Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. The examples, in which specific conditions are not specified, were conducted under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products available commercially.
The invention aims to solve the problems that the existing zinc oxide synthesis gas desulfurizer can not be repeatedly regenerated and reused; secondly, the existing zinc oxide synthesis gas desulfurizer has low organic sulfur removal rate and can not meet the requirements of downstream processes; thirdly, the physical state of the existing zinc oxide synthetic gas desulfurizer is not suitable for the fluidized bed process of the desulfurization regeneration cycle of the synthetic gas desulfurizer. Therefore, the synthesis gas desulfurizing agent which is suitable for the fluidized bed desulfurization process and can regeneratively remove the hydrogen sulfide and the organic sulfur in the synthesis gas and the preparation method thereof are provided.
In a first aspect, an embodiment of the present invention provides a syngas desulfurizing agent, which includes, by mass:
40-80% of metal oxide A, 3-10% of metal oxide B, 10-15% of metal oxide C and 1-3% of non-metal oxide D;
the metal oxide A is zinc oxide;
the metal oxide B is at least one selected from copper oxide and gallium oxide;
the metal oxide C is at least two selected from nickel oxide, cobalt oxide and molybdenum oxide;
the non-metal oxide D is at least one selected from phosphorus pentoxide and boron trioxide.
As a preferred embodiment, the syngas desulfurization agent further comprises a carrier and a binder;
preferably, the carrier and the adhesive account for 15 to 40 percent of the mass percent of the synthetic gas desulfurizer;
preferably, the support comprises at least one of pseudoboehmite and hydrated titanium dioxide powder;
preferably, the binder includes at least one of an aluminum sol and a silica sol.
Therefore, the active component in the syngas desulfurizer provided by the embodiment of the invention mainly comprises zinc oxide, and also comprises two or three of copper oxide and/or gallium oxide, nickel oxide and/or cobalt oxide and/or molybdenum oxide, phosphorus pentoxide and/or boron trioxide. And adding the active components into uniform slurry formed by a carrier and an adhesive, and performing spray forming, drying and roasting to obtain the target synthesis gas desulfurizer. Specifically, the method comprises the following steps:
(1) the main active component zinc oxide of the synthetic gas desulfurizer is from nanometer basic zinc carbonate, nanometer zinc oxide, zinc nitrate, zinc chloride and the like, preferably nanometer basic zinc carbonate and nanometer zinc oxide, and most preferably nanometer basic zinc carbonate. The content of zinc oxide in the synthetic gas desulfurizer is 40-70%, and preferably 60-70%.
(2) The active components of the synthesis gas desulfurizer, namely copper oxide and/or gallium oxide, are respectively from nitrate and/or chloride, preferably nitrate. The content of copper oxide and/or gallium oxide in the synthesis gas desulfurizer is 3-10%, preferably 5-8%.
(3) The hydrogenation active component of the synthesis gas desulfurizer is nickel oxide and/or cobalt oxide and/or molybdenum oxide which are respectively from nickel nitrate and/or cobalt nitrate and/or ammonium molybdate. The content of nickel oxide and/or cobalt oxide and/or molybdenum oxide in the synthesis gas desulfurizer is 10-15%, and preferably 11-13%.
(4) The active component phosphorus pentoxide of the synthesis gas desulfurizer is from phosphoric acid and/or ammonium phosphate and/or ammonium hydrogen phosphate and/or ammonium dihydrogen phosphate and the like; the active component of the synthesis gas desulfurizer, namely the diboron trioxide, is derived from boric acid. The content of phosphorus pentoxide and/or boron trioxide in the synthesis gas desulfurizer is 1-3%, preferably 1-2%.
(5) The synthesis gas desulfurizing agent component is from pseudo-boehmite, aluminum sol and/or silica sol and/or hydrated titanium dioxide powder. The content of alumina and/or silica and/or titania in the synthesis gas desulfurizing agent is 15-45%, preferably 15-35%.
