Talk:Membrane gas separation

Wiki Education Foundation-supported course assignment
This article is or was the subject of a Wiki Education Foundation-supported course assignment. Further details are available on the course page. Student editor(s): Colby.c, JoseZZ, Vstevenson96, Aditya.nandy, Bposson, Keyangsun, Neilrazdan, JamesM.Queen. Peer reviewers: Myenccs, Clo234, Brentwick, Tressamikel, Aditya.nandy, Yjmlow, Sop8hia, Bposson.

Above undated message substituted from Template:Dashboard.wikiedu.org assignment by PrimeBOT (talk) 03:51, 17 January 2022 (UTC)

Permeability of different gases
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Membrane Materials Update (CBE 195 - CCS)
We plan to expand the scope of the Membrane Gas Separations wikipedia page to include an in-depth, up-to-date discussion of membranes for CO2 separation. The current page only discusses polymeric and nanoporous membranes and lacks discussion of zeolitic, silica, perovskite oxide membranes, and more. In addition, there is a lack of meaningful discussion which summarizes the current state and future directions of CO2 capture by membrane processes. We will add sections on inorganic and hybrid membranes. Our additions will include information on material development and recent findings from mechanistic investigations. — Preceding unsigned comment added by Aditya.nandy (talk • contribs) 05:25, 21 April 2017 (UTC)

Bibliography: Keyangsun (talk) 05:32, 21 April 2017 (UTC)
 * 1) 1. Hirayama, Y., Y. Kase, N. Tanihara, Y. Sumiyama, Y. Kusuki, and K. Haraya. “Permeation Properties of CO2 and N2 of Poly(ethylene oxide)-Containing and Cross-linked Polymer Films.” J. Membrane Sci., 160 (1999). pp. 87-99.
 * 2) 2. Chen, C., B. Han, J. Li, T. Shang, J. Zou, and W. Jiang. “A New Model on the Diffusion of Small Molecule Penetrants in Dense Polymer Membranes.” J. Membrane Sci., 187 (2001). pp. 109-118.
 * 3) 3.Strathmann, H. “Membrane Separation Processes: Current Relevance and Future Opportunities.” AIChE J., 47(5) (2001). pp. 1,077-1,087.
 * 4) 4. Aoki, K., V.A. Tuan, J.L. Falconer, and R.D. Noble. “Gas Permeation Properties of Ion- Exchanged ZSM-5 Zeolite Membranes.” Microp. Mesop. Mater., 39 (2000). pp. 485- 492.
 * 5) 5. Tuan, V.A., J.L. Falconer, and R.D. Noble. “Alkali-Free ZSM-5 Membranes: Preparation Conditions and Separation Performance.” Ind. Eng. Chem. Res., 38 (1999). pp. 3,635- 3,646.
 * 6) 6. Kusakabe, K., T. Kuroda, A. Murata, and S. Morooka. “Formation of a Y-Type Zeolite Membrane on a Porous α-Alumina Tube for Gas Separation.” Ind. Eng. Chem. Res., 36 (1997). pp. 649-655.
 * This is fantastic to hear, thank you. Please ask if you have any questions about using wikipedia but others will be happy to tidy up anything that you've struggled with - your most useful contribution will just be your expertise :) Testem (talk) 21:11, 21 April 2017 (UTC)

How we plan to edit the page:

Lead Section (Italics are added content by us)

Gas mixtures can be effectively separated by synthetic membranes made from polymers such as polyamide or cellulose acetate, or from ceramic materials.[1] While polymeric membranes are economical and technologically useful, they have are bounded by their performance (permeability must be sacrificed for selectivity and vice versa).[2] Membrane materials have expanded into the realm of silica, zeolites, and perovskites due to their strong thermal and chemical resistance as well as high tunability. Membranes can be used for separating gas mixtures where they act as a permeable barrier through which different compounds move across at different rates or not move at all. The membranes can be nanoporous, polymer, etc. and the gas molecules penetrate according to their size, diffusivity, or solubility.

