Ammonia synthesis catalyst, method of preparation thereof, and a ammonia production process utilizing it
FIELD: inorganic synthesis catalysts.
SUBSTANCE: ammonia synthesis catalyst is based on ruthenium on carrier of inoxidizable pure polycrystalline graphite having specific BET surface above 10 m2/g, said graphite being characterized by diffraction pattern comprising only diffraction lines typical of crystalline graphite in absence of corresponding bands of amorphous carbon and which graphite being activated with at least one element selected from barium, cesium, and potassium and formed as pellets with minimal dimensions 2x2 mm (diameter x height). Catalyst is prepared by impregnating above-defined catalyst with aqueous potassium ruthenate solution, removing water, drying, reduction to ruthenium metal in hydrogen flow, cooling in nitrogen flow, water flushing-mediated removal of potassium, impregnation with aqueous solution of BaNO3 and/or CsOH, and/or KOH followed by removal of water and pelletizing of catalyst.
EFFECT: increased activity of catalyst even when charging ruthenium in amount considerably below known amounts and increased resistance of catalyst to methane formation.
12 cl, 1 tbl
The subject of this invention are catalysts for ammonia synthesis, which, in particular, a new one with the advantage of a media type. Moreover, the invention relates to innovative ways on obtaining as a carrier and catalyst, as well as to methods of their prior and residual processing.
Already in the course of a century of ammonia in the industry produced by the catalytic reduction of nitrogen with hydrogen process (Haber-Bosch), where the used catalyst is iron, adding activators, such as potassium oxide, aluminum oxide and other neustanovivshiesya oxides. It was found that a compromise solution from the point of view of thermodynamic and kinetic factors particularly promising is processed at a pressure of 120-220 bar and a temperature of 380-520°With (see, for example, Catalytic ammonia synthesis edited J.R.Jennings, Catalytic Ammonia Synthesis, Fundamentals and Practice, Plenum Press, New York, 1991; A.Nielsen, Ammonia Catalysts and Manufacture, Springer Verlag, Heidelberg, 1995).
In order to be able to run at a lower than previously indicated, the pressure (which allows to achieve considerable advantages from the point of view of constructing the installation, economy and security), discussed some other catalytic materials, ruthenium was recognized as the most promising. However high the th value of this metal requires media with large surface area, to ensure a higher dispersion of the metal, i.e. the use of reduced amounts of metal. For this purpose we have investigated some media, namely:
- SiO2see Lopez and others React. Kinet. Catal. Lett., 41 (1990) 217;
- Al2About3see Y.Kadowaki and others, J.Catal., 161 (1996) 178 and S.Murata and others, J.Catal., 136 (1992) 118;
- Zeolites, see ..Fishel and others, J.Catal., 163 (1996) 148 and J.Wellenbüscher and others, Stud. Surf. Sci. Catal., T.84, part b, Elsevier 1994,941;
- MgO, see .Hinrichsen etc., Chem. Eng. Sci., 51 (1996) 1983;
- Aluminium oxide with carbon coating, see K.S.Rama Rao and others, Appl. Catal., 62 (1990) L19 and S.K.Mashtan and others, J.Molec. Catal., 67 (1991) 1-1;
Spinel MgAlO4see .Fastrup, Catal. Lett., 48 (1997) 111;
- Oxides of the lanthanides, see Y.Niwa etc., Chem. Lett., 1996, 3; and, especially,
- Graphite carbon, see Z.Kowalczyk and others, Appl. Catal., A: General 138 (1996) 83.
Optimal media must meet several requirements: a) it should not be acidic, b) he must have a large surface area to facilitate dispersion of the metal) it must be chemically stable under the assumed conditions of the reaction, and d) it should have good mechanical strength.
With regard to the requirements a) and b), the most promising material is activated carbon. However, in the reaction medium ruthenium can catalyze the conversion of coal to methane. To avoid this inconvenience and to increase the mechanical strength of the catalyst, Biopreparat pre-treatment at high temperature, that, thanks to a greater or lesser graphitization of coal, allowed to increase the stability of the carrier, but at the same time, greatly reduced the surface area (L.Forni, D.Molinari, I.Rossetti, N.Pernicone, Appl. Catal., A: General, 185 (1999) 269). Further treatment in air at 425°was proposed to restore at least partially the surface area and porosity (U.S. Patent 4163775), whereas Z.Zhong and others (J.Catal., 173 (1998) 535), with suggested additional heating to 900°in a stream of hydrogen in order to remove the impurities present in the coal and/or added upon receipt of the catalyst.
To stimulate the generally low activity of the catalysts Ru/C (K.S.Rama Rao and others, Appl. Catal., 73 (1991) L1) was proposed addition of activators, such as alkali metals (S.Murata etc., Chem. Lett., 1990, 1067); alkaline earth metals (Kay and others, J.Catal., 136 (1992)); the lanthanides (Y.Kadowaki and others, quoted); Y.Niwa and others, cited location and J.Catal., 162 (1996) 138). See also U.S. patents 4142996, 4163775, 4250057 and 4600571).
