
[0079] Step 4, after the purge in step 3 is completed, the atmosphere is switched to an atmosphere containing CO2 at a temperature of 500-600°C and kept warm for 30-60 minutes to capture CO2;
[0080] In step 4, CO2 is preferably used as the reaction gas, N2 is used as the balance gas, the reaction pressure is normal pressure, the volume fraction based on CO2 is 8-30%, the preferred temperature is 600°C, and the preferred insulation time is 60 minutes.
[0081] Step 5, after step 4 is completed, the heating furnace is air-cooled to room temperature, and the CO2 capture agent that has captured CO2 is taken out and set aside;
[0082] Step 6, tableting the required reduced propane dehydrogenation catalyst, sieving it, and then loading it into the reactor;
[0083] In step 6, the tableting pressure is preferably 10 MPa, and the reduced propane dehydrogenation catalyst particles are preferably sieved to have a mesh size of 20-40 meshes.
[0084] Step 7, starting from room temperature 20-30°C, in an inert atmosphere, the heating furnace is heated to 600-800°C at a program heating rate of 2-10°C / min, and kept at this temperature for 30-60min to perform an inert atmosphere degassing treatment;
[0085] In step 7, the inert atmosphere is preferably N2 atmosphere; the heating rate is preferably 10°C / min, and the reactor temperature is preferably 600°C.
[0086] Step 8: After the degassing treatment in step 7 is completed, the inert atmosphere is maintained unchanged, the heating furnace is air-cooled to 500-600°C, and purged for 10 minutes;
[0087] Step 9, after the purging in step 8 is completed, the atmosphere is switched to an atmosphere containing H2 at a temperature of 500-600°C and kept warm for 30-60 minutes to perform a propane dehydrogenation catalyst reduction treatment;
[0088] In step 9, H2 is preferably used as the reaction gas, N2 is used as the balance gas, the reaction pressure is normal pressure, the volume fraction based on H2 is 10-100%, the preferred temperature is 600°C, and the preferred insulation time is 60 minutes.
[0089] Step 10, after step 9 is completed, air-cool the heating furnace to room temperature, take out the reduced propane dehydrogenation catalyst and set it aside;
[0090] Step 11, mixing the reduced propane dehydrogenation catalyst with the CO2 capture agent that captures CO2, and loading the mixture into a reactor;
[0091] In step 11, the mixing method can be filling the upper and lower beds separately, mixing particles, or mixing powder tablets;
[0092] Step 12, starting from room temperature 20-30° C., in an inert atmosphere, heating the heating furnace to 600-800° C. at a programmed heating rate of 2-10° C. / min;
[0093] In step 12, the inert atmosphere is preferably N2 atmosphere; the heating rate is preferably 10°C / min, and the reactor temperature is preferably 550°C.
[0094] Step 13, after the temperature in step 12 is stabilized, the atmosphere is switched to an atmosphere containing propane to carry out propane dehydrogenation and CO2 in-situ conversion reaction;
[0095] In step 13, C3H8 is preferably used as the reaction gas, N2 is used as the balance gas, the reaction pressure is normal pressure, and the volume fraction based on propane is 8-30%; the preferred temperature is 550°C.
[0096] Step 14, click on the gas chromatograph to start collecting reaction exhaust gas for analysis.
[0097] The present invention is further described below with reference to the accompanying drawings and specific embodiments, but the embodiments do not limit the present invention in any form.
[0098] In all the following examples, the catalyst activity is expressed as propane conversion, propylene selectivity and yield, and is calculated using the following formula:
[0099] Selectivity(S):
[0100]
[0101] Respectively represent the propane flow rates at the reactor inlet and outlet, in ml / min;
[0102] They represent the propylene flow rate at the reactor outlet, in ml / min;
[0103] Conversion rate (X):
[0104]
[0105] Respectively represent the propane flow rates at the reactor inlet and outlet, in ml / min;
[0106] Respectively represent the CO2 flow rate at the reactor inlet and outlet, in ml / min;
[0107] Productivity:
[0108]
[0109] Respectively represent the propylene flow rate at the reactor outlet and the mass of the catalyst used, in units of ml / min and g;
[0110] The reaction products were analyzed online by gas chromatography.
