The Comparative Study of Separation Process of CO2 and CH4 Mixture through Membrane and Adsorption Processes: A Short Review
Mustafa Aidin, Hedyeh Tafreshi, Husam Ali*
Department of Chemistry, Hi Tech Institute of Theoretical and Computational Chemistry, India.
*Corresponding Author E-mail: husam.ali@gmail.com
ABSTRACT:
In this work, the monetary correlation between a weight swing adsorption (PSA) process and a film unit for expulsion of carbon dioxide from a carbon dioxide/methane blend was contemplated. The adsorption procedure for the adsorbent of zeolite 13X and the film unit for layer of 6FDA TAPDO was considered. First, the calculation of TAC for membrane unit with the five prices of membrane including 20$/m2, 50$/m2, 100$/m2, 150$/m2 and 200$/m2 was done and the best pressure for every price of membrane with minimum of TAC was selected. Then, the PSA process was investigated for the adsorbent of Zeolite 13X in the two pressure of 10 bar and 15 bar. All the simulations of PSA (includes 4 beds and 8 steps) were done in the Aspen Adsorption v8.8 and the membrane process was simulated in the Matlab. For pressure of 15 bar and membrane price of 100$/m2, the results showed that the TAC for PSA unit is 12% less than the TAC for membrane unit in spite of that the mole fraction of CO2 in the product for PSA unit is 0.0001 and for membrane unit is 0.017. The cost of membrane unit and adsorption unit is mostly related to the compressor and electricity costs, and also the adsorbent cost is almost 2% of PSA process TAC while the membrane cost is more than 20% of membrane process TAC.
KEYWORDS: Membrane, Adsorption, Carbon dioxide, Separation.
INTRODUCTION:
The CO2 removal is an important process in industries such as transportation of natural gas through pipelines in order to avoid the corrosion problem[1-10]. Several methods have been studied and implemented for the separation of CO2 from CH4 including: Absorption, cryogenic distillation, membrane processes and adsorption[11-14]. Pressure swing adsorption of methane, carbon dioxide on zeolite 13X was studied in many works and the membrane process was used to removal CO2 from natural gas and flue gas[15-18].
Pressure Swing Adsorption (PSA) process occupies a large part in the unit operation for the purification and separation of gas mixtures. Starting from patents of Guerin de Montgareuil (French Patent No.1,233,261) and Skarstrom (US Patent No.2, 944,627) in 1957 and 1960, respectively, PSA is applied to various industrial field. Recently, there is a need to improve efficiency of bio-gas upgrading process which separate CH4, CO2 mixture gas emitted by anaerobic digestion. Pressure swing adsorption systems for oxygen production were first used in the 1970s. Since then, the technology has rapidly improved. The early systems operated the entire operational sequence above atmospheric pressure. However, incorporation of a sub-atmospheric regeneration step much more fully utilized the characteristics of the adsorbent. This vacuum pressure swing adsorption method resulted in a significant decrease in energy consumption (Smolarek et al., 2000). In 1989, the first vacuum pressure swing adsorption installation was started up. Today’s VPSA systems use less than 50% of the power of the earlier PSA designs. One-bed systems and two-bed systems are employed. The one-bed systems offer capital savings, but are limited to about one-half of the production of a two-bed system because a single machine provides both feed as well as vacuum functions as opposed to the individual feed and vacuum blowers of the two-bed system. The feed air blower supplies air to the on-stream adsorbent vessel. Nitrogen, water vapor, carbon dioxide, and atmospheric hydrocarbons are preferentially adsorbed, while most of the oxygen and argon pass through. The product oxygen stream is available at a natural pressure of 0.2–0.35 barg (3–5 psig) from the system. An oxygen compressor is used when higher pressures are needed. The oxygen purity is 90–93% by volume. System capacity and efficiency suffer dramatically above 93% oxygen purity. The off-stream adsorbent vessel is regenerated under vacuum (0.3–0.7 bara, 4–10 psia) using the vacuum pump (blower). The nitrogen, carbon dioxide, and moisture desorb during this time. At the end of the desorption period, a small quantity of product oxygen is used to purge the remaining desorbed contaminants prior to repressurizing the bed for the adsorption step. Today’s advanced systems have a cycle time of less than one minute. There is a period of time during each cycle in which no oxygen is produced. The surge tank, which is a low-pressure storage vessel downstream of the adsorbent bed, enables a smooth supply of gas oxygen to the customer[19-21].