As already mentioned, the subject of this invention is a new catalyst for the synthesis of ammonia, based on Ruthenia, characterized by immediate media from a special type of graphite that, compared with the previous speakers, coal-based, presents a number of advantages of high technological and economic importance. In fact, thanks to them and the use of, it is no longer necessary to subject the activated carbon as thermal pre-treatment to gravityball, at least partially, and further oxidizing the residual processing to restore the surface area and porosity (see above). In fact, the graphite used in this invention have characteristics that make them the best carriers for catalyst synthesis of ammonia.
Moreover, the graphite used in this invention have a resistance to conversion to methane (i.e. the formation of methane from carbon in the reaction environment, including damage to the carrier) is much greater than that exhibited by catalysts on the media of the pre-treated activated carbon; in practice, the formation of methane with the catalyst according to this invention can be recorded only after the temperature reaches 600°and it also remains minimal at temperatures of about 700°C.
In addition, the catalysts of this invention are particularly active in comparison with the catalysts, the media have of pre-treated activated carbon, and which, as stated, better catalysts using other carriers, they are very active as well and with much less load ruthenium. Don't even need to stress the importance of this result is as, considering the price of ruthenium.
Graphite is used as a catalyst carrier according to this invention must have a specific BET surface of more than 10 m2/g, more preferably 100 m2/g and more preferably more than 280 m2/, in Addition, it must be characterized by a diffraction pattern containing only the diffraction lines characteristic of crystalline graphite, with no corresponding bands of amorphous carbon. This implies that graphite shows oleophilic properties. The advantage of using oleophilic graphites in the catalysts according to this invention is unexpected, as in the previous patent (U.S. 4600571) argued that one should avoid oleophilic graphites. Not limiting examples of particularly suitable graphite graphite is produced in the form of fine powder Timcal SA, Bodio, Switzerland, bulleted HSAG 300, having a specific BET surface of approximately 300 m2/g, According to this invention, the graphite is impregnated with an aqueous solution of ruthenate potassium containing the exact amount of ruthenium required to obtain the desired concentration of ruthenium in the finished catalyst, in a minimum amount of water required for impregnation. After removing most of the water in a rotary evaporator (at approximately 30-90°preferably the ri about 70° C) the solid is dried in an oven overnight at approximately 50-100°C, preferably at 80°s Routenet then reduced to metallic ruthenium in a tubular furnace in a stream of hydrogen at 300-340°C, preferably at about 320°C and allowed to cool to room temperature in a stream of nitrogen. Then the solid is treated to remove residual potassium distilled water until neutral pH of the washing solution and again dried at approximately 50 to 100°C, preferably at 80°C.
Then add activators consisting of barium, cesium and potassium, following previously published results I.Rossetti, N.Pernicone and L.Forni (the last two are the inventors of the present invention) in Appl. Catal., A: General, 208 (2001) 271-278. Activation involves impregnation previously obtained solid first aqueous solution of barium nitrate with subsequent removal of excess water in a rotary evaporator under vacuum at approximately 35-40°With, then aqueous solution of CsOH+KOH, followed by the removal of water (see above). Number three actuators is such that the atomic ratios activators for ruthenium amount: Ba/Ru=0.4 to 0.8; Cs/Ru=0,8-1,2; K/Ru=3,0-4,0. Preferably these relations constitute Ba/EN=0,6; Cs/EN=1; K/Ru=3,5. Loading of ruthenium in the finished catalyst may be in the range from approximately 1% to approximately 10% of the Assos, depending on the circumstances.
Finally, the catalyst is formed in the form of tablets of a certain size [e.g., 2×2 to 6×6 mm, preferably 3 mm (diameter) × 2 mm (height)] by applying a pressure of 2-4 tons/cm2. To test the activity of the thus obtained catalyst was crushed and sieved to collect the fraction from 0.10 to 0.35 mm in size, preferably from 0.15 to 0.25 mm, diluted, as it is known in the art, inert solid fractions of the same size, for example quartz, with a volume ratio of the catalyst/inert solid substance in the range from 1:10 to 1:30; moreover, before the experiments on the synthesis of ammonia diluted catalyst was activated by heating in a current of hydrogen/nitrogen volume ratio of 3/2 for several hours (usually 4 up to 6) at a temperature of 420-470°and pressure of 25-35 bar with a bulk velocity (GHSV is an average hourly rate of gas flow) 15000-25000 h-1.
The following examples are intended to illustrate the invention. Three of them were carried out in order to show clearly the superiority of the media in this invention, respectively, compared with graphite carrier, first subjected to oxidation, and then restore (Example 2), and compared with native, obtained by partial graphitization asset is fragmented coal by known methods (Examples 7 and 8).
Sample industrial graphite, labeled as HSAG 300 manufactured by Timcal SA, Bodio, Switzerland in the form of fine powder with a specific surface area BET more than 290 m2/g, whose diffraction pattern does not contain any bands of amorphous carbon was impregnated with a solution of ruthenate potassium containing the exact amount of ruthenium required to obtain the desired loading of the metal of the finished catalyst, in a minimum amount of water required for impregnation. The water was then removed in a rotary evaporator under vacuum at 70°and the thus obtained solid substance was dried overnight in an oven at 80°s Routenet then restored to the metal ruthenium treatment in hydrogen flow in a tubular furnace at 320°C, then cooled to room temperature in a stream of nitrogen.
