Nano Science & Nano Technology: An Indian Journal


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The Journal was established in the year 2007 for dissemination of current developments and innovations in nano-science and nano-technology. The Journal publishes all forms of science communications on the fundamental, observational, experimental and advanced application oriented studies. The Journal is currently engaged in the production of 14th volume. The articles that are already published in this volume include reactor modeling for ethylene production, and commercialization of emerging nanotechnology based products. The Journal articles are cited 121 times in various related International publications. Authors are invited submit their manuscripts at the Journal dedicated online portal or can be send as email to the editorial office preferably by March 2021. The editorial board of the Journal comprising of 20 distinguished academicians and scientists takes adequate measures to adhere to the International publications standards. For additional information the corresponding authors can refer to the Journal author guidelines. The Journal invites manuscripts the present mathematical, scientific and engineering and technological interpretations as well as designing and assembly of nano scale structures, devices and molecules. The related sub topics include nanomaterial, thermodynamics and nanoelectronics.


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Nanoscience and Nanotechnology: An Indian Journal Research | Vol 14 Iss 1 Research | Vol 1 Iss 1 Citation: N.I. Fayzullayev SH.B Rakhmatov. Modeling of A Reactor Preparation Ethylene From Methane. Nano Tech Nano Sci Ind J. 141:130. © 2005 Trade Science Inc. 1 MODELING OF A REACTOR PREPARATION ETHYLENE FROM METHANE N.I. Fayzullayev and SH.B. Rakhmatov Samarkand State University Bukhara Medical Institution Uzbekistan Corresponding author: Samarkand State University Bukhara Medical Institution Uzbekistan Tel: + 998933589082 E- Mail: Received: February 29 2019 Accepted: March 12 2020 Published: March 20 2020 Introduction Uzbekistan has vast reserves of oil and natural gas. Natural gas and oil are known to be reserves of non-renewable and limited raw materials. The rational use of oil and gas will help develop the chemical industry at a higher level. Particular attention is paid to the use of highly efficient low-waste economical environmentally friendly technologies and environmental protection for the efficient use of oil and natural gas. Based on the foregoing one of the main challenges facing the scientists of the world is the introduction of new methods of producing sync. Tactical materials important for the national economy which can replace products imported on the basis of local raw materials and industrial waste and without waste environmentally friendly high-quality and competitive. The development of new technologies At the same time the only reasonable way to process natural gas is through oxygenation. This process occurs at one stage and at atmospheric pressure. This process passes through ethane and ethane is dehydrated with ethylene production. Considering the whole substance you can write the following sequence of reactions. 400CH4+259O2 → 90C2H6+70C2H4+64CO2+374H2O+16H2+16CO 514 0 800    C H kJ/mol. Experimental The gaseous products of the reaction was analyzed using a “Gazokhrom3101” thermochemical detector using the following thermostat: Thermostat temperature is 100°С transport gas air flow rate is 35 ml/min the length of the column filled with activated carbon is 1 m internal diameter is 3 mm. Quantitative analysis was carried out by the absolute rating method. The Abstract In this study catalytic oxygenation of methane and the influence of various factors in the process of ethylene production were studied. Based on the results obtained the optimal conditions and the structure of the catalyst were chosen : Mn2O3x ∙ Na2MoO4y ∙ ZrO2z. The process was thermodynamically evaluated to obtain the most appropriate technology for extracting ethylene from methane and the effect of various technological parameters on its main characteristics for mathematical modeling of the reactor was investigated. Keywords: temperature bulk velocity adiabatic reactor contact time conversion diameter film thickness mass transfer.

