Oxygen Separation with Polymeric Membrane_draftv3.pptx

oxygen separation

1. Oxygen Enriched Air (OEA) using Polymeric Membrane Technology 1 Group Members: Ahmed Alsaggaf (G202391230) Taha Najam (G202308870) Abdullah Yahya (G202301210) Abdisalam Mohamed(g202309790)

2. Outline 2

3. Introduction 3

4. What are Polymeric Membranes? Polymeric membranes are thin, selective barriers made from various synthetic or natural polymers. This Allows only certain substances to pass through while blocking others. They are crucial components in applications such: Water Treatment Gas Separation Biomedical Devices Food Processing 4 Various Applications based on pore sizes [2].

5. HOW IT WORKS? Theory of Gas Permeation 5 Transport Mechanism Quantitative Description Membranes are separate gas mixture components based on permeation rates. High-purity permeate requires a high partial pressure of the faster permeating gas in the feed stream Feed gas passes through the membrane under pressure, yielding permeate and retentate. Membranes are classified as porous (pore sizes: 5-100 nm) or nonporous (0.3-1 nm).

6. HOW IT WORKS? Theory of Gas Permeation 6 Transport Mechanism Quantitative Description Knudsen diffusion operates in pores smaller than 0.1 μm , facilitating gas separation based on molecular weight Molecular sieving prevents larger molecules from passing through small pores. The solution-diffusion involves three steps: absorption, diffusion, and desorption on the other side. Separation is based on concentration gradients and solubility differences.

7. HOW IT WORKS? Theory of Gas Permeation 7 Transport Mechanism Quantitative Description The permeability coefficient: The ideal separation factor (Selectivity): P X : Permeability coefficient l : Membrane Thickness (P h -P l ) : Upstream and downstream Pressure difference Fick’s 1st law: Sx : Solubility Dx : Diffusivity

8. Copolymer and blended polymeric membrane 8 Polymer of intrinsic microporosity Asymmetric Membranes Asymmetric membranes consist of a thin, dense top layer (skin or active layer) supported by a thicker porous substrate layer. Top layers are categorized as ultrathin (1000–5000 Å) or hyper-thin (<1000 Å), with defect-free layers crucial for effective gas separation. The bottom layer primarily provides mechanical support and structural integrity to the membrane. Interfacial Polymerization is the manufacturing technique. TYPES OF POLYMERIC MEMBRANES

9. TYPES OF POLYMERIC MEMBRANES Copolymer and blended polymeric membrane 9 Polymer of intrinsic microporosity Asymmetric Membranes Copolymer membranes combine multiple monomers, while blended polymeric membranes contain homopolymers formed post-synthesis. Block copolymer-based membranes, like (TMHF-NPSF), offer high selectivity and permeability for O2/N2 separation due to their structural properties. The cavity size in block copolymer membranes influences gas separation performance; larger cavities generally enhance permeability but decrease selectivity. Polymer Blending is the manufacturing technique.

10. TYPES OF POLYMERIC MEMBRANES Copolymer and blended polymeric membrane 10 Polymer of intrinsic microporosity Asymmetric Membranes A novel type of polymer characterized by its amorphous structure with twisted or bending features and a porous, rigid polymeric network. PIM exhibits high surface area and large free volume, leading to exceptional O2 permeability and O2/N2 selectivity. Specifically, PIM ladder polymers demonstrate remarkable selectivity for O2/N2 while maintaining high O2 permeability due to their extensive surface area and free volume. Step-growth Polymerization is the manufacturing method.

11. SUMMARY OF Membrane Types Asymmetric Membranes : 11 Copolymer and blended polymeric membrane: Microporous Polymers :

12. SUMMARY OF MANUFACTURING TECHNIQUES Interfacial Polymerization : Interfacial polymerization involves the reaction of two immiscible monomer solutions at a liquid-liquid interface. The reaction forms a thin, dense polymer film, typically consisting of a selective top layer and a porous substrate layer. 12 Polymer Blending : Polymer blending combines different homopolymers to form copolymers with unique chemical and physical properties. Blending allows for the incorporation of multiple monomers, enabling the creation of copolymers with desired characteristics such as improved flexibility, strength, or chemical resistance. Step-Growth Polymerization : Step-growth polymerization involves multifunctional monomers reacting in pairs to form covalent bonds, leading to the gradual growth of polymer chains. It proceeds through stepwise addition of monomers, allowing for the formation of diverse polymer structures and compositions.