After cooling, the solid is washed to remove residual potassium several times in distilled water until neutral pH of the washing solution. After following drying in an oven at 80°within 4 hours of added activators (VA, Cs and K) by impregnation using aqueous solutions, comprising in turn the exact number BaNO3and CsOH+KOH, in a minimum amount of water required for impregnation. After each impregnation, the excess water was removed in a rotary evaporator in vacuum at 35-40°C.
Upload Ru in the finished catalyst was 8.9 wt.%, and atomic relations of activators to the ruthenium were, respectively, Ba/EN=0,6; Cs/EN=1 and K/Ru=3,5.
Then, the finished catalyst is formed in the form of cylindrical pellets of size 4×4, with an excellent mechanical strength, by applying a pressure of 3 tons/cm2for 1.5 min, then to grind and sifted, collecting the fraction of 0.15-0.25 mm size.
The catalyst activity was determined at 430°C and 100 bar using a tubular reactor continuous with an inner diameter of 9 mm by passing the gas mixture reacting substances consisting of hydrogen and nitrogen to volume ratio of 3/2, with a bulk velocity (GHSV is an average hourly rate of gas flow) 60000 h-1through the catalyst bed of particles of 0.15-0.25 mm, diluted with quartz with the same particle size to volume ratio of the catalyst/quartz 1/22. To test the catalyst was activated in situ in a stream of the same gas mixture of reactive substances, the hydrogen/nitrogen 3/2 at a pressure of 30 bar and at 450°C for 5 hours at a flow rate (GHSV is an average hourly rate of gas supply) 20000 h-1. Activity was determined by estimating the volume concentration of ammonia in stemming the flow of gas by bubbling in excess of sulfuric acid solution of known concentration and back titration of the excess acid with NaOH solution of known concentration. The result is at KeepAlive shown in the Table.
The catalyst was then subjected to the test for resistance to conversion to methane under the same conditions as the test activity, by measuring the methane concentration in the gas leaving the reactor, while the temperature was raised at 2°C/min up to 700°C. the test result on the resistance to conversion to methane is given in the same Table.
Example 2 (comparative)
A sample of the same industrial graphite HSAG 300 of Example 1 was oxidized in a stream of air in a tubular furnace at 425°C for 1 h, After cooling in a stream of inert gas to remove air sample lost approximately 20% of the initial mass was reduced by treatment in a stream of hydrogen at 900°C for 3 h and then cooled in a stream of inert gas to room temperature. After this treatment, the graphite showed a BET specific surface 169 m2/g and a porosity of 0.51 cm3/year
The addition of Ru and activators was made as described in Example 1, and the finished catalyst had the download EN to 8.1 wt.% and atomic relations of each activator to EN equal to that specified in Example 1. The finished catalyst is formed in the form of tablets, then grind and screened as described in Example 1, collecting the fraction of 0.15-0.25 mm size.
Activity and resistance of the catalyst to the conversion to methane was determined as described in Example 1, and the results bring the us in the Table.
Samples of the same industrial graphite HSAG 300 of Example 1 was also used for obtaining catalysts of Examples 3-6 downloading Ru, respectively, 1,90, 3,06, 4,21 and to 4.92 wt.% and atomic relations of each activator to EN, identical to that specified in Example 1. The finished catalysts formed in the form of tablets, then grind and screened as described in Example 1, collecting the fraction of 0.15-0.25 mm size.
Activity and resistance of catalysts for conversion to methane was determined as described in Example 1, and the results have brought to the Table.
Example 7 (comparative)
Sample industrial activated carbon with particles of 2-4 mm, produced by PICA, Levallois (France), obtained from the shell of a coconut, with a specific surface area BET 1190 m2/g, porosity of 0.49 cm2/g and an ash content of 1.3 wt.% they were heated to 2000°C in argon for 2 hours. After cooling, the sample showed a BET specific surface 105 m2/g and a porosity of 0.12 cm2/, Then the sample was oxidized in air flow, as described in Example 2, with a weight loss of approximately 25%. Then came the recovery current of hydrogen as described in Example 2, which led to the finished coal with a specific surface area BET 410 m2/g and a porosity of 0.21 cm2/, Adding Ru and activators was made as described in Example 1, and the prepared catalyst showed zag is the DCU EN 4.6 wt.% and atomic relations of each activator to EN as in Example 1. The finished catalyst is formed in the form of tablets, then grind and screened as described in Example 1, collecting the fraction of 0.15-0.25 mm size.
Activity and resistance of the catalyst to the conversion to methane was determined as described in Example 1, and the results have brought to the Table.
