Introduction. Alkanolamines for Hydrogen Sulfide and Carbon Dioxide Removal. Mechanical Design and Operation of Alkanolamine Plants. Removal and Use of Ammonia in Gas Purification. Alkaline Salt Solutions for Acid Gas Removal. Water as an Absorbent for Gas Impurities. Sulfur Dioxide Removal. Sulfur Recovery Processes. Liquid Phase Oxidation Processes for Hydrogen Sulfide Removal. Control of Nitrogen Oxides. Absorption of Water Vapor by Dehydrating Solutions. Gas Dehydration and Purification by Adsorption. Thermal and Catalytic Conversion of Gas Impurities. Physical Solvents for Acid Gas Removal. Membrane Permeation Processes. Miscellaneous Gas Purification Techniques. Index.