[2] http://pubs.acs.org/doi/pdf/10.1021/cm200939d

Silica Membranes

Silica membranes are mesoporous and can be made with high uniformity. Synthesized membranes are continuous (and display high permeability) and can be modified on the surface to drastically improve selectivity. Amine containing molecules on silica membranes can be used as agents to separate CO2 from flue gas streams.[2] While previously, silica membranes were impractical due to their technical scalability and cost, Zhou et. al have demonstrated a simple method of producing silica-based MFI membranes on an alumina support that can effectively separate CO2 and H2 using economical materials.[3] Ordered mesoporous silica membranes have shown considerable potential for surface modification that allows for ease of CO2 separation. Surface silanol groups can be modified with amino groups that allow for CO2 to be easily separated from other gaseous streams.[4] Silica nanoparticles have been deposited in polymeric membranes to determine the effect of silica-polymer interactions on gas separation / permeability / selectivity.[5]

[3] http://onlinelibrary.wiley.com/doi/10.1002/anie.201311324/full

[4] http://www.sciencedirect.com/science/article/pii/S0001868609001092

[5] http://pubs.acs.org/doi/pdf/10.1021/cm504463c

'''Zeolite Membranes ''' Zeolites are crystalline aluminosilicates with a regular repeating structure of molecular-sized pores. Zeolite membranes selectively separate molecules based on pore size and polarity and are thus highly tunable to specific gas separation processes. In general, smaller molecules and those with stronger zeolite-adsorption permeate through zeolitic membranes with larger selectivity. The capacity to discriminate based on both molecular size and adsorption affinity makes zeolite membranes an attractive candidate for CO2 separation from  N2, CH4, and H2.

Poshusta et al found that the gas-phase enthalpy (heat) of adsorption on zeolites increases as follows: H2 < CH4 < N2 < CO2. It is generally accepted that CO2 has the largest adsorption energy because it has the largest quadrupolar moment, thereby increasing its affinity for charged or polar zeolite pores. At low temperatures, zeolite adsorption-capacity is large and the high concentration of adsorbed CO2 molecules blocks the flow of other gases. Therefore, at lower temperatures, CO2 selectively permeates through zeolite pores. Several recent research efforts have focused on developing new zeolite membranes that maximize the CO2 selectivity by taking advantage of the low-temperature blocking phenomena.

Kusakabe et al have synthesized Y-type (Si:Al>3) zeolite membranes which achieve room-temperature separation factors of 100 and 21 for CO2/N2 and CO2/CH4 mixtures. At similar CO2/CH4 selectivity, Venna et al have demonstrated ZIF-8 zeolite membranes achieve unprecedented CO2 permeance flux, two orders of magnitude above the previous standard. DDR-type (Himeno et al) and SAPO-34 (Li et al) membranes have also shown promise in separating CO2 and CH4 at a variety of pressures and feed compositions.

Perovskite Membranes:

Perovskite are mixed metal oxide with a well-defined cubic structure and a general formula of ABO3, where A is an alkaline earth or lanthanide element and B is a transition metal. These materials are attractive for CO2 separation because of the high tunability of the metal sites as well as their stability at elevated temperatures.

Kusakabe and co-workers investigated the separation of CO2 with an alpha-alumina membrane impregnated with BaTiO3, where the permeability of CO2, N2 and He in Ar were investigated. It was found that adsorption of CO2 was favorable at high temperatures due to an endothermic interaction between CO2 and the material, promoting mobile CO2 that enhanced CO2 adsorption-desorption rate and surface diffusion. This is exhibited in the experimental separation factor of CO2 to N2 obtain at 100-500C, which was found to be 1.1-1.2, much higher than the separation factor of 0.8 predicted by Knudsen diffusion, the predominant permeation mechanism in the alpha-alumina membrane, where the separation factor is the inverse square root ratio of the molecular weight of the two species. Though the separation factor was low due to pinholes observed in the membrane, this demonstrates the potential of perovskite materials in their selective surface chemistry for CO2 separation.