High purity methane gas can be used for transportation fuel and for domestic gas. However, for domestic gas, the methane purity has to be above 97%. The methane gas is distributed via pipe line and impurity of the gas can cause corrosion of the pipe. For that reason, methane for domestic gas has 97% purity limitations. With the PSA process, controlling the purity of methane gas is possible with adjusting the steptime. Generally, when producing 97% purity gas, the recovery of methane is lower than when producing 95% gas. Between these differences, the recovery of methane gas is defined as the objective[1, 19-22].
In this work, the economic comparison between a pressure swing adsorption (PSA) process and a membrane unit for removal of carbon dioxide from a carbon dioxide/methane mixture was studied.
MODELING AND SIMULATION:
In this work, the membrane unit and PSA system was simulated in Matlab and Aspen Adsorption, respectively. The feed flow rate is 0.1 m3/s and the mole fraction of methane in the feed stream is 0.75, and also the feed temperature is 300 K which are all constant in all the PSA and membrane unit cases studies[23-28].
Modeling of Membrane Unit:
A hollow fiber membrane unit with concurrent flow arrangement shown schematically in Fig. 1 is selected for the CH4 and CO2 mixture separation[29-32]. The membrane unit is divided into n elements and following assumptions are made including:
· Steady state process
· Ideal gas behavior
· Isothermal operation
· Negligible pressure drop
· Plug flow along the membrane
· Negligible deformation of the membrane under pressure.
Accordingly, the following model of a single-stage membrane unit is obtained:
- component material balance (tube side)
The rate of pure component diffusion across the membrane for per unit area of the membrane can be calculated using Eq. (7),
Where Pj is the permeability of component j, d is the thickness of the membrane, pt (ps) is the pressure in the tube (shell) side [33-36]. The pressure in the shell side is 1 bar and in the tube side is 5-30 bar, also the membrane price is 20-200 $/m2. In the Table.1, the permeability of CO2 and CH4 in the 6FDA TAPDO membrane is shown.
Table 1. Permeability of the CO2 and CH4 in a 6FDA TAPDO (polyimide) membrane (thickness 2 µm).
|
Feed component (j) |
P (Barrer) |
|
CH4 |
0.52 |
|
CO2 |
27.4 |
PSA simulation:
In this work, a PSA cycle with 4-beds and 8-stages is simulated. The 8 stages of cycle include adsorption, adsorption and interaction with repressurization, depressurization equalization, depressurization, blow down, purge, re-pressurization equalization and finally re-pressurization. The scheme of this PSA system simulated in the Aspen Adsorption environment is illustrated in Fig. 2[37-43].
The output pressure of stream from bottom of column and the column pressure are 1 bar and 15 bar, respectively. The pressure drop in the column is estimated using Ergun’s equation, and the heat transfer between the bed and the environment is ignored.
RESULTS AND DISCUSSION:
Before selecting the best process between PSA process and membrane process for separation CO2/CH4 mixture, the calculation of TAC for membrane unit in the five price of membrane 20$/m2, 50$/m2, 100$/m2, 150$/m2 and 200$/m2 and pressure range of 5-30 bar was done. Then, for every membrane price the best pressure according to minimum amount of TAC was selected that is illustrated in Fig. 3. After that the PSA process in the two pressure of 10 bar and 15 bar was done and for two pressure the mole fraction of CO2 in the upper output stream was 0.0001.
Fig. 3. The best pressure for every price of membrane in order to gain minimum TAC in the membrane unit
In the PSA unit, the mole fraction of CO2 in the upper product is less than 0.0001 but for the membrane unit the lowest amount of CO2 is about 0.005. For achieving this mole fraction of CO2 in the membrane unit, the TAC of membrane unit is several times more than the TAC of PSA unit. The TAC for pressure 15 bar and membrane price 100$/m2 in the PSA unit is 12% less than membrane unit, the cost of different part of these two processes is illustrated in Fig. 4.
