Membrane technology 2023.pptx

Membrane technology in food

1. Membrane technology 1 Presented to: Dr. Rakesh Sharma Presented by: Sachin Sharma

2. contents Membrane technology 2 Introduction Membrane separation process Types of membranes Categories of pressure driven membrane processes Reverse osmosis (RO) or Hyperfiltration Factors controlling membrane processing MEMBRANE CONFIGURATION AND MODULES MODES OF MEMBRANE FILTRATION ADVANTAGES OF MEMBRANE TECHNOLOGY MAJOR MEMBRANE MODULES MEMBRANE FOULING APPLICATIONS OF MEMBRANE TECHNOLOGY IN FOOD PROCESSING

3. Introduction M embrane technology 3 M embrane technology is defined as a broad term that contains several separation processes on molecular level i.e., membrane separation usually applied on < 10 µm size molecules. Membrane separation is performed above the atmospheric pressure (that varies with particular membrane process) in a closed system so, these processes are known as pressure-driven membrane processes.

4. Principle of membrane separation Membrane separation involves a semipermeable membrane that selectively permits certain molecules or ions to pass through while blocking others. Membrane separation is driven by a pressure difference between the feed and permeate sides of the membrane. The pressure difference causes the mixture to flow through the membrane. The permeate, which is the liquid or gas that passes through the membrane, is collected on the other side. The selectivity of the membrane is determined by its pore size, surface charge, and hydrophilicity. 4 Membrane technology

5. MEMBRANE SEPARATION PROCESS Feed system is divided into two streams : Retentate Permeate Either the concentrate (retentate) or filtrate(permeate) is the product of interest of any membrane filtration process. 5 Membrane technology

6. Types of membrane filtration 6 Membrane technology

7. Types of membrane filtration 7 Membrane technology Microfiltration (MF) Ultrafiltration(UF) Nanofiltration(NF) Reverse Osmosis(RO) Pore size (µm) 10-0.1 0.01 0.001 < 0.0001 Operating pressure(bar) < 1 1-10 20-40 30-60 Basis of rejection Absolute size of particles(0.02-10µm) MWCO (10 3 -10 5 ) MWCO(200-1000Da) MWCO Solutes to be separated Clay, paint, oil droplets, suspended matters, microorganisms Pectin’s, proteins, high mol. wt. polyphenols, enzymes Sugars, low mol. Wt. polyphenols , dyes. Salts, electrolytes. Purpose Clarification or turbidity removal Clarification or turbidity removal Decolorization and purity increase Concentration and desalination

8. Reverse osmosis Osmosis Reverse osmosis 8 Membrane technology The molecules of a solvent pass from a solution of low concentration to a solution of high concentration through a semi-permeable membrane.

9. Factors controlling membrane processing: 9 presentation title MEMBRANE PROPERTIES Factors Change Effect on flux Pore size Increase Increase Thickness Increase Decrease Porosity Increase Increase Tortuosity Increase Decrease Compaction Increase Decrease Feed properties Concentration Increase Decrease Viscosity Increase Decrease Temperature Increase Increase

10. Types of membrane materials Based on material composition Inorganic membranes Can resist high temperature process streams. Lowest pore size attainable is micron range. Examples: Ceramic, alumina, zirconia, etc. Polymeric membranes Temperature limitation, maximum 90 C. Can control the pore size, tune up to angstrom level. Examples: Cellulose acetate (CA), polysulphone (PS), polyether sulphone (PES), polyacrylonitrile (PAN), polyvinylidene fluoride (PVDF). 10 presentation title

11. Types of membrane materials 2 . In terms of developmental stage 1 st generation membranes 1 st membrane used in commercial scale was cellulose acetate (CA) membrane . These are prepared as 0.1-1µ thick skin; are held with thicker porous supports. They are pH (2-8) dependent and limited to temperature(< 40 C). Require very frequent cleaning due to problem of clogging. 2 nd generation membranes Polymeric membranes which are made of polyamide (PA), PS, PAN, PVDF, etc. These are much resistant to pH variations and higher temperature than CA membranes. 3 rd generation membranes Development of inorganic materials like glass, metal, Al, Ti coated on a solid support. They are tough, highly resistant to mechanical pressure, pH, temperature, etc. 11 Membrane technology