slide 2: |March-2020 2 catalytic activity of more than 10 catalysts was tested for the reaction of methane oxygenation. As is known manganese- based catalysts have high catalytic activity and selectivity in the process of ethylene oxidation with methane. Therefore we learned that manganese-based catalysts are a promoter feature of various compounds. The results are shown in the TABLE 1below. TABLE 1. Results of studying the promoting properties of various compounds in catalysts prepared from manganese. Serial No Promoter Reactor temperature ºC Methane conversion mol Selectivity Efficiency of ethylene C2-hydrocarbons ethylene 1 Na3PO4 700 146 100 580 85 750 247 100 634 158 800 388 939 700 273 2 Na2B4O7 700 156 657 487 76 750 232 550 681 158 800 356 377 761 271 3 Na2MoO4 700 113 100 647 112 750 280 100 701 198 800 430 100 765 329 4 Na2WO4 700 138 603 493 68 750 215 288 656 141 800 329 299 693 228 As can be seen from the TABLE 1 when Na2MoO 4 is added to the manganese catalyst the total conversion of methane is 43.0 at 800 ° С 32.9 of the efficiency ethylene and 76.5 ethylene selectivity. We then added d-metal compounds to Mn2O3 ∙ Na2MoO4. The best results were obtained by adding a catalyst ZrO2. The results of the experiments are shown in TABLE 2. TABLE 2. The effect of the catalyst on methane activity in the oxidative condensation reaction. Serial No Composition of catalyst Methane rotation level Selectivity Common С2Н4-а 1 La 2O 3 422 286 678 2 PbO 2 464 297 640 3 KCl 409 286 700 4 KBr 371 212 571 5 ZrO 2 526 428 814 6 BeO 482 346 718 The introduction of the ZrO 2 catalyst had a positive effect on its activation. When added ZrO2 catalyst the efficiency of ethylene increased from 32.9 to 42.8 and the selectivity to ethylene from 76.5 to 81.4 respectively. Further experiments

slide 3: |March-2020 3 Mn2O3 x∙ Na2MoO4 y ZrO2 z with the participation of an optimal catalyst were carried out. The conversion of methane depends on the C2-hydrocarbon process depends on the catalytic composition used but also depends on the reaction conditions temperature methane air specific bulk velocity. Thus we learned the effect of various factors on the reaction rate. The bulk velocity was investigated at a temperature of 800°C and a ratio of CH4: air1: 2. The change in bulk velocity was achieved by changing the size of the catalyst which must be applied to the reactor. The first methane-air mixture was sent continuously. The results are shown in TABLE 3. TABLE 3. Effect of bulk velocity on methane oxygenation. S.No Magnitude of bulk velocity h -1 Catalyst volume ml Conversion rate S General to С2Н4 1. 600 100 685 286 418 2. 800 75 619 358 578 3. 1000 60 526 428 814 4. 1200 50 433 329 759 5. 1400 42 348 236 678 However it was noted that additional products are formed decomposition of ethylene. The optimal value of the bulk velocity is 1000 h -1 the value of ethylene is 42.8 and the selectivity is 81.4. The effect of temperature on the methane oxidation reaction was investigated at constant bulk velocity 1000 h-1 and methane: air1: 2 with the presence of a catalyst of optimal composition with a range of 50°at intervals of 600-850°C. The results are shown in TABLE 4. The temperature of methane has a significant effect on the oxidation reaction as shown in TABLE 4. Production of ethylene starts at 600 ° C. The highest ethylene yield was observed at 800°C. Increasing the temperature from the optimum temperature can degrade the process. Therefore the ethylene content and selectivity decrease. TABLE 4.The effect of temperature on the methane oxygenation reaction. S.No Temperature ºC Methane conversion mol Selectivity General С2Н4 а 1. 600 150 следы - 2. 700 364 234 643 3. 750 456 332 728 4. 800 526 428 814 5. 850 580 365 630 The effect of methane: air with temperatures of 800°C and a bulk velocity of 1000 h -1 . The results are shown in TABLE 5. The results of the TABLE 5 show that when the amount of air in the compound increases methane conversion increases ethylene efficiency and selectivity decrease. TABLE 5. Results of studying the effect of methane-air ratio for methane oxygenation. T750ОС Vcat6 ml.