Fig. 4. The distribution of TAC for different parts of PSA and membrane units in the pressure 15 bar and membrane price 100$/m2
In the pressure 15 bar and membrane price 100 $/m2 the CO2 mole fraction is almost 0.017, and for production stream with high purity of methane nearer to PSA unit, the compressor pressure should be increased that increase the membrane unit cost very much relative to the PSA unit[19-21].
CONCLUSION:
In this work, the separation of CO2 and CH4 by two separation method is studied which these two-separation methods are as follow: membrane and PSA processes. The PSA process with 4 beds and 8 steps for two pressure of 10 bar and 15 bar was investigated and for two pressure the mole fraction of CH4 in the upper output stream was 0.9999.
Then the TAC of membrane process for five membrane price and pressure range of 5-30 bar was done and the best pressure for every membrane price with minimum the TAC for membrane unit was selected. The comparison of the TAC for membrane process and PSA process in the pressure of 15 bar and membrane price of 100$/m2 show that the TAC in the PSA process is 12% less than membrane process. Also, for PSA process in the pressure of 10 bar the TAC is 25% less than membrane process in the pressure of 15 bar and membrane price of 100$/m2.
ACKNOWLEDGEMENT:
The authors are grateful to the HiTech Institute for Theoretical and Computational Chemistry.
CONFLICT OF INTEREST:
The authors declare no conflict of interest.
REFERENCES:
1. Ghasemian, M.B., et al., Approaching Piezoelectric Response of Pb-Piezoelectrics in Hydrothermally Synthesized Bi0.5(Na1–xKx)0.5TiO3 Nanotubes. ACS Applied Materials and Interfaces, 2018. 10(24): p. 20816-20825.
2. Ghasemian, M.B., et al., Lattice evolution and enhanced piezoelectric properties of hydrothermally synthesised 0.94(Bi0.5Na0.5) TiO3–0.06BaTiO3 nanofibers. Journal of Materials Chemistry C, 2017. 5(42): p. 10976-10984.
3. Anbia, M., et al., Employing a new modified nanoporous carbon for extraction and determination of 1,10-phenanthroline and 2,2′-bipyridine by SPE and use of the Taguchi optimization method. Analytical Methods, 2012. 4(12): p. 4220-4229.
4. Mostafavi, S.M., et al. Electrochemical Study and Determination of Thiophene by Cobalt Oxide Nanoparticle Modified Glassy Carbon Electrode. in 6th Aegean Analytical Chemistry Days (AACD), Denizli, Turkey. 2008.
5. Seyed Mojtaba Mostafavi, S.A., Iman Seyedi, Mohammad Hoseini, Excel for Engineers. 2009, Toranj Group Publication, Ltd.
6. Seyed Mojtaba Mostafavi, A.R., Masoumeh Piryaei, Electrochemistry: principles, methods, and applications. 2009, Toranj Group Publication, Ltd.
7. Seyed Mojtaba Mostafavi, A.M., Determination of molecular structure by identification of functional groups. 2010, Toranj Group Publication, Ltd., Isfahan, Iran.
8. Seyed Mojtaba Mostafavi, O.Z., Thermodynamics: an engineering approach. 2010, Mani Publication, Ltd, Isfahan, Iran.
9. Seyed Mojtaba Mostafavi, B.R., Nanomaterial Chemistry. 2010, Toranj Group Publication, Ltd.
10. Ghasemian, M.B., et al., Morphology control and large piezoresponse of hydrothermally synthesized lead-free piezoelectric (Bi0.5Na0.5) TiO3 nanofibres. RSC Advances, 2017. 7(25): p. 15020-15026.
11. Zabihi, O., et al., The effect of zinc oxide nanoparticles on thermo-physical properties of diglycidyl ether of bisphenol A/2, 2′-Diamino-1, 1′-binaphthalene nanocomposites. Thermochimica acta, 2011. 521(1-2): p. 49-58.
12. Seyed Mojtaba Mostafavi, A.R., Mina Adibi, Farshid Pashaee, Masoumeh Piryaei, Modification of Glassy Carbon Electrode by a Simple, Inexpensive and Fast Method Using an Ionic Liquid Based on Immidazolium as Working Electrode in Electrochemical Determination of Some Biological Compounds. Asian Journal of Chemistry, 2011. 23(12).