The basic principle of desulfurization by using the synthesis gas desulfurizing agent is as follows:
in general, hydrogen sulfide in the synthesis gas can be removed by using a zinc oxide synthesis gas desulfurizing agent, and the reaction equation is shown as formula (1):
H2S+ZnO→ZnS+H2O (1)
however, the conventional zinc oxide synthesis gas desulfurizer can only be used once and cannot be regenerated circularly. According to the synthesis gas desulfurizer provided by the embodiment of the invention, the conventional zinc oxide synthesis gas desulfurizer is modified by metal oxide and nonmetal oxide, so that the synthesis gas desulfurizer has good structural stability, and still has high capability of removing hydrogen sulfide under the conditions of high water vapor partial pressure and high-temperature oxidation.
The synthesis gas desulfurizer which generates zinc sulfide in the desulfurization reactor is deactivated and then transferred to the regenerator, the zinc sulfide is converted into zinc oxide by air combustion and then returned to the desulfurization reactor for desulfurization, the reaction in the regenerator is shown as a formula (2), meanwhile, the hydrogenation active component used for modifying the synthesis gas desulfurizer also forms metal oxide in the regeneration process, and the reaction is shown as a formula (3) (M represents the hydrogenation metal active component).
2ZnS+3O2→2ZnO+2SO2 (2)
M+O2→MOx (3)
The synthesis gas desulfurizing agent with hydrogenation activity component forms metal oxide in the regeneration process so as to weaken the hydrogenation activity, so that the regenerated synthesis gas desulfurizing agent needs to reduce the metal oxide into metal with hydrogenation activity by hydrogenation, and the reaction equation is shown as (4):
MOx+H2→M+H2O (4)
the sulfur-containing compounds in the syngas are primarily hydrogen sulfide, but also contain small amounts of organic sulfides such as carbonyl sulfide, carbon disulfide, and the like. The reaction activity of the organic sulfide and the zinc oxide type synthetic gas desulfurizer is low, the removal rate is low, and the requirements of subsequent processes cannot be met. It is therefore necessary to convert the organic sulphides to hydrogen sulphide in order to ensure an effective removal of the sulphides from the synthesis gas.
Under a certain temperature and pressure, the catalyst containing hydrogenation active metal converts organic sulfide in the synthesis gas into hydrogen sulfide so as to be removed by utilizing a zinc oxide synthesis gas desulfurizer, and the reaction of converting the organic sulfide into the hydrogen sulfide is shown as formulas (5) and (6):
COS+H2→CO+H2S (5)
CS2+2H2→C+2H2S (6)
in a second aspect, an embodiment of the present invention provides a preparation method of the above syngas desulfurizing agent, including the following steps: and (3) forming and roasting the slurry containing the precursors of the components to obtain the synthesis gas desulfurizer.
The preparation method of the synthesis gas desulfurizer comprises the following specific steps:
adding a certain amount of deionized water into the alumina sol or the silica sol, slowly adding pseudo-boehmite and/or hydrated titanium dioxide powder, stirring and homogenizing for 6-10 hours to obtain slurry, continuously adding metered phosphoric acid and/or ammonium phosphate and/or ammonium hydrogen phosphate and/or ammonium dihydrogen phosphate and/or boric acid, copper oxide and/or nitrate and/or chloride of gallium, nano basic zinc carbonate and/or nano zinc oxide and/or zinc nitrate and/or zinc chloride and the like into the slurry in sequence, stirring and homogenizing the whole slurry for 6-10 hours, wherein the solid content of the slurry is 20-40%;
spray drying and forming all the slurry, controlling the temperature of a spray drying furnace chamber to be 350-450 ℃, the temperature of an outlet of a drying tower to be 150-250 ℃ and the spray pressure of the drying tower to be 2.5-4.5 MPa. Drying the spray-formed material at the temperature of 120-150 ℃ for 5-10 hours, and then roasting at the temperature of 520-650 ℃ for 4-8 hours to obtain a microspherical synthesis gas desulfurizer semi-finished product;
adding two or three of nickel nitrate, cobalt nitrate and ammonium molybdate into deionized water at room temperature to prepare a solution, soaking the synthesis gas desulfurizer semi-product in the solution at the temperature of 30-60 ℃ for 3-10 hours, filtering, drying at the temperature of 80-140 ℃ for 4-8 hours, and finally roasting at the temperature of 450-650 ℃ for 5-10 hours to obtain the finished synthesis gas desulfurizer.
