Gas Absorption PDF

GAS ABSORPTION Presentation of Group 1  Our Team Magalit, Lustado, Panaligan, Ramos, Miles Kristine Mae Marean joy Kharren Vhia Allen  Learning Objectives 1. Understand the fundamental principles of gas absorption, i...

GAS ABSORPTION Presentation of Group 1  Our Team Magalit, Lustado, Panaligan, Ramos, Miles Kristine Mae Marean joy Kharren Vhia Allen  Learning Objectives 1. Understand the fundamental principles of gas absorption, including diffusion, solubility, and mass transfer. 2. Identify and describe the various types of gas absorption processes, specifically physical and chemical absorption. 3. Recognize and explain the common equipment used in gas absorption, such as packed columns, plate columns, spray columns, and bubble columns. GAS ABSORPTION Gas Absorption is a mass transfer operation in which one or more species (solute) is removed from a gaseous stream by dissolution in a liquid (solvent). The insoluble components present in the gas which is not absorbed is called the carrier gas  A gas is absorbed by a process that breaks down into three stages. Firstly, the magnetic stirrer diffuses the compound within the gas phase towards the surface of the liquid and then the movement produces condensation and dissolution in the liquid phase. Finally, the compound is diffused into the liquid phase. Gas Absorption is an integral part of many chemical processes. PRINCIPLES OF GAS ABSORPTION 01 Diffusion Solubility 02 03 Mass Transfer Gas absorption usually carried out in vertical counter-current columns. The solvent is fed at the top of the absorber, whereas the gas mixture enters from the bottom. The solvent is often recovered in a subsequent stripping or desorption operation.  Gas Desorption or Stripping Gas desorption, on the other hand, is also referred to as stripping is a process that involves a mass transfer in the opposite direction, meaning that it is the transfer of liquid phase to the gas phase. In this case, the components or the liquid is separated by getting it into contact with the gas. TYPES OF GAS ABSORPTION PHYSICAL 01 ABSORPTION CHEMICAL ABSORPTION 02  PHYSICAL ABSORPTION Dissolves gas into liquid based on solubility No chemical reaction involved Used in pollutant removal and gas separation in natural gas processing.  CHEMICAL ABSORPTION Gas reacts with liquid solvent to form a compound Used for removing acidic/basic gases like CO2 and H2S Reactions can be reversible or irreversible, based on application.  PACKED COLUMNS PLATE COMMON COLUMNS EQUIPMENTS SPRAY OF GAS COLUMNS ABSORPTION BUBBLE COLUMNS PACKED COLUMNS Used in distillation, absorption, and stripping. Contains random or structured packing. Maximizes surface area for mass transfer between gas and liquid phase. Efficient separation based on component affinities Used in petrochemicals, pharmaceuticals, and food processing industries. PLATE COLUMNS also known tray columns, have horizontal trays bubble caps. vapor flows upward through trays, contacting downward on relative volatility. Promotes mass transfer and separatio based on relative volatility Widely used in distilaation for efficient separation based on boiling points. DIFFERENT TRAY TYPES SIEVE TRAY VALVE TRAY BUBBLE CAP TRAY SPRAY COLUMNS Used liquid spray for gas-liquid contact. Liquid is atomized into droplets, creating large surface area. Gas components absorbed by liquid droplets for separation. Used in gas absorption, odor control, and particulate removal. Common in environmental engineering, chemical processing, and air pollution control. BUBBLE COLUMNS Use gas bubbles for gas-liquid mass transfer. Bubbles create large surface area for absorption or desorption. Efficient separation based on component solubilities. Used in wastewater treatment, fermentation, and gas-liquid reactions. Optimized by controlling bubble size, gas flow rate, and liquid properties APPLICATIONS Brewing and Beverage Production Gas absorption can be used to control carbon dioxide levels during fermentation and carbonation processes. It ensures consistent product quality and carbonation levels in beverages like beer, soda, and sparkling water. Hydrogenation of Oils In the food industry, hydrogen gas is bubbled through edible oils (such as vegetable oil) during hydrogenation. The hydrogen is absorbed into the oil, reacting with unsaturated bonds to harden it.  CHOICE OF SOLVENT IN GAS ABSORPTION HIGH GAS LOW VAPOR Non-toxic, non-flammable, SOLUBILITY PRESSURE and chemically stable The solvent should These properties ensure This increases the have low vapor safety and stability during rate of absorption pressure to the process. Economical and reduces the minimize loss of materials of construction: amount of solvent solvent in the gas The equipment materials needed. leaving the should not be too absorption column. expensive.  FACTORS AFFECTING GAS ABSORPTION TEMPERATURE Generally, higher temperatures decrease the solubility of gases in liquids PRESSURE Increased pressure enhances gas solubility in liquids. LIQUID FLOW RATE Higher liquid flow rates increase the absorption capacity.  FACTORS AFFECTING GAS ABSORPTION GAS FLOW RATE Optimizing gas flow rate ensures efficient gas-liquid contact. TYPE OF SOLVENT The nature of the solvent, including its chemical reactivity and physical properties, significantly impacts absorption efficiency.  DESIGN CONSIDERATIONS Mass Transfer Height of Transfer Number of Transfer Coefficient Unit (HTU) Units (NTU) A critical parameter Represents the for designing gas height of the A measure of the absorption column required difficulty of equipment, achieving the for a specific reflecting the ease desired separation. degree of with which mass absorption. transfer occurs. THANK YOU FOR LISTENING!