بررسی تاثیرات دمایی پیرولیز بر ضرایب نفوذ اکسیژن و نیتروژن در غربالهای مولکولی کربنی

نویسندگان

1 دانشگاه سمنان

2 پژوهشگاه صنعت نفت تهران

چکیده

جدا سازی و تخلیص گازها یکی از مهمترین فرایندهای صنعتی می باشد. در این مقاله، جذب و نفوذ اکسیژن و نیتروژن از میان جاذب های غربال مولکولی کربنی (CMS) که از پیرولیز رزین فنولی در سه دمای مختلف ℃ 500، ℃ 700 و ℃800 ساخته شده، مورد مطالعه قرار گرفت. نفوذ میکروپور اکسیژن و نیتروژن در این سه جاذب با کمک روش حجم سنجی در دستگاه جذب ناپیوسته، با استفاده از معادله نفوذ شامل حالتهای زمان کوتاه و زمان طولانی، روش LDF و معادله ورمولن بررسی شد. نتایج نشان داد که داده های بدست آمده در کار حاضر با داده های حاصل از معادله نفوذ در حالت زمان طولانی، روش LDF و معادله ورمولن همخوانی مناسبی داشته و تقریب مناسبی از ثابت زمانی نفوذ را ارائه می کنند. همچنین مقایسه ثابت زمانی نفوذ اکسیژن و نیتروژن در دماهای مختلف پیرولیز، نشان داد که ثابت زمانی نفوذ، با افزایش دمای پیرولیز تا ℃700، روند افزایشی دارد ولی تا دمای ℃800 کاهش می یابد. برای اکسیژن نیز ثابت زمانی نفوذ با افزایش دمای پیرولیز تا ℃700، افزایش زیادی از خود نشان می دهد و در ادامه تا دمای ℃800 این روند افزایشی، ادامه دارد

کلیدواژه‌ها


عنوان مقاله [English]

Investigation of pyrolysis temperature effects on diffusion coefficients of oxygen and nitrogen in carbon molecular sieve

چکیده [English]

Separation and purification of gases is the most important industrial processes. In this article, adsorption and diffusion of oxygen and nitrogen through carbon molecular sieve (CMS) were investigated. CMS were made by pyrolysis of phenolic resin at three different temperatures, 500, 700 and 800℃ . Micro pore diffusion of oxygen and nitrogen into the CMS adsorbents were studied by volumetric method in batch adsorption unit. The diffusion data were yield from the batch system can be modeled by homogeneous diffusion (long and short time) equation, LDF method and Vermeulen model. The results showed that data of this work were in good agreement with diffusion equation (long time), LDF method and Vermeulen model. Therefore, they could give accurate estimation diffusion time constants of O2 and N2. Also, a comparison of diffusion time constants (DTC) of Oxygen and Nitrogen for different pyrolysis temperatures showed that the DTC of O2 and N2 increase with temperature increasing up to 700 ℃ and decrease with temperature rising to 800℃. In addition, DTC of O2 increase over the temperature range, 500℃ to 800℃.

کلیدواژه‌ها [English]

  • Micro pore diffusion
  • Batch adsorption
  • Carbon molecular sieve
  • LDF method
  • Vermeulen model

 

1- Lee, D. and Oyama, S. T.,(2002), Gas permeation characteristics of a hydrogen selective supported silica membrane, Membrane Science, Vol. 210, 291-306.

2- Burggraaf, A. J. and Cot, L.,(1996), Fundamentals of inorganic membrane science and technology,Membrane Science and Technology,Vol. 4, 1-690.

3- Chiang, H. L., Tsai, J. H., Chiang, D. H. &Jeng, F. T.,(2000), Diffusion of hydrojen sulfide and methyl mercaptan on to microporous alkaline activated carbon, Chemosphere, vol. 41, 1227-1232.

4- Do, D. D.,(1998), Adsorption analysis equation and kinetics, Imperial College Press, Department of Chemical Engineering, , University of Queensland, Australia.