Reference: Kusakabe, K., K. Ichiki, and S. Morooka. “Separation of CO2 with BaTiO3 Membrane Prepared by the Sol-Gel Method.” J. Membrane Sci., 95 (1994). pp. 171-177. — Preceding unsigned comment added by Aditya.nandy (talk • contribs) 07:24, 28 April 2017 (UTC)

Current Status of CO2 Capture with Membranes Update(CBE 195 - CCS)
We will describe the effects of changing the pressure ratio on the process, and how selectivity alone does not allocate the proper carbon dioxide separation. Energy costs alone, though, makes operating the pressure difference under close to vacuum conditions not feasible. We will describe the CO2 separation process designed by Dr. Baker’s works that makes membranes be competitive with absorption and adsorption technologies. We will discuss the advantages of process design in making membrane separation economical. For example, considering applications of appropriate contact area between phases. Also, we need to consider the use of multiple membranes, configured with streams going into many different pressure changes to optimize carbon dioxide separation.Methods in which to increase carbon dioxide concentration to maximize driving force. We will also explain the current status of CO2 capture with membranes in terms of research, feasibility, and implementation.

References we’ll use: JoseZZ (talk) 21:48, 21 April 2017 (UTC)
 * 1) 1. Brunetti, A.; Scura, F.; Barbieri, G. Membrane technologies for CO2 separation. Journal of Membrane Science 359 (2010) 115–125.
 * 2) 2. Baker, Richard W. Future Directions of Membrane Gas Separation Technology. Ind. Eng. Chem. Res. 2002, 41, 1393-1411.
 * 3) 3. Merkel, Tim C.; Lin, Haiqing; Wei, Xiaotong; Baker, Richard W. Power plant post-combustion carbon dioxide capture: An opportunity for membranes.Journal of Membrane Science 359 (2010) 126–139.
 * 4) 4. Huang, Yu; Merkel, Tim C.; Baker, Richard W. Pressure ratio and its impact on membrane gas separation processes. Journal of Membrane Science 463 (2014) 33–40.
 * 5) 5. Hao, Pingjiao; Wijmans, J.G.; Kniep, Jay; Baker, Richard W. Gas/gas membrane contactors - An emerging membrane unit operation. Journal of Membrane Science 462 (2014) 131–138.
 * 6) 6. Brice Freemana, Pingjiao Haoa, Richard Bakera, Jay Kniepa, Eric Chenb, Junyuan Dingb, Yue Zhangb, Gary T. Rochelle. Hybrid Membrane-absorption CO2 Capture process. Energy Procedia 63 (2014) 605 – 613.
 * 7) 7. Haiqing Lin, Zhenjie He, Zhen Sun, Jay Kniep, Alvin Ng, Richard W. Baker, Timothy C. Merkel. CO2-selective membranes for hydrogen production and CO2 capture – Part II: Techno-economic analysis.Journal of Membrane Science 493 (2015) 794–806.

Peer Review: Membrane Gas Separations: Membranes for CCS Capture-focus on Pressure Ratio Limitations and Process Design - Aditya Nandy
After reading your proposed plan on pressure ratio limitations and process design, I think you should mention the reasons for process engineering in membrane separations (tradeoff between permeability and selectivity). Also, though vacuum is economical infeasible to propose, how about something such as a sweep gas? Would that increase the driving force and improve separations? I think that your addition would be great for wikipedia (since it is general and unbiased). However, I would sway you from convincing the audience that membrane technologies are "better" than absorption and adsorption. I think you guys can do a great job of not doing that. Furthermore, economics are complicated. Putting membranes in series may improve separations, but how about capital and operating costs? This could become significantly more expensive if the lifetime of the membranes is not extremely long. Overall, great job! — Preceding unsigned comment added by Aditya.nandy (talk • contribs) 19:39, 2 May 2017 (UTC)

Peer Review from Meredith
Hi Keyang, I am Meredith from the Carbon Tax group and I am assigned to do a peer review on your article Lead Section -	This is a small issue, but remember to proof read your article to check for “extra” words “ they have are bounded by their performance” -	The word “tunability” could be unfamiliar to the general reading audience, even if you set up a link to the definition of the word (A general check on Google shows tunability under the music context, but I realised that there is a chemistry reference), it would be good if you can explain tunability with context with your membranes in question. -	Elaborate on the “different compounds”? Could provide an example to show what membrane separates what gases. The original article talks about a common example is of separating oxygen and nitrogen, so you could give another example?