[0111] Embodiment 1:
[0112] (1) 0.25 g of CaMnZr particles with a size of 20-40 mesh were loaded as CO2 capture agents. Figure 1 In the fixed bed reactor quartz tube shown;
[0113] (2) Starting from room temperature (25°C), in a N2 atmosphere, the heating furnace was heated to 600°C at a programmed heating rate of 10°C / min and kept at this temperature for 60 min to perform a degassing treatment;
[0114] (3) After the degassing treatment in step (2) is completed, the atmosphere is switched to a 25% CO2 / N2 atmosphere at a temperature of 600°C and kept at this temperature for 60 minutes to capture CO2; wherein the reaction pressure is normal pressure;
[0115] (4) After step (3) is completed, the heating furnace is air-cooled to room temperature, and the CO2 capture agent that has captured CO2 is taken out and set aside;
[0116] (5) 0.1 g of PtSn / SiO2 with a size of 20-40 mesh as a propane dehydrogenation catalyst requiring reduction was loaded into a quartz tube of a fixed bed reactor;
[0117] (6) Starting from room temperature (25°C), the heating furnace was heated to 600°C at a programmed heating rate of 10°C / min in a N2 atmosphere;
[0118] (7) After the temperature of step (6) is stabilized, the atmosphere is switched to a 10% H2 / N2 atmosphere at 600°C and kept at this temperature for 60 minutes to capture CO2 and carry out the reduction process of the propane dehydrogenation catalyst; wherein the reaction pressure is normal pressure;
[0119] (8) After step (7) is completed, the heating furnace is air-cooled to room temperature, and the propane dehydrogenation catalyst that has undergone reduction treatment is taken out and set aside;
[0120] (9) mixing the reduced propane dehydrogenation catalyst and the CO2 capture agent after CO2 capture in the form of particles, and loading them into a quartz tube of a fixed bed reactor;
[0121] (10) Starting from room temperature (25°C), the heating furnace was heated to 550°C at a programmed heating rate of 10°C / min under a N2 atmosphere;
[0122] (11) After the temperature of step (10) is stabilized, the atmosphere is switched to a 40% C3H8 / N2 atmosphere, wherein the reaction pressure is normal pressure;
[0123] (12) Click on the gas chromatograph to start collecting the reaction exhaust gas for analysis.
[0124] For CaMnZr before and after CO2 capture in Example 1, see Figure 4It can be seen that after CaMnZr captures CO2, an obvious CaCO3 diffraction peak appears in the XRD diagram, which shows that the CO2 capture process can capture CO2 very well and convert CaO into CaCO3.
[0125] Embodiment 2:
[0126] The coupled process reaction process is carried out using the method of Example 1, the only difference being that in step (1), the CO2 capture agent CaMnZr is replaced by quartz sand particles without CO2 capture capability.
[0127] Embodiment 3:
[0128] The coupled process reaction process is carried out using the method of Example 1, the only difference being that in step (9), the reduced propane dehydrogenation catalyst is mixed with the upper and lower beds of the CO2 capture agent after adsorption of CO2, the upper bed being the CO2 capture agent and the lower bed being the propane dehydrogenation catalyst, and the mixture is loaded into a quartz tube of a fixed bed reactor.
[0129] Embodiment 4:
[0130] The coupled process reaction process is carried out using the method of Example 1, the only difference being that in step (9), the reduced propane dehydrogenation catalyst and the CO2 capture agent after adsorbing CO2 are mixed in an upper and lower bed layer, wherein the upper bed layer is the propane dehydrogenation catalyst and the lower bed layer is the CO2 capture agent, and are loaded into a quartz tube of a fixed bed reactor.