13. Schematic representation of the membrane separation process [3]. Implementing membrane technology 13 Two-stage cascade membrane unit for production of O2 from air. Two-stage cascade membrane unit with recycle.

14. Comparison with membranes There are other processes for oxygen separation such as: Cryogenic Distillation (common) Pressure Swing Adsorption However, Polymeric membranes are found to be good for selective applications for the following general reasons[1]: 14 BENEFITS: Lower Energy Consumption Simplified Process Compact Footprint Continuous Operation Selective Separation Cost-Effectiveness

15. Pressure Swing Adsorption 15 Cryogenic Distillation Cryogenic distillation separates oxygen by exploiting differences in boiling points between oxygen and nitrogen. The air is cooled to very low temperatures, typically below the boiling point of nitrogen but above that of oxygen, causing nitrogen to liquefy while oxygen remains gaseous. The liquid nitrogen is then removed, leaving behind enriched oxygen, which can be further purified if necessary. Cryogenic distillation is energy-intensive but highly efficient, especially for large-scale oxygen production. Conventional methods

16. Pressure Swing Adsorption 16 Cryogenic Distillation Pressure swing adsorption (PSA) separates oxygen by selectively adsorbing nitrogen onto a solid material while allowing oxygen to pass through. It operates in cycles, with adsorption and desorption steps. During adsorption, nitrogen is captured at high pressure, while during desorption, nitrogen is released at reduced pressure. The cyclic variation in pressure allows for continuous oxygen production. Conventional methods

17. Applications of Oxygen-Enriched Air 17 Applications of OEA Application Distribution [5]

18. Coal gasification [C.G] Coal Gasification market is to grow by 16%. Coal gasification is a thermochemical process that transforms coal into syngas by reacting it with steam and oxygen or air. The syngas produced contains carbon monoxide, hydrogen, carbon dioxide, methane, and other gases. It offers higher efficiency due to better control over the combustion process. It also results in lower emissions. Additionally, coal gasification enables the potential for carbon capture and storage (CCS). Oxygen is a crucial component in C.G as it enhances the efficiency of the process by facilitating cleaner combustion. Oxygen purity required is greater than 90%. 18

19. O2 concentration required is at 30%. Single Stage System can achieve this. Types include: Feed Compression Comparison needs to be established 19 Feasibility of C.G using membranes OVERVIEW Process Flow Diagram Single Stage Double Stage Triple Stage

20. 20 Feasibility of C.G using membranes Cost Of Seperation Based On Membrane Material:

21. 21 Feasibility of C.G using membranes Cost Of Seperation Based On Membrane Material:

22. Selectivity 22 Feasibility of C.G using membranes DOUBLE-STAGE SYSTEM Permeability = 100 GPU 2 10 Purity 54.5% 96.8% Cost 0.22 $/kg 0.21 $/kg Selectivity TRIPLE-STAGE SYSTEM Permeability = 100 GPU 2 10 Purity 95% 99.7% Cost 0.38 $/kg 0.31 $/kg A conclusion from this analysis is that improvement in permeance appears to have a greater impact on the gas cost than does increasing selectivity. Polyimide Carbon membrane with selectivity of 15 and permeability of 200 B arrer has a very low cost of production of US$0.033/kg and purity of 98.5%. Polyimide based Carbon membrane with selectivity of 15 and permeability of 200 Barrer has a relatively low cost of production of US $0.039/kg with a purity of 99.9%.

23. 23 Feasibility of C.G using membranes Cost of Electricity Module Material Cost SUMMARY: - Cost changes with electricity cost: Single stage: US$0.085/kg to US$0.1/kg Double stage: US$0.22/kg to US$0.27/kg Triple stage: US$0.34/kg to US$0.4/kg - Based on membrane parameters: Permeance: 100 GPU Selectivity: 4

24. 24 Feasibility of C.G using membranes Cost of Electricity Module Material Cost SUMMARY: - Cost changes with electricity cost: Single stage: US$0.085/kg to US$0.1/kg Double stage: US$0.22/kg to US$0.27/kg Triple stage: US$0.34/kg to US$0.4/kg - Based on membrane parameters: Permeance: 100 GPU Selectivity: 4