slide 4: |March-2020 4 S.No Methane : air Methane conversion rate Selectivity General to С2Н4 1. 3:1 250 62 248 2. 2:1 324 125 386 3. 1:1 458 236 515 4. 1:2 526 428 814 5. 1:3 608 305 502 To study the kinetic regularities of the methane oxygenation reaction the effect of methane and oxygen partial pressure on the rate of production of ethylene at a temperature of 700 ÷ 800°C and a bulk velocity 600 ÷ 1200 h-1. In studying the effect of the partial pressure of the reactants on the process flow laws changed the partial pressure of the gas and left the latter unchanged. In order not to change the linear rate the required amount of argon gas was sent to the reaction zone. The catalyst size was adapted to the specific velocity test conditions for permanent storage. The Results of the Experiment and their Discussion. Thermodynamic evaluation of the process and mathematical modeling of the reactor which is the core of the technological process plays an important role in creating development technologies. Thermodynamic analysis of the methane oxygenation reaction: Thermodynamic parameters of the reaction calculated on the basis of the values of heat and Gibbs energy are given in TABLE 6. TABLE 6. Calculated values of heat and Gibbs energy of the reaction. S.No Reaction 0 298 H  kJ/mol 0 G  J/mol · K 1 4CH 4+O 2 → 2C 2H 6+2H 2O -1766 -197296 2 2C 2H 6+O 2 → 2C 2H 4+2H 2O -1047 -363242 3 2CH 4+O 2 → C 2H 4+2H 2O -281314 -28006 4 C 2H 4+2O 2 → 2CO+2H 2O -756162 -937574 5 CH 4+2O 2 → CO 2+2H 2O -801724 -1006544 6 C 2H 4+3O 2 → 2CO 2+2H 2O -1321716 -1286186 7 CH 4+15O 2 → CO+2H 2O -518738 -609026 The adiabatic heating of the gas mixture is an important characteristic of the reactor. The adiabatic heating of gases for different values of the methane-oxygen ratio based on the heat balance of the catalyst bed was calculated using the formula:                 Тla y e r Т Т р g dT С С e n t e r С e x i t enter C Wenter 0 i Tlayer i Tlayer i i Wenter H Wenter H The calculation results are shown in FIG. 1 below.

slide 5: |March-2020 5 FIG. 1. Relationship between the ratio of CH4:O2 and adiabatic heating on the source gas at p 0.1 MPa. As can be seen from the figure methane content increases with adiabatic heating. As can be seen from the TABLE 7 when Na2MoO4 is added to the manganese catalyst the total methane conversion is 43.0 at 800°C 32.9 of the efficiency of ethylene and 76.5 selectivity ethylene. In terms of the ratio of methane-oxygen adiabatic heating to 575°C. When the methane content in the source gases is 90 adiabatic heating decreases to 325°C. As it is known adiabatic type reactors are often used for carrying out catalytic processes while the selectivity of the processes varies widely in the temperature range. The advantage of these reactors is that 2-3 t/m 3 metal tanks at times are smaller and easy and cheap to manufacture. Its disadvantage is that the reactions are carried out with a large thermal effect and the selectivity in the catalyst layer is not the same to a high approximation methane oxygenation reaction may be carried out for 4-5-stage device. Under these conditions this process is a good way to work. TABLE 7. Parameters on the process are 5-step adiabatic reactor Mathematical modeling of methane oxygenation reactor P MPa CH4/O2 mol TinputºС Тoutput ºС  s 2 O K 4 CH K Yield С2 С2Н4 01 5 800 1000 013 956 448 432 403 The ideal isothermal reactor model for reactor simulation was used: The limiting stage of the process in the extraction of methane is the diffusion of oxygen on the outer surface. The oxygen concentration and the partial pressure on the particle surface were in the following equation: S O S O b O R C C 2 2 2    The change in the total pressure on the layer is expressed by the Ergan equation: 2 2 2 U f L P       . The coefficient of hydraulic resistance for colored particles was determined by the following formula: 586 0 Re 4 38   f in this     а р а л 4u Re э . In the automatic mode all the heat dissipated during the process is used to heat the unwanted gas.