[0131] Embodiment 5:
[0132] The coupled process reaction process is carried out using the method of Example 1, the only difference being that in step (9), the reduced propane dehydrogenation catalyst and the CO2 capture agent after adsorption of CO2 are ground into powder and then fully mixed, and then tableted and loaded into the quartz tube of the fixed bed reactor.
[0133] For Examples 1-5, see Figure 5It can be seen that for the propane dehydrogenation coupled CO2 capture-in-situ conversion process, compared with the addition of quartz sand without CO2 capture ability, the process with the addition of CaMnZr capture agent with CO2 capture ability can effectively improve the propane conversion rate and propylene yield when the upper bed layer is propane dehydrogenation catalyst, the lower bed layer is CO2 capture agent, the propane dehydrogenation catalyst is mixed with CO2 capture agent particles, and the propane dehydrogenation catalyst is ground and pressed into tablets. The propylene selectivity remains unchanged; when the upper bed layer is CO2 capture agent and the lower bed layer is propane dehydrogenation catalyst, the propane conversion rate, propylene selectivity, and propylene yield are unchanged. This shows that the CO2 capture agent does not provide additional propane activation sites during the reaction, but only consumes the hydrogen produced by propane dehydrogenation in situ, pulling the propane dehydrogenation reaction equilibrium to the right. This shows that the propane dehydrogenation coupled CO2 capture-in-situ conversion process can achieve the purpose of producing more propylene and utilize CO2 as a resource.
[0134] Embodiment 6:
[0135] The coupling process reaction process is carried out using the method of Example 1, the only difference being that in step (5), the amount of PtSn / SiO2 propane dehydrogenation catalyst added is reduced from 0.1 g of 20-40 mesh PtSn / SiO2 propane dehydrogenation catalyst to 0.02 g of 20-40 mesh PtSn / SiO2 propane dehydrogenation catalyst.
[0136] Embodiment 7:
[0137] The coupling process reaction process was carried out using the method of Example 1, with the only difference being that in step (5), 0.1 g of a 20-40 mesh PtSn / SiO2 propane dehydrogenation catalyst was replaced with 0.01 g of a 20-40 mesh PtSnCu / SBA-15 propane dehydrogenation catalyst.
[0138] Embodiment 8:
[0139] The coupling process reaction process is carried out using the method of Example 1, the only difference being that in step (5), 0.1 g of a 20-40 mesh PtSn / SiO2 propane dehydrogenation catalyst is replaced with 0.02 g of a 20-40 mesh PtZn / SiO2 propane dehydrogenation catalyst.
[0140] Embodiment 9:
[0141] (1) 0.3 g of CaMnZr particles with a size of 20-40 mesh were used as CO2 capture agents, and 0.3 g of VO x / Al2O3 (vanadium oxide-based) propane dehydrogenation catalyst particles are used as a propane dehydrogenation catalyst that does not require reduction, and are loaded into the quartz tube of a fixed bed reactor designed and built independently in the form of a particle mixture;
[0142] (2) Starting from room temperature (25°C), in a N2 atmosphere, the heating furnace was heated to 600°C at a programmed heating rate of 10°C / min and kept at this temperature for 60 min to perform a degassing treatment;
[0143] (3) After the degassing treatment in step (2) is completed, the atmosphere is switched to a 25% CO2 / N2 atmosphere at a temperature of 600°C and kept at this temperature for 60 minutes to capture CO2, wherein the reaction pressure is normal pressure;
[0144] (4) After the CO2 capture process in step (3) is completed, the atmosphere is switched to N2 atmosphere and maintained for 10 min to perform a purge treatment on the reactor bed;
[0145] (5) After the bed purge is completed, the reactor temperature is air-cooled to 550°C, and the atmosphere is switched to a 40% C3H8 / N2 atmosphere, wherein the reaction pressure is normal pressure;
[0146] (6) Click on the gas chromatograph to start collecting the reaction exhaust gas for analysis.