Example 8 (comparative)
The sample extruded activated carbon with a cylindrical particles of 4 mm in diameter, produced the SESSION, Paris la defense (France), with a commercial name AS, with a specific surface area BET 1250 m2/g and a porosity of 0.75 cm3/g was treated at 1500°C in argon for 2 hours, and then subjected to treatment by oxidation and reduction as described in Example 7. Finally was received BET specific surface 1470 m2/, This medium is used upon receipt of the catalyst according to the same procedure as in Example 1 except for the formation of tablets. The finished catalyst had the download EN 13 wt.% and atomic relations of each activator to EN as described in Example 1. The finished catalyst to grind and screened as described in Example 1, collecting the fraction of 0.15-0.25 mm size.
Activity and resistance of the catalyst to the conversion to methane was determined as described in Example 1, and the results have brought to the Table.
Activity is at GHSV (average hourly rate of gas supply) = 60000 h -1. 430°C and 100 bar and resistance of the catalyst to the conversion to methane based on the Examples 1-8.
|The catalyst (No. of example)||NH3(vol.% in the resulting gas stream)||The temperature of the beginning of the formation of CH4||The area of the signal SN4(mV × min) at 700°|
According to the Table we can draw the following conclusions:
all the catalysts on the media from graphite HSAG 300 (Examples 1, 3, 4, 5 and 6) are at least as active or more active than the catalysts on a carrier of activated carbon treated at a high temperature and then oxidized and reduced (Examples 7 and 8);
- machining of graphite HSAG 300 by oxidation and subsequent reduction (Example 2) strongly affects the activity katal the congestion;
- catalysts in the media from graphite HSAG 300 very active or even more active than the catalysts on the media of the pre-treated activated carbon and also at a much lower loading of Ru (compare Examples 3, 4, 5, 6 Examples 7, 8);
all the catalysts on the media from graphite HSAG 300 significantly more resistant to conversion to methane than the catalysts on the media of the pre-treated activated carbon (compare Examples 1, 3, 4, 5, 6 Examples 7, 8)as they begin to form methane at 600°or at a higher temperature and thus form very little methane even at 700°whereas the catalysts of Examples 7 and 8 begin to form methane at a temperature below 500°With, and at 700°they form methane from 8 to 20 times more;
- machining of graphite HSAG 300 by oxidation and subsequent reduction (Example 2) significantly affects the stability of the catalyst to the conversion to methane.
1. The catalyst for ammonia synthesis, based on the ruthenium on a medium of a non-oxidizing, clean, holocrystalline graphite having a specific surface area BET of more than 10 m2/g and a diffraction pattern containing only the diffraction lines of the crystalline graphite, with no corresponding bands of amorphous carbon, activated at IU is e one of the elements, selected from the group comprising barium, cesium, potassium, and formed into tablets having a minimum size of 2×2 mm, diameter - height.
2. The catalyst according to claim 1, in which a non-oxidizing, clean, holocrystalline graphite having a specific surface area BET of more than 10 m2/g and a diffraction pattern containing only the diffraction lines of the crystalline graphite, with no corresponding bands of amorphous carbon has a specific surface BET of more than 100 m2/year
3. The catalyst according to claim 1, in which a non-oxidizing, clean, holocrystalline graphite having a specific surface area BET of more than 10 m2/g and a diffraction pattern containing only the diffraction lines of the crystalline graphite, with no corresponding bands of amorphous carbon has a specific surface BET of more than 280 m2/year
4. The catalyst according to claims 1 to 3, wherein the activators are barium and cesium.
5. The catalyst according to claims 1 to 3, wherein the activators are barium and potassium.
6. The catalyst according to claims 1 to 3, wherein the activators are potassium and cesium.
7. The catalyst according to claims 1 to 3, wherein the activators are barium, cesium and potassium.
8. The catalyst according to claim 7, in which the atomic relations Ba/EN, Cs/EN and K/Ru are in the range respectively from 0.4 to 0.8; 0.8 to 1.2; from 3.0 to 4.0.
9. The catalyst according to claim 7, in which the atomic about the wearing of Ba/EN, Cs/EN and K/EN, respectively, about 0,6:1; 1:1; 3,5:1.
10. The catalyst according to claim 1, in which the loading of Ru is in the range from about 1 to about 10 wt.% the finished catalyst.
11. The method of producing catalyst according to claims 1 to 10, in which a non-oxidizing, clean, holocrystalline graphite having a specific surface area BET of more than 10 m2/g and a diffraction pattern containing only the diffraction lines of the crystalline graphite, with no corresponding bands of amorphous carbon, impregnated with an aqueous solution of ruthenate potassium containing the exact amount of ruthenium required to obtain the desired concentration of ruthenium in the finished catalyst, in a minimum amount of water necessary for impregnation; most of the water is removed in a rotary evaporator under vacuum at approximately 30-90°and the remaining solid is dried at approximately 50 to 100°s; routenet reduced to metallic ruthenium in a stream of hydrogen at 300-340°and cool in a stream of nitrogen; potassium removed by washing in distilled water until neutral pH values; solid substance previously dried at 50 to 100°With, impregnated with an aqueous solution BaNO3and/or CsOH, and/or customer, and these solutions contain the exact amount of reagent needed to obtain the required atomic relations Ba/EN, is/or Cs/Ku, and/or K/EN in the finished catalyst, in a minimum amount of water necessary for impregnation; excess water after each impregnation is removed in vacuum at approximately 35-40; then the catalyst was formed into tablets having dimensions of 2×2, diameter - height.