25. 25 Feasibility of C.G using membranes DOUBLE-STAGE SYSTEM TRIPLE-STAGE SYSTEM Final Cost: 0.05$/kg Final Cost: 0.071$/kg COMPARISON Cryogenic Distillation Pressure-Swing Adsorption

26. 26 Feasibility of C.G using membranes DOUBLE-STAGE SYSTEM Final Cost: 0.05$/kg COMMENTS CRYOGENIC DISTILLATION PRESSURE-SWING ADSORPTION Final Cost: 0.045$/kg Final Cost: 0.065$/kg Potential cost reduction strategies: Improve membrane cost and material used. Enhance both permeability and selectivity simultaneously. Cryogenic distillation technology: Cryogenic distillation's economics optimized for large-scale systems. Cost increases with decreased scale.

27. Natural GAS Combined cycle Combined cycle plants outperform traditional natural gas combustion by achieving efficiencies of 50% or higher, compared to 30-40%. NGCC plants have higher initial costs, their efficiency leads to lower long-term fuel expenses, potentially making them more economically viable over time. Oxygen is a crucial component in N.G.C.C as it enhances the efficiency of the process by facilitating cleaner combustion. Oxygen purity required is around 30%. 27

28. Single Stage System can achieve this. Feed Compression, Permeate Vacuum can achieve 30% purity. Vacuum operation is preferred for its lower energy demand compared to feed gas compression. These membrane processes remain economically uncompetitive with cryogenic distillation or pressure swing adsorption at industrial scales. 28 Feasibility of N.G.C.C using membranes OVERVIEW Process Flow Diagram Permeate Vacuum Feed Compression NEED A BETTER PROCESS TO COMPETE

29. A turboexpander that improves energy efficiency and A countercurrent/sweep membrane design that improves separation efficiency. The process produces 7.1 m3(STP)/s of 30% oxygen-enriched air, This is 262 tons O2/day or 100 tons/day EPO2 Membrane needs an oxygen permeance of 1200 gpu and an O2/N2 selectivity of 3.0. 29 Feasibility of C.G using membranes COUNTERCURRENT/SWEEP OPERATION

30. 30 Feasibility of C.G using membranes COMPARISON WITH OTHER METHODS

31. 31 Feasibility of C.G using membranes MEMBRANE MATERIAL High Permeance Low Selectivity Per-fluoropolymer (PFP) Based Composite Membrane EXPERIMENTAL SETUP

32. 32 Feasibility of C.G using membranes MEMBRANE OPTIMIZATION STUDIES PFP wt % variation PFP layer Thickness Variation

33. 33 Feasibility of C.G using membranes SYSTEM OPTIMIZATION STUDIES Feed Flow Variation at constant Pressure Feed Flow Variation at Varying Pressures

34. 34 Feasibility of C.G using membranes COST COMPARISON TO OTHER TECHNIQUES N.G.C.C EFFICIENCY

35. 35 COMMENTS At an exhaust gas temperature of 1649 °C, using oxygen-enriched air containing 30% oxygen can save 35% fuel compared to air combustion. Membrane-based oxygen-enriched combustion offers significant energy savings and economic benefits compared to cryogenic distillation, VSA, and PSA. Feasibility of C.G using membranes PFP MEMBRANE VS CONVENTIONAL

36. OTHER APPLICATIONS Magnetohydrodynamic (MHD) Power Generation (up to 1000 MW) PC (Pulverized Coal Combustion) Iron Blast Furnace Liquid Burner Applications 36 Applications include: The membrane technology is better than cryogenic distillation for producing oxygen enriched air. The estimated capital advantage is 3.8-4.1 million dollars for 300 Ton O2. The bottom-line cost advantage is $2.11 to $3.68 per ton O2. Existing carbon capture technology yields greater efficiency. Blast furnace capacity would be increased by about 16% Energy savings, due to elimination of heat would be about 0.7 Btu/ton iron (equal to cost of enrichment). Therefore, making it feasible.. Oxygen enrichment boosts fuel burning, achieving 51% power increase. Stable air flow crucial for maintaining optimal burner performance. Oxygen enrichment aids combustion engineers in enhancing power output.

37. Conclusion 37 Pulverized Coal Power Plant with OEA [8].

38. Thank you 38