[0147] Embodiment 10:
[0148] The coupling reaction process was carried out by the method of Example 10, the only difference being that in step (1), 0.3 g of VO with a size of 20-40 mesh was added. x / Al2O3 (vanadium oxide-based) propane dehydrogenation catalyst was replaced with 0.3 g of FeVO4 / SiO2 propane dehydrogenation catalyst with a size of 20-40 mesh.
[0149] Embodiment 11:
[0150] The coupling reaction process was carried out using the method of Example 10, the only difference being that in step (1), 0.3 g of VO2O3 having a size of 20-40 mesh was added. x / Al2O3 (vanadium oxide-based) propane dehydrogenation catalyst was replaced with 0.3 g of Cr2O3 / Al2O3 propane dehydrogenation catalyst with a size of 20-40 mesh.
[0151] For different propane dehydrogenation catalysts in Examples 6-11, the coupled process performance is represented by propane yield, see Figure 6 .from Figure 6 It can be seen that as the reaction changes from a single propane dehydrogenation process to a propane dehydrogenation coupled CO2 capture-in-situ conversion process, its propylene yield is significantly improved, which shows that the CO2 capture agent in the coupled reaction system can effectively improve the propylene production capacity of the existing process.
[0152] In summary, the present invention uses carbonate produced by the CO2 adsorbent after absorbing CO2 to consume hydrogen produced by propane dehydrogenation in situ, shift the equilibrium of propane dehydrogenation reaction to the right, and convert the captured CO2 in situ to produce synthesis gas, so as to utilize CO2 as a resource. While increasing the production of propylene, the process is intensive and energy-saving and consumption-reducing are achieved.
[0153] Although the preferred embodiments of the present invention have been described above in conjunction with the accompanying drawings, the present invention is not limited to the above-mentioned specific embodiments, which are merely illustrative and not restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms of specific changes without departing from the scope of protection of the present invention and the claims, all of which fall within the scope of protection of the present invention.
Claims
1. A propane dehydrogenation and CO2 capture-in-situ conversion coupling process, characterized in that: By loading the propane dehydrogenation catalyst and the CO2 capture agent in the same reactor, the integration of the propane dehydrogenation process to produce propylene and the capture-in-situ conversion of CO2 can be achieved; Firstly, the CO2 capture agent captures CO2 in a CO2-containing atmosphere; secondly, the propane dehydrogenation catalyst and the CO2 capture agent respectively carry out propane dehydrogenation reaction and CO2 in-situ conversion reaction in a propane-containing atmosphere; wherein, the propane dehydrogenation reaction produces propylene and hydrogen, the hydrogen is consumed in-situ by the reverse water gas reaction, and at the same time, the captured CO2 is converted into CO in-situ.
2. A propane dehydrogenation and CO2 capture-in-situ conversion coupling process according to claim 1, characterized in that: The propane dehydrogenation catalyst and the CO2 capture agent are loaded in the reactor in one of the following ways: upper and lower bed loading, particle mixed loading, and powder mixed and then molded loading; wherein, upper and lower bed loading means that the upper bed is loaded with the propane dehydrogenation catalyst and the lower bed is loaded with the CO2 capture agent.
3. A propane dehydrogenation and CO2 capture-in-situ conversion coupling process according to claim 1, characterized in that: The gas captured by CO2 is at least one of flue gas, pure CO2 gas, and diluted CO2 gas.
4. A propane dehydrogenation and CO2 capture-in-situ conversion coupling process according to claim 1, characterized in that: The CO2 capture agent is at least one of Mg-based, Ca-based, Li-based, Na-based, and Sr-based.
5. A propane dehydrogenation and CO2 capture-in-situ conversion coupling process according to any one of claims 1-3, characterized in that: The propane dehydrogenation catalyst is a type that does not require reduction or a type that requires reduction.