12. The method of producing ammonia from gaseous mixtures of hydrogen and nitrogen with the use of the catalyst according to claims 1-10.
FIELD: chemical industry; installations and the methods of production of the synthesis-gas from the natural gas.
SUBSTANCE: the invention is pertaining to the field of chemical industry, in particular, to the installation and the method for simultaneous production from the natural gas of the methanol synthesis-gas, the ammoniac synthesis-gas, carbon monoxide and carbon dioxide. The installation consists of the in-series connected to each other assembly units and includes: the first reactor (A), in which at feeding of oxygen realize the transformation of the natural gas into the synthesis gas consisting of carbon monoxide, carbon dioxide, hydrogen and the steam; the second reactor (B), in which exercise the regular transformation of carbon monoxide into carbon dioxide; if necessary the compressor (C) using which the formed gases may be contracted; absorbing apparatus D, which serves for absorption of carbon dioxide and production of he mixture of monoxide with hydrogen used for synthesizing methanol; the refrigerating separator E, in which at feeding of the liquid nitrogen receive the ammoniac synthesis gas and simultaneously produces carbon monoxide, argon and methane. The invention allows to increase profitability of the installation due to production at one installation of several products.
EFFECT: the invention ensures the increased profitability of the installation due to production at one installation of several products.
15 cl, 1 dwg, 1 tbl
FIELD: petrochemical industry; methods of the synthesis of ammonia from the nitrogen and hydrogen mixture produced from the natural gases.
SUBSTANCE: the invention is pertaining to the field of petrochemical industry, in particular, to the method of the synthesis of ammonia from the nitrogen and hydrogen mixture produced from the natural gases. The method of the catalytic synthesis of ammonia from the mixture of nitrogen and hydrogen provides, that the natural gas together with the oxygen-enriched gas containing at least 70 % of oxygen is subjected to the autothermal reforming at temperature from 900 up to 1200°C and the pressure from 40 up to 100 bar at the presence of the catalyzer of cracking, producing the unstripped synthesis gas containing in terms of the dry state 55-75 vol.% of H2, 15-30 vol.% of C and 5-30 vol.% CO2. At that the volumetric ratio of H2: CO makes from 1.6 : 1 up to 4 : 1. The unstripped synthesis gas is removed from the furnace of the autothermal reforming, cooled and subjected to the catalytic conversion producing the converted synthesis gas containing in terms of the dry state at least 55 vol.% of H2 and no more than 8 vol.% of CO. The converted synthesis gas is subjected to the multistage treatment for extraction ofCO2, CO and CH4. At that they realize the contact of the synthesis gas with the liquid nitrogen and using at least one stage of the absorption treatment produce the mixture of nitrogen and hydrogen, which is routed to the catalytic synthesizing of ammonia. At that at least a part of the synthesized ammonia may be transformed into carbamide by interaction with carbon dioxide. The realization of the method allows to solve the problem of the ammonia synthesis efficiency.
EFFECT: the invention ensures solution of the problem of the ammonia synthesis efficiency.
8 cl, 1 ex, 2 tbl, 2 dwg
FIELD: inorganic synthesis catalysts.
SUBSTANCE: ammonia synthesis catalyst includes, as catalytically active metal, ruthenium deposited on magnesium oxide having specific surface area at least 40 m2/g, while concentration of ruthenium ranges between 3 and 20 wt % and content of promoter between 0.2 and 0.5 mole per 1 mole ruthenium, said promoter being selected from alkali metals, alkali-earth metals, lanthanides, and mixtures thereof. Regeneration of catalytic components from catalyst comprises following steps: (i) washing-out of promoters from catalyst thereby forming promoter-depleted catalyst and obtaining solution enriched with dissolved promoter hydroxides; (ii) dissolution of magnesium oxide from promoter-depleted catalyst in acidic solvent wherein ruthenium is insoluble and thereby obtaining residual ruthenium metal in solution enriched with dissolved magnesium compound; and (iii) regeneration of residual ruthenium metal from solution enriched with dissolved magnesium compound via liquid-solids separation to form indicated solution enriched with dissolved magnesium compound and ruthenium metal.
EFFECT: increased catalyst activity.
6 cl, 6 ex
FIELD: industrial inorganic synthesis.
SUBSTANCE: process comprises passing nitrogen and hydrogen-containing synthesis gas stream through three stacked catalyst beds, wherein catalyst is based on iron with magnetite as principal constituent, which is reduced during the process until catalytically active form of alpha-iron is produced. Above-mentioned synthesis gas stream is obtained by combining stream directly supplied onto first catalyst bed with another stream, which is preheated via indirect heat exchange with products exiting first and second catalyst beds, whereupon product is recovered. Method is characterized by that gas under treatment is passed through middle catalyst bed at volume flow rate between 0.65 and 2.00 value of volume flow rate, at which gas under treatment is passed through upper catalyst bed, volume ratio of middle catalyst bed to upper catalyst bed lying preferably between 0.5 and 1.5.
