Gas absorbers are used extensively in industry for separation and purification of gas streams, as product recovery devices, and as pollution control devices. This course focuses on the application of absorption for pollution control on gas streams with typical pollutant concentrations ranging from 250 to 10,000 ppmv. Gas absorbers are most widely used to remove water soluble inorganic contaminants from air streams. Absorption is a process where one or more soluble components of a gas mixture are dissolved in a liquid (i.e., a solvent). The absorption process can be categorized as physical or chemical. Physical absorption occurs when the absorbed compound dissolves in the solvent; chemical absorption occurs when the absorbed compound and the solvent react. Liquids commonly used as solvents include water, mineral oils, nonvolatile hydrocarbon oils, and aqueous solutions. Topics: System Efficiencies and Performance Process Description Absorber System Configuration Types of Absorption Equipment Packed Tower Internals and Operation Design Procedures Determining Gas and Liquid Stream Conditions Determining Absorption Factor Determining Column Diameter Determining Tower Height and Surface Area Calculating Column Pressure Drop Alternative Design Procedure Estimating Total Capital Investment Equipment Costs for Packed Towers Estimating Installation, Direct/Indirect, and Total Annual Cost Example Problems: Required Information for Design Determine Gas and Liquid Stream Properties Calculate Absorption Factor Estimate Column Diameter Calculate Column Surface Area Calculate Pressure Drop Equipment Costs Total Annual Cost Alternate Example Intended Audience: environmental, piping, industrial, water resources, civil, construction engineers. Publication Source: Environmental Protection Agency