Therefore, the synthesis gas desulfurizer provided by the embodiment of the invention has the following advantages:
(1) the zinc oxide based synthetic gas desulfurizer has high desulfurization precision, and especially has high desulfurization activity and large sulfur capacity of nanometer basic zinc carbonate and nanometer zinc oxide.
(2) The zinc oxide-based synthetic gas desulfurizer can completely convert organic sulfides in the synthetic gas into hydrogen sulfide through modification treatment of metal oxides such as nickel oxide and/or cobalt oxide and/or molybdenum oxide, so that the desulfurization efficiency of the synthetic gas desulfurizer is improved.
(3) The zinc oxide-based synthetic gas desulfurizer is subjected to modification treatment by metal oxides such as copper oxide and/or gallium oxide, and the activity attenuation of the synthetic gas desulfurizer is not obvious after the synthetic gas desulfurizer is regenerated for many times.
(4) The synthesis gas desulfurizer containing phosphorus pentoxide and/or diboron trioxide, which is prepared by modifying the zinc oxide-based synthesis gas desulfurizer by phosphoric acid and/or ammonium phosphate and/or ammonium hydrogen phosphate and/or ammonium dihydrogen phosphate and/or boric acid, is particularly suitable for the synthesis gas desulfurization process and the oxidation regeneration process with high water vapor content so as to maintain the desulfurization activity and the desulfurization stability of the synthesis gas desulfurizer.
(5) The synthesis gas desulfurizer using alumina and/or silica and/or titanium dioxide as the carrier has strong wear resistance, large specific surface area and pore volume, and is particularly suitable for the working conditions of fluidized bed adsorption desulfurization and regeneration.
(6) The zinc oxide-based microsphere synthetic gas desulfurizer prepared by the spray drying and forming technology is particularly suitable for the working conditions of fluidized bed desulfurization and regeneration.
The desulfurizing agent for the synthesis gas prepared by the technology has high desulfurization precision and can be used for desulfurizing the synthesis gas H2The concentration of S (containing organic sulfide) is reduced to 1.0mg/m3(ii) a The sulfur capacity of the synthetic gas desulfurizer is as high as 15-25 g (sulfur)/100 g (synthetic gas desulfurizer); the desulfurization activity of the synthetic gas desulfurizer is maintained by more than 80 percent after 50 times of regeneration; the synthetic gas desulfurizer has strong wear resistance in the adsorption regeneration cycle process, and the wear index is not lower than 3.0%.
The features and properties of the present invention are described in further detail below with reference to examples.
Example 1
Collecting 1058g of alumina sol (Al)2O3Content 21%), 27g of ammonium dihydrogen phosphate, 94g of copper nitrate and 1500g of basic zinc carbonate were slowly added, followed by stirring for 5.0 hours. Spray drying and forming under the conditions of the hearth temperature of 400 ℃, the outlet temperature of 200 ℃ and the spray pressure of 4.0 MPa. Drying the formed synthesis gas desulfurizer at 150 ℃ for 5.0 hours, and roasting at 600 ℃ for 5.0 hours to obtain the synthesis gas desulfurizer E01.
190g of nickel nitrate and 207g of cobalt nitrate are dissolved in 600ml of water, the solution is used for soaking the synthesis gas desulfurizer E016 hours at the temperature of 50 ℃, then the synthesis gas desulfurizer E001 is obtained after drying for 4 hours at the temperature of 110 ℃ and finally roasting for 5 hours at the temperature of 500 ℃.
The desulfurizing agent E001 of the synthesis gas is at normal pressure, temperature of 400 ℃ and space velocity of 2000h-1Reducing the obtained product by using hydrogen for 60 minutes under the condition of (1) to obtain the finished product of the synthetic gas desulfurizer E1.