EFFECT: increased yield of product.
2 cl, 1 dwg, 1 tbl
FIELD: chemical industry; production of ammonia.
SUBSTANCE: the invention is pertaining to the process of synthesis of ammonia, in particular to improvement of the process of cleanout synthesis of the gas added into the catalytic reactor for substitution of the reacted synthesis gas. The method of synthesis of ammonia provides for compression of the synthesis gas containing hydrogen and nitrogen in a many-stage centrifugal compressor. On the first stage of this compressor the synthesis gas is compressed up to the pressure making from approximately 800 up to 900 pounds per a square inch - (56-63)·105 Pa, withdraw from this stage and cool, and also dehydrate by a contact to a liquid ammonia in a dehydrator. Then the cooled and dehydrated synthesis gas is fed back in the compressor and bring it on the second stage. The installation for realization of this process contains a centrifugal compressor supplied with the synthesis gas outlet, that connects the synthesis gas discharge outlet from the first stage of the compressor with the synthesis gas inlet in the dehydrator, and also an intermediate inlet of the synthesis gas connecting by a hydraulic link the inlet of the second stage of the compressor with the synthesis gas discharge (outlet) from the dehydrator. Due to the intermediate cooling and a dehydration the compressor rate is lowered, and due to favorable effect of the dehydrator on the last two stages of the compressor a significant saving of the consumed power is also achieved. The additional saving of the consumed power is possible due to decreased need of chill in the closed contour of the synthesis process.
EFFECT: the invention ensures a significant saving of the consumed power for the synthesis process in the installation.
13 cl, 1 dwg
FIELD: inorganic synthesis catalysts.
SUBSTANCE: invention provides ammonia synthesis catalyst containing ruthenium as active ingredient supported by boron nitride and/or silicon nitride. Catalyst can be promoted by one ore more metals selected from alkali, alkali-earth metal, or rare-earth metals. Ammonia synthesis process in presence of claimed catalyst is also described.
EFFECT: increased temperature resistance of catalyst under industrial ammonia synthesis conditions.
4 cl, 6 ex
FIELD: heat power and chemical industries, applicable in production of ammonia.
SUBSTANCE: in the method for steam generation at production of ammonia from hydrocarbon gases the mean-pressure steam used for the process of steam reforming and/or for the compressor drives is subjected to humidification by injection of the process condensate or feed water, and the obtained humidified steam is overheated by the heat of the flue gas in a unit of the heat-using equipment of the reforming tube furnace.
EFFECT: reduced consumption of energy due to reduction of the amount of generated steam and reduced of the amount of generated steam and reduced consumption of feed water; provided additional cleaning of the process condensate and recovering of gases dissolved in it in the process of steam humidification in the mass transfer device.
2 cl, 1 dwg
FIELD: heat power and chemical industries, applicable in production of ammonia.
SUBSTANCE: in the method for steam generation at production of ammonia from hydrocarbon gases, saturation of the hydrocarbon gas after desulfurization and/or process air fed to the secondary reforming is effected due to the use of the flue gas of a tube furnace at a temperature of 160 to 580C, preferably within 220 to 480C, by means of water recirculation.
EFFECT: reduced consumption of energy due to reduction of the total amount of generated steam, reduced consumption of feed water, and recovered gases dissolved in the process condensate.
4 cl, 1 dwg
FIELD: methods of preparation of catalysts for reforming of gasoline fractions in oil producing and petrochemical industries for production of high-octane motor fuels, aromatic hydrocarbons and commercial hydrogen.
SUBSTANCE: proposed method includes vacuum treatment of carrier, recirculation through aqueous solution of hydrochloric and acetic acids under vacuum, recirculation of impregnating solution; solutions of chloro-platinous and rhenium acids are introduced into impregnating solution at constant rate, after which solution is subjected to drying and calcination; treatment of carrier with impregnating solution is carried out at three stages: at first and second stages, temperature of circulating impregnating solution does not exceed 30°C and at third stage its temperature is not below 70°C.
EFFECT: enhanced activity, selectivity and stability of catalyst; reduced usage of metals; reduction of wastes and losses of platinum and rhenium.
10 cl, 2 dwg, 1 tbl, 8 ex
FIELD: oil refining; preparation of catalysts for refining of oil fractions; preparation of catalysts for benzene hydroisomerization process.
SUBSTANCE: proposed method includes mixing of components: zeolite component-mordenite with binder-aluminum hydroxide, plastification by means of peptizing by acid solution, granulation, application of platinum and reduction of catalyst; components are mixed at mass ratio of from 1:9 to 2:3 in terms of calcined mordenite and aluminum hydroxide; after application of platinum, heat treatment is carried out at two stages at temperature of 100-110°C at first stage and not above 250-300°C at second stage; reduction of catalyst is performed at temperature not below 500°C. Used as aluminum hydroxide is pseudo-boehmite of Catapal A grade. Used as zeolite component is high-modulus mordenite at silicate modulus M=20-30 at its content in catalyst of 20-30%. Used as zeolite component is low-modulus mordenite at silicate modulus M=10 at its content in catalyst not exceeding 10%.