6. A propane dehydrogenation and CO2 capture-in-situ conversion coupling process according to claim 5, characterized in that: The propane dehydrogenation catalyst without reduction is VO x / Al2O3,VO x / ZrO2, Cr2O3 / Al2O3, Ga2O3 / Al2O3; the propane dehydrogenation catalyst that needs to be reduced is one of PtSn / Al2O3, PtSn / SiO2, PtCu / SiO2, PtCu / SBA-15.
7. A propane dehydrogenation and CO2 capture-in-situ conversion coupling process according to claim 5, characterized in that: The propane dehydrogenation catalyst is a type that does not require reduction; the process comprises the following steps: S1: Loading a propane dehydrogenation catalyst that does not require reduction and a CO2 capture agent into a reactor; S2: heating the reactor to 600-800°C and performing inert atmosphere degassing treatment; S3: air-cooling the reactor to 500-600°C; S4: maintaining the reactor temperature at 500-600°C, switching to a CO2-containing atmosphere, and performing CO2 capture; S5: maintaining the reactor temperature at 500-600° C., switching to an inert atmosphere, and performing a reactor bed purge treatment; S6: Maintain the reactor temperature at 500-600°C, switch to a propane-containing atmosphere, and carry out propane dehydrogenation and CO2 in-situ conversion reactions.
8. A propane dehydrogenation and CO2 capture-in-situ conversion coupling process according to claim 7, characterized in that: In the CO2 capture process of S4: CO2 is the reaction gas, other inert gases are the balance gas, the reaction pressure is normal pressure, and the volume fraction based on CO2 is 1-100%; During the propane dehydrogenation and CO2 in-situ conversion reaction of S6: C3H8 is the reaction gas, other inert gases are the balance gas, the reaction pressure is normal pressure, and the volume fraction based on propane is 8-30%.
9. A propane dehydrogenation and CO2 capture-in-situ conversion coupling process according to claim 5, characterized in that: The propane dehydrogenation catalyst is a type that requires reduction; the process comprises the following steps: S1: Loading CO2 capture agent into the reactor; S2: heating the reactor to 600-800°C and performing inert atmosphere degassing treatment; S3: air-cooling the reactor to 500-600°C; S4: maintaining the reactor temperature at 500-600°C, switching to a CO2-containing atmosphere, and performing CO2 capture; S5: Cool the reactor to room temperature and take out the CO2 capture agent for standby use; S6: loading the propane dehydrogenation catalyst in the reduced form into the reactor; S7: heating the reactor to 600-800° C. and performing inert atmosphere degassing treatment; S8: air-cooling the reactor to 500-800°C, switching to an atmosphere containing H2, and performing a propane dehydrogenation catalyst reduction treatment; S9: air-cooling the reactor to room temperature, taking out the reduced propane dehydrogenation catalyst for standby use; S10: loading the propane dehydrogenation catalyst obtained in S9 and the CO2 capture agent obtained in S5 into a reactor, and heating the reactor to 500-600° C.; S11: The reactor temperature is maintained at 500-600°C, and the atmosphere is switched to propane-containing atmosphere to carry out propane dehydrogenation and CO2 in-situ conversion reaction.
10. A propane dehydrogenation and CO2 capture-in-situ conversion coupling process according to claim 9, characterized in that: In the CO2 capture process of S4: CO2 is the reaction gas, other inert gases are the balance gas, the reaction pressure is normal pressure, and the volume fraction based on CO2 is 1-100%; In the propane dehydrogenation catalyst reduction treatment process of S8: H2 is the reaction gas, other inert gases are the balance gas, the reaction pressure is normal pressure, and the volume fraction based on H2 is 10-100%; In the propane dehydrogenation and CO2 in-situ conversion reaction process of S11: C3H8 is the reaction gas, other inert gases are the balance gas, the reaction pressure is normal pressure, and the volume fraction based on propane is 8-30%.