Example 2
Taking 1184g of aluminum sol (Al)2O3Content 21%), 27g of ammonium dihydrogen phosphate, 80g of copper nitrate and 1500g of basic zinc carbonate were slowly added, followed by stirring for 5.0 hours. At furnace temperature 40Spray drying and forming under the conditions of 0 ℃, outlet temperature of 200 ℃ and spraying pressure of 4.0 MPa. Drying the formed adsorbent at 150 ℃ for 5.0 hours, and roasting at 600 ℃ for 5.0 hours to obtain the synthetic gas desulfurizer E02.
138g of nickel nitrate, 41g of ammonium paramolybdate and 132g of cobalt nitrate are dissolved in 600ml of water, the solution is used for soaking a synthesis gas desulfurizer E026 h at the temperature of 50 ℃, then the synthesis gas desulfurizer E002 is dried for 4 h at the temperature of 110 ℃, and finally the synthesis gas desulfurizer E002 is obtained by roasting for 5 h at the temperature of 500 ℃.
The desulfurizing agent E002 of the synthesis gas is at normal pressure, temperature of 400 ℃ and space velocity of 2000h-1Reducing the obtained product by using hydrogen for 60 minutes under the condition of (1) to obtain the finished product of the synthetic gas desulfurizer E2.
Comparative example 1
Collecting 1190g of aluminum sol (Al)2O3Content 21%), 120g of hydrated titanium dioxide powder was slowly added with stirring, 1350g of basic zinc carbonate was slowly added with stirring after 2.0 hours of stirring, and then further stirred for 5.0 hours. Spray drying and forming under the conditions of the hearth temperature of 400 ℃, the outlet temperature of 200 ℃ and the spray pressure of 4.0 MPa. Drying the formed synthesis gas desulfurizer at 150 ℃ for 5.0 hours, and roasting at 600 ℃ for 5.0 hours to obtain the synthesis gas desulfurizer A1.
Comparative example 2
1250g of silica Sol (SiO)2Content 16%), 180g of hydrated titanium dioxide powder was slowly added with stirring, 650g of nano zinc oxide was slowly added with stirring after 2.0 hours of stirring, and then further stirred for 5.0 hours. Spray drying and forming under the conditions of the hearth temperature of 400 ℃, the outlet temperature of 200 ℃ and the spray pressure of 4.0 MPa. Drying the formed synthesis gas desulfurizer at 150 ℃ for 5.0 hours, and roasting at 600 ℃ for 5.0 hours to obtain the synthesis gas desulfurizer A2.
Comparative example 3
Taking 950g of alumina sol (Al)2O3Content 21%), 180g of hydrated titanium dioxide powder was slowly added with stirring, after 2.0 hours of stirring, 1800g of basic zinc carbonate and 236g of copper nitrate were slowly added with stirring, and then further stirring was carried out for 5.0 hours. Spray drying and forming under the conditions of the hearth temperature of 400 ℃, the outlet temperature of 200 ℃ and the spray pressure of 4.0 MPa. Drying the formed synthesis gas desulfurizer at 150 ℃ for 5.0 hours, and roasting at 600 ℃ for 5.0 hours to obtain synthesis gas desulfurizationAnd a sulfur agent B1.
Comparative example 4
Taking 950g of alumina sol (Al)2O3Content 21%), 180g of hydrated titanium dioxide powder was slowly added with stirring, 1800g of basic zinc carbonate and 297g of gallium nitrate were slowly added with stirring after 2.0 hours of stirring, and then, stirring was further carried out for 5.0 hours. Spray drying and forming under the conditions of the hearth temperature of 400 ℃, the outlet temperature of 200 ℃ and the spray pressure of 4.0 MPa. Drying the formed synthesis gas desulfurizer at 150 ℃ for 5.0 hours, and roasting at 600 ℃ for 5.0 hours to obtain the synthesis gas desulfurizer B2.