EFFECT: enhanced selectivity of catalyst; considerable reduction of power requirements.
1 tbl, 3 ex
FIELD: catalytic chemistry; method of afterburning of organic admixtures and waste gases; chemical and petrochemical industries.
SUBSTANCE: proposed method is used for cleaning waste gases from styrene, toluene, isopropyl benzene, formaldehyde and oxidation products of higher fatty acids. Proposed method includes evacuation and impregnation of globular aluminosilicate zeolite-containing carrier; used as carrier is highly thermostable cracking catalyst to 100-% absorption by aqua solution of H2PtCl6 or PdCl2 at concentration of platinum or palladium of 0.4-0.8 g/l and volume ratio of impregnating solution to carrier of (0.6-0.08):1.0 of followed by sulfidizing with hydrogen sulfide and drying of catalyst. Proposed method makes it possible to clean waste gases from organic admixtures by 99.5-100%.
EFFECT: enhanced efficiency.
1 tbl, 5 ex
FIELD: organic chemistry, chemical technology, catalysts.
SUBSTANCE: invention describes a catalyst for dehydrogenation of (C2-C5)-hydrocarbons that comprises aluminum, chrome oxides, compound of modifying metal, alkaline and/or alkaline-earth metal. Catalyst comprises additionally silicon and/or boron compounds and as a modifying agent the proposed catalyst comprises at least one compound chosen from the following group: zirconium, titanium, iron, gallium, cobalt, molybdenum, manganese, tin. The catalyst is formed in the process of thermal treatment of aluminum compound of the formula Al2O3. n H2O wherein n = 0.3-1.5 and in common with compounds of abovementioned elements and shows the following composition, wt.-% (as measure for oxide): chrome oxide as measured for Cr2O3, 12-23; compound of a modifying metal from the group: Zr, Ti, Ga, Co, Sn, Mo and Mn, 0.1-1.5; silicon and/or boron compound, 0.1-10.0; alkaline and/or alkaline-earth metal compound, 0.5-3.5, and aluminum oxide, the balance. Catalyst shows the specific surface value 50-150 m2/g, the pore volume value 0.15-0.4 cm3/g and particles size 40-200 mcm. Also, invention describes a method for preparing this catalyst. Invention provides preparing the catalyst showing the enhanced strength and catalytic activity.
EFFECT: improved and valuable properties of catalyst.
12 cl, 2 tbl
FIELD: petroleum processing catalysts.
SUBSTANCE: catalyst designed for using in petroleum fraction hydrofining, which contains oxides of cobalt, molybdenum, phosphorus, lanthanum, boron, and aluminum, is prepared by mixing aluminum hydroxide with boric acid solution and nitric acid solution of lanthanum carbonate followed by drying, calcination, impregnation of resulting carrier with cobalt nitrate and ammonium paramolybdate solution in nitric acid at pH 2.0-3.5 and 40-80°C in presence of phosphoric acid followed by drying and calcination at elevated temperature.
EFFECT: enabled production of hydrogenate with reduced content of sulfur compounds.
FIELD: engineering of Fischer-Tropsch catalysts, technology for producing these and method for producing hydrocarbons using said catalyst.
SUBSTANCE: catalyst includes cobalt in amount ranging from 5 to 20 percents of mass of whole catalyst on argil substrate. Aforementioned substrate has specific surface area ranging from 5 to 50 m2/g. Catalyst is produced by thermal processing of argil particles at temperature ranging from 700 to 1300°C during period of time from 1 to 15 hours and by saturating thermally processed particles with cobalt. Method for producing hydrocarbon is realized accordingly to Fischer-Tropsch method in presence of proposed catalyst.
EFFECT: possible achievement of high selectivity relatively to C5+ at low values of diffusion resistance inside particles.
3 cl, 9 ex, 9 dwg
FIELD: structural chemistry and novel catalysts.
SUBSTANCE: invention provides composition including solid phase of aluminum trihydroxide, which has measurable bands in x-ray pattern between 2Θ=18.15° and 2Θ=18.50°, between 2Θ=36.1° and 2Θ=36.85°, between 2Θ=39.45° and 2Θ=40.30°, and between 2Θ=51.48° and 2Θ=52.59°, and has no measurable bands between 2Θ=20.15° and 2Θ=20.65°. Process of preparing catalyst precursor composition comprises moistening starting material containing silicon dioxide-aluminum oxide and amorphous aluminum oxide by bringing it into contact with chelating agent in liquid carrier and a metal compound; ageing moistened starting material; drying aged starting material; and calcining dried material. Catalyst includes carrier prepared from catalyst composition or catalyst precursor and catalytically active amount of one or several metals, metal compounds, or combinations thereof. Catalyst preparation process comprises preparing catalyst carrier from starting material containing silicon dioxide-aluminum oxide and amorphous aluminum oxide by bringing it into contact with chelating agent and catalytically active amount of one or several metals, metal compounds, or combinations thereof in liquid carrier, ageing starting material; drying and calcinations. Method of regenerating used material involves additional stage of removing material deposited on catalyst during preceding use, while other stages are carried out the same way as in catalyst preparation process. Catalyst is suitable for treating hydrocarbon feedstock.
