Patent ID: 6096239
Filing Date: 2000-08-01
Classification: B01D,Y02A

Abstract:
A method of removing sulfur dioxide from a gas stream, comprising;contacting said sulfur dioxide through a contacting means with an absorption liquid at a first location, said absorption liquid absorbing said sulfur dioxide, said absorption liquid comprising;water;a polyprotic inorganic acid, to act as a buffering agent, to buffer the pH of said absorption liquid within the range of 2 to 7;an inorganic base, chosen from the group consisting of: carbonates or hydroxides with alkali metal, to aid in the removal of unwanted side products, and to enhance sulfur dioxide solubility; and,an additive, said additive chosen to synergistically enhance the absorption and solubility of said sulfur dioxide and assist in buffering the pH, while still maintaining effective sulfur dioxide regeneration, said additive being chosen from one or more of the group consisting essentially of: a monoprotic organic acid; a polyprotic organic acid; an organic base buffer; a mixture of any of the preceeding three organic additives; a polyprotic inorganic acid; and a mixture of the preceeding five additives;transferring said absorption liquid containing said sulfur dioxide to a second location; and,desorbing said sulfur dioxide by altering the differences between the vapor pressures of said sulfur dioxide in said liquid and the gas phase above the surface of said absorption liquid, such that said vapor pressure of said sulfur dioxide in said absorption liquid is greater than said vapor pressure of said gas above said surface of said absorption liquid.