Comparative example 5
Taking 950g of alumina sol (Al)2O3Content 21%), 156g of hydrated titanium dioxide powder was slowly added with stirring, and after stirring for 2.0 hours, 32g of ammonium dihydrogen phosphate, 236g of copper nitrate and 1700g of basic zinc carbonate were slowly added with stirring, followed by further stirring for 5.0 hours. Spray drying and forming under the conditions of the hearth temperature of 400 ℃, the outlet temperature of 200 ℃ and the spray pressure of 4.0 MPa. Drying the formed synthesis gas desulfurizer at 150 ℃ for 5.0 hours, and roasting at 600 ℃ for 5.0 hours to obtain the synthesis gas desulfurizer C1.
Comparative example 6
Taking 950g of alumina sol (Al)2O3Content 21%), while stirring, silica sol 813g (SiO2 content 16%) was slowly added, and after stirring for 2.0 hours, boric acid 36g, gallium nitrate 297g, and basic zinc carbonate 1700g were slowly added, followed by further stirring for 5.0 hours. Spray drying and forming under the conditions of the hearth temperature of 400 ℃, the outlet temperature of 200 ℃ and the spray pressure of 4.0 MPa. Drying the formed synthesis gas desulfurizer at 150 ℃ for 5.0 hours, and roasting at 600 ℃ for 5.0 hours to obtain the synthesis gas desulfurizer C2.
Comparative example 7
807g of alumina sol (Al) was taken2O3Content 21%), 82g of hydrated titanium dioxide powder was slowly added with stirring, after 2.0 hours of stirring, 27g of ammonium dihydrogen phosphate, 100g of copper nitrate and 1700g of basic zinc carbonate were slowly added with stirring, and further stirred for 5.0 hours. Spray drying and forming under the conditions of the hearth temperature of 400 ℃, the outlet temperature of 200 ℃ and the spray pressure of 4.0 MPa. Drying the formed synthesis gas desulfurizer at 150 ℃ for 5.0 hours, and roasting at 600 ℃ for 5.0 hours to obtain the synthesis gas desulfurizer D01.
196g of nickel nitrate and 86g of ammonium paramolybdate are dissolved in 600ml of water, the solution is used for soaking a synthesis gas desulfurizer D016 h at the temperature of 50 ℃, then the synthesis gas desulfurizer D1 is dried for 4 h at the temperature of 110 ℃, and finally the synthesis gas desulfurizer D1 is obtained by roasting at the temperature of 500 ℃ for 5 h.
Comparative example 8
Taking 726g of alumina sol (Al)2O3Content 21%), 82g of titanium dioxide powder was slowly added with stirring, 27g of ammonium dihydrogen phosphate, 100g of copper nitrate and 1700g of basic zinc carbonate were slowly added with stirring after 2.0 hours of stirring, and then the mixture was stirred for 5.0 hours. Spray drying and forming under the conditions of the hearth temperature of 400 ℃, the outlet temperature of 200 ℃ and the spray pressure of 4.0 MPa. Drying the formed synthesis gas desulfurizer at 150 ℃ for 5.0 hours, and roasting at 600 ℃ for 5.0 hours to obtain the synthesis gas desulfurizer D02.
196g of nickel nitrate, 86g of ammonium paramolybdate and 20g of cobalt nitrate are dissolved in 600ml of water, the solution is used for soaking a synthesis gas desulfurizer D026 h at the temperature of 50 ℃, then the synthesis gas desulfurizer D2 is obtained after drying for 4 h at the temperature of 110 ℃ and finally roasting for 5 h at the temperature of 500 ℃.
H removal of synthesis gas desulfurizer2S evaluation method
(1) Evaluating a synthetic gas desulfurizer by using a fixed bed test device, wherein the filling amount of the synthetic gas desulfurizer is 5.0 g;
(2) the raw material gas for evaluation contains H2S2000mg/m3The water vapor content is 30 percent, and the balance is nitrogen;
(3) the evaluation conditions are normal pressure, temperature of 300 ℃ and gas space velocity of 2000h-1The total sulfur content of purified gas is more than 1mg/m3When the synthesis gas desulfurizer is considered to be penetrated and deactivated, the deactivated synthesis gas desulfurizer is regenerated by air at the temperature of 550 ℃ under normal pressure.