13. Seyed Mojtaba Mostafavi, A.R., Mina Adibi, Farshid Pashaee, Masoumeh Piryaei, Electrochemical Investigation of Thiophene on Glassy Carbon Electrode and Quantitative Determination of it in Simulated Oil Solution by Differential Pulse Voltammetry and Amperometry Techniques. Asian Journal of Chemistry, 2011. 23(12): p. 5356-5360.
14. Zabihi, O., A. Khodabandeh, and S.M. Mostafavi, Preparation, optimization and thermal characterization of a novel conductive thermoset nanocomposite containing polythiophene nanoparticles using dynamic thermal analysis. Polymer degradation and stability, 2012. 97(1): p. 3-13.
15. Shamsipur, M., et al., Biotransformation of methyl tert-butyl ether by human cytochrome P450 2A6. Biodegradation, 2012. 23(2): p. 311-318.
16. Seyed Mojtaba Mostafavi, A.R., Ali Akbar Miranbeigi, Handbook of Mineral Analysis. 2012, Mani Publication, Ltd, Isfahan, Iran.
17. Seyed Mojtaba Mostafavi, M.P., Ahmad Rouhollahi and A. Mohajeri, Separation and Quantification of Hydrocarbons of LPG Using Novel MWCNT-Silica Gel Nanocomposite as Packed Column Adsorbent of Gas Chromatography. Journal of NanoAnalysis, 2014. 1(01): p. 01.
18. Seyed Mojtaba Mostafavi, M.P., Ahmad Rouhollahi and A. Mohajeri, Separation of Aromatic and Alcoholic Mixtures using Novel MWCNT-Silica Gel Nanocomposite as an Adsorbent in Gas Chromatography. Journal of NanoAnalysis, 2014. 1(01): p. 11.
19. Ghasemian, M.B., et al., Self-Limiting Galvanic Growth of MnO2 Monolayers on a Liquid Metal—Applied to Photocatalysis. Advanced Functional Materials, 2019. 29(36): p. 1901649.
20. Ghasemian, M.B., et al., Evidence of phase coexistence in hydrothermally synthesized K0.5Na0.5NbO3 nanofibers. Journal of Materials Chemistry A, 2020.
21. Ghasemian, M.B., et al., Peculiar piezoelectricity of atomically thin planar structures. Nanoscale, 2020. 12(5): p. 2875-2901.
22. Heidari, M., S. Ghasemi, and R. Heidari, The Effects of Leadership and Employment in Technical Capabilities of Sport Teams. Journal of Humanities Insights, 2019. 3(02): p. 75-80.
23. Parvanian, S., S.M. Mostafavi, and M. Aghashiri, Multifunctional Nanoparticle Developments in Cancer Diagnosis and Treatmen. Sensing and Bio-Sensing Research, 2016. 1(2): p. 22.
24. Mostafavi, S.M. Enhancement of mechanical performance of polymer nanocomposites using ZnO nanoparticles. in 5th International Conference on Composites: Characterization, Fabrication and Application (CCFA-5). 2016. Iran University of Science and Technology.
25. Abolfazl Davoudiroknabadi, S.M.M., Seyed Sajad Sajadikhah, An Introduction to Nanotechnology. 2016, Mikima Book.
26. Abolfazl Davodiroknabadi, S.M.M., Ali Asghar Pasban, Fundamentals of Nanostructure and Nanomaterial. 2016, Mikima Book.
27. Pasban, A., et al., Quantitative Determination of LPG Hydrocarbons by Modified Packed Column Adsorbent of Gas Chromatography Via Full Factorial Design. Journal of Nanoanalysis, 2017. 4(1): p. 31-40.
28. Somayyeh Heidari, M.I., Seyed Mojtaba Mostafavi, , A Validated and Rapid HPLC Method for Quantification of Human Serum Albumin in Interferon beta-1a Biopharmaceutical Formulation. MedBioTech Journal, 2017. 1(01): p. 29.