5-Chiang, H. L., Chiang, P. C., Chiang, Y. C. & Chang, E. E.,(1999), Diffusivity of microporous

carbon for benzene and methyl ethyl ketone adsorption, Chemosphere, Vol. 38, 2733-2746.

6- Shi, J. Q. &Durucan, S.,(2003), A bidisperse pore diffusion model for methane displacement desorption in coal by CO2 injection,  Fuel,  Vol. 82, 1219–1229.

7- Huang H., Chen C. H., Xu L., Genuino H., Garcia M. J.,Garces H. F., Jin L.,  Kithongo C. K. and Suib S. L., (2010), Single-step synthesis of manganese oxide octahedral molecular sieves

with large pore sizesw,Chem. Commun., Vol. 46, 5945–5947.

8- Florescu, D., Stefanescu, I.  &Stanciu, V.,(2006), Experimental study about molecular diffusion in porousstructures", Chemia., Vol. 9, 81-88.

9- Jayaraman, A., Chiao, A. S., Padin, J.,  Yang, R. T.  & Munson, C.,(2002),Kenitic separation of methane- carbonedeoxid by molecular sievecarbone, Sepration science and technology, Vol 37, 2505-2528.

10- Chen, J., Loo, L.S., Wang, K. & Do, D. D., , (2009), The structural characterization of a CMS membrane using adsorption and permeation, Membrane Science, Vol. 335, 1-4.

11- Chihara, K. & Suzuki, M.,(1979), Control of micropore diffusivities of molecular sieving carbone by deposition of hydrocarbon,Carbon,  Vol.  17, 339-343.

12-  Hua Ma, Y. , Sun, W. , Bhandarkar, M. &  Wang, J.,(1990), Adsorption and diffusion oxygen, nitrogen, methane and argon in molecular sieve carbons, DTIC.

13- Ruthven, D. M.,(1992), Diffusion of oxygen and nitrogen in carbone molecular sieve,Chemical  Engineering  Science, Vol.  47,  4305-4308.

14- Campo, M.C., Magalhães, F.D. & Mendes A., (2010),Comparative study between a CMS membrane and a CMS adsorbent:PartI—Morphology,adsorptionequilibriumandkinetics,MembraneScience, Vol. 346, 15–25.

15- Giesy, T. J &Levan, M. D., (2013), Mass transfer rate of oxygen, nitrogen and argon in carbon molecular sieve determinate by pressure- swing frequency respone, Chemical engineering science, Vol. 90, 250-257.

16-Weng, T. H., Tseng, H. H.& Wey, M. Y., (2010), Fabrication and cracterization of poly(phenyleneoxid)/SBA-15/carbon molecular sieve multilayer mixed matrix membrane for gas separation, International journal of hydrogen energy, Vol. 35, 6971-6983.

17- Singh, R. &Koros, W. J., (2013), Carbon molecular sieve membrane dual temperature doping secondary oxygen doping (DTSOD), Membrane science, Vol. 427, 472-478.

18- Kiyono, M., Williams, P. J ,Koros, W. J., (2010), EffectofpyrolysisatmosphereonseparationperformanceofCarbonmolecularsievemembranes, Mem. Sci., Vol. 359, 2-10.

19- Campo, M.C., Magalhães, F.D. & Mendes A., (2010), Carbon molecular sieve membranes from cellophane paper,Membrane Science, Vol, 350 180–188.

20- Karge,  H. G. &Weitkamp,  J.,(2008), Adsorption and diffusion, Molecular sieves science and technology, Vol. 8.

21- Veliev, E. V., Ozturk, T., Veli, S. &Fatullayev, A. G.,(2006), Application of diffusion model for adsorption of Azo reactive dye on pumice,  Polish J. Environ. Stud., Vol. 15, 347-353.

22- Kyotani T, Ma Z, Tomita A. Template,(2003), synthesis of novel porous carbons usingvarious types of zeolites, Carbon, Vol.41,1451–9.

23- Glueckauf, E., (1955), Theory of chromatography, Trans. Faraday Sac.,Vol. 34, 1540-1551.