Silica Membranes -	“Mesoporous”? Explain a bit on mesoporous or link it to another wiki page that would best explain its meaning. -	I didn’t understand the link between “high uniformity” and silica membrane, maybe it is because I didn’t understand “mesoporous”. But I think you could elaborate on the uniformity on membranes? -	What is does “continuous” membranes mean? I am positioning myself as a general reading audience who doesn’t have much knowledge on membrane gas separations. So your wiki article would be a place that I am reading up on it thus technical terms on membrane would be difficult for me to understand. Furthermore, I didn’t see the link between “continuous” and “high permeability”. -	Why are silica membranes impractical due to their technical scalability and cost. By explaining this, maybe the reader could understand more about the properties of the silica membranes. -	What is MFI? What is alumina support? What are the economical materials? Either elaborate or provide links to their definition? -	Could explain the science behind the properties of silica membranes, like chemistry terms? I feel like I am just reading about what silica membranes can do and not why -	 Somehow, I feel that there is something missing to link the ideas together. Could it be that the ideas are from different articles? -	“Surface silanol groups can be modified with amino groups that allow for CO2 to be easily separated from other gaseous streams” could link with this “Amine containing molecules on silica membranes can be used as agents to separate CO2 from flue gas streams” above Zeolite Membranes -	This article has better flow of ideas and more chemistry explanation! -	Perhaps mention what DDR and SAPO stands for?

Perovskite Membranes -	Good explanation on what is perovskite -	What about the permeability of the rest of the gases? Did Kusakabe not mention the experimental results of the N2, He etc.? -	Link to Knudsen diffusion or have some equations to support it? -	Good example of Perovskite membranes

Sorry if I am too critical on certain parts of your revised article. Do take my suggestions with a pinch of salt as I may lack certain knowledge to be commenting on a relatively foreign topic to me.173.11.74.233 (talk) 22:33, 2 May 2017 (UTC)

Peer Review from Max Yen
Hi all, I am Max from the Zeolite Imidazolate Frameworks group here to do a peer review. It is exciting to read about the different chemistries used for the new membranes. One thing that I would want to see, as a general wikipedia reader, is if a "consensus" assessment could be made on the merits of any single type of chemistry. This would be in contrast to listing what individual scientists/groups have done (of which there is no shortage). For example, MOFs have a lot of promise as a class of CCS material due to their comparatively low adsorption/desorption energies. Myenccs (talk) 06:17, 4 May 2017 (UTC)

Peer Review from Clothilde Venereau
Hi, my name is Clothilde Venereau and I am from the Induced Seismicity group and was assigned to do a peer review of your article. In the lead section: "They have are bounded by their performance" does not make sense, you should probably get rid of the "have". Perhaps you could also add links to other Wikipedia pages for the words "silica", "zeolites" and "perovskites", which will make it easier for people to find out about what these materials are. What does "mesoporous" mean? What is an "MFI membrane"? perhaps this is too technical? You could add a link (or describe) what "silanol groups" are. Overall, you also seem to mention specific authors and their research in the main text instead of making of a summary. This sounds a lot like a literature review instead of a simplified Wikipedia summary but overall I found it very precise and detailed. Clo234 (talk) 23:41, 4 May 2017 (UTC)

Peer Review from Rahul Ramakrishnan
It would be interesting to include some cutting edge membrane technology and research going on for carbon capture such as ZIF-8 membranes and other type of MOFs. Also is there any preferred method for membrane diffusion? Just some things to consider, other than that great article. Rrahul24 (talk)

Peer Review Thank You - Aditya Nandy
Hi all who have peer reviewed our membrane materials section. Thank you for your kind and extensive peer reviews. We have incorporated all of your pieces of advice on to our final project, and added the sections that were suggested to us! — Preceding unsigned comment added by Aditya.nandy (talk • contribs) 18:51, 5 May 2017 (UTC)