12. Modes of membrane filtration Dead end flow Feed flow is perpendicular to the membrane surface. Dead end flow cause a large reduction in the flux . 2. Cross flow Flow of solution is parallel to the membrane surface. Flow causes turbulence and produces shear. 12 Membrane technology

13. Advantages of membrane technology membrane technology 13 Cost-effective and energy-efficient method for separating and purifying substances. Environmentally friendly and reduces operational costs. Produces high-quality and pure products, ideal for the food and beverage industry. Easily automated and scalable. Can recover valuable substances from waste streams, improving sustainability. Removes microorganisms, viruses, and bacteria, making it a popular method for sterilization and disinfection. Can be used in conjunction with other separation technologies for greater efficiency and purity.

14. Major Membrane Modules Flat sheet: Spiral wound module: Compact layout The basic unit is a sandwich of flat membrane sheets called a “leaf” wound around a central perforated tube. One leaf consists of two membrane sheets placed back to back and separated by a spacer called permeate carrier. Layers of the leaf are glued along three edges, while the unglued edge is sealed around the perforated central tube. Feed water enters the spacer channels at the end of the spiral-wound element in a path parallel to the central tube. 14 Membrane technology

15. Membrane technology 15 Filtered water in the permeate carrier travels spirally inward toward the central collector tube, while water in the feed spacer that does not permeate through the membranes continues to flow across the membrane surface. This concentrate stream exits the element parallel to the central tube through the opposite end from which the feed water entered. Relatively large amount of membrane area per element. Good cost- effective solutions to high volume applications. Primary advantage is of low capital investment and energy costs. Available for all types of filtration from microfiltration to reverse osmosis

16. Plate and frame module The earliest module designs were based on simple filters and consisted of flat sheets of membranes confined in a filter press called “plate-and-frame” modules. Due to its simplicity, these plate and frame modules have been widely used in lab-scale and industrial applications. Surface to volume ratio (m 2 /m 3 ) is typically 350-500 for plate and frame modules. 16 presentation title

17. Tubular module Tube like structures with porous walls. Work through tangential cross flow. Highly resistant to plugging. Tubular membranes are typically used when the feed stream contains large amounts of suspended solids or fibrous compounds. Tubular modules consist of a minimum of two tubes: the inner tube, called the membrane tube, and The outer tube, which is the shell The feed stream goes across the length of the membrane tube and is filtered out into the outer shell while concentrate collects at the opposite end of the membrane tube. 17 Membrane technology

18. Hollow fibre module Fibers can be bundled together longitudinally, potted in a resin on both ends, and encased in a pressure vessel. Extremely high packing density. High open channel design, high contact surface to volume ratio(7000-13000 m2/m3). Offers the possibility of backwashing from the permeate side, particularly suited for low solids liquid streams. 18 Membrane technology

19. Membrane fouling A phenomenon where solute or particles either deposit onto the membrane surface(concentration polarization)or held into membrane pores (pore blocking) in a manner that degrades the membranes performance (in terms of productivity and quality). Major foulants are bacterial growth, organic materials, biological materials, colloidal and suspended matters. Major factors influencing the rate of fouling are membrane properties, feed solution composition, and operating conditions. Additionally, process duration and mode of filtration (dead end or cross flow) affect the rate of local increase of solids over the membrane surface. 19 Membrane technology

20. Consequences of fouling Membrane technology 20 During filtration process, the longterm loss in membrane process throughout or performance capacity is primarily due to two phenomena: Concentration polarization : Formation of a boundary layer that builds up ( as cake or gel) on the membrane surface. Pore blocking : Blockage of membrane pores i.e. deposition within the membrane. The formed boundary or gel layer acts as a secondary membrane and rejects smaller solutes also, reducing the native design selectively of the membrane.