slide 6: |March-2020 6 Therefore the temperatures of the incoming and outgoing reactors are governed by the heat transfer equation 8 of the catalyst. As a result of studying the effect of mass transfer coefficients and other factors on the process parameters the main indicators of the oxidizer of methane oxidizer were determined. The results are given in TABLE 8. Thus methane oxygenation can be carried out in a single-stage adiabatic reactor in an auto thermal mode with an effective diameter of catalyst particles under external diffusion conditions of 5.0 mm and a linear rate of 0.36 m/s. The specific performance of the catalyst in the amount of C 2 hydrocarbons in the selected mode is 17280 kg C 2/m 3 ∙ hour in ethylene - 16253.5 kg/m3 ∙ hour. The thickness of the catalyst layer is 2.0 cm. Thus the capacity of the ethylene block is 16253.5 thousand units. kg/year the specific consumption of methane is 360 nm 3 /m 2 ∙ hour. TABLE 8. The Main Indicators of the Oxidizer of Methane Oxidizer were Determined. TABLE 9. Construction characteristic of the methane oxygenation reactor ACM. Main characteristics of the reactor Values Capacity to С 2ethylene thousand kg/year 17280.01616253.50 Diameter of the device m 7.9 Specific methane consumption nm 3 /m 2 ∙h 380 Oxygen concentration vol 16253.5 It should be noted that the power of methane oxygenation reactor can be increased by increasing the pressure in the system. For example when the pressure increases to 0.5 MPa the specific power of the methane oxygenation reactor is about 33.800 Kg/year. The main construction characteristics of the reactor are shown in TABLE 9. Parameter ACM Characteristic particle size  d mm 5.0 Layer thickness h m/sec 2.0 Gas speed u m/sec 0.36 Conditional contact time  sec 0.13 Conversion Х 95.6 Macrokinetic speed constant’s  с -1 36.7 Mass transfer coefficient  с -1 44.0 Kinetic speed constant’s k с -1 220.0 Constant relation  / k 5.0 Specific yield to С 2 g g/m 3 ∙hour 1.9

slide 7: |March-2020 7 Conclusion 1. The catalytic oxygenation of methane and the influence of various factors on the process of ethylene production were investigated. 2. The process was thermodynamically evaluated and a mathematical model of the reactor was modeled. 3. The basic parameters and design characteristics of the reactor RCM have been studied. 4. It was found that catalytic oxygenation of methane facilitates the process of producing ethylene in a 5-stage adatomic reactor. References 1. Daneshpayeh M Khodadadi A Talebizadeh A et al. Kinetic modeling of oxidative coupling of methane over Mn/Na 2WO 4/SiO 2 catalyst. Fuel Processing Technology. 2009903 403-10. 2. Ji S. Surface WO 4 tetrahedron: these sence of the oxidative coupling of methane over M–W–Mn/SiO 2 catalysts. J Catal. 20032201: 47-56. 3. Tyunyaev AA Nipan GD Koltsova TN et al. Polymorphic ODM catalysts Mn / W / Na K Rb Cs / SiO2. Int J Inorg Chem. 2009545:723-26. 4. Dedov AG Loktev AS Telpukhovskaya NO et al. Oxidative condensation of methane in the presence of lanthanum- cerium catalysts: fundamental character of the effect of nonadditivity. Chem Technol Fuels Oils. 2010462: 43-46. 5. Makhlin VA Podlesnaya MV Dedov AG et al. Oxidative dimerization of methane: Kinetics mathematical modeling and optimization with La/Ce catalysts. Russ Chem Bull. 2008799: 73-79. 6. Dedov AG Loktev AS Telpukhovskaya NO et al. Mesoporous amorphous rare earth silicates new catalysts of methane oxidative coupling. Doklady Akademii Nauk. 20084222: 253 -55 7. Taheri Z Seyed-Matin N Safekordi A et al. A comparative kinetic study on the oxidative coupling of methane over LSCF perovskite-type catalyst. Applied Catalysis. 2009 3541-2: 143-52. 8. Xin Y Song Z Tan YZ et al.The directed relation graph method for mechanism reduction in the oxidative coupling of methane. Catalysis Today. 20081311: 483-488. 9. Lomonosov VI Usmanov TR Sinev MYu et al. Patterns of Ethylene Oxidation under the Conditions of the Oxidative Condensation of Methane. Kinetics and Catalysis. 2014554: 498-505. 10. Magomedov RN Proshina AYu Peshnev BV et al. The effect of the gas environment and heterogeneous factors on the gas-phase oxidative cracking of ethane. Kinetics and Catalysis. 2013544: 413-19. 11. Lomonosov VI Gordienko YuA. Sinev MYu. Kinetic laws of oxidative condensation of methane in the presence of model catalysts. Kinetics and Catalysis. 2013544:474-86. 12. Ghose R Hwang HT Varma A. Oxidative coupling of methane using catalysts synthesized by solution combustion method. Applied Catalysis A:General. 2013 452: 147-54. 13. Kus S Otremba M. Taniewski M. The catalytic performance in oxidative coupling of methane and the surface basicity of La 2O 3 Nd 2O 3 ZrO 2. J Fuel. 2003:8211 1331-1338.