EFFECT: improved activity and regeneration of catalyst.
41 cl, 3 dwg, 8 tbl, 10 ex
FIELD: organic synthesis catalysts.
SUBSTANCE: invention relates to methods for preparing catalyst precursors and group VIII metal-based catalysts on carrier, and to a process of producing hydrocarbons from synthesis gas using catalyst of invention. Preparation of precursor of group VIII metal-based catalyst comprises: (i) imposing mechanical energy to mixture containing refractory oxide, combining catalyst precursor with water to form paste comprising at least 60 wt % of solids, wherein ratio of size of particles present in system in the end of stage (i) to that in the beginning of stage (i) ranges from 0.02 to 0.5; (ii) mixing above prepared paste with water to form suspension containing no more than 55% solids; (iii) formation and drying of suspension from stage (ii); and (iv) calcination. Described are also method of preparing group VIII metal-based catalyst using catalyst precursor involving reduction reaction and process for production of hydrocarbons by bringing carbon monoxide into contact with hydrogen are elevated temperature and pressure in presence of above-prepared catalyst.
EFFECT: increased catalytic activity and selectivity.
12 cl, 1 tbl, 3 ex
FIELD: reduction-oxidation catalysts.
SUBSTANCE: invention relates to catalytic chemistry and, in particular, to preparation of deep-oxidation supported palladium catalysts, suitable, for example, in afterburning of motor car exhaust. Preparation involves depositing palladium from aqueous solution of palladium precursors followed by drying and calcination. Precursors are selected from nitrite anionic or cationic palladium complexes [Pd(NO2 -)(H2O)3]Anx or [Pd(NO2 -)n(H2O)m](Kat)y, wherein An are anions of acids containing no chloride ions, Kat is proton or alkali metal cation, n=3-4, m=0-1, x=1-2, and y=1-2. Nitrite ions are introduced into impregnating solution in the form of nitrous acid salts or are created in situ by reducing nitrate ions or passing air containing nitrogen oxides through impregnating solution. Ratio [Pd]/[NO2 -] in impregnating solution is selected within a range 1:1 to 1:4.
EFFECT: eliminated chlorine-containing emissions, increased stability of chlorine-free impregnating solutions, reduced their acidity and corrosiveness, and increased catalytic activity in deep oxidation reactions.
2 cl, 1 tbl, 16 ex
FIELD: organic synthesis catalysts.
SUBSTANCE: catalyst includes Cu and Mg compounds deposited on alumina as carrier and has copper compounds, expressed as Cu, from 2 to 8%, Mg/Cu atomic ratio ranging from 1.2 to 2.5, wherein concentration of copper atoms is higher in the interior of catalyst particle than on the surface (layer 20-30 Å thick) thereof and concentration of magnesium atoms prevails on the surface of catalyst particle, while specific surface of catalyst ranged from 30 to 130 m2/g. Oxychlorination of ethylene is carried out under fluidized bed conditions using air and/or oxygen as oxidants in presence of above-defined catalyst. Catalyst is prepared by impregnating alumina with aqueous Cu and Mg solutions acidified with hydrochloric acid solution or other strong acids using volume of solution equal or lesser than porosity of alumina.
EFFECT: increased activity of catalyst at high temperatures and avoided adhesion of catalyst particles and loss of active components.
8 cl, 2 tbl, 5 ex
FIELD: petrochemical process catalysts.
SUBSTANCE: group of inventions relates to conversion of hydrocarbons using micro-mesoporous-structure catalysts. A hydrocarbon conversion process is provided involving bringing hydrocarbon raw material, under hydrocarbon conversion conditions, into contact with micro-mesoporous-structure catalyst containing microporous crystalline zeolite-structure silicates composed of T2O3(10-1000)SiO2, wherein T represents elements selected from group III p-elements and group IV-VIII d-elements, and mixture thereof, micro-mesoporous structure being characterized by micropore fraction between 0.03 and 0.40 and mesopore fraction between 0.60 and 0.97. Catalyst is prepared by suspending microporous zeolite-structure crystalline silicates having above composition in alkali solution with hydroxide ion concentration 0.2-1.5 mole/L until residual content of zeolite phase in suspension 3 to 40% is achieved. Thereafter, cationic surfactant in the form of quaternary alkylammonium of general formula CnH2n+1(CH3)3NAn (where n=12-18, An is Cl, Br, HSO4 -) is added to resulting silicate solution suspension and then acid is added formation of gel with pH 7.5-9.0. Gel is then subjected to hydrothermal treatment at 100-150°C at atmospheric pressure or in autoclave during 10 to 72 h to produce finished product.
EFFECT: enlarged assortment of hydrocarbons and increased selectivity of formation thereof.
16 cl, 2 dwg, 2 tbl