24- Yang, R. T.,(1997), Gas sepsration by adsorption processes, Imperial college press, Michigan, Vol. 1.

25- Li, Z. and Yang, R. T., (1999), Concentration Profile for Linear Driving Force Model for Diffusion in a Particle, AIChE , Vol.45.

26-Vermeulen, T.,(1953), Theory for Irreversible and Constant-pattern Solid Diffusion, Ind. Eng. Chem., 45, 1664.

27- Trgo, M., Peric, J. &Medvidovic, N. V., (2006), A comparative study of ion exchange kinetics inzinc/leadmodifiedzeolite-clinoptilolitesystems, HazardousMaterialsB136, 938–945.

28- Mahatantila, K., Seike, Y. & Okumura, M., (2011), Adsorptive  removal of lead(II) ion using Natural Red Earth from its iron and aluminum oxide forms, Engineering Science and Technology, Vol. 3, 1655-1666.

29-Aleghafouri, A., Mohsen-Nia, M., Mohajeri, A., Mahdyarfar, M and Asghari, A., (2012), Micropore Size Analysis of Activated Carbons Using Nitrogen, Carbon Dioxide and Methane Adsorption Isotherms: Experimental and Theoretical Studies, Adsorption Science & Technology, Vol. 30 (4)307.

30- - Mohamed, A. R.,  Mohammadi, M. &Darzi, G. N. ,(2010), Preparation of carbon molecular sieve from lignocelluloses biomass: A review, Renew.Sustain. Energy Rev.,Vol. 14, 1591-1599.

31- Gergova, K., Petrov, N., Minkova, V., (1993), A comparison of ad-sorption characteristics of various activated carbon", Chem. Tech. Biotech., Vol. 56, 77–82.

32- Rodriguez-Reinoso, F., In: Lahaye J, Ehrburger P, editors, (1991),Fundamental issues in control of carbon gasification reactivity, Netherlands: Kluwer Academic, 533–571.

33- Gonzalez, J. D. L., Vilchez, F. M. & Rodriguez-Reinoso, F., (1980), Characterization of active carbons from olive stones, Carbon, Vol. 18, 413–418.

34- Meng, L. U. and Park, S. J., ( 2012), Investigation of Narrow Pore Size Distribution on Carbon Dioxide Capture of Nanoporous Carbons, Chem. Soc., Vol. 33, 3749-3755.

35- Thomas, S., Schafer, R., Caro, J. and Morgenstern, A. S. (2001), Investigation of mass transfer through inorganic membrane with several layers, Catalysis Today, Vol. 67, PP. 205-216.

36- Shepparda D.A., Buckley C.E., (2008), Hydrogen adsorption on porous silica,  Int J

Hydrogen Energy, Vol., 33, 1688–92.

37- Gadkaree, K. P. &Jaroniec, M., (2000), Pore structure development in activated carbon honeycombs, Carbon, Vol. 38, 983–993.

38- Moreira, R.F.P.M., Jose, H.J. & Rodrigues, A.E., (2001), Modification of pore size in activated carbon by polymer deposition and its effects on molecular sieve selectivity, Carbon, Vol. 39, 2269–2276.

39- Campo, M.C., Magalhães, F.D. & Mendes, A., (2010), Separation of nitrogen from air bycarbonmolecularsievemembranes, MembraneScience,Vol. 350 ,139–147.

40- Reid,C.R., O’koye,I.P.&Thomas,K.M., (1998), AdsorptionofGasesonCarbonMolecularSievesUsedforAirSeparation.SphericalAdsorptivesasProbesforKineticSelectivity, Langmuir,Vol. 14, 2415-2425.

41-Trifonov, Y. &Golden,T., (1996), Non-linear kinetics of sorption of oxygen and nitrogen mixtures in carbon molecular sieve, jornal of porous materials, Vol. 3, 5-16.

42- Mostamand, A. &Mofarahi, M., (2011), Simulation of a Single Bed Pressure Swing Adsorption for Producing Nitrogen, Internatinal conference on chemical, biological and inviroment science, Bankokdec, 362-366.