The evaluation of the physical properties of the desulfurizing agent for synthesis gas provided in examples and comparative examples of the present invention is shown in Table 1.
TABLE 1 physical Properties of desulfurizing Agents for Synthesis gas
As can be seen from Table 1, the synthesis gas desulfurization agent obtained by the method provided by the embodiment of the invention has higher specific surface area and pore volume and better wear resistance than the synthesis gas desulfurization agent provided by the comparative example.
Evaluation of desulfurization and regeneration performance for the syngas desulfurization agent provided in examples of the present invention and comparative examples is shown in table 2.
TABLE 2 desulfurization and regeneration Performance of syngas desulfurization agent
Note: the sulfur capacity means that the total sulfur content of the purified gas is more than 1mg/m3Mass number (g) of sulfur on 100g of the syngas desulfurization agent upon breakthrough deactivation of the syngas desulfurization agent.
As can be seen from Table 2, the synthesis gas desulfurizing agent obtained by the method provided by the embodiment of the invention can be used for synthesizing the synthesis gas H2The S concentration is reduced to 1.0mg/m3(ii) a The sulfur capacity of the synthetic gas desulfurizer reaches up to 13.3-20.1 g (sulfur)/100 g (synthetic gas desulfurizer); the desulfurization activity of the synthetic gas desulfurizer is maintained by more than 80 percent after 50 times of regeneration; the synthetic gas desulfurizer has strong wear resistance in the adsorption regeneration cycle process, and the wear index is lower than 3.0%.
Although the fresh synthesis gas desulfurizer prepared in the comparative examples 1 to 8 has higher sulfur capacity, the activity of the synthesis gas desulfurizer is greatly reduced after 50 times of regeneration, and the activity of the synthesis gas desulfurizer subjected to metal modification and nonmetal modification is reduced little after 50 times of regeneration, which shows that the zinc oxide synthesis gas desulfurizer has good regeneration performance after metal modification and nonmetal modification, and the synthesis gas desulfurizer can be subjected to multiple reaction regeneration cycles.
H removal of synthesis gas desulfurizer2Method for evaluating S and organic sulfur
(1) Evaluating a synthetic gas desulfurizer by using a fixed bed test device, wherein the filling amount of the synthetic gas desulfurizer is 5.0 g;
(2) the raw material gas for evaluation contains H2S1800mg/m3、COS200mg/m3The water vapor content is 30 percent, and the balance is nitrogen;
(3) the evaluation conditions are normal pressure, temperature of 300 ℃ and gas space velocity of 2000h-1Purifying the gas H2S content greater than 1mg/m3The syngas desulfurization agent is believed to be breakthrough deactivation.
Evaluation of desulfurization and regeneration properties for the syngas desulfurization agents provided in examples of the present invention and comparative examples is shown in table 3.
TABLE 3 desulfurization and regeneration Performance of syngas desulfurization agent
Note: the sulfur capacity means that the total sulfur content of the purified gas is more than 1mg/m3Mass number (g) of sulfur on 100g of the syngas desulfurization agent upon breakthrough deactivation of the syngas desulfurization agent.
As can be seen from Table 3, the synthesis gas desulfurizing agent obtained by the method of the invention can efficiently remove H2S, but the ability to remove organic sulfur (COS) is particularly different. The synthetic gas desulfurizing agents D1 and D2 with hydrogenation active components have better capability of removing organic sulfur (COS), and the synthetic gas desulfurizing agents E1 and E2 with hydrogenation active components after hydrogenation reduction can not only completely remove hydrogen sulfide, but also completely remove organic sulfur (COS). Shows that the conventional synthesis gas desulfurizer can remove H by adding a hydrogenation active component and reducing with hydrogen2S, and also has the function of removing organic sulfur (COS).
The above is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes will occur to those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.