29. Mostafavi, S.M., K. Bagherzadeh, and M. Amanlou, A new attempt to introduce efficient inhibitors for Caspas-9 according to structure-based Pharmacophore Screening strategy and Molecular Dynamics Simulations. Medbiotech Journal, 2017. 01(01): p. 1-8.
30. Amanlou, M. and S.M. Mostafavi, In sillico screening to aim computational efficient inhibitors of caspase-9 by ligand-based pharmacophore modeling. Medbiotech Journal, 2017. 01(01): p. 34-41.
31. Mostafavi, S.M., et al., Acidity removal of Iranian heavy crude oils by nanofluid demulsifier: An experimental investigation. Journal of Nanoanalysis, 2017: p. 10-17.
32. Aida Badamchi Shabestari, B.A.A., Maryam Shekarchi, Seyed Mojtaba Mostafavi, Development of Environmental Analysis for Determination of Total Mercury in Fish Oil Pearls by Microwave Closed Vessels Digestion Coupled with ICP-OES. Ekoloji, 2018. 27(106): p. 1935.
33. Bayat, M. and S.M. Mostafavi, Investigation of Interleukin 2 as Signaling Molecule in Human Serum Albumin. The Pharmaceutical and Chemical Journal, 2018. 5(02): p. 183-189.
34. Samira Eissazadeh, S.M.M., Masoumeh Piryaei, and M.S. Taskhiri, Application Of Polyaniline Nanostructure Based Biosensor For Glucose And Cholesterol Detection. Research Journal of Pharmaceutical, Biological and Chemical Sciences, 2019. 10(1): p. 150.
35. Samira Eissazadeh, M.P., Mohammad Sadegh Taskhiri and S.M. Mostafavi, Improvement of Sensitivity of Antigen-Antibody Detection of Semen Through Gold Nanoparticle. Research Journal of Pharmaceutical, Biological and Chemical Sciences, 2019. 10(1): p. 144.
36. Samira Eissazadeh, M.P. and S.M. Mostafavi, Measurement of Some Amino Acid Using Biosensors Based on Silicon-Based Carbon Nanotubes. Journal of Computational and Theoretical Nanoscience, 2019. 16: p. 1.
37. Aida Badamchi Shabestari, S.M.M., Hanieh Malekzadeh, Force Degradation Comparative Study on Biosimilar Adalimumab and Humira. Revista Latinoamericana de Hipertensión, 2019. 13(06): p. 496-509.
38. Mostafavi, S.M., S. Eissazadeh, and M. Piryaei, Comparison of Polymer and Ceramic Membrane in the Separation of Proteins in Aqueous Solution Through Liquid Chromatography. Journal of Computational and Theoretical Nanoscience, 2019. 16(1): p. 157-164.
39. Ahmadipour, A., P. Shaibani, and S.A. Mostafavi, Assessment of empirical methods for estimating potential evapotranspiration in Zabol Synoptic Station by REF-ET model. Medbiotech Journal, 2019. 03(01): p. 1-4.
40. Jafari, S. and S.A. Mostafavi, Investigation of nitrogen contamination of important subterranean water in the plain. Medbiotech Journal, 2019. 03(01): p. 10-12.
41. Z. Man, A.G.E., S. M. Mostafavi, A. Surendar, Fuel oil characteristics and applications: economic and technological aspects. Petroleum Science and Technology, 2019.
42. Seyed Mojtaba Mostafavi1, H.M. and M.S. Taskhiri, In Silico Prediction of Gas Chromatographic Retention Time of Some Organic Compounds on the Modified Carbon Nanotube Capillary Column. Journal of Computational and Theoretical Nanoscience, 2019. 16(01): p. 151-156.
43. Mostafavi, S.M. and A. Ebrahimi, Mercury determination in work place air and human biological samples based on dispersive liquid-liquid micro-extraction coupled with cold vapor atomic absorption spectrometry. Analytical Methods in Environmental Chemistry Journal, 2019. 2(04): p. 49-58.
Received on 13.06.2020 Modified on 09.07.2020
Accepted on 04.08.2020 ©AJRC All right reserved
Asian J. Research Chem. 2020; 13(6):509-514.
DOI: 10.5958/0974-4150.2020.00090.5