21. Membrane technology 21 Pre-treatment of feed solution. Periodic pulsing filtrate (Backwashing). Periodic membrane cleaning with acid-alkali treatment. Increasing shear by rotating or vibrating membrane. Methods to reduce fouling

22. Application of membrane technology in juice industry Membrane technology 22 Clarification : Microfiltration and ultrafiltration membranes are commonly used to remove suspended solids, bacteria, and other impurities from juice. Concentration : Reverse osmosis and nanofiltration membranes are commonly used for juice concentration by removing water. De-acidification : Nanofiltration and RO is used to remove acid from acidic juices, such as orange juice. Aroma recovery : Permeation through membrane is used to recover aroma compounds from juices. Fractionation : Nanofiltration and ultrafiltration membranes are used to fractionate juice into different components, such as separating pulp from juice or separating different types of sugars.

23. Application of membrane technology in Dairy industry Membrane technology 23 Milk and whey processing : Ultrafiltration and microfiltration membranes are used to concentrate and fractionate milk and whey proteins. Cheese production : Ultrafiltration and nanofiltration membranes are used for cheese production to concentrate and purify milk proteins and remove lactose. Clarification : Microfiltration and ultrafiltration membranes are used to remove bacteria and other impurities from milk and whey. Concentration: Reverse osmosis and nanofiltration membranes are used to concentrate milk and whey by removing water. Standardization: Membrane filtration can be used to standardize the composition of milk, such as adjusting the fat content. Microfiltration and ultrafiltration membranes can also be used to remove bacteria and spores from milk for longer shelf life.

24. Application of membrane technology in fermented beverage Membrane technology 24 Clarification: Microfiltration and ultrafiltration membranes are used to remove yeast, bacteria, and other impurities from fermented beverages. Concentration: Reverse osmosis and nanofiltration membranes are used to concentrate fermented beverages by removing water. Aroma recovery : Permeation through membrane is used to recover aroma compounds from fermented beverages. Fractionation : Nanofiltration and ultrafiltration membranes are used to fractionate fermented beverages into different components, such as separating different types of sugars or removing alcohol from beer. Enzyme immobilization : Membrane technology is used to immobilize enzymes in the production of fermented beverages, allowing for more efficient and precise control of fermentation processes

25. Application of membrane technology in probiotic beverage Membrane technology 25 Cell harvesting: Microfiltration membranes are used to harvest probiotic cells, such as bacteria, from fermentation broth. Clarification: Microfiltration and ultrafiltration membranes are used to remove impurities and solid particles from probiotic beverages. Concentration: Reverse osmosis and ultrafiltration membranes are used to concentrate probiotic beverages by removing water. Sterilization: Membrane filtration can be used as a sterilization method to remove any remaining bacteria or other microorganisms in probiotic beverages. Encapsulation: Membrane technology is used to encapsulate and protect probiotics, such as bacteria, during the production process and to ensure their survival during storage and consumption.

26. Emerging Application of membrane technology Membrane technology 26 1. Novel food processing techniques Use of membranes in novel food processing techniques such as membrane distillation, membrane emulsification, and membrane crystallization. These techniques can improve food quality and create new products with unique properties. 2. High-pressure membrane processes Use of high-pressure membrane processes to reduce the use of heat and chemicals in food processing These processes can preserve the nutritional value and sensory properties of food products while increasing efficiency. 3. Membrane-based sensors Use of membrane-based sensors to detect foodborne pathogens and spoilage indicators in real-time These sensors can improve food safety and reduce food waste.

27. Emerging Application of membrane technology Membrane technology 27 4. Nano-filtration for food purification Use of nano-filtration membranes to remove impurities and contaminants from food and beverage products. These membranes can produce high-quality, pure food products that meet the highest industry standards. 5. Membrane-based separation and fractionation Use of membranes to separate and fractionate components of food products such as proteins, fats, and flavor compounds. This can improve the nutritional value and sensory properties of food products and create new functional ingredients. 6. Biopolymer membrane development Development of new biopolymer membranes that are environmentally friendly and biodegradable. These membranes can replace traditional synthetic membranes and reduce environmental impact.

28. Thank you